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Stuck at "waiting for root device ..." #8

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weiqi-chen opened this issue Jan 7, 2018 · 10 comments
Closed

Stuck at "waiting for root device ..." #8

weiqi-chen opened this issue Jan 7, 2018 · 10 comments
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@weiqi-chen
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Hi , Thank you for porting kernel for R2.

I compiled the kernel form your repository, and stuck at "Waiting for root device..".
I compare .config bewteen version 4.4 and 4.14 and it seem no option about enabling mmc.

Is it no emmc / sd mmc support yet?

@frank-w
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frank-w commented Jan 7, 2018

Hi,

Both should working (did it in my system).

please make sure your using main-branch, not master.

your root-device should be /dev/mmcblk0p2 if booting from sd and /dev/mmcblk1p2 if booting from emmc like numbered on 4.4. Please look at cmdline whe kernel starts booting (after loaded by uboot). Maybe you have to change your uEnv.txt. maybe i have to change default cmdline in kernel

ok, i have not defined a root-device in kernels cmdline...i set it via uboot's uEnv.txt...

CONFIG_CMDLINE="earlyprintk console=ttyS0,115200 vmalloc=496M debug=7 no_console_suspend"

you can add

root=/dev/mmcblk0p2

if booting from SD

@frank-w frank-w self-assigned this Jan 7, 2018
@weiqi-chen
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I re-compiled the kernel, still not work

Here is the full log:


[USBD] USB PRB0 LineState: 0

[USBD] USB cable/ No Cable inserted!

[PLFM] Keep stay in USB Mode
Platform initialization is ok
wait for frequency meter finish, CLK26CALI = 0x81
mt_pll_post_init: mt_get_cpu_freq = 1040000Khz
wait for frequency meter finish, CLK26CALI = 0x90
mt_pll_post_init: mt_get_bus_freq = 273000Khz
wait for frequency meter finish, CLK26CALI = 0x81
mt_pll_post_init: mt_get_mem_freq = 133250Khz
[PWRAP] pwrap_init_preloader
[PWRAP] pwrap_init
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=0,rdata=2D52
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=1,rdata=2D52
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=2,rdata=2D52
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=3,rdata=5AA4
[PWRAP] _pwrap_init_sistrobe [Read Test] pass,index=4 rdata=5AA5
[PWRAP] _pwrap_init_sistrobe [Read Test] pass,index=5 rdata=5AA5
[PWRAP] _pwrap_init_sistrobe [Read Test] pass,index=6 rdata=5AA5
[PWRAP] _pwrap_init_sistrobe [Read Test] pass,index=7 rdata=5AA5
[PWRAP] _pwrap_init_sistrobe [Read Test] pass,index=8 rdata=5AA5
[PWRAP] _pwrap_init_sistrobe [Read Test] pass,index=9 rdata=5AA5
[PWRAP] _pwrap_init_sistrobe [Read Test] pass,index=10 rdata=5AA5
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=11,rdata=B50B
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=12,rdata=B54B
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=13,rdata=B54B
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=14,rdata=B54B
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=15,rdata=B54B
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=16,rdata=B54B
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=17,rdata=B54B
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=18,rdata=B54B
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=19,rdata=6297
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=20,rdata=6A97
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=21,rdata=6A97
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=22,rdata=6A97
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=23,rdata=6A97
[PWRAP] _pwrap_init_reg_clock
[PMIC_WRAP]wrap_init pass,the return value=0.
[pmic6323_init] Preloader Start..................
[pmic6323_init] PMIC CHIP Code = 0x2023
INT_MISC_CON: 1  TOP_RST_MISC: 1
pl pmic powerkey Release
[pmic6323_init] powerKey = 0
[pmic6323_init] is USB in = 0xB004
[pmic6323_init] Reg[0x11A]=0x1B
pmic setup LED
[pmic6323_init] Done...................
mt7623 disable long press reset ->>>>>
mt7623 disable long press reset <<<<<-
mt7623 VPA supplied by 1.0V to MT7530 ->
mt7623 VPA supplied by 1.0V to MT7530 <-
mt7623 enables RG_VGP1_EN for LCM ->
mt7623 enables RG_VGP1_EN for LCM <-
MT7623 E2 setting =>
MT7623 E2 setting <=
[PLFM] Init I2C: OK(0)
[PLFM] Init PWRAP: OK(0)
[PLFM] Init PMIC: OK(0)
[PLFM] chip[CA00]

[BLDR] [Support SD/eMMC] Build Time: 20170905-120917
==== Dump RGU Reg ========
RGU MODE:     4D
RGU LENGTH:   FFE0
RGU STA:      0
RGU INTERVAL: FFF
RGU SWSYSRST: 0
==== Dump RGU Reg End ====
RGU: g_rgu_satus:0
 mtk_wdt_mode_config  mode value=10, tmp:22000010
PL P ON
WDT does not trigger reboot
RGU mtk_wdt_init:MTK_WDT_DEBUG_CTL(590200F3)
kpd read addr: 0x0040: data:0x4001
Enter mtk_kpd_gpio_set! 
kpd debug column : 0, 0, 0, 0, 0, 0, 0, 0
kpd debug row : 0, 0, 0, 0, 0, 0, 0, 0
after set KP enable: KP_SEL = 0x0 !
MTK_PMIC_RST_KEY is used for this project!
[RTC] get_frequency_meter: input=0x0, ouput=5
[RTC] get_frequency_meter: input=0x0, ouput=3968
[RTC] get_frequency_meter: input=0x0, ouput=5
[RTC] get_frequency_meter: input=0x0, ouput=0
[RTC] get_frequency_meter: input=0x0, ouput=0
[RTC] bbpu = 0xD, con = 0x426
[RTC] powerkey1 = 0xA357, powerkey2 = 0x67D2
Writeif_unlock
[RTC] RTC_SPAR0=0x40 
rtc_2sec_reboot_check cali=512
[RTC] irqsta = 0x0, pdn1 = 0x0, pdn2 = 0x201, spar0 = 0x40, spar1 = 0x800
[RTC] new_spare0 = 0x0, new_spare1 = 0x1, new_spare2 = 0x1, new_spare3 = 0x1
[RTC] bbpu = 0xD, con = 0x426, cali = 0x200
pl pmic powerkey Release
[PLFM] Power key boot!
[RTC] rtc_bbpu_power_on done
[EMI] mcp_dram_num:0,discrete_dram_num:1,enable_combo_dis:0
[EMI] PCDDR3
[Check]mt_get_mdl_number 0x0
[EMI] eMMC/NAND ID = 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
[EMI] MDL number = 0
[EMI] emi_set eMMC/NAND ID = 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
[EMI][Vcore]0x21E=0x48,0x220=0x48
[EMI][Vmem]0x554=0x0
wait for frequency meter finish, CLK26CALI = 0x81
[EMI] PCDDR3 DRAM Clock = 1600012 KHz, MEMPLL MODE = 2 
[EMI] PCDDR3 RXTDN Calibration:
Start REXTDN SW calibration...
drvp=0xB,drvn=0x8
[EMI] pinmux = 4
===============================================================================

        dramc_write_leveling_swcal
===============================================================================
delay  byte0  byte1  byte2  byte3
-----------------------------
0    0    1    1    1    
1    1    1    1    1    
2    1    1    1    1    
3    1    1    1    1    
4    1    1    1    1    
5    1    1    1    1    
6    1    1    1    1    
7    1    1    1    1    
8    1    1    1    1    
9    1    1    1    1    
10    1    1    1    1    
11    1    1    1    1    
12    1    1    1    1    
13    1    1    1    1    
14    1    1    1    1    
15    1    1    1    1    
pass bytecount = 4
byte_i    status    best delay
0    2    1
1    2    0
2    2    0
3    2    0
========================================
[write leveling]DQS: 0x1, DQM: 0x1
[write leveling after remap]DQ byte0 reg: 0x200 val: 0x11110000
[write leveling after remap]DQ byte1 reg: 0x204 val: 0x1111
[write leveling after remap]DQ byte2 reg: 0x208 val: 0x0
[write leveling after remap]DQ byte3 reg: 0x20C val: 0x0
=============================================
X-axis: DQS Gating Window Delay (Fine Scale)
Y-axis: DQS Gating Window Delay (Coarse Scale)
=============================================
          0    8   16   24   32   40   48   56   64   72   80   88   96  104  112  120
      --------------------------------------------------------------------------------
0000:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
0001:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
0002:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
0003:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
0004:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
0005:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
0006:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
0007:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
0008:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
0009:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
000A:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
000B:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
000C:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
000D:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
000E:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
000F:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
0010:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    1    1
0011:|    0    0    0    0    0    0    0    0    0    1    1    1    1    1    1    1
0012:|    0    0    0    1    1    1    1    1    1    1    1    1    0    0    0    0
0013:|    1    1    1    1    1    1    0    0    0    0    0    0    0    0    0    0
0014:|    1    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
0015:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
0016:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
0017:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
0018:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
0019:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
001A:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
001B:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
001C:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
001D:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
001E:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
001F:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
Rank 0 coarse tune value selection : 18, 18
18
56
rank 0 coarse = 18
rank 0 fine = 56
00:|    0    0    0    0    0    0    0    0    1    1    1    0
opt_dle value:13
==================================================================
                RX      DQS perbit delay software calibration 
==================================================================
1.0-31 bit dq delay value
==================================================================
bit|     0  1  2  3  4  5  6  7  8  9
--------------------------------------
0 |    0 0 0 0 0 0 0 0 0 0 
10 |    0 0 0 0 0 0 0 0 0 0 
20 |    0 0 0 0 0 0 0 0 0 0 
30 |    0 0 
--------------------------------------
==================================================================
2.dqs window
x=pass dqs delay value (min~max)center 
y=0-7bit DQ of every group
input delay:DQS0 =49 DQS1 = 38 DQS2 =51 DQS3 = 42
==================================================================
bit     DQS0     bit      DQS1     bit     DQS2     bit     DQS3
0  (17~67)42  8  (7~57)32  16  (22~69)45  24  (17~61)39
1  (19~66)42  9  (7~60)33  17  (25~70)47  25  (16~57)36
2  (19~67)43  10  (13~62)37  18  (25~70)47  26  (19~61)40
3  (17~69)43  11  (11~62)36  19  (21~68)44  27  (19~58)38
4  (21~72)46  12  (15~62)38  20  (25~72)48  28  (22~63)42
5  (19~70)44  13  (15~62)38  21  (25~73)49  29  (21~64)42
6  (22~70)46  14  (13~60)36  22  (25~72)48  30  (16~64)40
7  (26~72)49  15  (15~62)38  23  (29~74)51  31  (19~64)41
==================================================================
3.dq delay value last
==================================================================
bit|    0  1  2  3  4  5  6  7  8   9
--------------------------------------
0 |    7 7 6 6 3 5 3 0 6 5 
10 |    1 2 0 0 2 0 6 4 4 7 
20 |    3 2 3 0 3 6 2 4 0 0 
30 |    2 1 
==================================================================
*DQIDLY1 = 0x6060707
*DQIDLY2 = 0x30503
*DQIDLY3 = 0x2010506
*DQIDLY4 = 0x20000
*DQIDLY5 = 0x7040406
*DQIDLY6 = 0x30203
*DQIDLY7 = 0x4020603
*DQIDLY8 = 0x1020000
*DRAMC_R0DELDLY = 0x2A332631

[MEM]CONA:F3A2,conf1:F07486A3
DM4BitMux = 1 
[Warning] DQSO 0 in TX per-bit = 3 > DQSO 0 in WL = 1  
DQSO 1 in TX per-bit = 0 <= DQSO 1 in WL = 0  
[Warning] DQSO 2 in TX per-bit = 7 > DQSO 2 in WL = 0  
[Warning] DQSO 3 in TX per-bit = 3 > DQSO 3 in WL = 0  
Tx DQM dly  = 0x123
Tx DQM dly bit4 = 0x0
DRAMC_DQODLY1=4532434h
DRAMC_DQODLY2=24224354h
DRAMC_DQODLY3=1112002h
DRAMC_DQODLY4=3113h
Tx DQ dly bit4 = 0x0
Tx DQS dly = 0x3703
Tx DQS dly bit4 = 0x0
TX Byte0: DQ - 14, DQS - 16. win_sum= 29
TX Byte1: DQ - 20, DQS - 14. win_sum= 33
TX Byte2: DQ - 10, DQS - 22. win_sum= 31
TX Byte3: DQ - 12, DQS - 19. win_sum= 30
DRAMC calibration takes 650169057 CPU cycles

[EMI] DRAMC calibration passed

[MEM] complex R/W mem test pass
0:dram_rank_size:80000000
[Dram_Buffer] dram size:-2147483648 
[Dram_Buffer] structure size: 1725560 
[Dram_Buffer] MAX_TEE_DRAM_SIZE: 0 
Load u-boot from eMMC...
[PLFM] Init Boot Device: OK(0)

[PART] blksz: 512B
[PART] [0x0000000000000000-0x000000000003FFFF] "PRELOADER" (512 blocks) 
[PART] [0x0000000000000000-0x000000000003FFFF] "MBR" (512 blocks) 
[PART] [0x0000000000040000-0x00000000000BFFFF] "UBOOT" (1024 blocks) 
[PART] [0x00000000000C0000-0x00000000000FFFFF] "CONFIG" (512 blocks) 
[PART] [0x0000000000100000-0x000000000013FFFF] "FACTORY" (512 blocks) 
[PART] [0x0000000000140000-0x000000000213FFFF] "BOOTIMG" (65536 blocks) 
[PART] [0x0000000002140000-0x000000000413FFFF] "RECOVERY" (65536 blocks) 
[PART] [0x0000000004140000-0x000000004413FFFF] "ROOTFS" (2097152 blocks) 
[PART] [0x0000000044140000-0x000001FFC413FFFF] "USER" (-4194304 blocks) 
BPI: SD/eMMC SD=1 eMMC=0 id = 0 (drivers/mmc/mediatek/mtk_mmc.c)
__mmc_init ret = 0
ret2 = 1
ret2 = 1
BPI: g_mtk_mmc_block.dev = 0
<= [mmc1 block 0] =>
[0x00000000] 00 00 00 00 00 00 00 00
[0x00000008] 00 00 00 00 00 00 00 00
[0x00000010] 00 00 00 00 00 00 00 00
[0x00000018] 00 00 00 00 00 00 00 00
[0x00000020] 00 00 00 00 00 00 00 00
[0x00000028] 00 00 00 00 00 00 00 00
[0x00000030] 00 00 00 00 00 00 00 00
[0x00000038] 00 00 00 00 00 00 00 00
[0x00000040] 00 00 00 00 00 00 00 00
[0x00000048] 00 00 00 00 00 00 00 00
[0x00000050] 00 00 00 00 00 00 00 00
[0x00000058] 00 00 00 00 00 00 00 00
[0x00000060] 00 00 00 00 00 00 00 00
[0x00000068] 00 00 00 00 00 00 00 00
[0x00000070] 00 00 00 00 00 00 00 00
[0x00000078] 00 00 00 00 00 00 00 00
[0x00000080] 00 00 00 00 00 00 00 00
[0x00000088] 00 00 00 00 00 00 00 00
[0x00000090] 00 00 00 00 00 00 00 00
[0x00000098] 00 00 00 00 00 00 00 00
[0x000000a0] 00 00 00 00 00 00 00 00
[0x000000a8] 00 00 00 00 00 00 00 00
[0x000000b0] 00 00 00 00 00 00 00 00
[0x000000b8] 00 00 00 00 00 00 00 00
[0x000000c0] 00 00 00 00 00 00 00 00
[0x000000c8] 00 00 00 00 00 00 00 00
[0x000000d0] 00 00 00 00 00 00 00 00
[0x000000d8] 00 00 00 00 00 00 00 00
[0x000000e0] 00 00 00 00 00 00 00 00
[0x000000e8] 00 00 00 00 00 00 00 00
[0x000000f0] 00 00 00 00 00 00 00 00
[0x000000f8] 00 00 00 00 00 00 00 00
[0x00000100] 00 00 00 00 00 00 00 00
[0x00000108] 00 00 00 00 00 00 00 00
[0x00000110] 00 00 00 00 00 00 00 00
[0x00000118] 00 00 00 00 00 00 00 00
[0x00000120] 00 00 00 00 00 00 00 00
[0x00000128] 00 00 00 00 00 00 00 00
[0x00000130] 00 00 00 00 00 00 00 00
[0x00000138] 00 00 00 00 00 00 00 00
[0x00000140] 00 00 00 00 00 00 00 00
[0x00000148] 00 00 00 00 00 00 00 00
[0x00000150] 00 00 00 00 00 00 00 00
[0x00000158] 00 00 00 00 00 00 00 00
[0x00000160] 00 00 00 00 00 00 00 00
[0x00000168] 00 00 00 00 00 00 00 00
[0x00000170] 00 00 00 00 00 00 00 00
[0x00000178] 00 00 00 00 00 00 00 00
[0x00000180] 00 00 00 00 00 00 00 00
[0x00000188] 00 00 00 00 00 00 00 00
[0x00000190] 00 00 00 00 00 00 00 00
[0x00000198] 00 00 00 00 00 00 00 00
[0x000001a0] 00 00 00 00 00 00 00 00
[0x000001a8] 00 00 00 00 00 00 00 00
[0x000001b0] 00 00 00 00 00 00 00 00
[0x000001b8] 56 d0 00 57 00 00 00 00
[0x000001c0] 01 80 83 03 10 7f 00 20
[0x000001c8] 03 00 00 00 08 00 00 00
[0x000001d0] 01 80 83 03 d0 ff 00 20
[0x000001d8] 0b 00 00 e0 dd 00 00 00
[0x000001e0] 00 00 00 00 00 00 00 00
[0x000001e8] 00 00 00 00 00 00 00 00
[0x000001f0] 00 00 00 00 00 00 00 00
[0x000001f8] 00 00 00 00 00 00 55 aa

Partition Map for MMC device 0  --   Partition Type: DOS

Part    Start Sector    Num Sectors     UUID            Type
  1     204800          524288          5700d056-01     83
  2     729088          14540800        5700d056-02     83
mmc0 is available
reading bpi-r2/linux/uEnv.txt
** Unable to read file bpi-r2/linux/uEnv.txt **
reading uEnv.txt
1581 bytes read in 3 ms (514.6 KiB/s)
Banana Pi bpi-r2 chip: mt7623n Service: 4.14.12-bpi-r2
reading bpi-r2/4.14.12-bpi-r2/uImage
8766697 bytes read in 536 ms (15.6 MiB/s)
Kernel loaded.
reading bpi-r2/4.14.12-bpi-r2/uInitrd
** Unable to read file bpi-r2/4.14.12-bpi-r2/uInitrd **
reading bpi-r2/4.14.12-bpi-r2/mt7623n-bpi-r2.dtb
** Unable to read file bpi-r2/4.14.12-bpi-r2/mt7623n-bpi-r2.dtb **
bootm flag=0, states=70f
## Booting kernel from Legacy Image at 84000000 ...
   Image Name:   Linux Kernel v4.14-45-g2e651881b
   Image Type:   ARM Linux Kernel Image (uncompressed)
   Data Size:    8766633 Bytes = 8.4 MiB
   Load Address: 80008000
   Entry Point:  80008000
   Verifying Checksum ... OK
   Loading Kernel Image ... OK

Starting kernel ...

[    0.000000] Booting Linux on physical CPU 0x0
[    0.000000] Linux version 4.14.12-bpi-r2 (weiqi@B85i-PC) (gcc version 7.2.0 (Ubuntu/Linaro 7.2.0-6ubuntu1)) #6 SMP Sun Jan 7 19:01:36 CST 2018
[    0.000000] CPU: ARMv7 Processor [410fc073] revision 3 (ARMv7), cr=10c5387d
[    0.000000] CPU: div instructions available: patching division code
[    0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache
[    0.000000] OF: fdt: Machine model: Bananapi BPI-R2
[    0.000000] Memory policy: Data cache writealloc
[    0.000000] [WMT-CONSYS-HW][W]reserve_memory_consys_fn: name: consys-reserve-memory, base: 0xffe00000, size: 0x100000
[    0.000000] OF: reserved mem: initialized node consys-reserve-memory, compatible id mediatek,consys-reserve-memory
[    0.000000] cma: Reserved 64 MiB at 0xfb800000
[    0.000000] On node 0 totalpages: 524031
[    0.000000] free_area_init_node: node 0, pgdat c13cdb00, node_mem_map df5f9000
[    0.000000]   Normal zone: 1170 pages used for memmap
[    0.000000]   Normal zone: 0 pages reserved
[    0.000000]   Normal zone: 133120 pages, LIFO batch:31
[    0.000000]   HighMem zone: 390911 pages, LIFO batch:31
[    0.000000] random: fast init done
[    0.000000] percpu: Embedded 17 pages/cpu @df59e000 s38860 r8192 d22580 u69632
[    0.000000] pcpu-alloc: s38860 r8192 d22580 u69632 alloc=17*4096
[    0.000000] pcpu-alloc: [0] 0 [0] 1 [0] 2 [0] 3 
[    0.000000] Built 1 zonelists, mobility grouping on.  Total pages: 522861
[    0.000000] Kernel command line: board=bpi-r2 console=earlyprintk console=tty1 console=ttyS0,115200 fbcon=map:0 root=PARTUUID=5700d056-02 rootfstype=ext4 rootwait service=4.14.12-bpi-r2 vm0
[    0.000000] PID hash table entries: 2048 (order: 1, 8192 bytes)
[    0.000000] Dentry cache hash table entries: 65536 (order: 6, 262144 bytes)
[    0.000000] Inode-cache hash table entries: 32768 (order: 5, 131072 bytes)
[    0.000000] Memory: 1991340K/2096124K available (12288K kernel code, 876K rwdata, 3832K rodata, 1024K init, 634K bss, 39248K reserved, 65536K cma-reserved, 1498108K highmem)
[    0.000000] Virtual kernel memory layout:
[    0.000000]     vector  : 0xffff0000 - 0xffff1000   (   4 kB)
[    0.000000]     fixmap  : 0xffc00000 - 0xfff00000   (3072 kB)
[    0.000000]     vmalloc : 0xe1000000 - 0xff800000   ( 488 MB)
[    0.000000]     lowmem  : 0xc0000000 - 0xe0800000   ( 520 MB)
[    0.000000]     pkmap   : 0xbfe00000 - 0xc0000000   (   2 MB)
[    0.000000]     modules : 0xbf000000 - 0xbfe00000   (  14 MB)
[    0.000000]       .text : 0xc0008000 - 0xc0d00000   (13280 kB)
[    0.000000]       .init : 0xc1200000 - 0xc1300000   (1024 kB)
[    0.000000]       .data : 0xc1300000 - 0xc13db0b4   ( 877 kB)
[    0.000000]        .bss : 0xc13e73bc - 0xc1485c04   ( 635 kB)
[    0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=4, Nodes=1
[    0.000000] ftrace: allocating 40692 entries in 120 pages
[    0.000000] Hierarchical RCU implementation.
[    0.000000]  RCU restricting CPUs from NR_CPUS=16 to nr_cpu_ids=4.
[    0.000000] RCU: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=4
[    0.000000] NR_IRQS: 16, nr_irqs: 16, preallocated irqs: 16
[    0.000000] arch_timer: cp15 timer(s) running at 13.00MHz (phys).
[    0.000000] clocksource: arch_sys_counter: mask: 0xffffffffffffff max_cycles: 0x2ff89eacb, max_idle_ns: 440795202429 ns
[    0.000006] sched_clock: 56 bits at 13MHz, resolution 76ns, wraps every 4398046511101ns
[    0.000016] Switching to timer-based delay loop, resolution 76ns
[    0.000172] clocksource: timer: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 147020034397 ns
[    0.000186] sched_clock: 32 bits at 13MHz, resolution 76ns, wraps every 165191050201ns
[    0.000564] Console: colour dummy device 80x30
[    0.001085] console [tty1] enabled
[    0.001120] Calibrating delay loop (skipped), value calculated using timer frequency.. 26.00 BogoMIPS (lpj=130000)
[    0.001147] pid_max: default: 32768 minimum: 301
[    0.001304] Mount-cache hash table entries: 1024 (order: 0, 4096 bytes)
[    0.001326] Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes)
[    0.001986] CPU: Testing write buffer coherency: ok
[    0.002307] CPU0: update cpu_capacity 1024
[    0.002327] CPU0: thread -1, cpu 0, socket 0, mpidr 80000000
[    0.002679] Setting up static identity map for 0x80100000 - 0x80100060
[    0.002795] Hierarchical SRCU implementation.
[    0.003464] smp: Bringing up secondary CPUs ...
[    0.003885] CPU1: update cpu_capacity 1024
[    0.003891] CPU1: thread -1, cpu 1, socket 0, mpidr 80000001
[    0.004373] CPU2: update cpu_capacity 1024
[    0.004378] CPU2: thread -1, cpu 2, socket 0, mpidr 80000002
[    0.004841] CPU3: update cpu_capacity 1024
[    0.004847] CPU3: thread -1, cpu 3, socket 0, mpidr 80000003
[    0.004928] smp: Brought up 1 node, 4 CPUs
[    0.005005] SMP: Total of 4 processors activated (104.00 BogoMIPS).
[    0.005020] CPU: All CPU(s) started in SVC mode.
[    0.005904] devtmpfs: initialized
[    0.011988] VFP support v0.3: implementor 41 architecture 2 part 30 variant 7 rev 3
[    0.012204] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns
[    0.012238] futex hash table entries: 1024 (order: 4, 65536 bytes)
[    0.014884] xor: measuring software checksum speed
[    0.110023]    arm4regs  :  1288.800 MB/sec
[    0.210086]    8regs     :   897.600 MB/sec
[    0.310152]    32regs    :   921.600 MB/sec
[    0.410220]    neon      :  1301.600 MB/sec
[    0.410234] xor: using function: neon (1301.600 MB/sec)
[    0.410325] pinctrl core: initialized pinctrl subsystem
[    0.411109] NET: Registered protocol family 16
[    0.412878] DMA: preallocated 256 KiB pool for atomic coherent allocations
[    0.413957] No ATAGs?
[    0.414102] hw-breakpoint: found 5 (+1 reserved) breakpoint and 4 watchpoint registers.
[    0.414135] hw-breakpoint: maximum watchpoint size is 8 bytes.
[    0.650599] raid6: int32x1  gen()   182 MB/s
[    0.820563] raid6: int32x1  xor()   169 MB/s
[    0.990692] raid6: int32x2  gen()   222 MB/s
[    1.160766] raid6: int32x2  xor()   178 MB/s
[    1.330901] raid6: int32x4  gen()   211 MB/s
[    1.501093] raid6: int32x4  xor()   175 MB/s
[    1.671156] raid6: int32x8  gen()   220 MB/s
[    1.841279] raid6: int32x8  xor()   148 MB/s
[    2.011458] raid6: neonx1   gen()   510 MB/s
[    2.181498] raid6: neonx1   xor()   482 MB/s
[    2.351591] raid6: neonx2   gen()   683 MB/s
[    2.521741] raid6: neonx2   xor()   603 MB/s
[    2.691849] raid6: neonx4   gen()   754 MB/s
[    2.861945] raid6: neonx4   xor()   655 MB/s
[    3.032110] raid6: neonx8   gen()   725 MB/s
[    3.202195] raid6: neonx8   xor()   616 MB/s
[    3.202210] raid6: using algorithm neonx4 gen() 754 MB/s
[    3.202223] raid6: .... xor() 655 MB/s, rmw enabled
[    3.202236] raid6: using neon recovery algorithm
[    3.202830] vgaarb: loaded
[    3.203180] SCSI subsystem initialized
[    3.203366] usbcore: registered new interface driver usbfs
[    3.203419] usbcore: registered new interface driver hub
[    3.203499] usbcore: registered new device driver usb
[    3.204029] Advanced Linux Sound Architecture Driver Initialized.
[    3.204449] Bluetooth: Core ver 2.22
[    3.204493] NET: Registered protocol family 31
[    3.204508] Bluetooth: HCI device and connection manager initialized
[    3.204529] Bluetooth: HCI socket layer initialized
[    3.204545] Bluetooth: L2CAP socket layer initialized
[    3.204578] Bluetooth: SCO socket layer initialized
[    3.205491] clocksource: Switched to clocksource arch_sys_counter
[    3.296401] VFS: Disk quotas dquot_6.6.0
[    3.296489] VFS: Dquot-cache hash table entries: 1024 (order 0, 4096 bytes)
[    3.296659] FS-Cache: Loaded
[    3.296857] CacheFiles: Loaded
[    3.304563] NET: Registered protocol family 2
[    3.305121] TCP established hash table entries: 4096 (order: 2, 16384 bytes)
[    3.305182] TCP bind hash table entries: 4096 (order: 3, 32768 bytes)
[    3.305250] TCP: Hash tables configured (established 4096 bind 4096)
[    3.305354] UDP hash table entries: 256 (order: 1, 8192 bytes)
[    3.305393] UDP-Lite hash table entries: 256 (order: 1, 8192 bytes)
[    3.305641] NET: Registered protocol family 1
[    3.306045] RPC: Registered named UNIX socket transport module.
[    3.306067] RPC: Registered udp transport module.
[    3.306080] RPC: Registered tcp transport module.
[    3.306093] RPC: Registered tcp NFSv4.1 backchannel transport module.
[    3.306112] PCI: CLS 0 bytes, default 64
[    3.308598] audit: initializing netlink subsys (disabled)
[    3.309019] audit: type=2000 audit(3.300:1): state=initialized audit_enabled=0 res=1
[    3.309095] workingset: timestamp_bits=14 max_order=19 bucket_order=5
[    3.314843] squashfs: version 4.0 (2009/01/31) Phillip Lougher
[    3.316090] NFS: Registering the id_resolver key type
[    3.316135] Key type id_resolver registered
[    3.316149] Key type id_legacy registered
[    3.316169] Installing knfsd (copyright (C) 1996 [email protected]).
[    3.316674] ntfs: driver 2.1.32 [Flags: R/W].
[    3.317034] fuse init (API version 7.26)
[    3.317592] JFS: nTxBlock = 8192, nTxLock = 65536
[    3.324178] SGI XFS with ACLs, security attributes, no debug enabled
[    3.329884] bounce: pool size: 64 pages
[    3.329968] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 250)
[    3.330094] io scheduler noop registered
[    3.330111] io scheduler deadline registered
[    3.330336] io scheduler cfq registered (default)
[    3.330354] io scheduler mq-deadline registered
[    3.330368] io scheduler kyber registered
[    3.374526] Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled
[    3.376018] console [ttyS0] disabled
[    3.396239] 11004000.serial: ttyS0 at MMIO 0x11004000 (irq = 26, base_baud = 1625000) is a ST16650V2
[    4.262980] console [ttyS0] enabled
[    4.266765] mt6577-uart 11002000.serial: could not find pctldev for node /pinctrl@10005000/uart@0, deferring probe
[    4.277110] mt6577-uart 11003000.serial: could not find pctldev for node /pinctrl@10005000/uart@1, deferring probe
[    4.287431] mt6577-uart 11005000.serial: could not find pctldev for node /pinctrl@10005000/uart@3, deferring probe
[    4.309359] brd: module loaded
[    4.319085] loop: module loaded
[    4.335404] [WMT-DETECT][I]wmt_detect_driver_init:driver(major 154) installed success
[    4.343308] [SDIO-DETECT][I]sdio_detect_init:sdio_register_driver() ret=0
[    4.350239] MTK-BTIF[E]hal_btif_clk_get_and_prepare(286):[CCF]clk_btif=dd951980
[    4.357536] MTK-BTIF[E]hal_btif_clk_get_and_prepare(292):[CCF]clk_btif_apdma=dd951a00
[    4.366431] SCSI Media Changer driver v0.25 
[    4.371028] mtk-spi 1100a000.spi: could not find pctldev for node /pinctrl@10005000/spi@0, deferring probe
[    4.380821] Ethernet Channel Bonding Driver: v3.7.1 (April 27, 2011)
[    4.388741] libphy: Fixed MDIO Bus: probed
[    4.393358] PPP generic driver version 2.4.2
[    4.397796] PPP BSD Compression module registered
[    4.402468] PPP Deflate Compression module registered
[    4.407521] PPP MPPE Compression module registered
[    4.412278] NET: Registered protocol family 24
[    4.416765] usbcore: registered new interface driver asix
[    4.422166] usbcore: registered new interface driver ax88179_178a
[    4.428261] usbcore: registered new interface driver cdc_ether
[    4.434098] usbcore: registered new interface driver smsc95xx
[    4.439849] usbcore: registered new interface driver net1080
[    4.445511] usbcore: registered new interface driver cdc_subset
[    4.451416] usbcore: registered new interface driver zaurus
[    4.457006] usbcore: registered new interface driver cdc_ncm
[    4.463077] xhci-mtk 1a1c0000.usb: 1a1c0000.usb supply vbus not found, using dummy regulator
[    4.471544] xhci-mtk 1a1c0000.usb: fail to get vusb33
[    4.476829] xhci-mtk 1a240000.usb: 1a240000.usb supply vbus not found, using dummy regulator
[    4.485273] xhci-mtk 1a240000.usb: fail to get vusb33
[    4.490521] usbcore: registered new interface driver usb-storage
[    4.496544] usbcore: registered new interface driver ums-alauda
[    4.502447] usbcore: registered new interface driver ums-cypress
[    4.508450] usbcore: registered new interface driver ums-datafab
[    4.514438] usbcore: registered new interface driver ums_eneub6250
[    4.520622] usbcore: registered new interface driver ums-freecom
[    4.526626] usbcore: registered new interface driver ums-isd200
[    4.532527] usbcore: registered new interface driver ums-jumpshot
[    4.538616] usbcore: registered new interface driver ums-karma
[    4.544432] usbcore: registered new interface driver ums-onetouch
[    4.550528] usbcore: registered new interface driver ums-realtek
[    4.556533] usbcore: registered new interface driver ums-sddr09

[USBD] USB PRB0 LineState: 0

[USBD] USB cable/ No Cable inserted!

[PLFM] Keep stay in USB Mode
Platform initialization is ok
wait for frequency meter finish, CLK26CALI = 0x81
mt_pll_post_init: mt_get_cpu_freq = 1040000Khz
wait for frequency meter finish, CLK26CALI = 0x90
mt_pll_post_init: mt_get_bus_freq = 273000Khz
wait for frequency meter finish, CLK26CALI = 0x81
mt_pll_post_init: mt_get_mem_freq = 133250Khz
[PWRAP] pwrap_init_preloader
[PWRAP] pwrap_init
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=0,rdata=2D52
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=1,rdata=2D52
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=2,rdata=2D52
[PWRAP] _pwrap_init_sistrobe [Read Test] pass,index=3 rdata=5AA5
[PWRAP] _pwrap_init_sistrobe [Read Test] pass,index=4 rdata=5AA5
[PWRAP] _pwrap_init_sistrobe [Read Test] pass,index=5 rdata=5AA5
[PWRAP] _pwrap_init_sistrobe [Read Test] pass,index=6 rdata=5AA5
[PWRAP] _pwrap_init_sistrobe [Read Test] pass,index=7 rdata=5AA5
[PWRAP] _pwrap_init_sistrobe [Read Test] pass,index=8 rdata=5AA5
[PWRAP] _pwrap_init_sistrobe [Read Test] pass,index=9 rdata=5AA5
[PWRAP] _pwrap_init_sistrobe [Read Test] pass,index=10 rdata=5AA5
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=11,rdata=B54B
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=12,rdata=B54B
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=13,rdata=B54B
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=14,rdata=B54B
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=15,rdata=B54B
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=16,rdata=B54B
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=17,rdata=B54B
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=18,rdata=B54B
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=19,rdata=6A97
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=20,rdata=6A97
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=21,rdata=6A97
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=22,rdata=6A97
[PWRAP] _pwrap_init_sistrobe [Read Test] fail,index=23,rdata=6A97
[PWRAP] _pwrap_init_reg_clock
[PMIC_WRAP]wrap_init pass,the return value=0.
[pmic6323_init] Preloader Start..................
[pmic6323_init] PMIC CHIP Code = 0x2023
INT_MISC_CON: 1  TOP_RST_MISC: 1
pl pmic powerkey Release
[pmic6323_init] powerKey = 0
[pmic6323_init] is USB in = 0xB004
[pmic6323_init] Reg[0x11A]=0x1B
pmic setup LED
[pmic6323_init] Done...................
mt7623 disable long press reset ->>>>>
mt7623 disable long press reset <<<<<-
mt7623 VPA supplied by 1.0V to MT7530 ->
mt7623 VPA supplied by 1.0V to MT7530 <-
mt7623 enables RG_VGP1_EN for LCM ->
mt7623 enables RG_VGP1_EN for LCM <-
MT7623 E2 setting =>
MT7623 E2 setting <=
[PLFM] Init I2C: OK(0)
[PLFM] Init PWRAP: OK(0)
[PLFM] Init PMIC: OK(0)
[PLFM] chip[CA00]

[BLDR] [Support SD/eMMC] Build Time: 20170905-120917
==== Dump RGU Reg ========
RGU MODE:     4D
RGU LENGTH:   FFE0
RGU STA:      0
RGU INTERVAL: FFF
RGU SWSYSRST: 0
==== Dump RGU Reg End ====
RGU: g_rgu_satus:0
 mtk_wdt_mode_config  mode value=10, tmp:22000010
PL P ON
WDT does not trigger reboot
RGU mtk_wdt_init:MTK_WDT_DEBUG_CTL(590200F3)
kpd read addr: 0x0040: data:0x4001
Enter mtk_kpd_gpio_set! 
kpd debug column : 0, 0, 0, 0, 0, 0, 0, 0
kpd debug row : 0, 0, 0, 0, 0, 0, 0, 0
after set KP enable: KP_SEL = 0x0 !
MTK_PMIC_RST_KEY is used for this project!
[RTC] get_frequency_meter: input=0x0, ouput=5
[RTC] get_frequency_meter: input=0x0, ouput=3968
[RTC] get_frequency_meter: input=0x0, ouput=5
[RTC] get_frequency_meter: input=0x0, ouput=0
[RTC] get_frequency_meter: input=0x0, ouput=0
[RTC] bbpu = 0xD, con = 0x426
[RTC] powerkey1 = 0xA357, powerkey2 = 0x67D2
Writeif_unlock
[RTC] RTC_SPAR0=0x40 
rtc_2sec_reboot_check cali=512
[RTC] irqsta = 0x0, pdn1 = 0x0, pdn2 = 0x201, spar0 = 0x40, spar1 = 0x800
[RTC] new_spare0 = 0x0, new_spare1 = 0x1, new_spare2 = 0x1, new_spare3 = 0x1
[RTC] bbpu = 0xD, con = 0x426, cali = 0x200
pl pmic powerkey Release
[PLFM] Power key boot!
[RTC] rtc_bbpu_power_on done
[EMI] mcp_dram_num:0,discrete_dram_num:1,enable_combo_dis:0
[EMI] PCDDR3
[Check]mt_get_mdl_number 0x0
[EMI] eMMC/NAND ID = 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
[EMI] MDL number = 0
[EMI] emi_set eMMC/NAND ID = 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
[EMI][Vcore]0x21E=0x48,0x220=0x48
[EMI][Vmem]0x554=0x0
wait for frequency meter finish, CLK26CALI = 0x81
[EMI] PCDDR3 DRAM Clock = 1600012 KHz, MEMPLL MODE = 2 
[EMI] PCDDR3 RXTDN Calibration:
Start REXTDN SW calibration...
drvp=0xB,drvn=0x8
[EMI] pinmux = 4
===============================================================================

        dramc_write_leveling_swcal
===============================================================================
delay  byte0  byte1  byte2  byte3
-----------------------------
0    0    1    1    1    
1    1    1    1    1    
2    1    1    1    1    
3    1    1    1    1    
4    1    1    1    1    
5    1    1    1    1    
6    1    1    1    1    
7    1    1    1    1    
8    1    1    1    1    
9    1    1    1    1    
10    1    1    1    1    
11    1    1    1    1    
12    1    1    1    1    
13    1    1    1    1    
14    1    1    1    1    
15    1    1    1    1    
pass bytecount = 4
byte_i    status    best delay
0    2    1
1    2    0
2    2    0
3    2    0
========================================
[write leveling]DQS: 0x1, DQM: 0x1
[write leveling after remap]DQ byte0 reg: 0x200 val: 0x11110000
[write leveling after remap]DQ byte1 reg: 0x204 val: 0x1111
[write leveling after remap]DQ byte2 reg: 0x208 val: 0x0
[write leveling after remap]DQ byte3 reg: 0x20C val: 0x0
=============================================
X-axis: DQS Gating Window Delay (Fine Scale)
Y-axis: DQS Gating Window Delay (Coarse Scale)
=============================================
          0    8   16   24   32   40   48   56   64   72   80   88   96  104  112  120
      --------------------------------------------------------------------------------
0000:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
0001:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
0002:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
0003:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
0004:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
0005:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
0006:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
0007:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
0008:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
0009:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
000A:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
000B:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
000C:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
000D:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
000E:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
000F:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
0010:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    1    1
0011:|    0    0    0    0    0    0    0    0    0    1    1    1    1    1    1    1
0012:|    0    0    0    1    1    1    1    1    1    1    1    1    0    0    0    0
0013:|    1    1    1    1    1    1    0    0    0    0    0    0    0    0    0    0
0014:|    1    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
0015:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
0016:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
0017:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
0018:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
0019:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
001A:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
001B:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
001C:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
001D:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
001E:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
001F:|    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0
Rank 0 coarse tune value selection : 18, 18
18
56
rank 0 coarse = 18
rank 0 fine = 56
00:|    0    0    0    0    0    0    0    0    1    1    1    0
opt_dle value:13
==================================================================
                RX      DQS perbit delay software calibration 
==================================================================
1.0-31 bit dq delay value
==================================================================
bit|     0  1  2  3  4  5  6  7  8  9
--------------------------------------
0 |    0 0 0 0 0 0 0 0 0 0 
10 |    0 0 0 0 0 0 0 0 0 0 
20 |    0 0 0 0 0 0 0 0 0 0 
30 |    0 0 
--------------------------------------
==================================================================
2.dqs window
x=pass dqs delay value (min~max)center 
y=0-7bit DQ of every group
input delay:DQS0 =48 DQS1 = 38 DQS2 =51 DQS3 = 43
==================================================================
bit     DQS0     bit      DQS1     bit     DQS2     bit     DQS3
0  (17~67)42  8  (7~58)32  16  (23~70)46  24  (17~61)39
1  (19~66)42  9  (7~60)33  17  (24~70)47  25  (16~57)36
2  (19~67)43  10  (13~62)37  18  (25~71)48  26  (19~61)40
3  (17~68)42  11  (11~62)36  19  (21~68)44  27  (19~58)38
4  (21~72)46  12  (14~62)38  20  (24~72)48  28  (22~64)43
5  (19~70)44  13  (14~62)38  21  (25~74)49  29  (21~64)42
6  (22~70)46  14  (13~60)36  22  (25~72)48  30  (16~64)40
7  (26~71)48  15  (15~62)38  23  (29~74)51  31  (19~64)41
==================================================================
3.dq delay value last
==================================================================
bit|    0  1  2  3  4  5  6  7  8   9
--------------------------------------
0 |    6 6 5 6 2 4 2 0 6 5 
10 |    1 2 0 0 2 0 5 4 3 7 
20 |    3 2 3 0 4 7 3 5 0 1 
30 |    3 2 
==================================================================
*DQIDLY1 = 0x6050606
*DQIDLY2 = 0x20402
*DQIDLY3 = 0x2010506
*DQIDLY4 = 0x20000
*DQIDLY5 = 0x7030405
*DQIDLY6 = 0x30203
*DQIDLY7 = 0x5030704
*DQIDLY8 = 0x2030100
*DRAMC_R0DELDLY = 0x2B332630

[MEM]CONA:F3A2,conf1:F07486A3
DM4BitMux = 1 
[Warning] DQSO 0 in TX per-bit = 3 > DQSO 0 in WL = 1  
DQSO 1 in TX per-bit = 0 <= DQSO 1 in WL = 0  
[Warning] DQSO 2 in TX per-bit = 7 > DQSO 2 in WL = 0  
[Warning] DQSO 3 in TX per-bit = 3 > DQSO 3 in WL = 0  
Tx DQM dly  = 0x133
Tx DQM dly bit4 = 0x0
DRAMC_DQODLY1=4532434h
DRAMC_DQODLY2=24234354h
DRAMC_DQODLY3=2122002h
DRAMC_DQODLY4=2223h
Tx DQ dly bit4 = 0x0
Tx DQS dly = 0x3703
Tx DQS dly bit4 = 0x0
TX Byte0: DQ - 14, DQS - 16. win_sum= 29
TX Byte1: DQ - 20, DQS - 14. win_sum= 33
TX Byte2: DQ - 9, DQS - 22. win_sum= 30
TX Byte3: DQ - 12, DQS - 19. win_sum= 30
DRAMC calibration takes 650079957 CPU cycles

[EMI] DRAMC calibration passed

[MEM] complex R/W mem test pass
0:dram_rank_size:80000000
[Dram_Buffer] dram size:-2147483648 
[Dram_Buffer] structure size: 1725560 
[Dram_Buffer] MAX_TEE_DRAM_SIZE: 0 
Load u-boot from eMMC...
[PLFM] Init Boot Device: OK(0)

[PART] blksz: 512B
[PART] [0x0000000000000000-0x000000000003FFFF] "PRELOADER" (512 blocks) 
[PART] [0x0000000000000000-0x000000000003FFFF] "MBR" (512 blocks) 
[PART] [0x0000000000040000-0x00000000000BFFFF] "UBOOT" (1024 blocks) 
[PART] [0x00000000000C0000-0x00000000000FFFFF] "CONFIG" (512 blocks) 
[PART] [0x0000000000100000-0x000000000013FFFF] "FACTORY" (512 blocks) 
[PART] [0x0000000000140000-0x000000000213FFFF] "BOOTIMG" (65536 blocks) 
[PART] [0x0000000002140000-0x000000000413FFFF] "RECOVERY" (65536 blocks) 
[PART] [0x0000000004140000-0x000000004413FFFF] "ROOTFS" (2097152 blocks) 
[PART] [0x0000000044140000-0x000001FFC413FFFF] "USER" (-4194304 blocks) 
BPI: SD/eMMC SD=1 eMMC=0 id = 0 (drivers/mmc/mediatek/mtk_mmc.c)
__mmc_init ret = 0
ret2 = 1
ret2 = 1
BPI: g_mtk_mmc_block.dev = 0
<= [mmc1 block 0] =>
[0x00000000] 00 00 00 00 00 00 00 00
[0x00000008] 00 00 00 00 00 00 00 00
[0x00000010] 00 00 00 00 00 00 00 00
[0x00000018] 00 00 00 00 00 00 00 00
[0x00000020] 00 00 00 00 00 00 00 00
[0x00000028] 00 00 00 00 00 00 00 00
[0x00000030] 00 00 00 00 00 00 00 00
[0x00000038] 00 00 00 00 00 00 00 00
[0x00000040] 00 00 00 00 00 00 00 00
[0x00000048] 00 00 00 00 00 00 00 00
[0x00000050] 00 00 00 00 00 00 00 00
[0x00000058] 00 00 00 00 00 00 00 00
[0x00000060] 00 00 00 00 00 00 00 00
[0x00000068] 00 00 00 00 00 00 00 00
[0x00000070] 00 00 00 00 00 00 00 00
[0x00000078] 00 00 00 00 00 00 00 00
[0x00000080] 00 00 00 00 00 00 00 00
[0x00000088] 00 00 00 00 00 00 00 00
[0x00000090] 00 00 00 00 00 00 00 00
[0x00000098] 00 00 00 00 00 00 00 00
[0x000000a0] 00 00 00 00 00 00 00 00
[0x000000a8] 00 00 00 00 00 00 00 00
[0x000000b0] 00 00 00 00 00 00 00 00
[0x000000b8] 00 00 00 00 00 00 00 00
[0x000000c0] 00 00 00 00 00 00 00 00
[0x000000c8] 00 00 00 00 00 00 00 00
[0x000000d0] 00 00 00 00 00 00 00 00
[0x000000d8] 00 00 00 00 00 00 00 00
[0x000000e0] 00 00 00 00 00 00 00 00
[0x000000e8] 00 00 00 00 00 00 00 00
[0x000000f0] 00 00 00 00 00 00 00 00
[0x000000f8] 00 00 00 00 00 00 00 00
[0x00000100] 00 00 00 00 00 00 00 00
[0x00000108] 00 00 00 00 00 00 00 00
[0x00000110] 00 00 00 00 00 00 00 00
[0x00000118] 00 00 00 00 00 00 00 00
[0x00000120] 00 00 00 00 00 00 00 00
[0x00000128] 00 00 00 00 00 00 00 00
[0x00000130] 00 00 00 00 00 00 00 00
[0x00000138] 00 00 00 00 00 00 00 00
[0x00000140] 00 00 00 00 00 00 00 00
[0x00000148] 00 00 00 00 00 00 00 00
[0x00000150] 00 00 00 00 00 00 00 00
[0x00000158] 00 00 00 00 00 00 00 00
[0x00000160] 00 00 00 00 00 00 00 00
[0x00000168] 00 00 00 00 00 00 00 00
[0x00000170] 00 00 00 00 00 00 00 00
[0x00000178] 00 00 00 00 00 00 00 00
[0x00000180] 00 00 00 00 00 00 00 00
[0x00000188] 00 00 00 00 00 00 00 00
[0x00000190] 00 00 00 00 00 00 00 00
[0x00000198] 00 00 00 00 00 00 00 00
[0x000001a0] 00 00 00 00 00 00 00 00
[0x000001a8] 00 00 00 00 00 00 00 00
[0x000001b0] 00 00 00 00 00 00 00 00
[0x000001b8] 56 d0 00 57 00 00 00 00
[0x000001c0] 01 80 83 03 10 7f 00 20
[0x000001c8] 03 00 00 00 08 00 00 00
[0x000001d0] 01 80 83 03 d0 ff 00 20
[0x000001d8] 0b 00 00 e0 dd 00 00 00
[0x000001e0] 00 00 00 00 00 00 00 00
[0x000001e8] 00 00 00 00 00 00 00 00
[0x000001f0] 00 00 00 00 00 00 00 00
[0x000001f8] 00 00 00 00 00 00 55 aa

Partition Map for MMC device 0  --   Partition Type: DOS

Part    Start Sector    Num Sectors     UUID            Type
  1     204800          524288          5700d056-01     83
  2     729088          14540800        5700d056-02     83
mmc0 is available
reading bpi-r2/linux/uEnv.txt
** Unable to read file bpi-r2/linux/uEnv.txt **
reading uEnv.txt
1581 bytes read in 3 ms (514.6 KiB/s)
Banana Pi bpi-r2 chip: mt7623n Service: 4.14.12-bpi-r2
reading bpi-r2/4.14.12-bpi-r2/uImage
8766697 bytes read in 536 ms (15.6 MiB/s)
Kernel loaded.
reading bpi-r2/4.14.12-bpi-r2/uInitrd
** Unable to read file bpi-r2/4.14.12-bpi-r2/uInitrd **
reading bpi-r2/4.14.12-bpi-r2/mt7623n-bpi-r2.dtb
** Unable to read file bpi-r2/4.14.12-bpi-r2/mt7623n-bpi-r2.dtb **
bootm flag=0, states=70f
## Booting kernel from Legacy Image at 84000000 ...
   Image Name:   Linux Kernel v4.14-45-g2e651881b
   Image Type:   ARM Linux Kernel Image (uncompressed)
   Data Size:    8766633 Bytes = 8.4 MiB
   Load Address: 80008000
   Entry Point:  80008000
   Verifying Checksum ... OK
   Loading Kernel Image ... OK

Starting kernel ...

[    0.000000] Booting Linux on physical CPU 0x0
[    0.000000] Linux version 4.14.12-bpi-r2 (weiqi@B85i-PC) (gcc version 7.2.0 (Ubuntu/Linaro 7.2.0-6ubuntu1)) #6 SMP Sun Jan 7 19:01:36 CST 2018
[    0.000000] CPU: ARMv7 Processor [410fc073] revision 3 (ARMv7), cr=10c5387d
[    0.000000] CPU: div instructions available: patching division code
[    0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache
[    0.000000] OF: fdt: Machine model: Bananapi BPI-R2
[    0.000000] Memory policy: Data cache writealloc
[    0.000000] [WMT-CONSYS-HW][W]reserve_memory_consys_fn: name: consys-reserve-memory, base: 0xffe00000, size: 0x100000
[    0.000000] OF: reserved mem: initialized node consys-reserve-memory, compatible id mediatek,consys-reserve-memory
[    0.000000] cma: Reserved 64 MiB at 0xfb800000
[    0.000000] On node 0 totalpages: 524031
[    0.000000] free_area_init_node: node 0, pgdat c13cdb00, node_mem_map df5f9000
[    0.000000]   Normal zone: 1170 pages used for memmap
[    0.000000]   Normal zone: 0 pages reserved
[    0.000000]   Normal zone: 133120 pages, LIFO batch:31
[    0.000000]   HighMem zone: 390911 pages, LIFO batch:31
[    0.000000] random: fast init done
[    0.000000] percpu: Embedded 17 pages/cpu @df59e000 s38860 r8192 d22580 u69632
[    0.000000] pcpu-alloc: s38860 r8192 d22580 u69632 alloc=17*4096
[    0.000000] pcpu-alloc: [0] 0 [0] 1 [0] 2 [0] 3 
[    0.000000] Built 1 zonelists, mobility grouping on.  Total pages: 522861
[    0.000000] Kernel command line: board=bpi-r2 console=earlyprintk console=tty1 console=ttyS0,115200 fbcon=map:0 root=PARTUUID=5700d056-02 rootfstype=ext4 rootwait service=4.14.12-bpi-r2 vm0
[    0.000000] PID hash table entries: 2048 (order: 1, 8192 bytes)
[    0.000000] Dentry cache hash table entries: 65536 (order: 6, 262144 bytes)
[    0.000000] Inode-cache hash table entries: 32768 (order: 5, 131072 bytes)
[    0.000000] Memory: 1991340K/2096124K available (12288K kernel code, 876K rwdata, 3832K rodata, 1024K init, 634K bss, 39248K reserved, 65536K cma-reserved, 1498108K highmem)
[    0.000000] Virtual kernel memory layout:
[    0.000000]     vector  : 0xffff0000 - 0xffff1000   (   4 kB)
[    0.000000]     fixmap  : 0xffc00000 - 0xfff00000   (3072 kB)
[    0.000000]     vmalloc : 0xe1000000 - 0xff800000   ( 488 MB)
[    0.000000]     lowmem  : 0xc0000000 - 0xe0800000   ( 520 MB)
[    0.000000]     pkmap   : 0xbfe00000 - 0xc0000000   (   2 MB)
[    0.000000]     modules : 0xbf000000 - 0xbfe00000   (  14 MB)
[    0.000000]       .text : 0xc0008000 - 0xc0d00000   (13280 kB)
[    0.000000]       .init : 0xc1200000 - 0xc1300000   (1024 kB)
[    0.000000]       .data : 0xc1300000 - 0xc13db0b4   ( 877 kB)
[    0.000000]        .bss : 0xc13e73bc - 0xc1485c04   ( 635 kB)
[    0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=4, Nodes=1
[    0.000000] ftrace: allocating 40692 entries in 120 pages
[    0.000000] Hierarchical RCU implementation.
[    0.000000]  RCU restricting CPUs from NR_CPUS=16 to nr_cpu_ids=4.
[    0.000000] RCU: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=4
[    0.000000] NR_IRQS: 16, nr_irqs: 16, preallocated irqs: 16
[    0.000000] arch_timer: cp15 timer(s) running at 13.00MHz (phys).
[    0.000000] clocksource: arch_sys_counter: mask: 0xffffffffffffff max_cycles: 0x2ff89eacb, max_idle_ns: 440795202429 ns
[    0.000006] sched_clock: 56 bits at 13MHz, resolution 76ns, wraps every 4398046511101ns
[    0.000016] Switching to timer-based delay loop, resolution 76ns
[    0.000174] clocksource: timer: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 147020034397 ns
[    0.000188] sched_clock: 32 bits at 13MHz, resolution 76ns, wraps every 165191050201ns
[    0.000565] Console: colour dummy device 80x30
[    0.001086] console [tty1] enabled
[    0.001120] Calibrating delay loop (skipped), value calculated using timer frequency.. 26.00 BogoMIPS (lpj=130000)
[    0.001148] pid_max: default: 32768 minimum: 301
[    0.001303] Mount-cache hash table entries: 1024 (order: 0, 4096 bytes)
[    0.001326] Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes)
[    0.001984] CPU: Testing write buffer coherency: ok
[    0.002307] CPU0: update cpu_capacity 1024
[    0.002327] CPU0: thread -1, cpu 0, socket 0, mpidr 80000000
[    0.002683] Setting up static identity map for 0x80100000 - 0x80100060
[    0.002803] Hierarchical SRCU implementation.
[    0.003476] smp: Bringing up secondary CPUs ...
[    0.003898] CPU1: update cpu_capacity 1024
[    0.003904] CPU1: thread -1, cpu 1, socket 0, mpidr 80000001
[    0.004382] CPU2: update cpu_capacity 1024
[    0.004387] CPU2: thread -1, cpu 2, socket 0, mpidr 80000002
[    0.004849] CPU3: update cpu_capacity 1024
[    0.004855] CPU3: thread -1, cpu 3, socket 0, mpidr 80000003
[    0.004936] smp: Brought up 1 node, 4 CPUs
[    0.005013] SMP: Total of 4 processors activated (104.00 BogoMIPS).
[    0.005027] CPU: All CPU(s) started in SVC mode.
[    0.005917] devtmpfs: initialized
[    0.012006] VFP support v0.3: implementor 41 architecture 2 part 30 variant 7 rev 3
[    0.012218] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns
[    0.012252] futex hash table entries: 1024 (order: 4, 65536 bytes)
[    0.014866] xor: measuring software checksum speed
[    0.110018]    arm4regs  :  1288.800 MB/sec
[    0.210081]    8regs     :   897.600 MB/sec
[    0.310147]    32regs    :   921.600 MB/sec
[    0.410215]    neon      :  1301.600 MB/sec
[    0.410229] xor: using function: neon (1301.600 MB/sec)
[    0.410321] pinctrl core: initialized pinctrl subsystem
[    0.411110] NET: Registered protocol family 16
[    0.412882] DMA: preallocated 256 KiB pool for atomic coherent allocations
[    0.413964] No ATAGs?
[    0.414113] hw-breakpoint: found 5 (+1 reserved) breakpoint and 4 watchpoint registers.
[    0.414146] hw-breakpoint: maximum watchpoint size is 8 bytes.
[    0.650597] raid6: int32x1  gen()   182 MB/s
[    0.820581] raid6: int32x1  xor()   169 MB/s
[    0.990677] raid6: int32x2  gen()   222 MB/s
[    1.160909] raid6: int32x2  xor()   178 MB/s
[    1.330897] raid6: int32x4  gen()   211 MB/s
[    1.501100] raid6: int32x4  xor()   175 MB/s
[    1.671158] raid6: int32x8  gen()   220 MB/s
[    1.841267] raid6: int32x8  xor()   148 MB/s
[    2.011458] raid6: neonx1   gen()   510 MB/s
[    2.181470] raid6: neonx1   xor()   482 MB/s
[    2.351595] raid6: neonx2   gen()   683 MB/s
[    2.521709] raid6: neonx2   xor()   603 MB/s
[    2.691842] raid6: neonx4   gen()   754 MB/s
[    2.861946] raid6: neonx4   xor()   654 MB/s
[    3.032127] raid6: neonx8   gen()   725 MB/s
[    3.202184] raid6: neonx8   xor()   616 MB/s
[    3.202199] raid6: using algorithm neonx4 gen() 754 MB/s
[    3.202212] raid6: .... xor() 654 MB/s, rmw enabled
[    3.202225] raid6: using neon recovery algorithm
[    3.202810] vgaarb: loaded
[    3.203158] SCSI subsystem initialized
[    3.203343] usbcore: registered new interface driver usbfs
[    3.203396] usbcore: registered new interface driver hub
[    3.203474] usbcore: registered new device driver usb
[    3.204006] Advanced Linux Sound Architecture Driver Initialized.
[    3.204427] Bluetooth: Core ver 2.22
[    3.204470] NET: Registered protocol family 31
[    3.204485] Bluetooth: HCI device and connection manager initialized
[    3.204505] Bluetooth: HCI socket layer initialized
[    3.204522] Bluetooth: L2CAP socket layer initialized
[    3.204555] Bluetooth: SCO socket layer initialized
[    3.205468] clocksource: Switched to clocksource arch_sys_counter
[    3.296398] VFS: Disk quotas dquot_6.6.0
[    3.296487] VFS: Dquot-cache hash table entries: 1024 (order 0, 4096 bytes)
[    3.296659] FS-Cache: Loaded
[    3.296858] CacheFiles: Loaded
[    3.304546] NET: Registered protocol family 2
[    3.305108] TCP established hash table entries: 4096 (order: 2, 16384 bytes)
[    3.305169] TCP bind hash table entries: 4096 (order: 3, 32768 bytes)
[    3.305237] TCP: Hash tables configured (established 4096 bind 4096)
[    3.305344] UDP hash table entries: 256 (order: 1, 8192 bytes)
[    3.305382] UDP-Lite hash table entries: 256 (order: 1, 8192 bytes)
[    3.305629] NET: Registered protocol family 1
[    3.306023] RPC: Registered named UNIX socket transport module.
[    3.306044] RPC: Registered udp transport module.
[    3.306057] RPC: Registered tcp transport module.
[    3.306069] RPC: Registered tcp NFSv4.1 backchannel transport module.
[    3.306089] PCI: CLS 0 bytes, default 64
[    3.308563] audit: initializing netlink subsys (disabled)
[    3.308986] audit: type=2000 audit(3.300:1): state=initialized audit_enabled=0 res=1
[    3.309065] workingset: timestamp_bits=14 max_order=19 bucket_order=5
[    3.314801] squashfs: version 4.0 (2009/01/31) Phillip Lougher
[    3.316056] NFS: Registering the id_resolver key type
[    3.316096] Key type id_resolver registered
[    3.316110] Key type id_legacy registered
[    3.316130] Installing knfsd (copyright (C) 1996 [email protected]).
[    3.316638] ntfs: driver 2.1.32 [Flags: R/W].
[    3.316999] fuse init (API version 7.26)
[    3.317546] JFS: nTxBlock = 8192, nTxLock = 65536
[    3.324124] SGI XFS with ACLs, security attributes, no debug enabled
[    3.329840] bounce: pool size: 64 pages
[    3.329925] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 250)
[    3.330055] io scheduler noop registered
[    3.330071] io scheduler deadline registered
[    3.330311] io scheduler cfq registered (default)
[    3.330329] io scheduler mq-deadline registered
[    3.330343] io scheduler kyber registered
[    3.374673] Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled
[    3.376193] console [ttyS0] disabled
[    3.396378] 11004000.serial: ttyS0 at MMIO 0x11004000 (irq = 26, base_baud = 1625000) is a ST16650V2
[    4.263183] console [ttyS0] enabled
[    4.266927] mt6577-uart 11002000.serial: could not find pctldev for node /pinctrl@10005000/uart@0, deferring probe
[    4.277260] mt6577-uart 11003000.serial: could not find pctldev for node /pinctrl@10005000/uart@1, deferring probe
[    4.287579] mt6577-uart 11005000.serial: could not find pctldev for node /pinctrl@10005000/uart@3, deferring probe
[    4.309558] brd: module loaded
[    4.319294] loop: module loaded
[    4.335783] [WMT-DETECT][I]wmt_detect_driver_init:driver(major 154) installed success
[    4.343605] [SDIO-DETECT][I]sdio_detect_init:sdio_register_driver() ret=0
[    4.350544] MTK-BTIF[E]hal_btif_clk_get_and_prepare(286):[CCF]clk_btif=dd999440
[    4.357854] MTK-BTIF[E]hal_btif_clk_get_and_prepare(292):[CCF]clk_btif_apdma=dd9994c0
[    4.366740] SCSI Media Changer driver v0.25 
[    4.371328] mtk-spi 1100a000.spi: could not find pctldev for node /pinctrl@10005000/spi@0, deferring probe
[    4.381119] Ethernet Channel Bonding Driver: v3.7.1 (April 27, 2011)
[    4.389040] libphy: Fixed MDIO Bus: probed
[    4.393637] PPP generic driver version 2.4.2
[    4.398090] PPP BSD Compression module registered
[    4.402764] PPP Deflate Compression module registered
[    4.407818] PPP MPPE Compression module registered
[    4.412576] NET: Registered protocol family 24
[    4.417071] usbcore: registered new interface driver asix
[    4.422473] usbcore: registered new interface driver ax88179_178a
[    4.428571] usbcore: registered new interface driver cdc_ether
[    4.434399] usbcore: registered new interface driver smsc95xx
[    4.440149] usbcore: registered new interface driver net1080
[    4.445812] usbcore: registered new interface driver cdc_subset
[    4.451721] usbcore: registered new interface driver zaurus
[    4.457312] usbcore: registered new interface driver cdc_ncm
[    4.463393] xhci-mtk 1a1c0000.usb: 1a1c0000.usb supply vbus not found, using dummy regulator
[    4.471859] xhci-mtk 1a1c0000.usb: fail to get vusb33
[    4.477148] xhci-mtk 1a240000.usb: 1a240000.usb supply vbus not found, using dummy regulator
[    4.485628] xhci-mtk 1a240000.usb: fail to get vusb33
[    4.490854] usbcore: registered new interface driver usb-storage
[    4.496872] usbcore: registered new interface driver ums-alauda
[    4.502775] usbcore: registered new interface driver ums-cypress
[    4.508778] usbcore: registered new interface driver ums-datafab
[    4.514766] usbcore: registered new interface driver ums_eneub6250
[    4.520942] usbcore: registered new interface driver ums-freecom
[    4.526949] usbcore: registered new interface driver ums-isd200
[    4.532851] usbcore: registered new interface driver ums-jumpshot
[    4.538943] usbcore: registered new interface driver ums-karma
[    4.544761] usbcore: registered new interface driver ums-onetouch
[    4.550864] usbcore: registered new interface driver ums-realtek
[    4.556869] usbcore: registered new interface driver ums-sddr09
[    4.562772] usbcore: registered new interface driver ums-sddr55
[    4.568685] usbcore: registered new interface driver ums-usbat
[    4.574739] mousedev: PS/2 mouse device common for all mice
[    4.580545] i2c-mt65xx 11007000.i2c: could not find pctldev for node /pinctrl@10005000/i2c@0, deferring probe
[    4.590464] i2c-mt65xx 11008000.i2c: could not find pctldev for node /pinctrl@10005000/i2c@1, deferring probe
[    4.600505] IR NEC protocol handler initialized
[    4.605003] IR RC5(x/sz) protocol handler initialized
[    4.610034] IR RC6 protocol handler initialized
[    4.614531] IR JVC protocol handler initialized
[    4.619040] IR Sony protocol handler initialized
[    4.623621] IR SANYO protocol handler initialized
[    4.628302] IR Sharp protocol handler initialized
[    4.632971] IR MCE Keyboard/mouse protocol handler initialized
[    4.638772] IR XMP protocol handler initialized
[    4.643506] MTK_WDT_NONRST_REG(0)
[    4.647397] mtk-wdt 10007000.watchdog: Watchdog enabled (timeout=31 sec, nowayout=0)
[    4.656264] device-mapper: uevent: version 1.0.3
[    4.661099] device-mapper: ioctl: 4.37.0-ioctl (2017-09-20) initialised: [email protected]
[    4.669864] mtk-msdc 11240000.mmc: could not find pctldev for node /pinctrl@10005000/mmc1default, deferring probe
[    4.680107] mtk-msdc 11230000.mmc: could not find pctldev for node /pinctrl@10005000/mmc0default, deferring probe
[    4.690538] hidraw: raw HID events driver (C) Jiri Kosina
[    4.696299] usbcore: registered new interface driver usbhid
[    4.701833] usbhid: USB HID core driver
[    4.706710] ipip: IPv4 and MPLS over IPv4 tunneling driver
[    4.712613] Initializing XFRM netlink socket
[    4.717298] NET: Registered protocol family 10
[    4.722694] Segment Routing with IPv6
[    4.726415] sit: IPv6, IPv4 and MPLS over IPv4 tunneling driver
[    4.733263] NET: Registered protocol family 17
[    4.737770] Key type dns_resolver registered
[    4.742295] ThumbEE CPU extension supported.
[    4.746556] Registering SWP/SWPB emulation handler
[    4.752740] Btrfs loaded, crc32c=crc32c-generic
[    4.758046] Key type encrypted registered
[    4.770601] mt6577-uart 11002000.serial: could not find pctldev for node /pinctrl@10005000/uart@0, deferring probe
[    4.781118] mt6577-uart 11003000.serial: could not find pctldev for node /pinctrl@10005000/uart@1, deferring probe
[    4.791568] mt6577-uart 11005000.serial: could not find pctldev for node /pinctrl@10005000/uart@3, deferring probe
[    4.802206] mtk-spi 1100a000.spi: could not find pctldev for node /pinctrl@10005000/spi@0, deferring probe
[    4.812391] xhci-mtk 1a1c0000.usb: 1a1c0000.usb supply vbus not found, using dummy regulator
[    4.820861] xhci-mtk 1a1c0000.usb: fail to get vusb33
[    4.826411] xhci-mtk 1a240000.usb: 1a240000.usb supply vbus not found, using dummy regulator
[    4.834876] xhci-mtk 1a240000.usb: fail to get vusb33
[    4.840178] i2c-mt65xx 11007000.i2c: could not find pctldev for node /pinctrl@10005000/i2c@0, deferring probe
[    4.850191] i2c-mt65xx 11008000.i2c: could not find pctldev for node /pinctrl@10005000/i2c@1, deferring probe
[    4.860193] mtk-msdc 11240000.mmc: could not find pctldev for node /pinctrl@10005000/mmc1default, deferring probe
[    4.870528] mtk-msdc 11230000.mmc: could not find pctldev for node /pinctrl@10005000/mmc0default, deferring probe
[    4.881554] ALSA device list:
[    4.884506]   No soundcards found.
[    4.888377] md: Waiting for all devices to be available before autodetect
[    4.895120] md: If you don't use raid, use raid=noautodetect
[    4.901389] md: Autodetecting RAID arrays.
[    4.905488] md: autorun ...
[    4.908261] md: ... autorun DONE.
[    4.911737] Waiting for root device PARTUUID=5700d056-02...

@weiqi-chen
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Here is my uboot environment

BPI-EMMC> printenv
arch=arm
baudrate=115200
board=bpi-r2
board_name=mt7623_evb
boot0=setenv mmc 0; run bootcmd
boot1=setenv mmc 1; run bootcmd
boot2=run bootcmd
boot3=setenv mmc 0; run bootfallback
boot4=setenv mmc 1; run bootfallback
bootargs=board=bpi-r2 earlyprintk console=tty1 fbcon=map:0 console=ttyS0,115200 vmalloc=496M debug=7 t
bootcmd=mmc init $mmc; run loadbootenv; run uenvcmd
bootdelay=3
bootenv=uEnv.txt
bootfallback=mmc init $mmc; run loadbootenv; run ufallbackcmd
bootfile=iverson_uImage
bootmenu_0=1. Boot from internal emmc.=run boot0
bootmenu_1=2. Boot from external sd-card.=run boot1
bootmenu_2=3. Boot from default medium.=run boot2
bootmenu_3=4. Fallback boot from internam emmc.=run boot3
bootmenu_4=5. Fallback boot from external sd-card.=run boot4
bpi=bananapi
bpiver=1
chip=MT7623N
cpu=armv7
debug=7
device=mmc
ethact=mtk_eth
ethaddr=00:0C:E7:11:22:33
ipaddr=10.10.10.254
kernel=uImage
loadaddr=0x84000000
loadbootenv=fatload ${device} ${partition} ${scriptaddr} ${board}/${service}/${bootenv} ||fatload ${d;
mmc=0
partition=0:1
scriptaddr=0x83000000
serverip=10.10.10.3
service=linux
soc=mt7623
stderr=serial
stdin=serial
stdout=serial
vendor=mediatek

@weiqi-chen
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Here is the info in the fat32 partition:

$ find
.
./uEnv.txt
./bpi-r2
./bpi-r2/4.14.12-bpi-r2
./bpi-r2/4.14.12-bpi-r2/uImage
./bpi-r2/linux
./bpi-r2/linux/uImage
./bpi-r2/linux/uEnv.txt.backup
./bpi-r2/4.4.70-bpi-r2-2
./bpi-r2/4.4.70-bpi-r2-2/uImage
$ cat uEnv.txt 
bpi=bananapi
board=bpi-r2
chip=mt7623n
#
kernel=uImage
initrd=uInitrd
dtb=mt7623n-bpi-r2.dtb
#
target=4.14.12-bpi-r2
fallback=linux
root=PARTUUID="5700d056-02" rootfstype=ext4 rootwait
#
kaddr=0x84000000
rdaddr=0x86000000
dtaddr=0x88000000
#
console=earlyprintk console=tty1 console=ttyS0,115200 fbcon=map:0
bootopts=vmalloc=496M debug=7 initcall_debug=0
abootargs=setenv bootargs board=${board} console=${console} root=${root} service=${service} ${bootopt}
ahello=echo Banana Pi ${board} chip: $chip Service: $service
## load kernel
aload_kernel_cmd=fatload $device $partition $kaddr ${board}/${service}/${kernel}
aload_kernel=if run aload_kernel_cmd ; then echo Kernel loaded. ; else exit; fi
## load initrd
aload_initrd_cmd=fatload $device $partition $rdaddr ${board}/${service}/${initrd}
aload_initrd=if run aload_initrd_cmd; then echo Initrd loaded. ; else set rdaddr - ; fi
## load device tree
aload_device_tree_cmd=fatload $device $partition $rdaddr ${board}/${service}/${dtb}
aload_device_tree=if run aload_device_tree_cmd; then echo Device Tree loaded. ; else set dtaddr - ; fi
##bootm
abootm=bootm $kaddr $rdaddr $dtaddr
#
uenvcmd=setenv service ${target}; run ahello abootargs aload_kernel aload_initrd aload_device_tree abm
ufallbackcmd=setenv service ${fallback}; run ahello abootargs aload_kernel aload_initrd aload_device_m
########################################################
########################################################
########################################################
########################################################

@weiqi-chen
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I seem that some warnning message in boot-up log..

@weiqi-chen
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And here is how i compiled the kernel work.sh:

#!/bin/bash
export ARCH=arm
export KPKG_ARCH=armhf
export CROSS_COMPILE=arm-linux-gnueabihf-
export LOADADDR=0x80008000
export LOCALVERSION=""
##you may make mt7623n_evb_defconfig
#fakeroot make-kpkg --initrd --uimage --verbose binary-arch
#fakeroot make-kpkg --uimage --verbose binary-arch
make bindeb-pkg

mkimg.sh

#!/bin/bash
export ARCH=arm
export KPKG_ARCH=armhf
export CROSS_COMPILE=arm-linux-gnueabihf-
export LOADADDR=0x80008000
export LOCALVERSION=""
make uImage dtbs
cat arch/arm/boot/zImage arch/arm/boot/dts/mt7623n-bananapi-bpi-r2.dtb > arch/arm/boot/zImage-dtb
mkimage -A arm -O linux -T kernel -C none -a 80008000 -e 80008000 -n "Linux Kernel $(git describe --tags)" -d arch/arm/boot/zImage-dtb ./uImage

@frank-w
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frank-w commented Jan 7, 2018

Please try with my build.sh and define a root in uenv pointing to /dev not partuuid

@frank-w
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frank-w commented Jan 7, 2018

which config do you use?

./build.sh importconfig
./build.sh

also kernel has another name (appended bpi-r2...thats not with my config/script)

from where do you get the uenv.txt? there are much more options than in standard-uenv.txt

@weiqi-chen
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I copied .config from 4.4.70 before.
Now I'm trying the default config: make mt7623n_evb_fwu_defconfig...

@weiqi-chen
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It works now!!

make mt7623n_evb_fwu_defconfig

fix the problem.

Thank for your help!!!

frank-w pushed a commit that referenced this issue Mar 1, 2018
commit 7ba7166 upstream.

It was reported by Sergey Senozhatsky that if THP (Transparent Huge
Page) and frontswap (via zswap) are both enabled, when memory goes low
so that swap is triggered, segfault and memory corruption will occur in
random user space applications as follow,

kernel: urxvt[338]: segfault at 20 ip 00007fc08889ae0d sp 00007ffc73a7fc40 error 6 in libc-2.26.so[7fc08881a000+1ae000]
 #0  0x00007fc08889ae0d _int_malloc (libc.so.6)
 #1  0x00007fc08889c2f3 malloc (libc.so.6)
 #2  0x0000560e6004bff7 _Z14rxvt_wcstoutf8PKwi (urxvt)
 #3  0x0000560e6005e75c n/a (urxvt)
 #4  0x0000560e6007d9f1 _ZN16rxvt_perl_interp6invokeEP9rxvt_term9hook_typez (urxvt)
 #5  0x0000560e6003d988 _ZN9rxvt_term9cmd_parseEv (urxvt)
 #6  0x0000560e60042804 _ZN9rxvt_term6pty_cbERN2ev2ioEi (urxvt)
 #7  0x0000560e6005c10f _Z17ev_invoke_pendingv (urxvt)
 #8  0x0000560e6005cb55 ev_run (urxvt)
 #9  0x0000560e6003b9b9 main (urxvt)
 #10 0x00007fc08883af4a __libc_start_main (libc.so.6)
 #11 0x0000560e6003f9da _start (urxvt)

After bisection, it was found the first bad commit is bd4c82c ("mm,
THP, swap: delay splitting THP after swapped out").

The root cause is as follows:

When the pages are written to swap device during swapping out in
swap_writepage(), zswap (fontswap) is tried to compress the pages to
improve performance.  But zswap (frontswap) will treat THP as a normal
page, so only the head page is saved.  After swapping in, tail pages
will not be restored to their original contents, causing memory
corruption in the applications.

This is fixed by refusing to save page in the frontswap store functions
if the page is a THP.  So that the THP will be swapped out to swap
device.

Another choice is to split THP if frontswap is enabled.  But it is found
that the frontswap enabling isn't flexible.  For example, if
CONFIG_ZSWAP=y (cannot be module), frontswap will be enabled even if
zswap itself isn't enabled.

Frontswap has multiple backends, to make it easy for one backend to
enable THP support, the THP checking is put in backend frontswap store
functions instead of the general interfaces.

Link: http://lkml.kernel.org/r/[email protected]
Fixes: bd4c82c ("mm, THP, swap: delay splitting THP after swapped out")
Signed-off-by: "Huang, Ying" <[email protected]>
Reported-by: Sergey Senozhatsky <[email protected]>
Tested-by: Sergey Senozhatsky <[email protected]>
Suggested-by: Minchan Kim <[email protected]>	[put THP checking in backend]
Cc: Konrad Rzeszutek Wilk <[email protected]>
Cc: Dan Streetman <[email protected]>
Cc: Seth Jennings <[email protected]>
Cc: Tetsuo Handa <[email protected]>
Cc: Shaohua Li <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Shakeel Butt <[email protected]>
Cc: Boris Ostrovsky <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: <[email protected]>	[4.14]
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
frank-w pushed a commit that referenced this issue Mar 4, 2018
[ Upstream commit 36b0cb8 ]

An additional 'ip' will be pushed to the stack, for restoring the
DACR later, if CONFIG_CPU_SW_DOMAIN_PAN defined.

However, the fixup still get the err_ptr by add #8*4 to sp, which
results in the fact that the code area pointed by the LR will be
overwritten, or the kernel will crash if CONFIG_DEBUG_RODATA is enabled.

This patch fixes the stack mismatch.

Fixes: a5e090a ("ARM: software-based priviledged-no-access support")
Signed-off-by: Lvqiang Huang <[email protected]>
Signed-off-by: Chunyan Zhang <[email protected]>
Signed-off-by: Russell King <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
frank-w pushed a commit that referenced this issue Mar 11, 2018
[ upstream commit ca36960 ]

The requirements around atomic_add() / atomic64_add() resp. their
JIT implementations differ across architectures. E.g. while x86_64
seems just fine with BPF's xadd on unaligned memory, on arm64 it
triggers via interpreter but also JIT the following crash:

  [  830.864985] Unable to handle kernel paging request at virtual address ffff8097d7ed6703
  [...]
  [  830.916161] Internal error: Oops: 96000021 [#1] SMP
  [  830.984755] CPU: 37 PID: 2788 Comm: test_verifier Not tainted 4.16.0-rc2+ #8
  [  830.991790] Hardware name: Huawei TaiShan 2280 /BC11SPCD, BIOS 1.29 07/17/2017
  [  830.998998] pstate: 80400005 (Nzcv daif +PAN -UAO)
  [  831.003793] pc : __ll_sc_atomic_add+0x4/0x18
  [  831.008055] lr : ___bpf_prog_run+0x1198/0x1588
  [  831.012485] sp : ffff00001ccabc20
  [  831.015786] x29: ffff00001ccabc20 x28: ffff8017d56a0f00
  [  831.021087] x27: 0000000000000001 x26: 0000000000000000
  [  831.026387] x25: 000000c168d9db98 x24: 0000000000000000
  [  831.031686] x23: ffff000008203878 x22: ffff000009488000
  [  831.036986] x21: ffff000008b14e28 x20: ffff00001ccabcb0
  [  831.042286] x19: ffff0000097b5080 x18: 0000000000000a03
  [  831.047585] x17: 0000000000000000 x16: 0000000000000000
  [  831.052885] x15: 0000ffffaeca8000 x14: 0000000000000000
  [  831.058184] x13: 0000000000000000 x12: 0000000000000000
  [  831.063484] x11: 0000000000000001 x10: 0000000000000000
  [  831.068783] x9 : 0000000000000000 x8 : 0000000000000000
  [  831.074083] x7 : 0000000000000000 x6 : 000580d428000000
  [  831.079383] x5 : 0000000000000018 x4 : 0000000000000000
  [  831.084682] x3 : ffff00001ccabcb0 x2 : 0000000000000001
  [  831.089982] x1 : ffff8097d7ed6703 x0 : 0000000000000001
  [  831.095282] Process test_verifier (pid: 2788, stack limit = 0x0000000018370044)
  [  831.102577] Call trace:
  [  831.105012]  __ll_sc_atomic_add+0x4/0x18
  [  831.108923]  __bpf_prog_run32+0x4c/0x70
  [  831.112748]  bpf_test_run+0x78/0xf8
  [  831.116224]  bpf_prog_test_run_xdp+0xb4/0x120
  [  831.120567]  SyS_bpf+0x77c/0x1110
  [  831.123873]  el0_svc_naked+0x30/0x34
  [  831.127437] Code: 97fffe97 17ffffec 00000000 f9800031 (885f7c31)

Reason for this is because memory is required to be aligned. In
case of BPF, we always enforce alignment in terms of stack access,
but not when accessing map values or packet data when the underlying
arch (e.g. arm64) has CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS set.

xadd on packet data that is local to us anyway is just wrong, so
forbid this case entirely. The only place where xadd makes sense in
fact are map values; xadd on stack is wrong as well, but it's been
around for much longer. Specifically enforce strict alignment in case
of xadd, so that we handle this case generically and avoid such crashes
in the first place.

Fixes: 17a5267 ("bpf: verifier (add verifier core)")
Signed-off-by: Daniel Borkmann <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
frank-w pushed a commit that referenced this issue Mar 22, 2018
commit 047fdea upstream.

On detaching of a disk which is a part of a RAID6 filesystem, the
following kernel OOPS may happen:

[63122.680461] BTRFS error (device sdo): bdev /dev/sdo errs: wr 0, rd 0, flush 1, corrupt 0, gen 0
[63122.719584] BTRFS warning (device sdo): lost page write due to IO error on /dev/sdo
[63122.719587] BTRFS error (device sdo): bdev /dev/sdo errs: wr 1, rd 0, flush 1, corrupt 0, gen 0
[63122.803516] BTRFS warning (device sdo): lost page write due to IO error on /dev/sdo
[63122.803519] BTRFS error (device sdo): bdev /dev/sdo errs: wr 2, rd 0, flush 1, corrupt 0, gen 0
[63122.863902] BTRFS critical (device sdo): fatal error on device /dev/sdo
[63122.935338] BUG: unable to handle kernel NULL pointer dereference at 0000000000000080
[63122.946554] IP: fail_bio_stripe+0x58/0xa0 [btrfs]
[63122.958185] PGD 9ecda067 P4D 9ecda067 PUD b2b37067 PMD 0
[63122.971202] Oops: 0000 [#1] SMP
[63123.006760] CPU: 0 PID: 3979 Comm: kworker/u8:9 Tainted: G W 4.14.2-16-scst34x+ #8
[63123.007091] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[63123.007402] Workqueue: btrfs-worker btrfs_worker_helper [btrfs]
[63123.007595] task: ffff880036ea4040 task.stack: ffffc90006384000
[63123.007796] RIP: 0010:fail_bio_stripe+0x58/0xa0 [btrfs]
[63123.007968] RSP: 0018:ffffc90006387ad8 EFLAGS: 00010287
[63123.008140] RAX: 0000000000000002 RBX: ffff88004beaa0b8 RCX: ffff8800b2bd5690
[63123.008359] RDX: 0000000000000000 RSI: ffff88007bb43500 RDI: ffff88004beaa000
[63123.008621] RBP: ffffc90006387ae8 R08: 0000000099100000 R09: ffff8800b2bd5600
[63123.008840] R10: 0000000000000004 R11: 0000000000010000 R12: ffff88007bb43500
[63123.009059] R13: 00000000fffffffb R14: ffff880036fc5180 R15: 0000000000000004
[63123.009278] FS: 0000000000000000(0000) GS:ffff8800b7000000(0000) knlGS:0000000000000000
[63123.009564] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[63123.009748] CR2: 0000000000000080 CR3: 00000000b0866000 CR4: 00000000000406f0
[63123.009969] Call Trace:
[63123.010085] raid_write_end_io+0x7e/0x80 [btrfs]
[63123.010251] bio_endio+0xa1/0x120
[63123.010378] generic_make_request+0x218/0x270
[63123.010921] submit_bio+0x66/0x130
[63123.011073] finish_rmw+0x3fc/0x5b0 [btrfs]
[63123.011245] full_stripe_write+0x96/0xc0 [btrfs]
[63123.011428] raid56_parity_write+0x117/0x170 [btrfs]
[63123.011604] btrfs_map_bio+0x2ec/0x320 [btrfs]
[63123.011759] ? ___cache_free+0x1c5/0x300
[63123.011909] __btrfs_submit_bio_done+0x26/0x50 [btrfs]
[63123.012087] run_one_async_done+0x9c/0xc0 [btrfs]
[63123.012257] normal_work_helper+0x19e/0x300 [btrfs]
[63123.012429] btrfs_worker_helper+0x12/0x20 [btrfs]
[63123.012656] process_one_work+0x14d/0x350
[63123.012888] worker_thread+0x4d/0x3a0
[63123.013026] ? _raw_spin_unlock_irqrestore+0x15/0x20
[63123.013192] kthread+0x109/0x140
[63123.013315] ? process_scheduled_works+0x40/0x40
[63123.013472] ? kthread_stop+0x110/0x110
[63123.013610] ret_from_fork+0x25/0x30
[63123.014469] RIP: fail_bio_stripe+0x58/0xa0 [btrfs] RSP: ffffc90006387ad8
[63123.014678] CR2: 0000000000000080
[63123.016590] ---[ end trace a295ea7259c17880 ]—

This is reproducible in a cycle, where a series of writes is followed by
SCSI device delete command. The test may take up to few minutes.

Fixes: 74d4699 ("block: replace bi_bdev with a gendisk pointer and partitions index")
[ no signed-off-by provided ]
Author: Dmitriy Gorokh <[email protected]>
Reviewed-by: Liu Bo <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
frank-w pushed a commit that referenced this issue Apr 12, 2018
[ Upstream commit d754941 ]

If, for any reason, userland shuts down iscsi transport interfaces
before proper logouts - like when logging in to LUNs manually, without
logging out on server shutdown, or when automated scripts can't
umount/logout from logged LUNs - kernel will hang forever on its
sd_sync_cache() logic, after issuing the SYNCHRONIZE_CACHE cmd to all
still existent paths.

PID: 1 TASK: ffff8801a69b8000 CPU: 1 COMMAND: "systemd-shutdow"
 #0 [ffff8801a69c3a30] __schedule at ffffffff8183e9ee
 #1 [ffff8801a69c3a80] schedule at ffffffff8183f0d5
 #2 [ffff8801a69c3a98] schedule_timeout at ffffffff81842199
 #3 [ffff8801a69c3b40] io_schedule_timeout at ffffffff8183e604
 #4 [ffff8801a69c3b70] wait_for_completion_io_timeout at ffffffff8183fc6c
 #5 [ffff8801a69c3bd0] blk_execute_rq at ffffffff813cfe10
 #6 [ffff8801a69c3c88] scsi_execute at ffffffff815c3fc7
 #7 [ffff8801a69c3cc8] scsi_execute_req_flags at ffffffff815c60fe
 #8 [ffff8801a69c3d30] sd_sync_cache at ffffffff815d37d7
 #9 [ffff8801a69c3da8] sd_shutdown at ffffffff815d3c3c

This happens because iscsi_eh_cmd_timed_out(), the transport layer
timeout helper, would tell the queue timeout function (scsi_times_out)
to reset the request timer over and over, until the session state is
back to logged in state. Unfortunately, during server shutdown, this
might never happen again.

Other option would be "not to handle" the issue in the transport
layer. That would trigger the error handler logic, which would also need
the session state to be logged in again.

Best option, for such case, is to tell upper layers that the command was
handled during the transport layer error handler helper, marking it as
DID_NO_CONNECT, which will allow completion and inform about the
problem.

After the session was marked as ISCSI_STATE_FAILED, due to the first
timeout during the server shutdown phase, all subsequent cmds will fail
to be queued, allowing upper logic to fail faster.

Signed-off-by: Rafael David Tinoco <[email protected]>
Reviewed-by: Lee Duncan <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
frank-w pushed a commit that referenced this issue Apr 26, 2018
[ Upstream commit 2c0aa08 ]

Scenario:
1. Port down and do fail over
2. Ap do rds_bind syscall

PID: 47039  TASK: ffff89887e2fe640  CPU: 47  COMMAND: "kworker/u:6"
 #0 [ffff898e35f159f0] machine_kexec at ffffffff8103abf9
 #1 [ffff898e35f15a60] crash_kexec at ffffffff810b96e3
 #2 [ffff898e35f15b30] oops_end at ffffffff8150f518
 #3 [ffff898e35f15b60] no_context at ffffffff8104854c
 #4 [ffff898e35f15ba0] __bad_area_nosemaphore at ffffffff81048675
 #5 [ffff898e35f15bf0] bad_area_nosemaphore at ffffffff810487d3
 #6 [ffff898e35f15c00] do_page_fault at ffffffff815120b8
 #7 [ffff898e35f15d10] page_fault at ffffffff8150ea95
    [exception RIP: unknown or invalid address]
    RIP: 0000000000000000  RSP: ffff898e35f15dc8  RFLAGS: 00010282
    RAX: 00000000fffffffe  RBX: ffff889b77f6fc00  RCX:ffffffff81c99d88
    RDX: 0000000000000000  RSI: ffff896019ee08e8  RDI:ffff889b77f6fc00
    RBP: ffff898e35f15df0   R8: ffff896019ee08c8  R9:0000000000000000
    R10: 0000000000000400  R11: 0000000000000000  R12:ffff896019ee08c0
    R13: ffff889b77f6fe68  R14: ffffffff81c99d80  R15: ffffffffa022a1e0
    ORIG_RAX: ffffffffffffffff  CS: 0010 SS: 0018
 #8 [ffff898e35f15dc8] cma_ndev_work_handler at ffffffffa022a228 [rdma_cm]
 #9 [ffff898e35f15df8] process_one_work at ffffffff8108a7c6
 #10 [ffff898e35f15e58] worker_thread at ffffffff8108bda0
 #11 [ffff898e35f15ee8] kthread at ffffffff81090fe6

PID: 45659  TASK: ffff880d313d2500  CPU: 31  COMMAND: "oracle_45659_ap"
 #0 [ffff881024ccfc98] __schedule at ffffffff8150bac4
 #1 [ffff881024ccfd40] schedule at ffffffff8150c2cf
 #2 [ffff881024ccfd50] __mutex_lock_slowpath at ffffffff8150cee7
 #3 [ffff881024ccfdc0] mutex_lock at ffffffff8150cdeb
 #4 [ffff881024ccfde0] rdma_destroy_id at ffffffffa022a027 [rdma_cm]
 #5 [ffff881024ccfe10] rds_ib_laddr_check at ffffffffa0357857 [rds_rdma]
 #6 [ffff881024ccfe50] rds_trans_get_preferred at ffffffffa0324c2a [rds]
 #7 [ffff881024ccfe80] rds_bind at ffffffffa031d690 [rds]
 #8 [ffff881024ccfeb0] sys_bind at ffffffff8142a670

PID: 45659                          PID: 47039
rds_ib_laddr_check
  /* create id_priv with a null event_handler */
  rdma_create_id
  rdma_bind_addr
    cma_acquire_dev
      /* add id_priv to cma_dev->id_list */
      cma_attach_to_dev
                                    cma_ndev_work_handler
                                      /* event_hanlder is null */
                                      id_priv->id.event_handler

Signed-off-by: Guanglei Li <[email protected]>
Signed-off-by: Honglei Wang <[email protected]>
Reviewed-by: Junxiao Bi <[email protected]>
Reviewed-by: Yanjun Zhu <[email protected]>
Reviewed-by: Leon Romanovsky <[email protected]>
Acked-by: Santosh Shilimkar <[email protected]>
Acked-by: Doug Ledford <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
frank-w pushed a commit that referenced this issue May 21, 2018
[ Upstream commit af50e4b ]

syzbot caught an infinite recursion in nsh_gso_segment().

Problem here is that we need to make sure the NSH header is of
reasonable length.

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by syz-executor0/10189:
 #0:         (ptrval) (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x30f/0x34c0 net/core/dev.c:3517
 #1:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #1:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #2:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #2:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #3:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #3:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #4:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #4:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #5:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #5:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #6:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #6:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #7:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #7:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #8:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #8:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #9:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #9:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #10:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #10:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #11:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #11:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #12:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #12:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #13:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #13:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #14:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #14:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #15:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #15:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #16:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #16:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #17:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #17:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #18:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #18:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #19:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #19:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #20:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #20:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #21:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #21:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #22:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #22:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #23:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #23:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #24:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #24:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #25:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #25:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #26:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #26:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #27:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #27:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #28:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #28:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #29:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #29:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #30:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #30:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #31:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #31:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
dccp_close: ABORT with 65423 bytes unread
 #32:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #32:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #33:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #33:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #34:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #34:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #35:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #35:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #36:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #36:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #37:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #37:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #38:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #38:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #39:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #39:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #40:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #40:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #41:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #41:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #42:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #42:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #43:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #43:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #44:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #44:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #45:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #45:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #46:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #46:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #47:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #47:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
INFO: lockdep is turned off.
CPU: 1 PID: 10189 Comm: syz-executor0 Not tainted 4.17.0-rc2+ #26
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 __lock_acquire+0x1788/0x5140 kernel/locking/lockdep.c:3449
 lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920
 rcu_lock_acquire include/linux/rcupdate.h:246 [inline]
 rcu_read_lock include/linux/rcupdate.h:632 [inline]
 skb_mac_gso_segment+0x25b/0x720 net/core/dev.c:2789
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 __skb_gso_segment+0x3bb/0x870 net/core/dev.c:2865
 skb_gso_segment include/linux/netdevice.h:4025 [inline]
 validate_xmit_skb+0x54d/0xd90 net/core/dev.c:3118
 validate_xmit_skb_list+0xbf/0x120 net/core/dev.c:3168
 sch_direct_xmit+0x354/0x11e0 net/sched/sch_generic.c:312
 qdisc_restart net/sched/sch_generic.c:399 [inline]
 __qdisc_run+0x741/0x1af0 net/sched/sch_generic.c:410
 __dev_xmit_skb net/core/dev.c:3243 [inline]
 __dev_queue_xmit+0x28ea/0x34c0 net/core/dev.c:3551
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3616
 packet_snd net/packet/af_packet.c:2951 [inline]
 packet_sendmsg+0x40f8/0x6070 net/packet/af_packet.c:2976
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:639
 __sys_sendto+0x3d7/0x670 net/socket.c:1789
 __do_sys_sendto net/socket.c:1801 [inline]
 __se_sys_sendto net/socket.c:1797 [inline]
 __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1797
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: c411ed8 ("nsh: add GSO support")
Signed-off-by: Eric Dumazet <[email protected]>
Cc: Jiri Benc <[email protected]>
Reported-by: syzbot <[email protected]>
Acked-by: Jiri Benc <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
frank-w pushed a commit that referenced this issue May 21, 2018
[ Upstream commit af50e4b ]

syzbot caught an infinite recursion in nsh_gso_segment().

Problem here is that we need to make sure the NSH header is of
reasonable length.

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by syz-executor0/10189:
 #0:         (ptrval) (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x30f/0x34c0 net/core/dev.c:3517
 #1:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #1:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #2:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #2:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #3:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #3:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #4:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #4:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #5:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #5:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #6:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #6:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #7:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #7:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #8:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #8:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #9:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #9:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #10:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #10:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #11:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #11:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #12:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #12:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #13:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #13:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #14:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #14:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #15:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #15:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #16:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #16:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #17:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #17:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #18:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #18:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #19:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #19:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #20:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #20:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #21:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #21:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #22:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #22:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #23:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #23:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #24:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #24:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #25:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #25:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #26:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #26:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #27:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #27:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #28:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #28:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #29:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #29:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #30:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #30:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #31:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #31:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
dccp_close: ABORT with 65423 bytes unread
 #32:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #32:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #33:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #33:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #34:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #34:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #35:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #35:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #36:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #36:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #37:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #37:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #38:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #38:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #39:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #39:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #40:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #40:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #41:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #41:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #42:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #42:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #43:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #43:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #44:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #44:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #45:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #45:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #46:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #46:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #47:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #47:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
INFO: lockdep is turned off.
CPU: 1 PID: 10189 Comm: syz-executor0 Not tainted 4.17.0-rc2+ #26
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 __lock_acquire+0x1788/0x5140 kernel/locking/lockdep.c:3449
 lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920
 rcu_lock_acquire include/linux/rcupdate.h:246 [inline]
 rcu_read_lock include/linux/rcupdate.h:632 [inline]
 skb_mac_gso_segment+0x25b/0x720 net/core/dev.c:2789
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 __skb_gso_segment+0x3bb/0x870 net/core/dev.c:2865
 skb_gso_segment include/linux/netdevice.h:4025 [inline]
 validate_xmit_skb+0x54d/0xd90 net/core/dev.c:3118
 validate_xmit_skb_list+0xbf/0x120 net/core/dev.c:3168
 sch_direct_xmit+0x354/0x11e0 net/sched/sch_generic.c:312
 qdisc_restart net/sched/sch_generic.c:399 [inline]
 __qdisc_run+0x741/0x1af0 net/sched/sch_generic.c:410
 __dev_xmit_skb net/core/dev.c:3243 [inline]
 __dev_queue_xmit+0x28ea/0x34c0 net/core/dev.c:3551
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3616
 packet_snd net/packet/af_packet.c:2951 [inline]
 packet_sendmsg+0x40f8/0x6070 net/packet/af_packet.c:2976
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:639
 __sys_sendto+0x3d7/0x670 net/socket.c:1789
 __do_sys_sendto net/socket.c:1801 [inline]
 __se_sys_sendto net/socket.c:1797 [inline]
 __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1797
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: c411ed8 ("nsh: add GSO support")
Signed-off-by: Eric Dumazet <[email protected]>
Cc: Jiri Benc <[email protected]>
Reported-by: syzbot <[email protected]>
Acked-by: Jiri Benc <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
frank-w pushed a commit that referenced this issue May 31, 2018
[ Upstream commit 8a5a916 ]

While running btrfs/011, I hit the following lockdep splat.

This is the important bit:
   pcpu_alloc+0x1ac/0x5e0
   __percpu_counter_init+0x4e/0xb0
   btrfs_init_fs_root+0x99/0x1c0 [btrfs]
   btrfs_get_fs_root.part.54+0x5b/0x150 [btrfs]
   resolve_indirect_refs+0x130/0x830 [btrfs]
   find_parent_nodes+0x69e/0xff0 [btrfs]
   btrfs_find_all_roots_safe+0xa0/0x110 [btrfs]
   btrfs_find_all_roots+0x50/0x70 [btrfs]
   btrfs_qgroup_prepare_account_extents+0x53/0x90 [btrfs]
   btrfs_commit_transaction+0x3ce/0x9b0 [btrfs]

The percpu_counter_init call in btrfs_alloc_subvolume_writers
uses GFP_KERNEL, which we can't do during transaction commit.

This switches it to GFP_NOFS.

========================================================
WARNING: possible irq lock inversion dependency detected
4.12.14-kvmsmall #8 Tainted: G        W
--------------------------------------------------------
kswapd0/50 just changed the state of lock:
 (&delayed_node->mutex){+.+.-.}, at: [<ffffffffc06994fa>] __btrfs_release_delayed_node+0x3a/0x1f0 [btrfs]
but this lock took another, RECLAIM_FS-unsafe lock in the past:
 (pcpu_alloc_mutex){+.+.+.}

and interrupts could create inverse lock ordering between them.

other info that might help us debug this:
Chain exists of:
  &delayed_node->mutex --> &found->groups_sem --> pcpu_alloc_mutex

 Possible interrupt unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(pcpu_alloc_mutex);
                               local_irq_disable();
                               lock(&delayed_node->mutex);
                               lock(&found->groups_sem);
  <Interrupt>
    lock(&delayed_node->mutex);

 *** DEADLOCK ***

2 locks held by kswapd0/50:
 #0:  (shrinker_rwsem){++++..}, at: [<ffffffff811dc11f>] shrink_slab+0x7f/0x5b0
 #1:  (&type->s_umount_key#30){+++++.}, at: [<ffffffff8126dec6>] trylock_super+0x16/0x50

the shortest dependencies between 2nd lock and 1st lock:
   -> (pcpu_alloc_mutex){+.+.+.} ops: 4904 {
      HARDIRQ-ON-W at:
                          __mutex_lock+0x4e/0x8c0
                          pcpu_alloc+0x1ac/0x5e0
                          alloc_kmem_cache_cpus.isra.70+0x25/0xa0
                          __do_tune_cpucache+0x2c/0x220
                          do_tune_cpucache+0x26/0xc0
                          enable_cpucache+0x6d/0xf0
                          kmem_cache_init_late+0x42/0x75
                          start_kernel+0x343/0x4cb
                          x86_64_start_kernel+0x127/0x134
                          secondary_startup_64+0xa5/0xb0
      SOFTIRQ-ON-W at:
                          __mutex_lock+0x4e/0x8c0
                          pcpu_alloc+0x1ac/0x5e0
                          alloc_kmem_cache_cpus.isra.70+0x25/0xa0
                          __do_tune_cpucache+0x2c/0x220
                          do_tune_cpucache+0x26/0xc0
                          enable_cpucache+0x6d/0xf0
                          kmem_cache_init_late+0x42/0x75
                          start_kernel+0x343/0x4cb
                          x86_64_start_kernel+0x127/0x134
                          secondary_startup_64+0xa5/0xb0
      RECLAIM_FS-ON-W at:
                             __kmalloc+0x47/0x310
                             pcpu_extend_area_map+0x2b/0xc0
                             pcpu_alloc+0x3ec/0x5e0
                             alloc_kmem_cache_cpus.isra.70+0x25/0xa0
                             __do_tune_cpucache+0x2c/0x220
                             do_tune_cpucache+0x26/0xc0
                             enable_cpucache+0x6d/0xf0
                             __kmem_cache_create+0x1bf/0x390
                             create_cache+0xba/0x1b0
                             kmem_cache_create+0x1f8/0x2b0
                             ksm_init+0x6f/0x19d
                             do_one_initcall+0x50/0x1b0
                             kernel_init_freeable+0x201/0x289
                             kernel_init+0xa/0x100
                             ret_from_fork+0x3a/0x50
      INITIAL USE at:
                         __mutex_lock+0x4e/0x8c0
                         pcpu_alloc+0x1ac/0x5e0
                         alloc_kmem_cache_cpus.isra.70+0x25/0xa0
                         setup_cpu_cache+0x2f/0x1f0
                         __kmem_cache_create+0x1bf/0x390
                         create_boot_cache+0x8b/0xb1
                         kmem_cache_init+0xa1/0x19e
                         start_kernel+0x270/0x4cb
                         x86_64_start_kernel+0x127/0x134
                         secondary_startup_64+0xa5/0xb0
    }
    ... key      at: [<ffffffff821d8e70>] pcpu_alloc_mutex+0x70/0xa0
    ... acquired at:
   pcpu_alloc+0x1ac/0x5e0
   __percpu_counter_init+0x4e/0xb0
   btrfs_init_fs_root+0x99/0x1c0 [btrfs]
   btrfs_get_fs_root.part.54+0x5b/0x150 [btrfs]
   resolve_indirect_refs+0x130/0x830 [btrfs]
   find_parent_nodes+0x69e/0xff0 [btrfs]
   btrfs_find_all_roots_safe+0xa0/0x110 [btrfs]
   btrfs_find_all_roots+0x50/0x70 [btrfs]
   btrfs_qgroup_prepare_account_extents+0x53/0x90 [btrfs]
   btrfs_commit_transaction+0x3ce/0x9b0 [btrfs]
   transaction_kthread+0x176/0x1b0 [btrfs]
   kthread+0x102/0x140
   ret_from_fork+0x3a/0x50

  -> (&fs_info->commit_root_sem){++++..} ops: 1566382 {
     HARDIRQ-ON-W at:
                        down_write+0x3e/0xa0
                        cache_block_group+0x287/0x420 [btrfs]
                        find_free_extent+0x106c/0x12d0 [btrfs]
                        btrfs_reserve_extent+0xd8/0x170 [btrfs]
                        cow_file_range.isra.66+0x133/0x470 [btrfs]
                        run_delalloc_range+0x121/0x410 [btrfs]
                        writepage_delalloc.isra.50+0xfe/0x180 [btrfs]
                        __extent_writepage+0x19a/0x360 [btrfs]
                        extent_write_cache_pages.constprop.56+0x249/0x3e0 [btrfs]
                        extent_writepages+0x4d/0x60 [btrfs]
                        do_writepages+0x1a/0x70
                        __filemap_fdatawrite_range+0xa7/0xe0
                        btrfs_rename+0x5ee/0xdb0 [btrfs]
                        vfs_rename+0x52a/0x7e0
                        SyS_rename+0x351/0x3b0
                        do_syscall_64+0x79/0x1e0
                        entry_SYSCALL_64_after_hwframe+0x42/0xb7
     HARDIRQ-ON-R at:
                        down_read+0x35/0x90
                        caching_thread+0x57/0x560 [btrfs]
                        normal_work_helper+0x1c0/0x5e0 [btrfs]
                        process_one_work+0x1e0/0x5c0
                        worker_thread+0x44/0x390
                        kthread+0x102/0x140
                        ret_from_fork+0x3a/0x50
     SOFTIRQ-ON-W at:
                        down_write+0x3e/0xa0
                        cache_block_group+0x287/0x420 [btrfs]
                        find_free_extent+0x106c/0x12d0 [btrfs]
                        btrfs_reserve_extent+0xd8/0x170 [btrfs]
                        cow_file_range.isra.66+0x133/0x470 [btrfs]
                        run_delalloc_range+0x121/0x410 [btrfs]
                        writepage_delalloc.isra.50+0xfe/0x180 [btrfs]
                        __extent_writepage+0x19a/0x360 [btrfs]
                        extent_write_cache_pages.constprop.56+0x249/0x3e0 [btrfs]
                        extent_writepages+0x4d/0x60 [btrfs]
                        do_writepages+0x1a/0x70
                        __filemap_fdatawrite_range+0xa7/0xe0
                        btrfs_rename+0x5ee/0xdb0 [btrfs]
                        vfs_rename+0x52a/0x7e0
                        SyS_rename+0x351/0x3b0
                        do_syscall_64+0x79/0x1e0
                        entry_SYSCALL_64_after_hwframe+0x42/0xb7
     SOFTIRQ-ON-R at:
                        down_read+0x35/0x90
                        caching_thread+0x57/0x560 [btrfs]
                        normal_work_helper+0x1c0/0x5e0 [btrfs]
                        process_one_work+0x1e0/0x5c0
                        worker_thread+0x44/0x390
                        kthread+0x102/0x140
                        ret_from_fork+0x3a/0x50
     INITIAL USE at:
                       down_write+0x3e/0xa0
                       cache_block_group+0x287/0x420 [btrfs]
                       find_free_extent+0x106c/0x12d0 [btrfs]
                       btrfs_reserve_extent+0xd8/0x170 [btrfs]
                       cow_file_range.isra.66+0x133/0x470 [btrfs]
                       run_delalloc_range+0x121/0x410 [btrfs]
                       writepage_delalloc.isra.50+0xfe/0x180 [btrfs]
                       __extent_writepage+0x19a/0x360 [btrfs]
                       extent_write_cache_pages.constprop.56+0x249/0x3e0 [btrfs]
                       extent_writepages+0x4d/0x60 [btrfs]
                       do_writepages+0x1a/0x70
                       __filemap_fdatawrite_range+0xa7/0xe0
                       btrfs_rename+0x5ee/0xdb0 [btrfs]
                       vfs_rename+0x52a/0x7e0
                       SyS_rename+0x351/0x3b0
                       do_syscall_64+0x79/0x1e0
                       entry_SYSCALL_64_after_hwframe+0x42/0xb7
   }
   ... key      at: [<ffffffffc0729578>] __key.61970+0x0/0xfffffffffff9aa88 [btrfs]
   ... acquired at:
   cache_block_group+0x287/0x420 [btrfs]
   find_free_extent+0x106c/0x12d0 [btrfs]
   btrfs_reserve_extent+0xd8/0x170 [btrfs]
   btrfs_alloc_tree_block+0x12f/0x4c0 [btrfs]
   btrfs_create_tree+0xbb/0x2a0 [btrfs]
   btrfs_create_uuid_tree+0x37/0x140 [btrfs]
   open_ctree+0x23c0/0x2660 [btrfs]
   btrfs_mount+0xd36/0xf90 [btrfs]
   mount_fs+0x3a/0x160
   vfs_kern_mount+0x66/0x150
   btrfs_mount+0x18c/0xf90 [btrfs]
   mount_fs+0x3a/0x160
   vfs_kern_mount+0x66/0x150
   do_mount+0x1c1/0xcc0
   SyS_mount+0x7e/0xd0
   do_syscall_64+0x79/0x1e0
   entry_SYSCALL_64_after_hwframe+0x42/0xb7

 -> (&found->groups_sem){++++..} ops: 2134587 {
    HARDIRQ-ON-W at:
                      down_write+0x3e/0xa0
                      __link_block_group+0x34/0x130 [btrfs]
                      btrfs_read_block_groups+0x33d/0x7b0 [btrfs]
                      open_ctree+0x2054/0x2660 [btrfs]
                      btrfs_mount+0xd36/0xf90 [btrfs]
                      mount_fs+0x3a/0x160
                      vfs_kern_mount+0x66/0x150
                      btrfs_mount+0x18c/0xf90 [btrfs]
                      mount_fs+0x3a/0x160
                      vfs_kern_mount+0x66/0x150
                      do_mount+0x1c1/0xcc0
                      SyS_mount+0x7e/0xd0
                      do_syscall_64+0x79/0x1e0
                      entry_SYSCALL_64_after_hwframe+0x42/0xb7
    HARDIRQ-ON-R at:
                      down_read+0x35/0x90
                      btrfs_calc_num_tolerated_disk_barrier_failures+0x113/0x1f0 [btrfs]
                      open_ctree+0x207b/0x2660 [btrfs]
                      btrfs_mount+0xd36/0xf90 [btrfs]
                      mount_fs+0x3a/0x160
                      vfs_kern_mount+0x66/0x150
                      btrfs_mount+0x18c/0xf90 [btrfs]
                      mount_fs+0x3a/0x160
                      vfs_kern_mount+0x66/0x150
                      do_mount+0x1c1/0xcc0
                      SyS_mount+0x7e/0xd0
                      do_syscall_64+0x79/0x1e0
                      entry_SYSCALL_64_after_hwframe+0x42/0xb7
    SOFTIRQ-ON-W at:
                      down_write+0x3e/0xa0
                      __link_block_group+0x34/0x130 [btrfs]
                      btrfs_read_block_groups+0x33d/0x7b0 [btrfs]
                      open_ctree+0x2054/0x2660 [btrfs]
                      btrfs_mount+0xd36/0xf90 [btrfs]
                      mount_fs+0x3a/0x160
                      vfs_kern_mount+0x66/0x150
                      btrfs_mount+0x18c/0xf90 [btrfs]
                      mount_fs+0x3a/0x160
                      vfs_kern_mount+0x66/0x150
                      do_mount+0x1c1/0xcc0
                      SyS_mount+0x7e/0xd0
                      do_syscall_64+0x79/0x1e0
                      entry_SYSCALL_64_after_hwframe+0x42/0xb7
    SOFTIRQ-ON-R at:
                      down_read+0x35/0x90
                      btrfs_calc_num_tolerated_disk_barrier_failures+0x113/0x1f0 [btrfs]
                      open_ctree+0x207b/0x2660 [btrfs]
                      btrfs_mount+0xd36/0xf90 [btrfs]
                      mount_fs+0x3a/0x160
                      vfs_kern_mount+0x66/0x150
                      btrfs_mount+0x18c/0xf90 [btrfs]
                      mount_fs+0x3a/0x160
                      vfs_kern_mount+0x66/0x150
                      do_mount+0x1c1/0xcc0
                      SyS_mount+0x7e/0xd0
                      do_syscall_64+0x79/0x1e0
                      entry_SYSCALL_64_after_hwframe+0x42/0xb7
    INITIAL USE at:
                     down_write+0x3e/0xa0
                     __link_block_group+0x34/0x130 [btrfs]
                     btrfs_read_block_groups+0x33d/0x7b0 [btrfs]
                     open_ctree+0x2054/0x2660 [btrfs]
                     btrfs_mount+0xd36/0xf90 [btrfs]
                     mount_fs+0x3a/0x160
                     vfs_kern_mount+0x66/0x150
                     btrfs_mount+0x18c/0xf90 [btrfs]
                     mount_fs+0x3a/0x160
                     vfs_kern_mount+0x66/0x150
                     do_mount+0x1c1/0xcc0
                     SyS_mount+0x7e/0xd0
                     do_syscall_64+0x79/0x1e0
                     entry_SYSCALL_64_after_hwframe+0x42/0xb7
  }
  ... key      at: [<ffffffffc0729488>] __key.59101+0x0/0xfffffffffff9ab78 [btrfs]
  ... acquired at:
   find_free_extent+0xcb4/0x12d0 [btrfs]
   btrfs_reserve_extent+0xd8/0x170 [btrfs]
   btrfs_alloc_tree_block+0x12f/0x4c0 [btrfs]
   __btrfs_cow_block+0x110/0x5b0 [btrfs]
   btrfs_cow_block+0xd7/0x290 [btrfs]
   btrfs_search_slot+0x1f6/0x960 [btrfs]
   btrfs_lookup_inode+0x2a/0x90 [btrfs]
   __btrfs_update_delayed_inode+0x65/0x210 [btrfs]
   btrfs_commit_inode_delayed_inode+0x121/0x130 [btrfs]
   btrfs_evict_inode+0x3fe/0x6a0 [btrfs]
   evict+0xc4/0x190
   __dentry_kill+0xbf/0x170
   dput+0x2ae/0x2f0
   SyS_rename+0x2a6/0x3b0
   do_syscall_64+0x79/0x1e0
   entry_SYSCALL_64_after_hwframe+0x42/0xb7

-> (&delayed_node->mutex){+.+.-.} ops: 5580204 {
   HARDIRQ-ON-W at:
                    __mutex_lock+0x4e/0x8c0
                    btrfs_delayed_update_inode+0x46/0x6e0 [btrfs]
                    btrfs_update_inode+0x83/0x110 [btrfs]
                    btrfs_dirty_inode+0x62/0xe0 [btrfs]
                    touch_atime+0x8c/0xb0
                    do_generic_file_read+0x818/0xb10
                    __vfs_read+0xdc/0x150
                    vfs_read+0x8a/0x130
                    SyS_read+0x45/0xa0
                    do_syscall_64+0x79/0x1e0
                    entry_SYSCALL_64_after_hwframe+0x42/0xb7
   SOFTIRQ-ON-W at:
                    __mutex_lock+0x4e/0x8c0
                    btrfs_delayed_update_inode+0x46/0x6e0 [btrfs]
                    btrfs_update_inode+0x83/0x110 [btrfs]
                    btrfs_dirty_inode+0x62/0xe0 [btrfs]
                    touch_atime+0x8c/0xb0
                    do_generic_file_read+0x818/0xb10
                    __vfs_read+0xdc/0x150
                    vfs_read+0x8a/0x130
                    SyS_read+0x45/0xa0
                    do_syscall_64+0x79/0x1e0
                    entry_SYSCALL_64_after_hwframe+0x42/0xb7
   IN-RECLAIM_FS-W at:
                       __mutex_lock+0x4e/0x8c0
                       __btrfs_release_delayed_node+0x3a/0x1f0 [btrfs]
                       btrfs_evict_inode+0x22c/0x6a0 [btrfs]
                       evict+0xc4/0x190
                       dispose_list+0x35/0x50
                       prune_icache_sb+0x42/0x50
                       super_cache_scan+0x139/0x190
                       shrink_slab+0x262/0x5b0
                       shrink_node+0x2eb/0x2f0
                       kswapd+0x2eb/0x890
                       kthread+0x102/0x140
                       ret_from_fork+0x3a/0x50
   INITIAL USE at:
                   __mutex_lock+0x4e/0x8c0
                   btrfs_delayed_update_inode+0x46/0x6e0 [btrfs]
                   btrfs_update_inode+0x83/0x110 [btrfs]
                   btrfs_dirty_inode+0x62/0xe0 [btrfs]
                   touch_atime+0x8c/0xb0
                   do_generic_file_read+0x818/0xb10
                   __vfs_read+0xdc/0x150
                   vfs_read+0x8a/0x130
                   SyS_read+0x45/0xa0
                   do_syscall_64+0x79/0x1e0
                   entry_SYSCALL_64_after_hwframe+0x42/0xb7
 }
 ... key      at: [<ffffffffc072d488>] __key.56935+0x0/0xfffffffffff96b78 [btrfs]
 ... acquired at:
   __lock_acquire+0x264/0x11c0
   lock_acquire+0xbd/0x1e0
   __mutex_lock+0x4e/0x8c0
   __btrfs_release_delayed_node+0x3a/0x1f0 [btrfs]
   btrfs_evict_inode+0x22c/0x6a0 [btrfs]
   evict+0xc4/0x190
   dispose_list+0x35/0x50
   prune_icache_sb+0x42/0x50
   super_cache_scan+0x139/0x190
   shrink_slab+0x262/0x5b0
   shrink_node+0x2eb/0x2f0
   kswapd+0x2eb/0x890
   kthread+0x102/0x140
   ret_from_fork+0x3a/0x50

stack backtrace:
CPU: 1 PID: 50 Comm: kswapd0 Tainted: G        W        4.12.14-kvmsmall #8 SLE15 (unreleased)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014
Call Trace:
 dump_stack+0x78/0xb7
 print_irq_inversion_bug.part.38+0x19f/0x1aa
 check_usage_forwards+0x102/0x120
 ? ret_from_fork+0x3a/0x50
 ? check_usage_backwards+0x110/0x110
 mark_lock+0x16c/0x270
 __lock_acquire+0x264/0x11c0
 ? pagevec_lookup_entries+0x1a/0x30
 ? truncate_inode_pages_range+0x2b3/0x7f0
 lock_acquire+0xbd/0x1e0
 ? __btrfs_release_delayed_node+0x3a/0x1f0 [btrfs]
 __mutex_lock+0x4e/0x8c0
 ? __btrfs_release_delayed_node+0x3a/0x1f0 [btrfs]
 ? __btrfs_release_delayed_node+0x3a/0x1f0 [btrfs]
 ? btrfs_evict_inode+0x1f6/0x6a0 [btrfs]
 __btrfs_release_delayed_node+0x3a/0x1f0 [btrfs]
 btrfs_evict_inode+0x22c/0x6a0 [btrfs]
 evict+0xc4/0x190
 dispose_list+0x35/0x50
 prune_icache_sb+0x42/0x50
 super_cache_scan+0x139/0x190
 shrink_slab+0x262/0x5b0
 shrink_node+0x2eb/0x2f0
 kswapd+0x2eb/0x890
 kthread+0x102/0x140
 ? mem_cgroup_shrink_node+0x2c0/0x2c0
 ? kthread_create_on_node+0x40/0x40
 ret_from_fork+0x3a/0x50

Signed-off-by: Jeff Mahoney <[email protected]>
Reviewed-by: Liu Bo <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
frank-w pushed a commit that referenced this issue May 31, 2018
[ Upstream commit fca3234 ]

Executing command 'perf stat -T -- ls' dumps core on x86 and s390.

Here is the call back chain (done on x86):

 # gdb ./perf
 ....
 (gdb) r stat -T -- ls
...
Program received signal SIGSEGV, Segmentation fault.
0x00007ffff56d1963 in vasprintf () from /lib64/libc.so.6
(gdb) where
 #0  0x00007ffff56d1963 in vasprintf () from /lib64/libc.so.6
 #1  0x00007ffff56ae484 in asprintf () from /lib64/libc.so.6
 #2  0x00000000004f1982 in __parse_events_add_pmu (parse_state=0x7fffffffd580,
    list=0xbfb970, name=0xbf3ef0 "cpu",
    head_config=0xbfb930, auto_merge_stats=false) at util/parse-events.c:1233
 #3  0x00000000004f1c8e in parse_events_add_pmu (parse_state=0x7fffffffd580,
    list=0xbfb970, name=0xbf3ef0 "cpu",
    head_config=0xbfb930) at util/parse-events.c:1288
 #4  0x0000000000537ce3 in parse_events_parse (_parse_state=0x7fffffffd580,
    scanner=0xbf4210) at util/parse-events.y:234
 #5  0x00000000004f2c7a in parse_events__scanner (str=0x6b66c0
    "task-clock,{instructions,cycles,cpu/cycles-t/,cpu/tx-start/}",
    parse_state=0x7fffffffd580, start_token=258) at util/parse-events.c:1673
 #6  0x00000000004f2e23 in parse_events (evlist=0xbe9990, str=0x6b66c0
    "task-clock,{instructions,cycles,cpu/cycles-t/,cpu/tx-start/}", err=0x0)
    at util/parse-events.c:1713
 #7  0x000000000044e137 in add_default_attributes () at builtin-stat.c:2281
 #8  0x000000000044f7b5 in cmd_stat (argc=1, argv=0x7fffffffe3b0) at
    builtin-stat.c:2828
 #9  0x00000000004c8b0f in run_builtin (p=0xab01a0 <commands+288>, argc=4,
    argv=0x7fffffffe3b0) at perf.c:297
 #10 0x00000000004c8d7c in handle_internal_command (argc=4,
    argv=0x7fffffffe3b0) at perf.c:349
 #11 0x00000000004c8ece in run_argv (argcp=0x7fffffffe20c,
   argv=0x7fffffffe200) at perf.c:393
 #12 0x00000000004c929c in main (argc=4, argv=0x7fffffffe3b0) at perf.c:537
(gdb)

It turns out that a NULL pointer is referenced. Here are the
function calls:

  ...
  cmd_stat()
  +---> add_default_attributes()
	+---> parse_events(evsel_list, transaction_attrs, NULL);
	             3rd parameter set to NULL

Function parse_events(xx, xx, struct parse_events_error *err) dives
into a bison generated scanner and creates
parser state information for it first:

   struct parse_events_state parse_state = {
                .list   = LIST_HEAD_INIT(parse_state.list),
                .idx    = evlist->nr_entries,
                .error  = err,   <--- NULL POINTER !!!
                .evlist = evlist,
        };

Now various functions inside the bison scanner are called to end up in
__parse_events_add_pmu(struct parse_events_state *parse_state, ..) with
first parameter being a pointer to above structure definition.

Now the PMU event name is not found (because being executed in a VM) and
this function tries to create an error message with

   asprintf(&parse_state->error.str, ....)

which references a NULL pointer and dumps core.

Fix this by providing a pointer to the necessary error information
instead of NULL. Technically only the else part is needed to avoid the
core dump, just lets be safe...

Signed-off-by: Thomas Richter <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Hendrik Brueckner <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
frank-w pushed a commit that referenced this issue May 31, 2018
[ Upstream commit 2bbea6e ]

when mounting an ISO filesystem sometimes (very rarely)
the system hangs because of a race condition between two tasks.

PID: 6766   TASK: ffff88007b2a6dd0  CPU: 0   COMMAND: "mount"
 #0 [ffff880078447ae0] __schedule at ffffffff8168d605
 #1 [ffff880078447b48] schedule_preempt_disabled at ffffffff8168ed49
 #2 [ffff880078447b58] __mutex_lock_slowpath at ffffffff8168c995
 #3 [ffff880078447bb8] mutex_lock at ffffffff8168bdef
 #4 [ffff880078447bd0] sr_block_ioctl at ffffffffa00b6818 [sr_mod]
 #5 [ffff880078447c10] blkdev_ioctl at ffffffff812fea50
 #6 [ffff880078447c70] ioctl_by_bdev at ffffffff8123a8b3
 #7 [ffff880078447c90] isofs_fill_super at ffffffffa04fb1e1 [isofs]
 #8 [ffff880078447da8] mount_bdev at ffffffff81202570
 #9 [ffff880078447e18] isofs_mount at ffffffffa04f9828 [isofs]
#10 [ffff880078447e28] mount_fs at ffffffff81202d09
#11 [ffff880078447e70] vfs_kern_mount at ffffffff8121ea8f
#12 [ffff880078447ea8] do_mount at ffffffff81220fee
#13 [ffff880078447f28] sys_mount at ffffffff812218d6
#14 [ffff880078447f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007fd9ea914e9a  RSP: 00007ffd5d9bf648  RFLAGS: 00010246
    RAX: 00000000000000a5  RBX: ffffffff81698c49  RCX: 0000000000000010
    RDX: 00007fd9ec2bc210  RSI: 00007fd9ec2bc290  RDI: 00007fd9ec2bcf30
    RBP: 0000000000000000   R8: 0000000000000000   R9: 0000000000000010
    R10: 00000000c0ed0001  R11: 0000000000000206  R12: 00007fd9ec2bc040
    R13: 00007fd9eb6b2380  R14: 00007fd9ec2bc210  R15: 00007fd9ec2bcf30
    ORIG_RAX: 00000000000000a5  CS: 0033  SS: 002b

This task was trying to mount the cdrom.  It allocated and configured a
super_block struct and owned the write-lock for the super_block->s_umount
rwsem. While exclusively owning the s_umount lock, it called
sr_block_ioctl and waited to acquire the global sr_mutex lock.

PID: 6785   TASK: ffff880078720fb0  CPU: 0   COMMAND: "systemd-udevd"
 #0 [ffff880078417898] __schedule at ffffffff8168d605
 #1 [ffff880078417900] schedule at ffffffff8168dc59
 #2 [ffff880078417910] rwsem_down_read_failed at ffffffff8168f605
 #3 [ffff880078417980] call_rwsem_down_read_failed at ffffffff81328838
 #4 [ffff8800784179d0] down_read at ffffffff8168cde0
 #5 [ffff8800784179e8] get_super at ffffffff81201cc7
 #6 [ffff880078417a10] __invalidate_device at ffffffff8123a8de
 #7 [ffff880078417a40] flush_disk at ffffffff8123a94b
 #8 [ffff880078417a88] check_disk_change at ffffffff8123ab50
 #9 [ffff880078417ab0] cdrom_open at ffffffffa00a29e1 [cdrom]
#10 [ffff880078417b68] sr_block_open at ffffffffa00b6f9b [sr_mod]
#11 [ffff880078417b98] __blkdev_get at ffffffff8123ba86
#12 [ffff880078417bf0] blkdev_get at ffffffff8123bd65
#13 [ffff880078417c78] blkdev_open at ffffffff8123bf9b
#14 [ffff880078417c90] do_dentry_open at ffffffff811fc7f7
#15 [ffff880078417cd8] vfs_open at ffffffff811fc9cf
#16 [ffff880078417d00] do_last at ffffffff8120d53d
#17 [ffff880078417db0] path_openat at ffffffff8120e6b2
#18 [ffff880078417e48] do_filp_open at ffffffff8121082b
#19 [ffff880078417f18] do_sys_open at ffffffff811fdd33
#20 [ffff880078417f70] sys_open at ffffffff811fde4e
#21 [ffff880078417f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007f29438b0c20  RSP: 00007ffc76624b78  RFLAGS: 00010246
    RAX: 0000000000000002  RBX: ffffffff81698c49  RCX: 0000000000000000
    RDX: 00007f2944a5fa70  RSI: 00000000000a0800  RDI: 00007f2944a5fa70
    RBP: 00007f2944a5f540   R8: 0000000000000000   R9: 0000000000000020
    R10: 00007f2943614c40  R11: 0000000000000246  R12: ffffffff811fde4e
    R13: ffff880078417f78  R14: 000000000000000c  R15: 00007f2944a4b010
    ORIG_RAX: 0000000000000002  CS: 0033  SS: 002b

This task tried to open the cdrom device, the sr_block_open function
acquired the global sr_mutex lock. The call to check_disk_change()
then saw an event flag indicating a possible media change and tried
to flush any cached data for the device.
As part of the flush, it tried to acquire the super_block->s_umount
lock associated with the cdrom device.
This was the same super_block as created and locked by the previous task.

The first task acquires the s_umount lock and then the sr_mutex_lock;
the second task acquires the sr_mutex_lock and then the s_umount lock.

This patch fixes the issue by moving check_disk_change() out of
cdrom_open() and let the caller take care of it.

Signed-off-by: Maurizio Lombardi <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
frank-w pushed a commit that referenced this issue May 31, 2018
[ Upstream commit 60eb34e ]

Kernel crashed when run fio in a RAID5 backend bcache device, the call
trace is bellow:
[  440.012034] kernel BUG at block/blk-ioc.c:146!
[  440.012696] invalid opcode: 0000 [#1] SMP NOPTI
[  440.026537] CPU: 2 PID: 2205 Comm: md127_raid5 Not tainted 4.15.0 #8
[  440.027441] Hardware name: HP ProLiant MicroServer Gen8, BIOS J06 07/16
/2015
[  440.028615] RIP: 0010:put_io_context+0x8b/0x90
[  440.029246] RSP: 0018:ffffa8c882b43af8 EFLAGS: 00010246
[  440.029990] RAX: 0000000000000000 RBX: ffffa8c88294fca0 RCX: 0000000000
0f4240
[  440.031006] RDX: 0000000000000004 RSI: 0000000000000286 RDI: ffffa8c882
94fca0
[  440.032030] RBP: ffffa8c882b43b10 R08: 0000000000000003 R09: ffff949cb8
0c1700
[  440.033206] R10: 0000000000000104 R11: 000000000000b71c R12: 00000000000
01000
[  440.034222] R13: 0000000000000000 R14: ffff949cad84db70 R15: ffff949cb11
bd1e0
[  440.035239] FS:  0000000000000000(0000) GS:ffff949cba280000(0000) knlGS:
0000000000000000
[  440.060190] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  440.084967] CR2: 00007ff0493ef000 CR3: 00000002f1e0a002 CR4: 00000000001
606e0
[  440.110498] Call Trace:
[  440.135443]  bio_disassociate_task+0x1b/0x60
[  440.160355]  bio_free+0x1b/0x60
[  440.184666]  bio_put+0x23/0x30
[  440.208272]  search_free+0x23/0x40 [bcache]
[  440.231448]  cached_dev_write_complete+0x31/0x70 [bcache]
[  440.254468]  closure_put+0xb6/0xd0 [bcache]
[  440.277087]  request_endio+0x30/0x40 [bcache]
[  440.298703]  bio_endio+0xa1/0x120
[  440.319644]  handle_stripe+0x418/0x2270 [raid456]
[  440.340614]  ? load_balance+0x17b/0x9c0
[  440.360506]  handle_active_stripes.isra.58+0x387/0x5a0 [raid456]
[  440.380675]  ? __release_stripe+0x15/0x20 [raid456]
[  440.400132]  raid5d+0x3ed/0x5d0 [raid456]
[  440.419193]  ? schedule+0x36/0x80
[  440.437932]  ? schedule_timeout+0x1d2/0x2f0
[  440.456136]  md_thread+0x122/0x150
[  440.473687]  ? wait_woken+0x80/0x80
[  440.491411]  kthread+0x102/0x140
[  440.508636]  ? find_pers+0x70/0x70
[  440.524927]  ? kthread_associate_blkcg+0xa0/0xa0
[  440.541791]  ret_from_fork+0x35/0x40
[  440.558020] Code: c2 48 00 5b 41 5c 41 5d 5d c3 48 89 c6 4c 89 e7 e8 bb c2
48 00 48 8b 3d bc 36 4b 01 48 89 de e8 7c f7 e0 ff 5b 41 5c 41 5d 5d c3 <0f> 0b
0f 1f 00 0f 1f 44 00 00 55 48 8d 47 b8 48 89 e5 41 57 41
[  440.610020] RIP: put_io_context+0x8b/0x90 RSP: ffffa8c882b43af8
[  440.628575] ---[ end trace a1fd79d85643a73e ]--

All the crash issue happened when a bypass IO coming, in such scenario
s->iop.bio is pointed to the s->orig_bio. In search_free(), it finishes the
s->orig_bio by calling bio_complete(), and after that, s->iop.bio became
invalid, then kernel would crash when calling bio_put(). Maybe its upper
layer's faulty, since bio should not be freed before we calling bio_put(),
but we'd better calling bio_put() first before calling bio_complete() to
notify upper layer ending this bio.

This patch moves bio_complete() under bio_put() to avoid kernel crash.

[mlyle: fixed commit subject for character limits]

Reported-by: Matthias Ferdinand <[email protected]>
Tested-by: Matthias Ferdinand <[email protected]>
Signed-off-by: Tang Junhui <[email protected]>
Reviewed-by: Michael Lyle <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
frank-w pushed a commit that referenced this issue May 31, 2018
[ Upstream commit ad46e48 ]

Currently we can crash perf record when running in pipe mode, like:

  $ perf record ls | perf report
  # To display the perf.data header info, please use --header/--header-only options.
  #
  perf: Segmentation fault
  Error:
  The - file has no samples!

The callstack of the crash is:

    0x0000000000515242 in perf_event__synthesize_event_update_name
  3513            ev = event_update_event__new(len + 1, PERF_EVENT_UPDATE__NAME, evsel->id[0]);
  (gdb) bt
  #0  0x0000000000515242 in perf_event__synthesize_event_update_name
  #1  0x00000000005158a4 in perf_event__synthesize_extra_attr
  #2  0x0000000000443347 in record__synthesize
  #3  0x00000000004438e3 in __cmd_record
  #4  0x000000000044514e in cmd_record
  #5  0x00000000004cbc95 in run_builtin
  #6  0x00000000004cbf02 in handle_internal_command
  #7  0x00000000004cc054 in run_argv
  #8  0x00000000004cc422 in main

The reason of the crash is that the evsel does not have ids array
allocated and the pipe's synthesize code tries to access it.

We don't force evsel ids allocation when we have single event, because
it's not needed. However we need it when we are in pipe mode even for
single event as a key for evsel update event.

Fixing this by forcing evsel ids allocation event for single event, when
we are in pipe mode.

Signed-off-by: Jiri Olsa <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
frank-w pushed a commit that referenced this issue May 31, 2018
[ Upstream commit 803fafb ]

__dev_mc_add grabs an adress spinlock so use
atomic context in kmalloc.

/ # ifconfig eth0 inet 192.168.0.111
[   89.331622] BUG: sleeping function called from invalid context at mm/slab.h:420
[   89.339002] in_atomic(): 1, irqs_disabled(): 0, pid: 1035, name: ifconfig
[   89.345799] 2 locks held by ifconfig/1035:
[   89.349908]  #0:  (rtnl_mutex){+.+.}, at: [<(ptrval)>] devinet_ioctl+0xc0/0x8a0
[   89.357258]  #1:  (_xmit_ETHER){+...}, at: [<(ptrval)>] __dev_mc_add+0x28/0x80
[   89.364520] CPU: 1 PID: 1035 Comm: ifconfig Not tainted 4.16.0-rc3-dirty #8
[   89.371464] Call Trace:
[   89.373908] [e959db60] [c066f948] dump_stack+0xa4/0xfc (unreliable)
[   89.380177] [e959db80] [c00671d8] ___might_sleep+0x248/0x280
[   89.385833] [e959dba0] [c01aec34] kmem_cache_alloc_trace+0x174/0x320
[   89.392179] [e959dbd0] [c04ab920] dtsec_add_hash_mac_address+0x130/0x240
[   89.398874] [e959dc00] [c04a9d74] set_multi+0x174/0x1b0
[   89.404093] [e959dc30] [c04afb68] dpaa_set_rx_mode+0x68/0xe0
[   89.409745] [e959dc40] [c057baf8] __dev_mc_add+0x58/0x80
[   89.415052] [e959dc60] [c060fd64] igmp_group_added+0x164/0x190
[   89.420878] [e959dca0] [c060ffa8] ip_mc_inc_group+0x218/0x460
[   89.426617] [e959dce0] [c06120fc] ip_mc_up+0x3c/0x190
[   89.431662] [e959dd10] [c0607270] inetdev_event+0x250/0x620
[   89.437227] [e959dd50] [c005f190] notifier_call_chain+0x80/0xf0
[   89.443138] [e959dd80] [c0573a74] __dev_notify_flags+0x54/0xf0
[   89.448964] [e959dda0] [c05743f8] dev_change_flags+0x48/0x60
[   89.454615] [e959ddc0] [c0606744] devinet_ioctl+0x544/0x8a0
[   89.460180] [e959de10] [c060987c] inet_ioctl+0x9c/0x1f0
[   89.465400] [e959de80] [c05479a8] sock_ioctl+0x168/0x460
[   89.470708] [e959ded0] [c01cf3ec] do_vfs_ioctl+0xac/0x8c0
[   89.476099] [e959df20] [c01cfc40] SyS_ioctl+0x40/0xc0
[   89.481147] [e959df40] [c0011318] ret_from_syscall+0x0/0x3c
[   89.486715] --- interrupt: c01 at 0x1006943c
[   89.486715]     LR = 0x100c45ec

Signed-off-by: Denis Kirjanov <[email protected]>
Acked-by: Madalin Bucur <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
frank-w pushed a commit that referenced this issue May 31, 2018
[ Upstream commit 8a5a916 ]

While running btrfs/011, I hit the following lockdep splat.

This is the important bit:
   pcpu_alloc+0x1ac/0x5e0
   __percpu_counter_init+0x4e/0xb0
   btrfs_init_fs_root+0x99/0x1c0 [btrfs]
   btrfs_get_fs_root.part.54+0x5b/0x150 [btrfs]
   resolve_indirect_refs+0x130/0x830 [btrfs]
   find_parent_nodes+0x69e/0xff0 [btrfs]
   btrfs_find_all_roots_safe+0xa0/0x110 [btrfs]
   btrfs_find_all_roots+0x50/0x70 [btrfs]
   btrfs_qgroup_prepare_account_extents+0x53/0x90 [btrfs]
   btrfs_commit_transaction+0x3ce/0x9b0 [btrfs]

The percpu_counter_init call in btrfs_alloc_subvolume_writers
uses GFP_KERNEL, which we can't do during transaction commit.

This switches it to GFP_NOFS.

========================================================
WARNING: possible irq lock inversion dependency detected
4.12.14-kvmsmall #8 Tainted: G        W
--------------------------------------------------------
kswapd0/50 just changed the state of lock:
 (&delayed_node->mutex){+.+.-.}, at: [<ffffffffc06994fa>] __btrfs_release_delayed_node+0x3a/0x1f0 [btrfs]
but this lock took another, RECLAIM_FS-unsafe lock in the past:
 (pcpu_alloc_mutex){+.+.+.}

and interrupts could create inverse lock ordering between them.

other info that might help us debug this:
Chain exists of:
  &delayed_node->mutex --> &found->groups_sem --> pcpu_alloc_mutex

 Possible interrupt unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(pcpu_alloc_mutex);
                               local_irq_disable();
                               lock(&delayed_node->mutex);
                               lock(&found->groups_sem);
  <Interrupt>
    lock(&delayed_node->mutex);

 *** DEADLOCK ***

2 locks held by kswapd0/50:
 #0:  (shrinker_rwsem){++++..}, at: [<ffffffff811dc11f>] shrink_slab+0x7f/0x5b0
 #1:  (&type->s_umount_key#30){+++++.}, at: [<ffffffff8126dec6>] trylock_super+0x16/0x50

the shortest dependencies between 2nd lock and 1st lock:
   -> (pcpu_alloc_mutex){+.+.+.} ops: 4904 {
      HARDIRQ-ON-W at:
                          __mutex_lock+0x4e/0x8c0
                          pcpu_alloc+0x1ac/0x5e0
                          alloc_kmem_cache_cpus.isra.70+0x25/0xa0
                          __do_tune_cpucache+0x2c/0x220
                          do_tune_cpucache+0x26/0xc0
                          enable_cpucache+0x6d/0xf0
                          kmem_cache_init_late+0x42/0x75
                          start_kernel+0x343/0x4cb
                          x86_64_start_kernel+0x127/0x134
                          secondary_startup_64+0xa5/0xb0
      SOFTIRQ-ON-W at:
                          __mutex_lock+0x4e/0x8c0
                          pcpu_alloc+0x1ac/0x5e0
                          alloc_kmem_cache_cpus.isra.70+0x25/0xa0
                          __do_tune_cpucache+0x2c/0x220
                          do_tune_cpucache+0x26/0xc0
                          enable_cpucache+0x6d/0xf0
                          kmem_cache_init_late+0x42/0x75
                          start_kernel+0x343/0x4cb
                          x86_64_start_kernel+0x127/0x134
                          secondary_startup_64+0xa5/0xb0
      RECLAIM_FS-ON-W at:
                             __kmalloc+0x47/0x310
                             pcpu_extend_area_map+0x2b/0xc0
                             pcpu_alloc+0x3ec/0x5e0
                             alloc_kmem_cache_cpus.isra.70+0x25/0xa0
                             __do_tune_cpucache+0x2c/0x220
                             do_tune_cpucache+0x26/0xc0
                             enable_cpucache+0x6d/0xf0
                             __kmem_cache_create+0x1bf/0x390
                             create_cache+0xba/0x1b0
                             kmem_cache_create+0x1f8/0x2b0
                             ksm_init+0x6f/0x19d
                             do_one_initcall+0x50/0x1b0
                             kernel_init_freeable+0x201/0x289
                             kernel_init+0xa/0x100
                             ret_from_fork+0x3a/0x50
      INITIAL USE at:
                         __mutex_lock+0x4e/0x8c0
                         pcpu_alloc+0x1ac/0x5e0
                         alloc_kmem_cache_cpus.isra.70+0x25/0xa0
                         setup_cpu_cache+0x2f/0x1f0
                         __kmem_cache_create+0x1bf/0x390
                         create_boot_cache+0x8b/0xb1
                         kmem_cache_init+0xa1/0x19e
                         start_kernel+0x270/0x4cb
                         x86_64_start_kernel+0x127/0x134
                         secondary_startup_64+0xa5/0xb0
    }
    ... key      at: [<ffffffff821d8e70>] pcpu_alloc_mutex+0x70/0xa0
    ... acquired at:
   pcpu_alloc+0x1ac/0x5e0
   __percpu_counter_init+0x4e/0xb0
   btrfs_init_fs_root+0x99/0x1c0 [btrfs]
   btrfs_get_fs_root.part.54+0x5b/0x150 [btrfs]
   resolve_indirect_refs+0x130/0x830 [btrfs]
   find_parent_nodes+0x69e/0xff0 [btrfs]
   btrfs_find_all_roots_safe+0xa0/0x110 [btrfs]
   btrfs_find_all_roots+0x50/0x70 [btrfs]
   btrfs_qgroup_prepare_account_extents+0x53/0x90 [btrfs]
   btrfs_commit_transaction+0x3ce/0x9b0 [btrfs]
   transaction_kthread+0x176/0x1b0 [btrfs]
   kthread+0x102/0x140
   ret_from_fork+0x3a/0x50

  -> (&fs_info->commit_root_sem){++++..} ops: 1566382 {
     HARDIRQ-ON-W at:
                        down_write+0x3e/0xa0
                        cache_block_group+0x287/0x420 [btrfs]
                        find_free_extent+0x106c/0x12d0 [btrfs]
                        btrfs_reserve_extent+0xd8/0x170 [btrfs]
                        cow_file_range.isra.66+0x133/0x470 [btrfs]
                        run_delalloc_range+0x121/0x410 [btrfs]
                        writepage_delalloc.isra.50+0xfe/0x180 [btrfs]
                        __extent_writepage+0x19a/0x360 [btrfs]
                        extent_write_cache_pages.constprop.56+0x249/0x3e0 [btrfs]
                        extent_writepages+0x4d/0x60 [btrfs]
                        do_writepages+0x1a/0x70
                        __filemap_fdatawrite_range+0xa7/0xe0
                        btrfs_rename+0x5ee/0xdb0 [btrfs]
                        vfs_rename+0x52a/0x7e0
                        SyS_rename+0x351/0x3b0
                        do_syscall_64+0x79/0x1e0
                        entry_SYSCALL_64_after_hwframe+0x42/0xb7
     HARDIRQ-ON-R at:
                        down_read+0x35/0x90
                        caching_thread+0x57/0x560 [btrfs]
                        normal_work_helper+0x1c0/0x5e0 [btrfs]
                        process_one_work+0x1e0/0x5c0
                        worker_thread+0x44/0x390
                        kthread+0x102/0x140
                        ret_from_fork+0x3a/0x50
     SOFTIRQ-ON-W at:
                        down_write+0x3e/0xa0
                        cache_block_group+0x287/0x420 [btrfs]
                        find_free_extent+0x106c/0x12d0 [btrfs]
                        btrfs_reserve_extent+0xd8/0x170 [btrfs]
                        cow_file_range.isra.66+0x133/0x470 [btrfs]
                        run_delalloc_range+0x121/0x410 [btrfs]
                        writepage_delalloc.isra.50+0xfe/0x180 [btrfs]
                        __extent_writepage+0x19a/0x360 [btrfs]
                        extent_write_cache_pages.constprop.56+0x249/0x3e0 [btrfs]
                        extent_writepages+0x4d/0x60 [btrfs]
                        do_writepages+0x1a/0x70
                        __filemap_fdatawrite_range+0xa7/0xe0
                        btrfs_rename+0x5ee/0xdb0 [btrfs]
                        vfs_rename+0x52a/0x7e0
                        SyS_rename+0x351/0x3b0
                        do_syscall_64+0x79/0x1e0
                        entry_SYSCALL_64_after_hwframe+0x42/0xb7
     SOFTIRQ-ON-R at:
                        down_read+0x35/0x90
                        caching_thread+0x57/0x560 [btrfs]
                        normal_work_helper+0x1c0/0x5e0 [btrfs]
                        process_one_work+0x1e0/0x5c0
                        worker_thread+0x44/0x390
                        kthread+0x102/0x140
                        ret_from_fork+0x3a/0x50
     INITIAL USE at:
                       down_write+0x3e/0xa0
                       cache_block_group+0x287/0x420 [btrfs]
                       find_free_extent+0x106c/0x12d0 [btrfs]
                       btrfs_reserve_extent+0xd8/0x170 [btrfs]
                       cow_file_range.isra.66+0x133/0x470 [btrfs]
                       run_delalloc_range+0x121/0x410 [btrfs]
                       writepage_delalloc.isra.50+0xfe/0x180 [btrfs]
                       __extent_writepage+0x19a/0x360 [btrfs]
                       extent_write_cache_pages.constprop.56+0x249/0x3e0 [btrfs]
                       extent_writepages+0x4d/0x60 [btrfs]
                       do_writepages+0x1a/0x70
                       __filemap_fdatawrite_range+0xa7/0xe0
                       btrfs_rename+0x5ee/0xdb0 [btrfs]
                       vfs_rename+0x52a/0x7e0
                       SyS_rename+0x351/0x3b0
                       do_syscall_64+0x79/0x1e0
                       entry_SYSCALL_64_after_hwframe+0x42/0xb7
   }
   ... key      at: [<ffffffffc0729578>] __key.61970+0x0/0xfffffffffff9aa88 [btrfs]
   ... acquired at:
   cache_block_group+0x287/0x420 [btrfs]
   find_free_extent+0x106c/0x12d0 [btrfs]
   btrfs_reserve_extent+0xd8/0x170 [btrfs]
   btrfs_alloc_tree_block+0x12f/0x4c0 [btrfs]
   btrfs_create_tree+0xbb/0x2a0 [btrfs]
   btrfs_create_uuid_tree+0x37/0x140 [btrfs]
   open_ctree+0x23c0/0x2660 [btrfs]
   btrfs_mount+0xd36/0xf90 [btrfs]
   mount_fs+0x3a/0x160
   vfs_kern_mount+0x66/0x150
   btrfs_mount+0x18c/0xf90 [btrfs]
   mount_fs+0x3a/0x160
   vfs_kern_mount+0x66/0x150
   do_mount+0x1c1/0xcc0
   SyS_mount+0x7e/0xd0
   do_syscall_64+0x79/0x1e0
   entry_SYSCALL_64_after_hwframe+0x42/0xb7

 -> (&found->groups_sem){++++..} ops: 2134587 {
    HARDIRQ-ON-W at:
                      down_write+0x3e/0xa0
                      __link_block_group+0x34/0x130 [btrfs]
                      btrfs_read_block_groups+0x33d/0x7b0 [btrfs]
                      open_ctree+0x2054/0x2660 [btrfs]
                      btrfs_mount+0xd36/0xf90 [btrfs]
                      mount_fs+0x3a/0x160
                      vfs_kern_mount+0x66/0x150
                      btrfs_mount+0x18c/0xf90 [btrfs]
                      mount_fs+0x3a/0x160
                      vfs_kern_mount+0x66/0x150
                      do_mount+0x1c1/0xcc0
                      SyS_mount+0x7e/0xd0
                      do_syscall_64+0x79/0x1e0
                      entry_SYSCALL_64_after_hwframe+0x42/0xb7
    HARDIRQ-ON-R at:
                      down_read+0x35/0x90
                      btrfs_calc_num_tolerated_disk_barrier_failures+0x113/0x1f0 [btrfs]
                      open_ctree+0x207b/0x2660 [btrfs]
                      btrfs_mount+0xd36/0xf90 [btrfs]
                      mount_fs+0x3a/0x160
                      vfs_kern_mount+0x66/0x150
                      btrfs_mount+0x18c/0xf90 [btrfs]
                      mount_fs+0x3a/0x160
                      vfs_kern_mount+0x66/0x150
                      do_mount+0x1c1/0xcc0
                      SyS_mount+0x7e/0xd0
                      do_syscall_64+0x79/0x1e0
                      entry_SYSCALL_64_after_hwframe+0x42/0xb7
    SOFTIRQ-ON-W at:
                      down_write+0x3e/0xa0
                      __link_block_group+0x34/0x130 [btrfs]
                      btrfs_read_block_groups+0x33d/0x7b0 [btrfs]
                      open_ctree+0x2054/0x2660 [btrfs]
                      btrfs_mount+0xd36/0xf90 [btrfs]
                      mount_fs+0x3a/0x160
                      vfs_kern_mount+0x66/0x150
                      btrfs_mount+0x18c/0xf90 [btrfs]
                      mount_fs+0x3a/0x160
                      vfs_kern_mount+0x66/0x150
                      do_mount+0x1c1/0xcc0
                      SyS_mount+0x7e/0xd0
                      do_syscall_64+0x79/0x1e0
                      entry_SYSCALL_64_after_hwframe+0x42/0xb7
    SOFTIRQ-ON-R at:
                      down_read+0x35/0x90
                      btrfs_calc_num_tolerated_disk_barrier_failures+0x113/0x1f0 [btrfs]
                      open_ctree+0x207b/0x2660 [btrfs]
                      btrfs_mount+0xd36/0xf90 [btrfs]
                      mount_fs+0x3a/0x160
                      vfs_kern_mount+0x66/0x150
                      btrfs_mount+0x18c/0xf90 [btrfs]
                      mount_fs+0x3a/0x160
                      vfs_kern_mount+0x66/0x150
                      do_mount+0x1c1/0xcc0
                      SyS_mount+0x7e/0xd0
                      do_syscall_64+0x79/0x1e0
                      entry_SYSCALL_64_after_hwframe+0x42/0xb7
    INITIAL USE at:
                     down_write+0x3e/0xa0
                     __link_block_group+0x34/0x130 [btrfs]
                     btrfs_read_block_groups+0x33d/0x7b0 [btrfs]
                     open_ctree+0x2054/0x2660 [btrfs]
                     btrfs_mount+0xd36/0xf90 [btrfs]
                     mount_fs+0x3a/0x160
                     vfs_kern_mount+0x66/0x150
                     btrfs_mount+0x18c/0xf90 [btrfs]
                     mount_fs+0x3a/0x160
                     vfs_kern_mount+0x66/0x150
                     do_mount+0x1c1/0xcc0
                     SyS_mount+0x7e/0xd0
                     do_syscall_64+0x79/0x1e0
                     entry_SYSCALL_64_after_hwframe+0x42/0xb7
  }
  ... key      at: [<ffffffffc0729488>] __key.59101+0x0/0xfffffffffff9ab78 [btrfs]
  ... acquired at:
   find_free_extent+0xcb4/0x12d0 [btrfs]
   btrfs_reserve_extent+0xd8/0x170 [btrfs]
   btrfs_alloc_tree_block+0x12f/0x4c0 [btrfs]
   __btrfs_cow_block+0x110/0x5b0 [btrfs]
   btrfs_cow_block+0xd7/0x290 [btrfs]
   btrfs_search_slot+0x1f6/0x960 [btrfs]
   btrfs_lookup_inode+0x2a/0x90 [btrfs]
   __btrfs_update_delayed_inode+0x65/0x210 [btrfs]
   btrfs_commit_inode_delayed_inode+0x121/0x130 [btrfs]
   btrfs_evict_inode+0x3fe/0x6a0 [btrfs]
   evict+0xc4/0x190
   __dentry_kill+0xbf/0x170
   dput+0x2ae/0x2f0
   SyS_rename+0x2a6/0x3b0
   do_syscall_64+0x79/0x1e0
   entry_SYSCALL_64_after_hwframe+0x42/0xb7

-> (&delayed_node->mutex){+.+.-.} ops: 5580204 {
   HARDIRQ-ON-W at:
                    __mutex_lock+0x4e/0x8c0
                    btrfs_delayed_update_inode+0x46/0x6e0 [btrfs]
                    btrfs_update_inode+0x83/0x110 [btrfs]
                    btrfs_dirty_inode+0x62/0xe0 [btrfs]
                    touch_atime+0x8c/0xb0
                    do_generic_file_read+0x818/0xb10
                    __vfs_read+0xdc/0x150
                    vfs_read+0x8a/0x130
                    SyS_read+0x45/0xa0
                    do_syscall_64+0x79/0x1e0
                    entry_SYSCALL_64_after_hwframe+0x42/0xb7
   SOFTIRQ-ON-W at:
                    __mutex_lock+0x4e/0x8c0
                    btrfs_delayed_update_inode+0x46/0x6e0 [btrfs]
                    btrfs_update_inode+0x83/0x110 [btrfs]
                    btrfs_dirty_inode+0x62/0xe0 [btrfs]
                    touch_atime+0x8c/0xb0
                    do_generic_file_read+0x818/0xb10
                    __vfs_read+0xdc/0x150
                    vfs_read+0x8a/0x130
                    SyS_read+0x45/0xa0
                    do_syscall_64+0x79/0x1e0
                    entry_SYSCALL_64_after_hwframe+0x42/0xb7
   IN-RECLAIM_FS-W at:
                       __mutex_lock+0x4e/0x8c0
                       __btrfs_release_delayed_node+0x3a/0x1f0 [btrfs]
                       btrfs_evict_inode+0x22c/0x6a0 [btrfs]
                       evict+0xc4/0x190
                       dispose_list+0x35/0x50
                       prune_icache_sb+0x42/0x50
                       super_cache_scan+0x139/0x190
                       shrink_slab+0x262/0x5b0
                       shrink_node+0x2eb/0x2f0
                       kswapd+0x2eb/0x890
                       kthread+0x102/0x140
                       ret_from_fork+0x3a/0x50
   INITIAL USE at:
                   __mutex_lock+0x4e/0x8c0
                   btrfs_delayed_update_inode+0x46/0x6e0 [btrfs]
                   btrfs_update_inode+0x83/0x110 [btrfs]
                   btrfs_dirty_inode+0x62/0xe0 [btrfs]
                   touch_atime+0x8c/0xb0
                   do_generic_file_read+0x818/0xb10
                   __vfs_read+0xdc/0x150
                   vfs_read+0x8a/0x130
                   SyS_read+0x45/0xa0
                   do_syscall_64+0x79/0x1e0
                   entry_SYSCALL_64_after_hwframe+0x42/0xb7
 }
 ... key      at: [<ffffffffc072d488>] __key.56935+0x0/0xfffffffffff96b78 [btrfs]
 ... acquired at:
   __lock_acquire+0x264/0x11c0
   lock_acquire+0xbd/0x1e0
   __mutex_lock+0x4e/0x8c0
   __btrfs_release_delayed_node+0x3a/0x1f0 [btrfs]
   btrfs_evict_inode+0x22c/0x6a0 [btrfs]
   evict+0xc4/0x190
   dispose_list+0x35/0x50
   prune_icache_sb+0x42/0x50
   super_cache_scan+0x139/0x190
   shrink_slab+0x262/0x5b0
   shrink_node+0x2eb/0x2f0
   kswapd+0x2eb/0x890
   kthread+0x102/0x140
   ret_from_fork+0x3a/0x50

stack backtrace:
CPU: 1 PID: 50 Comm: kswapd0 Tainted: G        W        4.12.14-kvmsmall #8 SLE15 (unreleased)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014
Call Trace:
 dump_stack+0x78/0xb7
 print_irq_inversion_bug.part.38+0x19f/0x1aa
 check_usage_forwards+0x102/0x120
 ? ret_from_fork+0x3a/0x50
 ? check_usage_backwards+0x110/0x110
 mark_lock+0x16c/0x270
 __lock_acquire+0x264/0x11c0
 ? pagevec_lookup_entries+0x1a/0x30
 ? truncate_inode_pages_range+0x2b3/0x7f0
 lock_acquire+0xbd/0x1e0
 ? __btrfs_release_delayed_node+0x3a/0x1f0 [btrfs]
 __mutex_lock+0x4e/0x8c0
 ? __btrfs_release_delayed_node+0x3a/0x1f0 [btrfs]
 ? __btrfs_release_delayed_node+0x3a/0x1f0 [btrfs]
 ? btrfs_evict_inode+0x1f6/0x6a0 [btrfs]
 __btrfs_release_delayed_node+0x3a/0x1f0 [btrfs]
 btrfs_evict_inode+0x22c/0x6a0 [btrfs]
 evict+0xc4/0x190
 dispose_list+0x35/0x50
 prune_icache_sb+0x42/0x50
 super_cache_scan+0x139/0x190
 shrink_slab+0x262/0x5b0
 shrink_node+0x2eb/0x2f0
 kswapd+0x2eb/0x890
 kthread+0x102/0x140
 ? mem_cgroup_shrink_node+0x2c0/0x2c0
 ? kthread_create_on_node+0x40/0x40
 ret_from_fork+0x3a/0x50

Signed-off-by: Jeff Mahoney <[email protected]>
Reviewed-by: Liu Bo <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
frank-w pushed a commit that referenced this issue May 31, 2018
[ Upstream commit fca3234 ]

Executing command 'perf stat -T -- ls' dumps core on x86 and s390.

Here is the call back chain (done on x86):

 # gdb ./perf
 ....
 (gdb) r stat -T -- ls
...
Program received signal SIGSEGV, Segmentation fault.
0x00007ffff56d1963 in vasprintf () from /lib64/libc.so.6
(gdb) where
 #0  0x00007ffff56d1963 in vasprintf () from /lib64/libc.so.6
 #1  0x00007ffff56ae484 in asprintf () from /lib64/libc.so.6
 #2  0x00000000004f1982 in __parse_events_add_pmu (parse_state=0x7fffffffd580,
    list=0xbfb970, name=0xbf3ef0 "cpu",
    head_config=0xbfb930, auto_merge_stats=false) at util/parse-events.c:1233
 #3  0x00000000004f1c8e in parse_events_add_pmu (parse_state=0x7fffffffd580,
    list=0xbfb970, name=0xbf3ef0 "cpu",
    head_config=0xbfb930) at util/parse-events.c:1288
 #4  0x0000000000537ce3 in parse_events_parse (_parse_state=0x7fffffffd580,
    scanner=0xbf4210) at util/parse-events.y:234
 #5  0x00000000004f2c7a in parse_events__scanner (str=0x6b66c0
    "task-clock,{instructions,cycles,cpu/cycles-t/,cpu/tx-start/}",
    parse_state=0x7fffffffd580, start_token=258) at util/parse-events.c:1673
 #6  0x00000000004f2e23 in parse_events (evlist=0xbe9990, str=0x6b66c0
    "task-clock,{instructions,cycles,cpu/cycles-t/,cpu/tx-start/}", err=0x0)
    at util/parse-events.c:1713
 #7  0x000000000044e137 in add_default_attributes () at builtin-stat.c:2281
 #8  0x000000000044f7b5 in cmd_stat (argc=1, argv=0x7fffffffe3b0) at
    builtin-stat.c:2828
 #9  0x00000000004c8b0f in run_builtin (p=0xab01a0 <commands+288>, argc=4,
    argv=0x7fffffffe3b0) at perf.c:297
 #10 0x00000000004c8d7c in handle_internal_command (argc=4,
    argv=0x7fffffffe3b0) at perf.c:349
 #11 0x00000000004c8ece in run_argv (argcp=0x7fffffffe20c,
   argv=0x7fffffffe200) at perf.c:393
 #12 0x00000000004c929c in main (argc=4, argv=0x7fffffffe3b0) at perf.c:537
(gdb)

It turns out that a NULL pointer is referenced. Here are the
function calls:

  ...
  cmd_stat()
  +---> add_default_attributes()
	+---> parse_events(evsel_list, transaction_attrs, NULL);
	             3rd parameter set to NULL

Function parse_events(xx, xx, struct parse_events_error *err) dives
into a bison generated scanner and creates
parser state information for it first:

   struct parse_events_state parse_state = {
                .list   = LIST_HEAD_INIT(parse_state.list),
                .idx    = evlist->nr_entries,
                .error  = err,   <--- NULL POINTER !!!
                .evlist = evlist,
        };

Now various functions inside the bison scanner are called to end up in
__parse_events_add_pmu(struct parse_events_state *parse_state, ..) with
first parameter being a pointer to above structure definition.

Now the PMU event name is not found (because being executed in a VM) and
this function tries to create an error message with

   asprintf(&parse_state->error.str, ....)

which references a NULL pointer and dumps core.

Fix this by providing a pointer to the necessary error information
instead of NULL. Technically only the else part is needed to avoid the
core dump, just lets be safe...

Signed-off-by: Thomas Richter <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Hendrik Brueckner <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
frank-w pushed a commit that referenced this issue May 31, 2018
[ Upstream commit 2bbea6e ]

when mounting an ISO filesystem sometimes (very rarely)
the system hangs because of a race condition between two tasks.

PID: 6766   TASK: ffff88007b2a6dd0  CPU: 0   COMMAND: "mount"
 #0 [ffff880078447ae0] __schedule at ffffffff8168d605
 #1 [ffff880078447b48] schedule_preempt_disabled at ffffffff8168ed49
 #2 [ffff880078447b58] __mutex_lock_slowpath at ffffffff8168c995
 #3 [ffff880078447bb8] mutex_lock at ffffffff8168bdef
 #4 [ffff880078447bd0] sr_block_ioctl at ffffffffa00b6818 [sr_mod]
 #5 [ffff880078447c10] blkdev_ioctl at ffffffff812fea50
 #6 [ffff880078447c70] ioctl_by_bdev at ffffffff8123a8b3
 #7 [ffff880078447c90] isofs_fill_super at ffffffffa04fb1e1 [isofs]
 #8 [ffff880078447da8] mount_bdev at ffffffff81202570
 #9 [ffff880078447e18] isofs_mount at ffffffffa04f9828 [isofs]
#10 [ffff880078447e28] mount_fs at ffffffff81202d09
#11 [ffff880078447e70] vfs_kern_mount at ffffffff8121ea8f
#12 [ffff880078447ea8] do_mount at ffffffff81220fee
#13 [ffff880078447f28] sys_mount at ffffffff812218d6
#14 [ffff880078447f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007fd9ea914e9a  RSP: 00007ffd5d9bf648  RFLAGS: 00010246
    RAX: 00000000000000a5  RBX: ffffffff81698c49  RCX: 0000000000000010
    RDX: 00007fd9ec2bc210  RSI: 00007fd9ec2bc290  RDI: 00007fd9ec2bcf30
    RBP: 0000000000000000   R8: 0000000000000000   R9: 0000000000000010
    R10: 00000000c0ed0001  R11: 0000000000000206  R12: 00007fd9ec2bc040
    R13: 00007fd9eb6b2380  R14: 00007fd9ec2bc210  R15: 00007fd9ec2bcf30
    ORIG_RAX: 00000000000000a5  CS: 0033  SS: 002b

This task was trying to mount the cdrom.  It allocated and configured a
super_block struct and owned the write-lock for the super_block->s_umount
rwsem. While exclusively owning the s_umount lock, it called
sr_block_ioctl and waited to acquire the global sr_mutex lock.

PID: 6785   TASK: ffff880078720fb0  CPU: 0   COMMAND: "systemd-udevd"
 #0 [ffff880078417898] __schedule at ffffffff8168d605
 #1 [ffff880078417900] schedule at ffffffff8168dc59
 #2 [ffff880078417910] rwsem_down_read_failed at ffffffff8168f605
 #3 [ffff880078417980] call_rwsem_down_read_failed at ffffffff81328838
 #4 [ffff8800784179d0] down_read at ffffffff8168cde0
 #5 [ffff8800784179e8] get_super at ffffffff81201cc7
 #6 [ffff880078417a10] __invalidate_device at ffffffff8123a8de
 #7 [ffff880078417a40] flush_disk at ffffffff8123a94b
 #8 [ffff880078417a88] check_disk_change at ffffffff8123ab50
 #9 [ffff880078417ab0] cdrom_open at ffffffffa00a29e1 [cdrom]
#10 [ffff880078417b68] sr_block_open at ffffffffa00b6f9b [sr_mod]
#11 [ffff880078417b98] __blkdev_get at ffffffff8123ba86
#12 [ffff880078417bf0] blkdev_get at ffffffff8123bd65
#13 [ffff880078417c78] blkdev_open at ffffffff8123bf9b
#14 [ffff880078417c90] do_dentry_open at ffffffff811fc7f7
#15 [ffff880078417cd8] vfs_open at ffffffff811fc9cf
#16 [ffff880078417d00] do_last at ffffffff8120d53d
#17 [ffff880078417db0] path_openat at ffffffff8120e6b2
#18 [ffff880078417e48] do_filp_open at ffffffff8121082b
#19 [ffff880078417f18] do_sys_open at ffffffff811fdd33
#20 [ffff880078417f70] sys_open at ffffffff811fde4e
#21 [ffff880078417f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007f29438b0c20  RSP: 00007ffc76624b78  RFLAGS: 00010246
    RAX: 0000000000000002  RBX: ffffffff81698c49  RCX: 0000000000000000
    RDX: 00007f2944a5fa70  RSI: 00000000000a0800  RDI: 00007f2944a5fa70
    RBP: 00007f2944a5f540   R8: 0000000000000000   R9: 0000000000000020
    R10: 00007f2943614c40  R11: 0000000000000246  R12: ffffffff811fde4e
    R13: ffff880078417f78  R14: 000000000000000c  R15: 00007f2944a4b010
    ORIG_RAX: 0000000000000002  CS: 0033  SS: 002b

This task tried to open the cdrom device, the sr_block_open function
acquired the global sr_mutex lock. The call to check_disk_change()
then saw an event flag indicating a possible media change and tried
to flush any cached data for the device.
As part of the flush, it tried to acquire the super_block->s_umount
lock associated with the cdrom device.
This was the same super_block as created and locked by the previous task.

The first task acquires the s_umount lock and then the sr_mutex_lock;
the second task acquires the sr_mutex_lock and then the s_umount lock.

This patch fixes the issue by moving check_disk_change() out of
cdrom_open() and let the caller take care of it.

Signed-off-by: Maurizio Lombardi <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
frank-w pushed a commit that referenced this issue Jul 3, 2018
commit 1105a2f upstream.

In our armv8a server(QDF2400), I noticed lots of WARN_ON caused by
PAGE_SIZE unaligned for rmap_item->address under memory pressure
tests(start 20 guests and run memhog in the host).

  WARNING: CPU: 4 PID: 4641 at virt/kvm/arm/mmu.c:1826 kvm_age_hva_handler+0xc0/0xc8
  CPU: 4 PID: 4641 Comm: memhog Tainted: G        W 4.17.0-rc3+ #8
  Call trace:
   kvm_age_hva_handler+0xc0/0xc8
   handle_hva_to_gpa+0xa8/0xe0
   kvm_age_hva+0x4c/0xe8
   kvm_mmu_notifier_clear_flush_young+0x54/0x98
   __mmu_notifier_clear_flush_young+0x6c/0xa0
   page_referenced_one+0x154/0x1d8
   rmap_walk_ksm+0x12c/0x1d0
   rmap_walk+0x94/0xa0
   page_referenced+0x194/0x1b0
   shrink_page_list+0x674/0xc28
   shrink_inactive_list+0x26c/0x5b8
   shrink_node_memcg+0x35c/0x620
   shrink_node+0x100/0x430
   do_try_to_free_pages+0xe0/0x3a8
   try_to_free_pages+0xe4/0x230
   __alloc_pages_nodemask+0x564/0xdc0
   alloc_pages_vma+0x90/0x228
   do_anonymous_page+0xc8/0x4d0
   __handle_mm_fault+0x4a0/0x508
   handle_mm_fault+0xf8/0x1b0
   do_page_fault+0x218/0x4b8
   do_translation_fault+0x90/0xa0
   do_mem_abort+0x68/0xf0
   el0_da+0x24/0x28

In rmap_walk_ksm, the rmap_item->address might still have the
STABLE_FLAG, then the start and end in handle_hva_to_gpa might not be
PAGE_SIZE aligned.  Thus it will cause exceptions in handle_hva_to_gpa
on arm64.

This patch fixes it by ignoring (not removing) the low bits of address
when doing rmap_walk_ksm.

IMO, it should be backported to stable tree.  the storm of WARN_ONs is
very easy for me to reproduce.  More than that, I watched a panic (not
reproducible) as follows:

  page:ffff7fe003742d80 count:-4871 mapcount:-2126053375 mapping: (null) index:0x0
  flags: 0x1fffc00000000000()
  raw: 1fffc00000000000 0000000000000000 0000000000000000 ffffecf981470000
  raw: dead000000000100 dead000000000200 ffff8017c001c000 0000000000000000
  page dumped because: nonzero _refcount
  CPU: 29 PID: 18323 Comm: qemu-kvm Tainted: G W 4.14.15-5.hxt.aarch64 #1
  Hardware name: <snip for confidential issues>
  Call trace:
    dump_backtrace+0x0/0x22c
    show_stack+0x24/0x2c
    dump_stack+0x8c/0xb0
    bad_page+0xf4/0x154
    free_pages_check_bad+0x90/0x9c
    free_pcppages_bulk+0x464/0x518
    free_hot_cold_page+0x22c/0x300
    __put_page+0x54/0x60
    unmap_stage2_range+0x170/0x2b4
    kvm_unmap_hva_handler+0x30/0x40
    handle_hva_to_gpa+0xb0/0xec
    kvm_unmap_hva_range+0x5c/0xd0

I even injected a fault on purpose in kvm_unmap_hva_range by seting
size=size-0x200, the call trace is similar as above.  So I thought the
panic is similarly caused by the root cause of WARN_ON.

Andrea said:

: It looks a straightforward safe fix, on x86 hva_to_gfn_memslot would
: zap those bits and hide the misalignment caused by the low metadata
: bits being erroneously left set in the address, but the arm code
: notices when that's the last page in the memslot and the hva_end is
: getting aligned and the size is below one page.
:
: I think the problem triggers in the addr += PAGE_SIZE of
: unmap_stage2_ptes that never matches end because end is aligned but
: addr is not.
:
: 	} while (pte++, addr += PAGE_SIZE, addr != end);
:
: x86 again only works on hva_start/hva_end after converting it to
: gfn_start/end and that being in pfn units the bits are zapped before
: they risk to cause trouble.

Jia He said:

: I've tested by myself in arm64 server (QDF2400,46 cpus,96G mem) Without
: this patch, the WARN_ON is very easy for reproducing.  After this patch, I
: have run the same benchmarch for a whole day without any WARN_ONs

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Jia He <[email protected]>
Reviewed-by: Andrea Arcangeli <[email protected]>
Tested-by: Jia He <[email protected]>
Cc: Suzuki K Poulose <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Claudio Imbrenda <[email protected]>
Cc: Arvind Yadav <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
frank-w pushed a commit that referenced this issue Aug 11, 2024
commit 1723f04 upstream.

Currently if we request a feature that is not set in the Kernel config we
fail silently and return all the available features.  However, the man
page indicates we should return an EINVAL.

We need to fix this issue since we can end up with a Kernel warning should
a program request the feature UFFD_FEATURE_WP_UNPOPULATED on a kernel with
the config not set with this feature.

 [  200.812896] WARNING: CPU: 91 PID: 13634 at mm/memory.c:1660 zap_pte_range+0x43d/0x660
 [  200.820738] Modules linked in:
 [  200.869387] CPU: 91 PID: 13634 Comm: userfaultfd Kdump: loaded Not tainted 6.9.0-rc5+ #8
 [  200.877477] Hardware name: Dell Inc. PowerEdge R6525/0N7YGH, BIOS 2.7.3 03/30/2022
 [  200.885052] RIP: 0010:zap_pte_range+0x43d/0x660

Link: https://lkml.kernel.org/r/[email protected]
Fixes: e06f1e1 ("userfaultfd: wp: enabled write protection in userfaultfd API")
Signed-off-by: Audra Mitchell <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Rafael Aquini <[email protected]>
Cc: Shaohua Li <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
frank-w pushed a commit that referenced this issue Aug 11, 2024
commit be346c1 upstream.

The code in ocfs2_dio_end_io_write() estimates number of necessary
transaction credits using ocfs2_calc_extend_credits().  This however does
not take into account that the IO could be arbitrarily large and can
contain arbitrary number of extents.

Extent tree manipulations do often extend the current transaction but not
in all of the cases.  For example if we have only single block extents in
the tree, ocfs2_mark_extent_written() will end up calling
ocfs2_replace_extent_rec() all the time and we will never extend the
current transaction and eventually exhaust all the transaction credits if
the IO contains many single block extents.  Once that happens a
WARN_ON(jbd2_handle_buffer_credits(handle) <= 0) is triggered in
jbd2_journal_dirty_metadata() and subsequently OCFS2 aborts in response to
this error.  This was actually triggered by one of our customers on a
heavily fragmented OCFS2 filesystem.

To fix the issue make sure the transaction always has enough credits for
one extent insert before each call of ocfs2_mark_extent_written().

Heming Zhao said:

------
PANIC: "Kernel panic - not syncing: OCFS2: (device dm-1): panic forced after error"

PID: xxx  TASK: xxxx  CPU: 5  COMMAND: "SubmitThread-CA"
  #0 machine_kexec at ffffffff8c069932
  #1 __crash_kexec at ffffffff8c1338fa
  #2 panic at ffffffff8c1d69b9
  #3 ocfs2_handle_error at ffffffffc0c86c0c [ocfs2]
  #4 __ocfs2_abort at ffffffffc0c88387 [ocfs2]
  #5 ocfs2_journal_dirty at ffffffffc0c51e98 [ocfs2]
  #6 ocfs2_split_extent at ffffffffc0c27ea3 [ocfs2]
  #7 ocfs2_change_extent_flag at ffffffffc0c28053 [ocfs2]
  #8 ocfs2_mark_extent_written at ffffffffc0c28347 [ocfs2]
  #9 ocfs2_dio_end_io_write at ffffffffc0c2bef9 [ocfs2]
#10 ocfs2_dio_end_io at ffffffffc0c2c0f5 [ocfs2]
#11 dio_complete at ffffffff8c2b9fa7
#12 do_blockdev_direct_IO at ffffffff8c2bc09f
#13 ocfs2_direct_IO at ffffffffc0c2b653 [ocfs2]
#14 generic_file_direct_write at ffffffff8c1dcf14
#15 __generic_file_write_iter at ffffffff8c1dd07b
#16 ocfs2_file_write_iter at ffffffffc0c49f1f [ocfs2]
#17 aio_write at ffffffff8c2cc72e
#18 kmem_cache_alloc at ffffffff8c248dde
#19 do_io_submit at ffffffff8c2ccada
#20 do_syscall_64 at ffffffff8c004984
#21 entry_SYSCALL_64_after_hwframe at ffffffff8c8000ba

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: c15471f ("ocfs2: fix sparse file & data ordering issue in direct io")
Signed-off-by: Jan Kara <[email protected]>
Reviewed-by: Joseph Qi <[email protected]>
Reviewed-by: Heming Zhao <[email protected]>
Cc: Mark Fasheh <[email protected]>
Cc: Joel Becker <[email protected]>
Cc: Junxiao Bi <[email protected]>
Cc: Changwei Ge <[email protected]>
Cc: Gang He <[email protected]>
Cc: Jun Piao <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
frank-w pushed a commit that referenced this issue Aug 11, 2024
[ Upstream commit ffbf4fb ]

When CONFIG_DEBUG_BUGVERBOSE=n, we fail to add necessary padding bytes
to bug_table entries, and as a result the last entry in a bug table will
be ignored, potentially leading to an unexpected panic(). All prior
entries in the table will be handled correctly.

The arm64 ABI requires that struct fields of up to 8 bytes are
naturally-aligned, with padding added within a struct such that struct
are suitably aligned within arrays.

When CONFIG_DEBUG_BUGVERPOSE=y, the layout of a bug_entry is:

	struct bug_entry {
		signed int      bug_addr_disp;	// 4 bytes
		signed int      file_disp;	// 4 bytes
		unsigned short  line;		// 2 bytes
		unsigned short  flags;		// 2 bytes
	}

... with 12 bytes total, requiring 4-byte alignment.

When CONFIG_DEBUG_BUGVERBOSE=n, the layout of a bug_entry is:

	struct bug_entry {
		signed int      bug_addr_disp;	// 4 bytes
		unsigned short  flags;		// 2 bytes
		< implicit padding >		// 2 bytes
	}

... with 8 bytes total, with 6 bytes of data and 2 bytes of trailing
padding, requiring 4-byte alginment.

When we create a bug_entry in assembly, we align the start of the entry
to 4 bytes, which implicitly handles padding for any prior entries.
However, we do not align the end of the entry, and so when
CONFIG_DEBUG_BUGVERBOSE=n, the final entry lacks the trailing padding
bytes.

For the main kernel image this is not a problem as find_bug() doesn't
depend on the trailing padding bytes when searching for entries:

	for (bug = __start___bug_table; bug < __stop___bug_table; ++bug)
		if (bugaddr == bug_addr(bug))
			return bug;

However for modules, module_bug_finalize() depends on the trailing
bytes when calculating the number of entries:

	mod->num_bugs = sechdrs[i].sh_size / sizeof(struct bug_entry);

... and as the last bug_entry lacks the necessary padding bytes, this entry
will not be counted, e.g. in the case of a single entry:

	sechdrs[i].sh_size == 6
	sizeof(struct bug_entry) == 8;

	sechdrs[i].sh_size / sizeof(struct bug_entry) == 0;

Consequently module_find_bug() will miss the last bug_entry when it does:

	for (i = 0; i < mod->num_bugs; ++i, ++bug)
		if (bugaddr == bug_addr(bug))
			goto out;

... which can lead to a kenrel panic due to an unhandled bug.

This can be demonstrated with the following module:

	static int __init buginit(void)
	{
		WARN(1, "hello\n");
		return 0;
	}

	static void __exit bugexit(void)
	{
	}

	module_init(buginit);
	module_exit(bugexit);
	MODULE_LICENSE("GPL");

... which will trigger a kernel panic when loaded:

	------------[ cut here ]------------
	hello
	Unexpected kernel BRK exception at EL1
	Internal error: BRK handler: 00000000f2000800 [#1] PREEMPT SMP
	Modules linked in: hello(O+)
	CPU: 0 PID: 50 Comm: insmod Tainted: G           O       6.9.1 #8
	Hardware name: linux,dummy-virt (DT)
	pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
	pc : buginit+0x18/0x1000 [hello]
	lr : buginit+0x18/0x1000 [hello]
	sp : ffff800080533ae0
	x29: ffff800080533ae0 x28: 0000000000000000 x27: 0000000000000000
	x26: ffffaba8c4e70510 x25: ffff800080533c30 x24: ffffaba8c4a28a58
	x23: 0000000000000000 x22: 0000000000000000 x21: ffff3947c0eab3c0
	x20: ffffaba8c4e3f000 x19: ffffaba846464000 x18: 0000000000000006
	x17: 0000000000000000 x16: ffffaba8c2492834 x15: 0720072007200720
	x14: 0720072007200720 x13: ffffaba8c49b27c8 x12: 0000000000000312
	x11: 0000000000000106 x10: ffffaba8c4a0a7c8 x9 : ffffaba8c49b27c8
	x8 : 00000000ffffefff x7 : ffffaba8c4a0a7c8 x6 : 80000000fffff000
	x5 : 0000000000000107 x4 : 0000000000000000 x3 : 0000000000000000
	x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff3947c0eab3c0
	Call trace:
	 buginit+0x18/0x1000 [hello]
	 do_one_initcall+0x80/0x1c8
	 do_init_module+0x60/0x218
	 load_module+0x1ba4/0x1d70
	 __do_sys_init_module+0x198/0x1d0
	 __arm64_sys_init_module+0x1c/0x28
	 invoke_syscall+0x48/0x114
	 el0_svc_common.constprop.0+0x40/0xe0
	 do_el0_svc+0x1c/0x28
	 el0_svc+0x34/0xd8
	 el0t_64_sync_handler+0x120/0x12c
	 el0t_64_sync+0x190/0x194
	Code: d0ffffe0 910003fd 91000000 9400000b (d4210000)
	---[ end trace 0000000000000000 ]---
	Kernel panic - not syncing: BRK handler: Fatal exception

Fix this by always aligning the end of a bug_entry to 4 bytes, which is
correct regardless of CONFIG_DEBUG_BUGVERBOSE.

Fixes: 9fb7410 ("arm64/BUG: Use BRK instruction for generic BUG traps")

Signed-off-by: Yuanbin Xie <[email protected]>
Signed-off-by: Jiangfeng Xiao <[email protected]>
Reviewed-by: Mark Rutland <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Will Deacon <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
frank-w pushed a commit that referenced this issue Aug 11, 2024
commit d4f9d5a upstream.

A system crash like this

  Failing address: 200000cb7df6f000 TEID: 200000cb7df6f403
  Fault in home space mode while using kernel ASCE.
  AS:00000002d71bc007 R3:00000003fe5b8007 S:000000011a446000 P:000000015660c13d
  Oops: 0038 ilc:3 [#1] PREEMPT SMP
  Modules linked in: mlx5_ib ...
  CPU: 8 PID: 7556 Comm: bash Not tainted 6.9.0-rc7 #8
  Hardware name: IBM 3931 A01 704 (LPAR)
  Krnl PSW : 0704e00180000000 0000014b75e7b606 (ap_parse_bitmap_str+0x10e/0x1f8)
  R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3
  Krnl GPRS: 0000000000000001 ffffffffffffffc0 0000000000000001 00000048f96b75d3
  000000cb00000100 ffffffffffffffff ffffffffffffffff 000000cb7df6fce0
  000000cb7df6fce0 00000000ffffffff 000000000000002b 00000048ffffffff
  000003ff9b2dbc80 200000cb7df6fcd8 0000014bffffffc0 000000cb7df6fbc8
  Krnl Code: 0000014b75e7b5fc: a7840047            brc     8,0000014b75e7b68a
  0000014b75e7b600: 18b2                lr      %r11,%r2
  #0000014b75e7b602: a7f4000a            brc     15,0000014b75e7b616
  >0000014b75e7b606: eb22d00000e6        laog    %r2,%r2,0(%r13)
  0000014b75e7b60c: a7680001            lhi     %r6,1
  0000014b75e7b610: 187b                lr      %r7,%r11
  0000014b75e7b612: 84960021            brxh    %r9,%r6,0000014b75e7b654
  0000014b75e7b616: 18e9                lr      %r14,%r9
  Call Trace:
  [<0000014b75e7b606>] ap_parse_bitmap_str+0x10e/0x1f8
  ([<0000014b75e7b5dc>] ap_parse_bitmap_str+0xe4/0x1f8)
  [<0000014b75e7b758>] apmask_store+0x68/0x140
  [<0000014b75679196>] kernfs_fop_write_iter+0x14e/0x1e8
  [<0000014b75598524>] vfs_write+0x1b4/0x448
  [<0000014b7559894c>] ksys_write+0x74/0x100
  [<0000014b7618a440>] __do_syscall+0x268/0x328
  [<0000014b761a3558>] system_call+0x70/0x98
  INFO: lockdep is turned off.
  Last Breaking-Event-Address:
  [<0000014b75e7b636>] ap_parse_bitmap_str+0x13e/0x1f8
  Kernel panic - not syncing: Fatal exception: panic_on_oops

occured when /sys/bus/ap/a[pq]mask was updated with a relative mask value
(like +0x10-0x12,+60,-90) with one of the numeric values exceeding INT_MAX.

The fix is simple: use unsigned long values for the internal variables. The
correct checks are already in place in the function but a simple int for
the internal variables was used with the possibility to overflow.

Reported-by: Marc Hartmayer <[email protected]>
Signed-off-by: Harald Freudenberger <[email protected]>
Tested-by: Marc Hartmayer <[email protected]>
Reviewed-by: Holger Dengler <[email protected]>
Cc: <[email protected]>
Signed-off-by: Heiko Carstens <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
frank-w pushed a commit that referenced this issue Aug 11, 2024
commit be346c1 upstream.

The code in ocfs2_dio_end_io_write() estimates number of necessary
transaction credits using ocfs2_calc_extend_credits().  This however does
not take into account that the IO could be arbitrarily large and can
contain arbitrary number of extents.

Extent tree manipulations do often extend the current transaction but not
in all of the cases.  For example if we have only single block extents in
the tree, ocfs2_mark_extent_written() will end up calling
ocfs2_replace_extent_rec() all the time and we will never extend the
current transaction and eventually exhaust all the transaction credits if
the IO contains many single block extents.  Once that happens a
WARN_ON(jbd2_handle_buffer_credits(handle) <= 0) is triggered in
jbd2_journal_dirty_metadata() and subsequently OCFS2 aborts in response to
this error.  This was actually triggered by one of our customers on a
heavily fragmented OCFS2 filesystem.

To fix the issue make sure the transaction always has enough credits for
one extent insert before each call of ocfs2_mark_extent_written().

Heming Zhao said:

------
PANIC: "Kernel panic - not syncing: OCFS2: (device dm-1): panic forced after error"

PID: xxx  TASK: xxxx  CPU: 5  COMMAND: "SubmitThread-CA"
  #0 machine_kexec at ffffffff8c069932
  #1 __crash_kexec at ffffffff8c1338fa
  #2 panic at ffffffff8c1d69b9
  #3 ocfs2_handle_error at ffffffffc0c86c0c [ocfs2]
  #4 __ocfs2_abort at ffffffffc0c88387 [ocfs2]
  #5 ocfs2_journal_dirty at ffffffffc0c51e98 [ocfs2]
  #6 ocfs2_split_extent at ffffffffc0c27ea3 [ocfs2]
  #7 ocfs2_change_extent_flag at ffffffffc0c28053 [ocfs2]
  #8 ocfs2_mark_extent_written at ffffffffc0c28347 [ocfs2]
  #9 ocfs2_dio_end_io_write at ffffffffc0c2bef9 [ocfs2]
#10 ocfs2_dio_end_io at ffffffffc0c2c0f5 [ocfs2]
#11 dio_complete at ffffffff8c2b9fa7
#12 do_blockdev_direct_IO at ffffffff8c2bc09f
#13 ocfs2_direct_IO at ffffffffc0c2b653 [ocfs2]
#14 generic_file_direct_write at ffffffff8c1dcf14
#15 __generic_file_write_iter at ffffffff8c1dd07b
#16 ocfs2_file_write_iter at ffffffffc0c49f1f [ocfs2]
#17 aio_write at ffffffff8c2cc72e
#18 kmem_cache_alloc at ffffffff8c248dde
#19 do_io_submit at ffffffff8c2ccada
#20 do_syscall_64 at ffffffff8c004984
#21 entry_SYSCALL_64_after_hwframe at ffffffff8c8000ba

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: c15471f ("ocfs2: fix sparse file & data ordering issue in direct io")
Signed-off-by: Jan Kara <[email protected]>
Reviewed-by: Joseph Qi <[email protected]>
Reviewed-by: Heming Zhao <[email protected]>
Cc: Mark Fasheh <[email protected]>
Cc: Joel Becker <[email protected]>
Cc: Junxiao Bi <[email protected]>
Cc: Changwei Ge <[email protected]>
Cc: Gang He <[email protected]>
Cc: Jun Piao <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
frank-w pushed a commit that referenced this issue Aug 11, 2024
commit 1723f04 upstream.

Currently if we request a feature that is not set in the Kernel config we
fail silently and return all the available features.  However, the man
page indicates we should return an EINVAL.

We need to fix this issue since we can end up with a Kernel warning should
a program request the feature UFFD_FEATURE_WP_UNPOPULATED on a kernel with
the config not set with this feature.

 [  200.812896] WARNING: CPU: 91 PID: 13634 at mm/memory.c:1660 zap_pte_range+0x43d/0x660
 [  200.820738] Modules linked in:
 [  200.869387] CPU: 91 PID: 13634 Comm: userfaultfd Kdump: loaded Not tainted 6.9.0-rc5+ #8
 [  200.877477] Hardware name: Dell Inc. PowerEdge R6525/0N7YGH, BIOS 2.7.3 03/30/2022
 [  200.885052] RIP: 0010:zap_pte_range+0x43d/0x660

Link: https://lkml.kernel.org/r/[email protected]
Fixes: e06f1e1 ("userfaultfd: wp: enabled write protection in userfaultfd API")
Signed-off-by: Audra Mitchell <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Rafael Aquini <[email protected]>
Cc: Shaohua Li <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
frank-w pushed a commit that referenced this issue Aug 11, 2024
commit 1723f04 upstream.

Currently if we request a feature that is not set in the Kernel config we
fail silently and return all the available features.  However, the man
page indicates we should return an EINVAL.

We need to fix this issue since we can end up with a Kernel warning should
a program request the feature UFFD_FEATURE_WP_UNPOPULATED on a kernel with
the config not set with this feature.

 [  200.812896] WARNING: CPU: 91 PID: 13634 at mm/memory.c:1660 zap_pte_range+0x43d/0x660
 [  200.820738] Modules linked in:
 [  200.869387] CPU: 91 PID: 13634 Comm: userfaultfd Kdump: loaded Not tainted 6.9.0-rc5+ #8
 [  200.877477] Hardware name: Dell Inc. PowerEdge R6525/0N7YGH, BIOS 2.7.3 03/30/2022
 [  200.885052] RIP: 0010:zap_pte_range+0x43d/0x660

Link: https://lkml.kernel.org/r/[email protected]
Fixes: e06f1e1 ("userfaultfd: wp: enabled write protection in userfaultfd API")
Signed-off-by: Audra Mitchell <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Rafael Aquini <[email protected]>
Cc: Shaohua Li <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
frank-w pushed a commit that referenced this issue Aug 20, 2024
[ Upstream commit 86a41ea ]

When l2tp tunnels use a socket provided by userspace, we can hit
lockdep splats like the below when data is transmitted through another
(unrelated) userspace socket which then gets routed over l2tp.

This issue was previously discussed here:
https://lore.kernel.org/netdev/[email protected]/

The solution is to have lockdep treat socket locks of l2tp tunnel
sockets separately than those of standard INET sockets. To do so, use
a different lockdep subclass where lock nesting is possible.

  ============================================
  WARNING: possible recursive locking detected
  6.10.0+ #34 Not tainted
  --------------------------------------------
  iperf3/771 is trying to acquire lock:
  ffff8881027601d8 (slock-AF_INET/1){+.-.}-{2:2}, at: l2tp_xmit_skb+0x243/0x9d0

  but task is already holding lock:
  ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(slock-AF_INET/1);
    lock(slock-AF_INET/1);

   *** DEADLOCK ***

   May be due to missing lock nesting notation

  10 locks held by iperf3/771:
   #0: ffff888102650258 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x1a/0x40
   #1: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0
   #2: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130
   #3: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x28b/0x9f0
   #4: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0xf9/0x260
   #5: ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10
   #6: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0
   #7: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130
   #8: ffffffff822ac1e0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0xcc/0x1450
   #9: ffff888101f33258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#2){+...}-{2:2}, at: __dev_queue_xmit+0x513/0x1450

  stack backtrace:
  CPU: 2 UID: 0 PID: 771 Comm: iperf3 Not tainted 6.10.0+ #34
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
  Call Trace:
   <IRQ>
   dump_stack_lvl+0x69/0xa0
   dump_stack+0xc/0x20
   __lock_acquire+0x135d/0x2600
   ? srso_alias_return_thunk+0x5/0xfbef5
   lock_acquire+0xc4/0x2a0
   ? l2tp_xmit_skb+0x243/0x9d0
   ? __skb_checksum+0xa3/0x540
   _raw_spin_lock_nested+0x35/0x50
   ? l2tp_xmit_skb+0x243/0x9d0
   l2tp_xmit_skb+0x243/0x9d0
   l2tp_eth_dev_xmit+0x3c/0xc0
   dev_hard_start_xmit+0x11e/0x420
   sch_direct_xmit+0xc3/0x640
   __dev_queue_xmit+0x61c/0x1450
   ? ip_finish_output2+0xf4c/0x1130
   ip_finish_output2+0x6b6/0x1130
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __ip_finish_output+0x217/0x380
   ? srso_alias_return_thunk+0x5/0xfbef5
   __ip_finish_output+0x217/0x380
   ip_output+0x99/0x120
   __ip_queue_xmit+0xae4/0xbc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? tcp_options_write.constprop.0+0xcb/0x3e0
   ip_queue_xmit+0x34/0x40
   __tcp_transmit_skb+0x1625/0x1890
   __tcp_send_ack+0x1b8/0x340
   tcp_send_ack+0x23/0x30
   __tcp_ack_snd_check+0xa8/0x530
   ? srso_alias_return_thunk+0x5/0xfbef5
   tcp_rcv_established+0x412/0xd70
   tcp_v4_do_rcv+0x299/0x420
   tcp_v4_rcv+0x1991/0x1e10
   ip_protocol_deliver_rcu+0x50/0x220
   ip_local_deliver_finish+0x158/0x260
   ip_local_deliver+0xc8/0xe0
   ip_rcv+0xe5/0x1d0
   ? __pfx_ip_rcv+0x10/0x10
   __netif_receive_skb_one_core+0xce/0xe0
   ? process_backlog+0x28b/0x9f0
   __netif_receive_skb+0x34/0xd0
   ? process_backlog+0x28b/0x9f0
   process_backlog+0x2cb/0x9f0
   __napi_poll.constprop.0+0x61/0x280
   net_rx_action+0x332/0x670
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? find_held_lock+0x2b/0x80
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   handle_softirqs+0xda/0x480
   ? __dev_queue_xmit+0xa2c/0x1450
   do_softirq+0xa1/0xd0
   </IRQ>
   <TASK>
   __local_bh_enable_ip+0xc8/0xe0
   ? __dev_queue_xmit+0xa2c/0x1450
   __dev_queue_xmit+0xa48/0x1450
   ? ip_finish_output2+0xf4c/0x1130
   ip_finish_output2+0x6b6/0x1130
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __ip_finish_output+0x217/0x380
   ? srso_alias_return_thunk+0x5/0xfbef5
   __ip_finish_output+0x217/0x380
   ip_output+0x99/0x120
   __ip_queue_xmit+0xae4/0xbc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? tcp_options_write.constprop.0+0xcb/0x3e0
   ip_queue_xmit+0x34/0x40
   __tcp_transmit_skb+0x1625/0x1890
   tcp_write_xmit+0x766/0x2fb0
   ? __entry_text_end+0x102ba9/0x102bad
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __might_fault+0x74/0xc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   __tcp_push_pending_frames+0x56/0x190
   tcp_push+0x117/0x310
   tcp_sendmsg_locked+0x14c1/0x1740
   tcp_sendmsg+0x28/0x40
   inet_sendmsg+0x5d/0x90
   sock_write_iter+0x242/0x2b0
   vfs_write+0x68d/0x800
   ? __pfx_sock_write_iter+0x10/0x10
   ksys_write+0xc8/0xf0
   __x64_sys_write+0x3d/0x50
   x64_sys_call+0xfaf/0x1f50
   do_syscall_64+0x6d/0x140
   entry_SYSCALL_64_after_hwframe+0x76/0x7e
  RIP: 0033:0x7f4d143af992
  Code: c3 8b 07 85 c0 75 24 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> e9 01 cc ff ff 41 54 b8 02 00 00 0
  RSP: 002b:00007ffd65032058 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
  RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f4d143af992
  RDX: 0000000000000025 RSI: 00007f4d143f3bcc RDI: 0000000000000005
  RBP: 00007f4d143f2b28 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4d143f3bcc
  R13: 0000000000000005 R14: 0000000000000000 R15: 00007ffd650323f0
   </TASK>

Fixes: 0b2c597 ("l2tp: close all race conditions in l2tp_tunnel_register()")
Suggested-by: Eric Dumazet <[email protected]>
Reported-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=6acef9e0a4d1f46c83d4
CC: [email protected]
CC: [email protected]
Signed-off-by: James Chapman <[email protected]>
Signed-off-by: Tom Parkin <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
frank-w pushed a commit that referenced this issue Aug 20, 2024
[ Upstream commit 86a41ea ]

When l2tp tunnels use a socket provided by userspace, we can hit
lockdep splats like the below when data is transmitted through another
(unrelated) userspace socket which then gets routed over l2tp.

This issue was previously discussed here:
https://lore.kernel.org/netdev/[email protected]/

The solution is to have lockdep treat socket locks of l2tp tunnel
sockets separately than those of standard INET sockets. To do so, use
a different lockdep subclass where lock nesting is possible.

  ============================================
  WARNING: possible recursive locking detected
  6.10.0+ #34 Not tainted
  --------------------------------------------
  iperf3/771 is trying to acquire lock:
  ffff8881027601d8 (slock-AF_INET/1){+.-.}-{2:2}, at: l2tp_xmit_skb+0x243/0x9d0

  but task is already holding lock:
  ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(slock-AF_INET/1);
    lock(slock-AF_INET/1);

   *** DEADLOCK ***

   May be due to missing lock nesting notation

  10 locks held by iperf3/771:
   #0: ffff888102650258 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x1a/0x40
   #1: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0
   #2: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130
   #3: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x28b/0x9f0
   #4: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0xf9/0x260
   #5: ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10
   #6: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0
   #7: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130
   #8: ffffffff822ac1e0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0xcc/0x1450
   #9: ffff888101f33258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#2){+...}-{2:2}, at: __dev_queue_xmit+0x513/0x1450

  stack backtrace:
  CPU: 2 UID: 0 PID: 771 Comm: iperf3 Not tainted 6.10.0+ #34
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
  Call Trace:
   <IRQ>
   dump_stack_lvl+0x69/0xa0
   dump_stack+0xc/0x20
   __lock_acquire+0x135d/0x2600
   ? srso_alias_return_thunk+0x5/0xfbef5
   lock_acquire+0xc4/0x2a0
   ? l2tp_xmit_skb+0x243/0x9d0
   ? __skb_checksum+0xa3/0x540
   _raw_spin_lock_nested+0x35/0x50
   ? l2tp_xmit_skb+0x243/0x9d0
   l2tp_xmit_skb+0x243/0x9d0
   l2tp_eth_dev_xmit+0x3c/0xc0
   dev_hard_start_xmit+0x11e/0x420
   sch_direct_xmit+0xc3/0x640
   __dev_queue_xmit+0x61c/0x1450
   ? ip_finish_output2+0xf4c/0x1130
   ip_finish_output2+0x6b6/0x1130
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __ip_finish_output+0x217/0x380
   ? srso_alias_return_thunk+0x5/0xfbef5
   __ip_finish_output+0x217/0x380
   ip_output+0x99/0x120
   __ip_queue_xmit+0xae4/0xbc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? tcp_options_write.constprop.0+0xcb/0x3e0
   ip_queue_xmit+0x34/0x40
   __tcp_transmit_skb+0x1625/0x1890
   __tcp_send_ack+0x1b8/0x340
   tcp_send_ack+0x23/0x30
   __tcp_ack_snd_check+0xa8/0x530
   ? srso_alias_return_thunk+0x5/0xfbef5
   tcp_rcv_established+0x412/0xd70
   tcp_v4_do_rcv+0x299/0x420
   tcp_v4_rcv+0x1991/0x1e10
   ip_protocol_deliver_rcu+0x50/0x220
   ip_local_deliver_finish+0x158/0x260
   ip_local_deliver+0xc8/0xe0
   ip_rcv+0xe5/0x1d0
   ? __pfx_ip_rcv+0x10/0x10
   __netif_receive_skb_one_core+0xce/0xe0
   ? process_backlog+0x28b/0x9f0
   __netif_receive_skb+0x34/0xd0
   ? process_backlog+0x28b/0x9f0
   process_backlog+0x2cb/0x9f0
   __napi_poll.constprop.0+0x61/0x280
   net_rx_action+0x332/0x670
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? find_held_lock+0x2b/0x80
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   handle_softirqs+0xda/0x480
   ? __dev_queue_xmit+0xa2c/0x1450
   do_softirq+0xa1/0xd0
   </IRQ>
   <TASK>
   __local_bh_enable_ip+0xc8/0xe0
   ? __dev_queue_xmit+0xa2c/0x1450
   __dev_queue_xmit+0xa48/0x1450
   ? ip_finish_output2+0xf4c/0x1130
   ip_finish_output2+0x6b6/0x1130
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __ip_finish_output+0x217/0x380
   ? srso_alias_return_thunk+0x5/0xfbef5
   __ip_finish_output+0x217/0x380
   ip_output+0x99/0x120
   __ip_queue_xmit+0xae4/0xbc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? tcp_options_write.constprop.0+0xcb/0x3e0
   ip_queue_xmit+0x34/0x40
   __tcp_transmit_skb+0x1625/0x1890
   tcp_write_xmit+0x766/0x2fb0
   ? __entry_text_end+0x102ba9/0x102bad
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __might_fault+0x74/0xc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   __tcp_push_pending_frames+0x56/0x190
   tcp_push+0x117/0x310
   tcp_sendmsg_locked+0x14c1/0x1740
   tcp_sendmsg+0x28/0x40
   inet_sendmsg+0x5d/0x90
   sock_write_iter+0x242/0x2b0
   vfs_write+0x68d/0x800
   ? __pfx_sock_write_iter+0x10/0x10
   ksys_write+0xc8/0xf0
   __x64_sys_write+0x3d/0x50
   x64_sys_call+0xfaf/0x1f50
   do_syscall_64+0x6d/0x140
   entry_SYSCALL_64_after_hwframe+0x76/0x7e
  RIP: 0033:0x7f4d143af992
  Code: c3 8b 07 85 c0 75 24 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> e9 01 cc ff ff 41 54 b8 02 00 00 0
  RSP: 002b:00007ffd65032058 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
  RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f4d143af992
  RDX: 0000000000000025 RSI: 00007f4d143f3bcc RDI: 0000000000000005
  RBP: 00007f4d143f2b28 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4d143f3bcc
  R13: 0000000000000005 R14: 0000000000000000 R15: 00007ffd650323f0
   </TASK>

Fixes: 0b2c597 ("l2tp: close all race conditions in l2tp_tunnel_register()")
Suggested-by: Eric Dumazet <[email protected]>
Reported-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=6acef9e0a4d1f46c83d4
CC: [email protected]
CC: [email protected]
Signed-off-by: James Chapman <[email protected]>
Signed-off-by: Tom Parkin <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
frank-w pushed a commit that referenced this issue Aug 31, 2024
When l2tp tunnels use a socket provided by userspace, we can hit
lockdep splats like the below when data is transmitted through another
(unrelated) userspace socket which then gets routed over l2tp.

This issue was previously discussed here:
https://lore.kernel.org/netdev/[email protected]/

The solution is to have lockdep treat socket locks of l2tp tunnel
sockets separately than those of standard INET sockets. To do so, use
a different lockdep subclass where lock nesting is possible.

  ============================================
  WARNING: possible recursive locking detected
  6.10.0+ #34 Not tainted
  --------------------------------------------
  iperf3/771 is trying to acquire lock:
  ffff8881027601d8 (slock-AF_INET/1){+.-.}-{2:2}, at: l2tp_xmit_skb+0x243/0x9d0

  but task is already holding lock:
  ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(slock-AF_INET/1);
    lock(slock-AF_INET/1);

   *** DEADLOCK ***

   May be due to missing lock nesting notation

  10 locks held by iperf3/771:
   #0: ffff888102650258 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x1a/0x40
   #1: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0
   #2: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130
   #3: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x28b/0x9f0
   #4: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0xf9/0x260
   #5: ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10
   #6: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0
   #7: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130
   #8: ffffffff822ac1e0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0xcc/0x1450
   #9: ffff888101f33258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#2){+...}-{2:2}, at: __dev_queue_xmit+0x513/0x1450

  stack backtrace:
  CPU: 2 UID: 0 PID: 771 Comm: iperf3 Not tainted 6.10.0+ #34
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
  Call Trace:
   <IRQ>
   dump_stack_lvl+0x69/0xa0
   dump_stack+0xc/0x20
   __lock_acquire+0x135d/0x2600
   ? srso_alias_return_thunk+0x5/0xfbef5
   lock_acquire+0xc4/0x2a0
   ? l2tp_xmit_skb+0x243/0x9d0
   ? __skb_checksum+0xa3/0x540
   _raw_spin_lock_nested+0x35/0x50
   ? l2tp_xmit_skb+0x243/0x9d0
   l2tp_xmit_skb+0x243/0x9d0
   l2tp_eth_dev_xmit+0x3c/0xc0
   dev_hard_start_xmit+0x11e/0x420
   sch_direct_xmit+0xc3/0x640
   __dev_queue_xmit+0x61c/0x1450
   ? ip_finish_output2+0xf4c/0x1130
   ip_finish_output2+0x6b6/0x1130
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __ip_finish_output+0x217/0x380
   ? srso_alias_return_thunk+0x5/0xfbef5
   __ip_finish_output+0x217/0x380
   ip_output+0x99/0x120
   __ip_queue_xmit+0xae4/0xbc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? tcp_options_write.constprop.0+0xcb/0x3e0
   ip_queue_xmit+0x34/0x40
   __tcp_transmit_skb+0x1625/0x1890
   __tcp_send_ack+0x1b8/0x340
   tcp_send_ack+0x23/0x30
   __tcp_ack_snd_check+0xa8/0x530
   ? srso_alias_return_thunk+0x5/0xfbef5
   tcp_rcv_established+0x412/0xd70
   tcp_v4_do_rcv+0x299/0x420
   tcp_v4_rcv+0x1991/0x1e10
   ip_protocol_deliver_rcu+0x50/0x220
   ip_local_deliver_finish+0x158/0x260
   ip_local_deliver+0xc8/0xe0
   ip_rcv+0xe5/0x1d0
   ? __pfx_ip_rcv+0x10/0x10
   __netif_receive_skb_one_core+0xce/0xe0
   ? process_backlog+0x28b/0x9f0
   __netif_receive_skb+0x34/0xd0
   ? process_backlog+0x28b/0x9f0
   process_backlog+0x2cb/0x9f0
   __napi_poll.constprop.0+0x61/0x280
   net_rx_action+0x332/0x670
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? find_held_lock+0x2b/0x80
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   handle_softirqs+0xda/0x480
   ? __dev_queue_xmit+0xa2c/0x1450
   do_softirq+0xa1/0xd0
   </IRQ>
   <TASK>
   __local_bh_enable_ip+0xc8/0xe0
   ? __dev_queue_xmit+0xa2c/0x1450
   __dev_queue_xmit+0xa48/0x1450
   ? ip_finish_output2+0xf4c/0x1130
   ip_finish_output2+0x6b6/0x1130
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __ip_finish_output+0x217/0x380
   ? srso_alias_return_thunk+0x5/0xfbef5
   __ip_finish_output+0x217/0x380
   ip_output+0x99/0x120
   __ip_queue_xmit+0xae4/0xbc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? tcp_options_write.constprop.0+0xcb/0x3e0
   ip_queue_xmit+0x34/0x40
   __tcp_transmit_skb+0x1625/0x1890
   tcp_write_xmit+0x766/0x2fb0
   ? __entry_text_end+0x102ba9/0x102bad
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __might_fault+0x74/0xc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   __tcp_push_pending_frames+0x56/0x190
   tcp_push+0x117/0x310
   tcp_sendmsg_locked+0x14c1/0x1740
   tcp_sendmsg+0x28/0x40
   inet_sendmsg+0x5d/0x90
   sock_write_iter+0x242/0x2b0
   vfs_write+0x68d/0x800
   ? __pfx_sock_write_iter+0x10/0x10
   ksys_write+0xc8/0xf0
   __x64_sys_write+0x3d/0x50
   x64_sys_call+0xfaf/0x1f50
   do_syscall_64+0x6d/0x140
   entry_SYSCALL_64_after_hwframe+0x76/0x7e
  RIP: 0033:0x7f4d143af992
  Code: c3 8b 07 85 c0 75 24 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> e9 01 cc ff ff 41 54 b8 02 00 00 0
  RSP: 002b:00007ffd65032058 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
  RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f4d143af992
  RDX: 0000000000000025 RSI: 00007f4d143f3bcc RDI: 0000000000000005
  RBP: 00007f4d143f2b28 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4d143f3bcc
  R13: 0000000000000005 R14: 0000000000000000 R15: 00007ffd650323f0
   </TASK>

Fixes: 0b2c597 ("l2tp: close all race conditions in l2tp_tunnel_register()")
Suggested-by: Eric Dumazet <[email protected]>
Reported-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=6acef9e0a4d1f46c83d4
CC: [email protected]
CC: [email protected]
Signed-off-by: James Chapman <[email protected]>
Signed-off-by: Tom Parkin <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
BtbN pushed a commit to BtbN/BPI-Router-Linux that referenced this issue Sep 7, 2024
[ Upstream commit a699781 ]

A sysfs reader can race with a device reset or removal, attempting to
read device state when the device is not actually present. eg:

     [exception RIP: qed_get_current_link+17]
  frank-w#8 [ffffb9e4f2907c48] qede_get_link_ksettings at ffffffffc07a994a [qede]
  frank-w#9 [ffffb9e4f2907cd8] __rh_call_get_link_ksettings at ffffffff992b01a3
 frank-w#10 [ffffb9e4f2907d38] __ethtool_get_link_ksettings at ffffffff992b04e4
 frank-w#11 [ffffb9e4f2907d90] duplex_show at ffffffff99260300
 frank-w#12 [ffffb9e4f2907e38] dev_attr_show at ffffffff9905a01c
 frank-w#13 [ffffb9e4f2907e50] sysfs_kf_seq_show at ffffffff98e0145b
 frank-w#14 [ffffb9e4f2907e68] seq_read at ffffffff98d902e3
 frank-w#15 [ffffb9e4f2907ec8] vfs_read at ffffffff98d657d1
 frank-w#16 [ffffb9e4f2907f00] ksys_read at ffffffff98d65c3f
 frank-w#17 [ffffb9e4f2907f38] do_syscall_64 at ffffffff98a052fb

 crash> struct net_device.state ffff9a9d21336000
    state = 5,

state 5 is __LINK_STATE_START (0b1) and __LINK_STATE_NOCARRIER (0b100).
The device is not present, note lack of __LINK_STATE_PRESENT (0b10).

This is the same sort of panic as observed in commit 4224cfd
("net-sysfs: add check for netdevice being present to speed_show").

There are many other callers of __ethtool_get_link_ksettings() which
don't have a device presence check.

Move this check into ethtool to protect all callers.

Fixes: d519e17 ("net: export device speed and duplex via sysfs")
Fixes: 4224cfd ("net-sysfs: add check for netdevice being present to speed_show")
Signed-off-by: Jamie Bainbridge <[email protected]>
Link: https://patch.msgid.link/8bae218864beaa44ed01628140475b9bf641c5b0.1724393671.git.jamie.bainbridge@gmail.com
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
frank-w pushed a commit that referenced this issue Sep 14, 2024
A sysfs reader can race with a device reset or removal, attempting to
read device state when the device is not actually present. eg:

     [exception RIP: qed_get_current_link+17]
  #8 [ffffb9e4f2907c48] qede_get_link_ksettings at ffffffffc07a994a [qede]
  #9 [ffffb9e4f2907cd8] __rh_call_get_link_ksettings at ffffffff992b01a3
 #10 [ffffb9e4f2907d38] __ethtool_get_link_ksettings at ffffffff992b04e4
 #11 [ffffb9e4f2907d90] duplex_show at ffffffff99260300
 #12 [ffffb9e4f2907e38] dev_attr_show at ffffffff9905a01c
 #13 [ffffb9e4f2907e50] sysfs_kf_seq_show at ffffffff98e0145b
 #14 [ffffb9e4f2907e68] seq_read at ffffffff98d902e3
 #15 [ffffb9e4f2907ec8] vfs_read at ffffffff98d657d1
 #16 [ffffb9e4f2907f00] ksys_read at ffffffff98d65c3f
 #17 [ffffb9e4f2907f38] do_syscall_64 at ffffffff98a052fb

 crash> struct net_device.state ffff9a9d21336000
    state = 5,

state 5 is __LINK_STATE_START (0b1) and __LINK_STATE_NOCARRIER (0b100).
The device is not present, note lack of __LINK_STATE_PRESENT (0b10).

This is the same sort of panic as observed in commit 4224cfd
("net-sysfs: add check for netdevice being present to speed_show").

There are many other callers of __ethtool_get_link_ksettings() which
don't have a device presence check.

Move this check into ethtool to protect all callers.

Fixes: d519e17 ("net: export device speed and duplex via sysfs")
Fixes: 4224cfd ("net-sysfs: add check for netdevice being present to speed_show")
Signed-off-by: Jamie Bainbridge <[email protected]>
Link: https://patch.msgid.link/8bae218864beaa44ed01628140475b9bf641c5b0.1724393671.git.jamie.bainbridge@gmail.com
Signed-off-by: Jakub Kicinski <[email protected]>
frank-w pushed a commit that referenced this issue Sep 14, 2024
[ Upstream commit ffbf4fb ]

When CONFIG_DEBUG_BUGVERBOSE=n, we fail to add necessary padding bytes
to bug_table entries, and as a result the last entry in a bug table will
be ignored, potentially leading to an unexpected panic(). All prior
entries in the table will be handled correctly.

The arm64 ABI requires that struct fields of up to 8 bytes are
naturally-aligned, with padding added within a struct such that struct
are suitably aligned within arrays.

When CONFIG_DEBUG_BUGVERPOSE=y, the layout of a bug_entry is:

	struct bug_entry {
		signed int      bug_addr_disp;	// 4 bytes
		signed int      file_disp;	// 4 bytes
		unsigned short  line;		// 2 bytes
		unsigned short  flags;		// 2 bytes
	}

... with 12 bytes total, requiring 4-byte alignment.

When CONFIG_DEBUG_BUGVERBOSE=n, the layout of a bug_entry is:

	struct bug_entry {
		signed int      bug_addr_disp;	// 4 bytes
		unsigned short  flags;		// 2 bytes
		< implicit padding >		// 2 bytes
	}

... with 8 bytes total, with 6 bytes of data and 2 bytes of trailing
padding, requiring 4-byte alginment.

When we create a bug_entry in assembly, we align the start of the entry
to 4 bytes, which implicitly handles padding for any prior entries.
However, we do not align the end of the entry, and so when
CONFIG_DEBUG_BUGVERBOSE=n, the final entry lacks the trailing padding
bytes.

For the main kernel image this is not a problem as find_bug() doesn't
depend on the trailing padding bytes when searching for entries:

	for (bug = __start___bug_table; bug < __stop___bug_table; ++bug)
		if (bugaddr == bug_addr(bug))
			return bug;

However for modules, module_bug_finalize() depends on the trailing
bytes when calculating the number of entries:

	mod->num_bugs = sechdrs[i].sh_size / sizeof(struct bug_entry);

... and as the last bug_entry lacks the necessary padding bytes, this entry
will not be counted, e.g. in the case of a single entry:

	sechdrs[i].sh_size == 6
	sizeof(struct bug_entry) == 8;

	sechdrs[i].sh_size / sizeof(struct bug_entry) == 0;

Consequently module_find_bug() will miss the last bug_entry when it does:

	for (i = 0; i < mod->num_bugs; ++i, ++bug)
		if (bugaddr == bug_addr(bug))
			goto out;

... which can lead to a kenrel panic due to an unhandled bug.

This can be demonstrated with the following module:

	static int __init buginit(void)
	{
		WARN(1, "hello\n");
		return 0;
	}

	static void __exit bugexit(void)
	{
	}

	module_init(buginit);
	module_exit(bugexit);
	MODULE_LICENSE("GPL");

... which will trigger a kernel panic when loaded:

	------------[ cut here ]------------
	hello
	Unexpected kernel BRK exception at EL1
	Internal error: BRK handler: 00000000f2000800 [#1] PREEMPT SMP
	Modules linked in: hello(O+)
	CPU: 0 PID: 50 Comm: insmod Tainted: G           O       6.9.1 #8
	Hardware name: linux,dummy-virt (DT)
	pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
	pc : buginit+0x18/0x1000 [hello]
	lr : buginit+0x18/0x1000 [hello]
	sp : ffff800080533ae0
	x29: ffff800080533ae0 x28: 0000000000000000 x27: 0000000000000000
	x26: ffffaba8c4e70510 x25: ffff800080533c30 x24: ffffaba8c4a28a58
	x23: 0000000000000000 x22: 0000000000000000 x21: ffff3947c0eab3c0
	x20: ffffaba8c4e3f000 x19: ffffaba846464000 x18: 0000000000000006
	x17: 0000000000000000 x16: ffffaba8c2492834 x15: 0720072007200720
	x14: 0720072007200720 x13: ffffaba8c49b27c8 x12: 0000000000000312
	x11: 0000000000000106 x10: ffffaba8c4a0a7c8 x9 : ffffaba8c49b27c8
	x8 : 00000000ffffefff x7 : ffffaba8c4a0a7c8 x6 : 80000000fffff000
	x5 : 0000000000000107 x4 : 0000000000000000 x3 : 0000000000000000
	x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff3947c0eab3c0
	Call trace:
	 buginit+0x18/0x1000 [hello]
	 do_one_initcall+0x80/0x1c8
	 do_init_module+0x60/0x218
	 load_module+0x1ba4/0x1d70
	 __do_sys_init_module+0x198/0x1d0
	 __arm64_sys_init_module+0x1c/0x28
	 invoke_syscall+0x48/0x114
	 el0_svc_common.constprop.0+0x40/0xe0
	 do_el0_svc+0x1c/0x28
	 el0_svc+0x34/0xd8
	 el0t_64_sync_handler+0x120/0x12c
	 el0t_64_sync+0x190/0x194
	Code: d0ffffe0 910003fd 91000000 9400000b (d4210000)
	---[ end trace 0000000000000000 ]---
	Kernel panic - not syncing: BRK handler: Fatal exception

Fix this by always aligning the end of a bug_entry to 4 bytes, which is
correct regardless of CONFIG_DEBUG_BUGVERBOSE.

Fixes: 9fb7410 ("arm64/BUG: Use BRK instruction for generic BUG traps")

Signed-off-by: Yuanbin Xie <[email protected]>
Signed-off-by: Jiangfeng Xiao <[email protected]>
Reviewed-by: Mark Rutland <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Will Deacon <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
frank-w pushed a commit that referenced this issue Sep 14, 2024
commit d4f9d5a upstream.

A system crash like this

  Failing address: 200000cb7df6f000 TEID: 200000cb7df6f403
  Fault in home space mode while using kernel ASCE.
  AS:00000002d71bc007 R3:00000003fe5b8007 S:000000011a446000 P:000000015660c13d
  Oops: 0038 ilc:3 [#1] PREEMPT SMP
  Modules linked in: mlx5_ib ...
  CPU: 8 PID: 7556 Comm: bash Not tainted 6.9.0-rc7 #8
  Hardware name: IBM 3931 A01 704 (LPAR)
  Krnl PSW : 0704e00180000000 0000014b75e7b606 (ap_parse_bitmap_str+0x10e/0x1f8)
  R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3
  Krnl GPRS: 0000000000000001 ffffffffffffffc0 0000000000000001 00000048f96b75d3
  000000cb00000100 ffffffffffffffff ffffffffffffffff 000000cb7df6fce0
  000000cb7df6fce0 00000000ffffffff 000000000000002b 00000048ffffffff
  000003ff9b2dbc80 200000cb7df6fcd8 0000014bffffffc0 000000cb7df6fbc8
  Krnl Code: 0000014b75e7b5fc: a7840047            brc     8,0000014b75e7b68a
  0000014b75e7b600: 18b2                lr      %r11,%r2
  #0000014b75e7b602: a7f4000a            brc     15,0000014b75e7b616
  >0000014b75e7b606: eb22d00000e6        laog    %r2,%r2,0(%r13)
  0000014b75e7b60c: a7680001            lhi     %r6,1
  0000014b75e7b610: 187b                lr      %r7,%r11
  0000014b75e7b612: 84960021            brxh    %r9,%r6,0000014b75e7b654
  0000014b75e7b616: 18e9                lr      %r14,%r9
  Call Trace:
  [<0000014b75e7b606>] ap_parse_bitmap_str+0x10e/0x1f8
  ([<0000014b75e7b5dc>] ap_parse_bitmap_str+0xe4/0x1f8)
  [<0000014b75e7b758>] apmask_store+0x68/0x140
  [<0000014b75679196>] kernfs_fop_write_iter+0x14e/0x1e8
  [<0000014b75598524>] vfs_write+0x1b4/0x448
  [<0000014b7559894c>] ksys_write+0x74/0x100
  [<0000014b7618a440>] __do_syscall+0x268/0x328
  [<0000014b761a3558>] system_call+0x70/0x98
  INFO: lockdep is turned off.
  Last Breaking-Event-Address:
  [<0000014b75e7b636>] ap_parse_bitmap_str+0x13e/0x1f8
  Kernel panic - not syncing: Fatal exception: panic_on_oops

occured when /sys/bus/ap/a[pq]mask was updated with a relative mask value
(like +0x10-0x12,+60,-90) with one of the numeric values exceeding INT_MAX.

The fix is simple: use unsigned long values for the internal variables. The
correct checks are already in place in the function but a simple int for
the internal variables was used with the possibility to overflow.

Reported-by: Marc Hartmayer <[email protected]>
Signed-off-by: Harald Freudenberger <[email protected]>
Tested-by: Marc Hartmayer <[email protected]>
Reviewed-by: Holger Dengler <[email protected]>
Cc: <[email protected]>
Signed-off-by: Heiko Carstens <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
frank-w pushed a commit that referenced this issue Sep 14, 2024
[ Upstream commit a699781 ]

A sysfs reader can race with a device reset or removal, attempting to
read device state when the device is not actually present. eg:

     [exception RIP: qed_get_current_link+17]
  #8 [ffffb9e4f2907c48] qede_get_link_ksettings at ffffffffc07a994a [qede]
  #9 [ffffb9e4f2907cd8] __rh_call_get_link_ksettings at ffffffff992b01a3
 #10 [ffffb9e4f2907d38] __ethtool_get_link_ksettings at ffffffff992b04e4
 #11 [ffffb9e4f2907d90] duplex_show at ffffffff99260300
 #12 [ffffb9e4f2907e38] dev_attr_show at ffffffff9905a01c
 #13 [ffffb9e4f2907e50] sysfs_kf_seq_show at ffffffff98e0145b
 #14 [ffffb9e4f2907e68] seq_read at ffffffff98d902e3
 #15 [ffffb9e4f2907ec8] vfs_read at ffffffff98d657d1
 #16 [ffffb9e4f2907f00] ksys_read at ffffffff98d65c3f
 #17 [ffffb9e4f2907f38] do_syscall_64 at ffffffff98a052fb

 crash> struct net_device.state ffff9a9d21336000
    state = 5,

state 5 is __LINK_STATE_START (0b1) and __LINK_STATE_NOCARRIER (0b100).
The device is not present, note lack of __LINK_STATE_PRESENT (0b10).

This is the same sort of panic as observed in commit 4224cfd
("net-sysfs: add check for netdevice being present to speed_show").

There are many other callers of __ethtool_get_link_ksettings() which
don't have a device presence check.

Move this check into ethtool to protect all callers.

Fixes: d519e17 ("net: export device speed and duplex via sysfs")
Fixes: 4224cfd ("net-sysfs: add check for netdevice being present to speed_show")
Signed-off-by: Jamie Bainbridge <[email protected]>
Link: https://patch.msgid.link/8bae218864beaa44ed01628140475b9bf641c5b0.1724393671.git.jamie.bainbridge@gmail.com
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
frank-w pushed a commit that referenced this issue Sep 14, 2024
[ Upstream commit 86a41ea ]

When l2tp tunnels use a socket provided by userspace, we can hit
lockdep splats like the below when data is transmitted through another
(unrelated) userspace socket which then gets routed over l2tp.

This issue was previously discussed here:
https://lore.kernel.org/netdev/[email protected]/

The solution is to have lockdep treat socket locks of l2tp tunnel
sockets separately than those of standard INET sockets. To do so, use
a different lockdep subclass where lock nesting is possible.

  ============================================
  WARNING: possible recursive locking detected
  6.10.0+ #34 Not tainted
  --------------------------------------------
  iperf3/771 is trying to acquire lock:
  ffff8881027601d8 (slock-AF_INET/1){+.-.}-{2:2}, at: l2tp_xmit_skb+0x243/0x9d0

  but task is already holding lock:
  ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(slock-AF_INET/1);
    lock(slock-AF_INET/1);

   *** DEADLOCK ***

   May be due to missing lock nesting notation

  10 locks held by iperf3/771:
   #0: ffff888102650258 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x1a/0x40
   #1: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0
   #2: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130
   #3: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x28b/0x9f0
   #4: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0xf9/0x260
   #5: ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10
   #6: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0
   #7: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130
   #8: ffffffff822ac1e0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0xcc/0x1450
   #9: ffff888101f33258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#2){+...}-{2:2}, at: __dev_queue_xmit+0x513/0x1450

  stack backtrace:
  CPU: 2 UID: 0 PID: 771 Comm: iperf3 Not tainted 6.10.0+ #34
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
  Call Trace:
   <IRQ>
   dump_stack_lvl+0x69/0xa0
   dump_stack+0xc/0x20
   __lock_acquire+0x135d/0x2600
   ? srso_alias_return_thunk+0x5/0xfbef5
   lock_acquire+0xc4/0x2a0
   ? l2tp_xmit_skb+0x243/0x9d0
   ? __skb_checksum+0xa3/0x540
   _raw_spin_lock_nested+0x35/0x50
   ? l2tp_xmit_skb+0x243/0x9d0
   l2tp_xmit_skb+0x243/0x9d0
   l2tp_eth_dev_xmit+0x3c/0xc0
   dev_hard_start_xmit+0x11e/0x420
   sch_direct_xmit+0xc3/0x640
   __dev_queue_xmit+0x61c/0x1450
   ? ip_finish_output2+0xf4c/0x1130
   ip_finish_output2+0x6b6/0x1130
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __ip_finish_output+0x217/0x380
   ? srso_alias_return_thunk+0x5/0xfbef5
   __ip_finish_output+0x217/0x380
   ip_output+0x99/0x120
   __ip_queue_xmit+0xae4/0xbc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? tcp_options_write.constprop.0+0xcb/0x3e0
   ip_queue_xmit+0x34/0x40
   __tcp_transmit_skb+0x1625/0x1890
   __tcp_send_ack+0x1b8/0x340
   tcp_send_ack+0x23/0x30
   __tcp_ack_snd_check+0xa8/0x530
   ? srso_alias_return_thunk+0x5/0xfbef5
   tcp_rcv_established+0x412/0xd70
   tcp_v4_do_rcv+0x299/0x420
   tcp_v4_rcv+0x1991/0x1e10
   ip_protocol_deliver_rcu+0x50/0x220
   ip_local_deliver_finish+0x158/0x260
   ip_local_deliver+0xc8/0xe0
   ip_rcv+0xe5/0x1d0
   ? __pfx_ip_rcv+0x10/0x10
   __netif_receive_skb_one_core+0xce/0xe0
   ? process_backlog+0x28b/0x9f0
   __netif_receive_skb+0x34/0xd0
   ? process_backlog+0x28b/0x9f0
   process_backlog+0x2cb/0x9f0
   __napi_poll.constprop.0+0x61/0x280
   net_rx_action+0x332/0x670
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? find_held_lock+0x2b/0x80
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   handle_softirqs+0xda/0x480
   ? __dev_queue_xmit+0xa2c/0x1450
   do_softirq+0xa1/0xd0
   </IRQ>
   <TASK>
   __local_bh_enable_ip+0xc8/0xe0
   ? __dev_queue_xmit+0xa2c/0x1450
   __dev_queue_xmit+0xa48/0x1450
   ? ip_finish_output2+0xf4c/0x1130
   ip_finish_output2+0x6b6/0x1130
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __ip_finish_output+0x217/0x380
   ? srso_alias_return_thunk+0x5/0xfbef5
   __ip_finish_output+0x217/0x380
   ip_output+0x99/0x120
   __ip_queue_xmit+0xae4/0xbc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? tcp_options_write.constprop.0+0xcb/0x3e0
   ip_queue_xmit+0x34/0x40
   __tcp_transmit_skb+0x1625/0x1890
   tcp_write_xmit+0x766/0x2fb0
   ? __entry_text_end+0x102ba9/0x102bad
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __might_fault+0x74/0xc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   __tcp_push_pending_frames+0x56/0x190
   tcp_push+0x117/0x310
   tcp_sendmsg_locked+0x14c1/0x1740
   tcp_sendmsg+0x28/0x40
   inet_sendmsg+0x5d/0x90
   sock_write_iter+0x242/0x2b0
   vfs_write+0x68d/0x800
   ? __pfx_sock_write_iter+0x10/0x10
   ksys_write+0xc8/0xf0
   __x64_sys_write+0x3d/0x50
   x64_sys_call+0xfaf/0x1f50
   do_syscall_64+0x6d/0x140
   entry_SYSCALL_64_after_hwframe+0x76/0x7e
  RIP: 0033:0x7f4d143af992
  Code: c3 8b 07 85 c0 75 24 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> e9 01 cc ff ff 41 54 b8 02 00 00 0
  RSP: 002b:00007ffd65032058 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
  RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f4d143af992
  RDX: 0000000000000025 RSI: 00007f4d143f3bcc RDI: 0000000000000005
  RBP: 00007f4d143f2b28 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4d143f3bcc
  R13: 0000000000000005 R14: 0000000000000000 R15: 00007ffd650323f0
   </TASK>

Fixes: 0b2c597 ("l2tp: close all race conditions in l2tp_tunnel_register()")
Suggested-by: Eric Dumazet <[email protected]>
Reported-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=6acef9e0a4d1f46c83d4
CC: [email protected]
CC: [email protected]
Signed-off-by: James Chapman <[email protected]>
Signed-off-by: Tom Parkin <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
frank-w pushed a commit that referenced this issue Sep 14, 2024
[ Upstream commit a699781 ]

A sysfs reader can race with a device reset or removal, attempting to
read device state when the device is not actually present. eg:

     [exception RIP: qed_get_current_link+17]
  #8 [ffffb9e4f2907c48] qede_get_link_ksettings at ffffffffc07a994a [qede]
  #9 [ffffb9e4f2907cd8] __rh_call_get_link_ksettings at ffffffff992b01a3
 #10 [ffffb9e4f2907d38] __ethtool_get_link_ksettings at ffffffff992b04e4
 #11 [ffffb9e4f2907d90] duplex_show at ffffffff99260300
 #12 [ffffb9e4f2907e38] dev_attr_show at ffffffff9905a01c
 #13 [ffffb9e4f2907e50] sysfs_kf_seq_show at ffffffff98e0145b
 #14 [ffffb9e4f2907e68] seq_read at ffffffff98d902e3
 #15 [ffffb9e4f2907ec8] vfs_read at ffffffff98d657d1
 #16 [ffffb9e4f2907f00] ksys_read at ffffffff98d65c3f
 #17 [ffffb9e4f2907f38] do_syscall_64 at ffffffff98a052fb

 crash> struct net_device.state ffff9a9d21336000
    state = 5,

state 5 is __LINK_STATE_START (0b1) and __LINK_STATE_NOCARRIER (0b100).
The device is not present, note lack of __LINK_STATE_PRESENT (0b10).

This is the same sort of panic as observed in commit 4224cfd
("net-sysfs: add check for netdevice being present to speed_show").

There are many other callers of __ethtool_get_link_ksettings() which
don't have a device presence check.

Move this check into ethtool to protect all callers.

Fixes: d519e17 ("net: export device speed and duplex via sysfs")
Fixes: 4224cfd ("net-sysfs: add check for netdevice being present to speed_show")
Signed-off-by: Jamie Bainbridge <[email protected]>
Link: https://patch.msgid.link/8bae218864beaa44ed01628140475b9bf641c5b0.1724393671.git.jamie.bainbridge@gmail.com
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
frank-w pushed a commit that referenced this issue Sep 14, 2024
[ Upstream commit a699781 ]

A sysfs reader can race with a device reset or removal, attempting to
read device state when the device is not actually present. eg:

     [exception RIP: qed_get_current_link+17]
  #8 [ffffb9e4f2907c48] qede_get_link_ksettings at ffffffffc07a994a [qede]
  #9 [ffffb9e4f2907cd8] __rh_call_get_link_ksettings at ffffffff992b01a3
 #10 [ffffb9e4f2907d38] __ethtool_get_link_ksettings at ffffffff992b04e4
 #11 [ffffb9e4f2907d90] duplex_show at ffffffff99260300
 #12 [ffffb9e4f2907e38] dev_attr_show at ffffffff9905a01c
 #13 [ffffb9e4f2907e50] sysfs_kf_seq_show at ffffffff98e0145b
 #14 [ffffb9e4f2907e68] seq_read at ffffffff98d902e3
 #15 [ffffb9e4f2907ec8] vfs_read at ffffffff98d657d1
 #16 [ffffb9e4f2907f00] ksys_read at ffffffff98d65c3f
 #17 [ffffb9e4f2907f38] do_syscall_64 at ffffffff98a052fb

 crash> struct net_device.state ffff9a9d21336000
    state = 5,

state 5 is __LINK_STATE_START (0b1) and __LINK_STATE_NOCARRIER (0b100).
The device is not present, note lack of __LINK_STATE_PRESENT (0b10).

This is the same sort of panic as observed in commit 4224cfd
("net-sysfs: add check for netdevice being present to speed_show").

There are many other callers of __ethtool_get_link_ksettings() which
don't have a device presence check.

Move this check into ethtool to protect all callers.

Fixes: d519e17 ("net: export device speed and duplex via sysfs")
Fixes: 4224cfd ("net-sysfs: add check for netdevice being present to speed_show")
Signed-off-by: Jamie Bainbridge <[email protected]>
Link: https://patch.msgid.link/8bae218864beaa44ed01628140475b9bf641c5b0.1724393671.git.jamie.bainbridge@gmail.com
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
frank-w pushed a commit that referenced this issue Sep 14, 2024
[ Upstream commit 54624ac ]

The test thread will start N benchmark kthreads and then schedule out
until the test time finished and notify the benchmark kthreads to stop.
The benchmark kthreads will keep running until notified to stop.
There's a problem with current implementation when the benchmark
kthreads number is equal to the CPUs on a non-preemptible kernel:
since the scheduler will balance the kthreads across the CPUs and
when the test time's out the test thread won't get a chance to be
scheduled on any CPU then cannot notify the benchmark kthreads to stop.

This can be easily reproduced on a VM (simulated with 16 CPUs) with
PREEMPT_VOLUNTARY:
estuary:/mnt$ ./dma_map_benchmark -t 16 -s 1
 rcu: INFO: rcu_sched self-detected stall on CPU
 rcu:     10-...!: (5221 ticks this GP) idle=ed24/1/0x4000000000000000 softirq=142/142 fqs=0
 rcu:     (t=5254 jiffies g=-559 q=45 ncpus=16)
 rcu: rcu_sched kthread starved for 5255 jiffies! g-559 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=12
 rcu:     Unless rcu_sched kthread gets sufficient CPU time, OOM is now expected behavior.
 rcu: RCU grace-period kthread stack dump:
 task:rcu_sched       state:R  running task     stack:0     pid:16    tgid:16    ppid:2      flags:0x00000008
 Call trace
  __switch_to+0xec/0x138
  __schedule+0x2f8/0x1080
  schedule+0x30/0x130
  schedule_timeout+0xa0/0x188
  rcu_gp_fqs_loop+0x128/0x528
  rcu_gp_kthread+0x1c8/0x208
  kthread+0xec/0xf8
  ret_from_fork+0x10/0x20
 Sending NMI from CPU 10 to CPUs 0:
 NMI backtrace for cpu 0
 CPU: 0 PID: 332 Comm: dma-map-benchma Not tainted 6.10.0-rc1-vanilla-LSE #8
 Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
 pstate: 20400005 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 pc : arm_smmu_cmdq_issue_cmdlist+0x218/0x730
 lr : arm_smmu_cmdq_issue_cmdlist+0x488/0x730
 sp : ffff80008748b630
 x29: ffff80008748b630 x28: 0000000000000000 x27: ffff80008748b780
 x26: 0000000000000000 x25: 000000000000bc70 x24: 000000000001bc70
 x23: ffff0000c12af080 x22: 0000000000010000 x21: 000000000000ffff
 x20: ffff80008748b700 x19: ffff0000c12af0c0 x18: 0000000000010000
 x17: 0000000000000001 x16: 0000000000000040 x15: ffffffffffffffff
 x14: 0001ffffffffffff x13: 000000000000ffff x12: 00000000000002f1
 x11: 000000000001ffff x10: 0000000000000031 x9 : ffff800080b6b0b8
 x8 : ffff0000c2a48000 x7 : 000000000001bc71 x6 : 0001800000000000
 x5 : 00000000000002f1 x4 : 01ffffffffffffff x3 : 000000000009aaf1
 x2 : 0000000000000018 x1 : 000000000000000f x0 : ffff0000c12af18c
 Call trace:
  arm_smmu_cmdq_issue_cmdlist+0x218/0x730
  __arm_smmu_tlb_inv_range+0xe0/0x1a8
  arm_smmu_iotlb_sync+0xc0/0x128
  __iommu_dma_unmap+0x248/0x320
  iommu_dma_unmap_page+0x5c/0xe8
  dma_unmap_page_attrs+0x38/0x1d0
  map_benchmark_thread+0x118/0x2c0
  kthread+0xec/0xf8
  ret_from_fork+0x10/0x20

Solve this by adding scheduling point in the kthread loop,
so if there're other threads in the system they may have
a chance to run, especially the thread to notify the test
end. However this may degrade the test concurrency so it's
recommended to run this on an idle system.

Signed-off-by: Yicong Yang <[email protected]>
Acked-by: Barry Song <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
frank-w pushed a commit that referenced this issue Sep 14, 2024
[ Upstream commit 86a41ea ]

When l2tp tunnels use a socket provided by userspace, we can hit
lockdep splats like the below when data is transmitted through another
(unrelated) userspace socket which then gets routed over l2tp.

This issue was previously discussed here:
https://lore.kernel.org/netdev/[email protected]/

The solution is to have lockdep treat socket locks of l2tp tunnel
sockets separately than those of standard INET sockets. To do so, use
a different lockdep subclass where lock nesting is possible.

  ============================================
  WARNING: possible recursive locking detected
  6.10.0+ #34 Not tainted
  --------------------------------------------
  iperf3/771 is trying to acquire lock:
  ffff8881027601d8 (slock-AF_INET/1){+.-.}-{2:2}, at: l2tp_xmit_skb+0x243/0x9d0

  but task is already holding lock:
  ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(slock-AF_INET/1);
    lock(slock-AF_INET/1);

   *** DEADLOCK ***

   May be due to missing lock nesting notation

  10 locks held by iperf3/771:
   #0: ffff888102650258 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x1a/0x40
   #1: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0
   #2: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130
   #3: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x28b/0x9f0
   #4: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0xf9/0x260
   #5: ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10
   #6: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0
   #7: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130
   #8: ffffffff822ac1e0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0xcc/0x1450
   #9: ffff888101f33258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#2){+...}-{2:2}, at: __dev_queue_xmit+0x513/0x1450

  stack backtrace:
  CPU: 2 UID: 0 PID: 771 Comm: iperf3 Not tainted 6.10.0+ #34
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
  Call Trace:
   <IRQ>
   dump_stack_lvl+0x69/0xa0
   dump_stack+0xc/0x20
   __lock_acquire+0x135d/0x2600
   ? srso_alias_return_thunk+0x5/0xfbef5
   lock_acquire+0xc4/0x2a0
   ? l2tp_xmit_skb+0x243/0x9d0
   ? __skb_checksum+0xa3/0x540
   _raw_spin_lock_nested+0x35/0x50
   ? l2tp_xmit_skb+0x243/0x9d0
   l2tp_xmit_skb+0x243/0x9d0
   l2tp_eth_dev_xmit+0x3c/0xc0
   dev_hard_start_xmit+0x11e/0x420
   sch_direct_xmit+0xc3/0x640
   __dev_queue_xmit+0x61c/0x1450
   ? ip_finish_output2+0xf4c/0x1130
   ip_finish_output2+0x6b6/0x1130
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __ip_finish_output+0x217/0x380
   ? srso_alias_return_thunk+0x5/0xfbef5
   __ip_finish_output+0x217/0x380
   ip_output+0x99/0x120
   __ip_queue_xmit+0xae4/0xbc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? tcp_options_write.constprop.0+0xcb/0x3e0
   ip_queue_xmit+0x34/0x40
   __tcp_transmit_skb+0x1625/0x1890
   __tcp_send_ack+0x1b8/0x340
   tcp_send_ack+0x23/0x30
   __tcp_ack_snd_check+0xa8/0x530
   ? srso_alias_return_thunk+0x5/0xfbef5
   tcp_rcv_established+0x412/0xd70
   tcp_v4_do_rcv+0x299/0x420
   tcp_v4_rcv+0x1991/0x1e10
   ip_protocol_deliver_rcu+0x50/0x220
   ip_local_deliver_finish+0x158/0x260
   ip_local_deliver+0xc8/0xe0
   ip_rcv+0xe5/0x1d0
   ? __pfx_ip_rcv+0x10/0x10
   __netif_receive_skb_one_core+0xce/0xe0
   ? process_backlog+0x28b/0x9f0
   __netif_receive_skb+0x34/0xd0
   ? process_backlog+0x28b/0x9f0
   process_backlog+0x2cb/0x9f0
   __napi_poll.constprop.0+0x61/0x280
   net_rx_action+0x332/0x670
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? find_held_lock+0x2b/0x80
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   handle_softirqs+0xda/0x480
   ? __dev_queue_xmit+0xa2c/0x1450
   do_softirq+0xa1/0xd0
   </IRQ>
   <TASK>
   __local_bh_enable_ip+0xc8/0xe0
   ? __dev_queue_xmit+0xa2c/0x1450
   __dev_queue_xmit+0xa48/0x1450
   ? ip_finish_output2+0xf4c/0x1130
   ip_finish_output2+0x6b6/0x1130
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __ip_finish_output+0x217/0x380
   ? srso_alias_return_thunk+0x5/0xfbef5
   __ip_finish_output+0x217/0x380
   ip_output+0x99/0x120
   __ip_queue_xmit+0xae4/0xbc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? tcp_options_write.constprop.0+0xcb/0x3e0
   ip_queue_xmit+0x34/0x40
   __tcp_transmit_skb+0x1625/0x1890
   tcp_write_xmit+0x766/0x2fb0
   ? __entry_text_end+0x102ba9/0x102bad
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __might_fault+0x74/0xc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   __tcp_push_pending_frames+0x56/0x190
   tcp_push+0x117/0x310
   tcp_sendmsg_locked+0x14c1/0x1740
   tcp_sendmsg+0x28/0x40
   inet_sendmsg+0x5d/0x90
   sock_write_iter+0x242/0x2b0
   vfs_write+0x68d/0x800
   ? __pfx_sock_write_iter+0x10/0x10
   ksys_write+0xc8/0xf0
   __x64_sys_write+0x3d/0x50
   x64_sys_call+0xfaf/0x1f50
   do_syscall_64+0x6d/0x140
   entry_SYSCALL_64_after_hwframe+0x76/0x7e
  RIP: 0033:0x7f4d143af992
  Code: c3 8b 07 85 c0 75 24 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> e9 01 cc ff ff 41 54 b8 02 00 00 0
  RSP: 002b:00007ffd65032058 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
  RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f4d143af992
  RDX: 0000000000000025 RSI: 00007f4d143f3bcc RDI: 0000000000000005
  RBP: 00007f4d143f2b28 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4d143f3bcc
  R13: 0000000000000005 R14: 0000000000000000 R15: 00007ffd650323f0
   </TASK>

Fixes: 0b2c597 ("l2tp: close all race conditions in l2tp_tunnel_register()")
Suggested-by: Eric Dumazet <[email protected]>
Reported-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=6acef9e0a4d1f46c83d4
CC: [email protected]
CC: [email protected]
Signed-off-by: James Chapman <[email protected]>
Signed-off-by: Tom Parkin <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
frank-w pushed a commit that referenced this issue Sep 14, 2024
[ Upstream commit a699781 ]

A sysfs reader can race with a device reset or removal, attempting to
read device state when the device is not actually present. eg:

     [exception RIP: qed_get_current_link+17]
  #8 [ffffb9e4f2907c48] qede_get_link_ksettings at ffffffffc07a994a [qede]
  #9 [ffffb9e4f2907cd8] __rh_call_get_link_ksettings at ffffffff992b01a3
 #10 [ffffb9e4f2907d38] __ethtool_get_link_ksettings at ffffffff992b04e4
 #11 [ffffb9e4f2907d90] duplex_show at ffffffff99260300
 #12 [ffffb9e4f2907e38] dev_attr_show at ffffffff9905a01c
 #13 [ffffb9e4f2907e50] sysfs_kf_seq_show at ffffffff98e0145b
 #14 [ffffb9e4f2907e68] seq_read at ffffffff98d902e3
 #15 [ffffb9e4f2907ec8] vfs_read at ffffffff98d657d1
 #16 [ffffb9e4f2907f00] ksys_read at ffffffff98d65c3f
 #17 [ffffb9e4f2907f38] do_syscall_64 at ffffffff98a052fb

 crash> struct net_device.state ffff9a9d21336000
    state = 5,

state 5 is __LINK_STATE_START (0b1) and __LINK_STATE_NOCARRIER (0b100).
The device is not present, note lack of __LINK_STATE_PRESENT (0b10).

This is the same sort of panic as observed in commit 4224cfd
("net-sysfs: add check for netdevice being present to speed_show").

There are many other callers of __ethtool_get_link_ksettings() which
don't have a device presence check.

Move this check into ethtool to protect all callers.

Fixes: d519e17 ("net: export device speed and duplex via sysfs")
Fixes: 4224cfd ("net-sysfs: add check for netdevice being present to speed_show")
Signed-off-by: Jamie Bainbridge <[email protected]>
Link: https://patch.msgid.link/8bae218864beaa44ed01628140475b9bf641c5b0.1724393671.git.jamie.bainbridge@gmail.com
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
frank-w pushed a commit that referenced this issue Sep 14, 2024
[ Upstream commit 54624ac ]

The test thread will start N benchmark kthreads and then schedule out
until the test time finished and notify the benchmark kthreads to stop.
The benchmark kthreads will keep running until notified to stop.
There's a problem with current implementation when the benchmark
kthreads number is equal to the CPUs on a non-preemptible kernel:
since the scheduler will balance the kthreads across the CPUs and
when the test time's out the test thread won't get a chance to be
scheduled on any CPU then cannot notify the benchmark kthreads to stop.

This can be easily reproduced on a VM (simulated with 16 CPUs) with
PREEMPT_VOLUNTARY:
estuary:/mnt$ ./dma_map_benchmark -t 16 -s 1
 rcu: INFO: rcu_sched self-detected stall on CPU
 rcu:     10-...!: (5221 ticks this GP) idle=ed24/1/0x4000000000000000 softirq=142/142 fqs=0
 rcu:     (t=5254 jiffies g=-559 q=45 ncpus=16)
 rcu: rcu_sched kthread starved for 5255 jiffies! g-559 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=12
 rcu:     Unless rcu_sched kthread gets sufficient CPU time, OOM is now expected behavior.
 rcu: RCU grace-period kthread stack dump:
 task:rcu_sched       state:R  running task     stack:0     pid:16    tgid:16    ppid:2      flags:0x00000008
 Call trace
  __switch_to+0xec/0x138
  __schedule+0x2f8/0x1080
  schedule+0x30/0x130
  schedule_timeout+0xa0/0x188
  rcu_gp_fqs_loop+0x128/0x528
  rcu_gp_kthread+0x1c8/0x208
  kthread+0xec/0xf8
  ret_from_fork+0x10/0x20
 Sending NMI from CPU 10 to CPUs 0:
 NMI backtrace for cpu 0
 CPU: 0 PID: 332 Comm: dma-map-benchma Not tainted 6.10.0-rc1-vanilla-LSE #8
 Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
 pstate: 20400005 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 pc : arm_smmu_cmdq_issue_cmdlist+0x218/0x730
 lr : arm_smmu_cmdq_issue_cmdlist+0x488/0x730
 sp : ffff80008748b630
 x29: ffff80008748b630 x28: 0000000000000000 x27: ffff80008748b780
 x26: 0000000000000000 x25: 000000000000bc70 x24: 000000000001bc70
 x23: ffff0000c12af080 x22: 0000000000010000 x21: 000000000000ffff
 x20: ffff80008748b700 x19: ffff0000c12af0c0 x18: 0000000000010000
 x17: 0000000000000001 x16: 0000000000000040 x15: ffffffffffffffff
 x14: 0001ffffffffffff x13: 000000000000ffff x12: 00000000000002f1
 x11: 000000000001ffff x10: 0000000000000031 x9 : ffff800080b6b0b8
 x8 : ffff0000c2a48000 x7 : 000000000001bc71 x6 : 0001800000000000
 x5 : 00000000000002f1 x4 : 01ffffffffffffff x3 : 000000000009aaf1
 x2 : 0000000000000018 x1 : 000000000000000f x0 : ffff0000c12af18c
 Call trace:
  arm_smmu_cmdq_issue_cmdlist+0x218/0x730
  __arm_smmu_tlb_inv_range+0xe0/0x1a8
  arm_smmu_iotlb_sync+0xc0/0x128
  __iommu_dma_unmap+0x248/0x320
  iommu_dma_unmap_page+0x5c/0xe8
  dma_unmap_page_attrs+0x38/0x1d0
  map_benchmark_thread+0x118/0x2c0
  kthread+0xec/0xf8
  ret_from_fork+0x10/0x20

Solve this by adding scheduling point in the kthread loop,
so if there're other threads in the system they may have
a chance to run, especially the thread to notify the test
end. However this may degrade the test concurrency so it's
recommended to run this on an idle system.

Signed-off-by: Yicong Yang <[email protected]>
Acked-by: Barry Song <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
frank-w pushed a commit that referenced this issue Sep 14, 2024
[ Upstream commit a699781 ]

A sysfs reader can race with a device reset or removal, attempting to
read device state when the device is not actually present. eg:

     [exception RIP: qed_get_current_link+17]
  #8 [ffffb9e4f2907c48] qede_get_link_ksettings at ffffffffc07a994a [qede]
  #9 [ffffb9e4f2907cd8] __rh_call_get_link_ksettings at ffffffff992b01a3
 #10 [ffffb9e4f2907d38] __ethtool_get_link_ksettings at ffffffff992b04e4
 #11 [ffffb9e4f2907d90] duplex_show at ffffffff99260300
 #12 [ffffb9e4f2907e38] dev_attr_show at ffffffff9905a01c
 #13 [ffffb9e4f2907e50] sysfs_kf_seq_show at ffffffff98e0145b
 #14 [ffffb9e4f2907e68] seq_read at ffffffff98d902e3
 #15 [ffffb9e4f2907ec8] vfs_read at ffffffff98d657d1
 #16 [ffffb9e4f2907f00] ksys_read at ffffffff98d65c3f
 #17 [ffffb9e4f2907f38] do_syscall_64 at ffffffff98a052fb

 crash> struct net_device.state ffff9a9d21336000
    state = 5,

state 5 is __LINK_STATE_START (0b1) and __LINK_STATE_NOCARRIER (0b100).
The device is not present, note lack of __LINK_STATE_PRESENT (0b10).

This is the same sort of panic as observed in commit 4224cfd
("net-sysfs: add check for netdevice being present to speed_show").

There are many other callers of __ethtool_get_link_ksettings() which
don't have a device presence check.

Move this check into ethtool to protect all callers.

Fixes: d519e17 ("net: export device speed and duplex via sysfs")
Fixes: 4224cfd ("net-sysfs: add check for netdevice being present to speed_show")
Signed-off-by: Jamie Bainbridge <[email protected]>
Link: https://patch.msgid.link/8bae218864beaa44ed01628140475b9bf641c5b0.1724393671.git.jamie.bainbridge@gmail.com
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
frank-w pushed a commit that referenced this issue Sep 14, 2024
[ Upstream commit 54624ac ]

The test thread will start N benchmark kthreads and then schedule out
until the test time finished and notify the benchmark kthreads to stop.
The benchmark kthreads will keep running until notified to stop.
There's a problem with current implementation when the benchmark
kthreads number is equal to the CPUs on a non-preemptible kernel:
since the scheduler will balance the kthreads across the CPUs and
when the test time's out the test thread won't get a chance to be
scheduled on any CPU then cannot notify the benchmark kthreads to stop.

This can be easily reproduced on a VM (simulated with 16 CPUs) with
PREEMPT_VOLUNTARY:
estuary:/mnt$ ./dma_map_benchmark -t 16 -s 1
 rcu: INFO: rcu_sched self-detected stall on CPU
 rcu:     10-...!: (5221 ticks this GP) idle=ed24/1/0x4000000000000000 softirq=142/142 fqs=0
 rcu:     (t=5254 jiffies g=-559 q=45 ncpus=16)
 rcu: rcu_sched kthread starved for 5255 jiffies! g-559 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=12
 rcu:     Unless rcu_sched kthread gets sufficient CPU time, OOM is now expected behavior.
 rcu: RCU grace-period kthread stack dump:
 task:rcu_sched       state:R  running task     stack:0     pid:16    tgid:16    ppid:2      flags:0x00000008
 Call trace
  __switch_to+0xec/0x138
  __schedule+0x2f8/0x1080
  schedule+0x30/0x130
  schedule_timeout+0xa0/0x188
  rcu_gp_fqs_loop+0x128/0x528
  rcu_gp_kthread+0x1c8/0x208
  kthread+0xec/0xf8
  ret_from_fork+0x10/0x20
 Sending NMI from CPU 10 to CPUs 0:
 NMI backtrace for cpu 0
 CPU: 0 PID: 332 Comm: dma-map-benchma Not tainted 6.10.0-rc1-vanilla-LSE #8
 Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
 pstate: 20400005 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 pc : arm_smmu_cmdq_issue_cmdlist+0x218/0x730
 lr : arm_smmu_cmdq_issue_cmdlist+0x488/0x730
 sp : ffff80008748b630
 x29: ffff80008748b630 x28: 0000000000000000 x27: ffff80008748b780
 x26: 0000000000000000 x25: 000000000000bc70 x24: 000000000001bc70
 x23: ffff0000c12af080 x22: 0000000000010000 x21: 000000000000ffff
 x20: ffff80008748b700 x19: ffff0000c12af0c0 x18: 0000000000010000
 x17: 0000000000000001 x16: 0000000000000040 x15: ffffffffffffffff
 x14: 0001ffffffffffff x13: 000000000000ffff x12: 00000000000002f1
 x11: 000000000001ffff x10: 0000000000000031 x9 : ffff800080b6b0b8
 x8 : ffff0000c2a48000 x7 : 000000000001bc71 x6 : 0001800000000000
 x5 : 00000000000002f1 x4 : 01ffffffffffffff x3 : 000000000009aaf1
 x2 : 0000000000000018 x1 : 000000000000000f x0 : ffff0000c12af18c
 Call trace:
  arm_smmu_cmdq_issue_cmdlist+0x218/0x730
  __arm_smmu_tlb_inv_range+0xe0/0x1a8
  arm_smmu_iotlb_sync+0xc0/0x128
  __iommu_dma_unmap+0x248/0x320
  iommu_dma_unmap_page+0x5c/0xe8
  dma_unmap_page_attrs+0x38/0x1d0
  map_benchmark_thread+0x118/0x2c0
  kthread+0xec/0xf8
  ret_from_fork+0x10/0x20

Solve this by adding scheduling point in the kthread loop,
so if there're other threads in the system they may have
a chance to run, especially the thread to notify the test
end. However this may degrade the test concurrency so it's
recommended to run this on an idle system.

Signed-off-by: Yicong Yang <[email protected]>
Acked-by: Barry Song <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
frank-w pushed a commit that referenced this issue Sep 23, 2024
iter_finish_branch_entry() doesn't put the branch_info from/to map
elements creating memory leaks. This can be seen with:

```
$ perf record -e cycles -b perf test -w noploop
$ perf report -D
...
Direct leak of 984344 byte(s) in 123043 object(s) allocated from:
    #0 0x7fb2654f3bd7 in malloc libsanitizer/asan/asan_malloc_linux.cpp:69
    #1 0x564d3400d10b in map__get util/map.h:186
    #2 0x564d3400d10b in ip__resolve_ams util/machine.c:1981
    #3 0x564d34014d81 in sample__resolve_bstack util/machine.c:2151
    #4 0x564d34094790 in iter_prepare_branch_entry util/hist.c:898
    #5 0x564d34098fa4 in hist_entry_iter__add util/hist.c:1238
    #6 0x564d33d1f0c7 in process_sample_event tools/perf/builtin-report.c:334
    #7 0x564d34031eb7 in perf_session__deliver_event util/session.c:1655
    #8 0x564d3403ba52 in do_flush util/ordered-events.c:245
    #9 0x564d3403ba52 in __ordered_events__flush util/ordered-events.c:324
    #10 0x564d3402d32e in perf_session__process_user_event util/session.c:1708
    #11 0x564d34032480 in perf_session__process_event util/session.c:1877
    #12 0x564d340336ad in reader__read_event util/session.c:2399
    #13 0x564d34033fdc in reader__process_events util/session.c:2448
    #14 0x564d34033fdc in __perf_session__process_events util/session.c:2495
    #15 0x564d34033fdc in perf_session__process_events util/session.c:2661
    #16 0x564d33d27113 in __cmd_report tools/perf/builtin-report.c:1065
    #17 0x564d33d27113 in cmd_report tools/perf/builtin-report.c:1805
    #18 0x564d33e0ccb7 in run_builtin tools/perf/perf.c:350
    #19 0x564d33e0d45e in handle_internal_command tools/perf/perf.c:403
    #20 0x564d33cdd827 in run_argv tools/perf/perf.c:447
    #21 0x564d33cdd827 in main tools/perf/perf.c:561
...
```

Clearing up the map_symbols properly creates maps reference count
issues so resolve those. Resolving this issue doesn't improve peak
heap consumption for the test above.

Committer testing:

  $ sudo dnf install libasan
  $ make -k CORESIGHT=1 EXTRA_CFLAGS="-fsanitize=address" CC=clang O=/tmp/build/$(basename $PWD)/ -C tools/perf install-bin

Reviewed-by: Kan Liang <[email protected]>
Signed-off-by: Ian Rogers <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Sun Haiyong <[email protected]>
Cc: Yanteng Si <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
frank-w pushed a commit that referenced this issue Sep 23, 2024
AddressSanitizer found a use-after-free bug in the symbol code which
manifested as 'perf top' segfaulting.

  ==1238389==ERROR: AddressSanitizer: heap-use-after-free on address 0x60b00c48844b at pc 0x5650d8035961 bp 0x7f751aaecc90 sp 0x7f751aaecc80
  READ of size 1 at 0x60b00c48844b thread T193
      #0 0x5650d8035960 in _sort__sym_cmp util/sort.c:310
      #1 0x5650d8043744 in hist_entry__cmp util/hist.c:1286
      #2 0x5650d8043951 in hists__findnew_entry util/hist.c:614
      #3 0x5650d804568f in __hists__add_entry util/hist.c:754
      #4 0x5650d8045bf9 in hists__add_entry util/hist.c:772
      #5 0x5650d8045df1 in iter_add_single_normal_entry util/hist.c:997
      #6 0x5650d8043326 in hist_entry_iter__add util/hist.c:1242
      #7 0x5650d7ceeefe in perf_event__process_sample /home/matt/src/linux/tools/perf/builtin-top.c:845
      #8 0x5650d7ceeefe in deliver_event /home/matt/src/linux/tools/perf/builtin-top.c:1208
      #9 0x5650d7fdb51b in do_flush util/ordered-events.c:245
      #10 0x5650d7fdb51b in __ordered_events__flush util/ordered-events.c:324
      #11 0x5650d7ced743 in process_thread /home/matt/src/linux/tools/perf/builtin-top.c:1120
      #12 0x7f757ef1f133 in start_thread nptl/pthread_create.c:442
      #13 0x7f757ef9f7db in clone3 ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81

When updating hist maps it's also necessary to update the hist symbol
reference because the old one gets freed in map__put().

While this bug was probably introduced with 5c24b67 ("perf
tools: Replace map->referenced & maps->removed_maps with map->refcnt"),
the symbol objects were leaked until c087e94 ("perf machine:
Fix refcount usage when processing PERF_RECORD_KSYMBOL") was merged so
the bug was masked.

Fixes: c087e94 ("perf machine: Fix refcount usage when processing PERF_RECORD_KSYMBOL")
Reported-by: Yunzhao Li <[email protected]>
Signed-off-by: Matt Fleming (Cloudflare) <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: [email protected]
Cc: Namhyung Kim <[email protected]>
Cc: Riccardo Mancini <[email protected]>
Cc: [email protected] # v5.13+
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
frank-w pushed a commit that referenced this issue Sep 23, 2024
Eduard Zingerman says:

====================
__jited test tag to check disassembly after jit

Some of the logic in the BPF jits might be non-trivial.
It might be useful to allow testing this logic by comparing
generated native code with expected code template.
This patch set adds a macro __jited() that could be used for
test_loader based tests in a following manner:

    SEC("tp")
    __arch_x86_64
    __jited("   endbr64")
    __jited("   nopl    (%rax,%rax)")
    __jited("   xorq    %rax, %rax")
    ...
    __naked void some_test(void) { ... }

Also add a test for jit code generated for tail calls handling to
demonstrate the feature.

The feature uses LLVM libraries to do the disassembly.
At selftests compilation time Makefile detects if these libraries are
available. When libraries are not available tests using __jit_x86()
are skipped.
Current CI environment does not include llvm development libraries,
but changes to add these are trivial.

This was previously discussed here:
https://lore.kernel.org/bpf/[email protected]/

Patch-set includes a few auxiliary steps:
- patches #2 and #3 fix a few bugs in test_loader behaviour;
- patch #4 replaces __regex macro with ability to specify regular
  expressions in __msg and __xlated using "{{" "}}" escapes;
- patch #8 updates __xlated to match disassembly lines consequently,
  same way as __jited does.

Changes v2->v3:
- changed macro name from __jit_x86 to __jited with __arch_* to
  specify disassembly arch (Yonghong);
- __jited matches disassembly lines consequently with "..."
  allowing to skip some number of lines (Andrii);
- __xlated matches disassembly lines consequently, same as __jited;
- "{{...}}" regex brackets instead of __regex macro;
- bug fixes for old commits.

Changes v1->v2:
- stylistic changes suggested by Yonghong;
- fix for -Wformat-truncation related warning when compiled with
  llvm15 (Yonghong).

v1: https://lore.kernel.org/bpf/[email protected]/
v2: https://lore.kernel.org/bpf/[email protected]/
====================

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
frank-w pushed a commit that referenced this issue Sep 23, 2024
The fields in the hist_entry are filled on-demand which means they only
have meaningful values when relevant sort keys are used.

So if neither of 'dso' nor 'sym' sort keys are used, the map/symbols in
the hist entry can be garbage.  So it shouldn't access it
unconditionally.

I got a segfault, when I wanted to see cgroup profiles.

  $ sudo perf record -a --all-cgroups --synth=cgroup true

  $ sudo perf report -s cgroup

  Program received signal SIGSEGV, Segmentation fault.
  0x00005555557a8d90 in map__dso (map=0x0) at util/map.h:48
  48		return RC_CHK_ACCESS(map)->dso;
  (gdb) bt
  #0  0x00005555557a8d90 in map__dso (map=0x0) at util/map.h:48
  #1  0x00005555557aa39b in map__load (map=0x0) at util/map.c:344
  #2  0x00005555557aa592 in map__find_symbol (map=0x0, addr=140736115941088) at util/map.c:385
  #3  0x00005555557ef000 in hists__findnew_entry (hists=0x555556039d60, entry=0x7fffffffa4c0, al=0x7fffffffa8c0, sample_self=true)
      at util/hist.c:644
  #4  0x00005555557ef61c in __hists__add_entry (hists=0x555556039d60, al=0x7fffffffa8c0, sym_parent=0x0, bi=0x0, mi=0x0, ki=0x0,
      block_info=0x0, sample=0x7fffffffaa90, sample_self=true, ops=0x0) at util/hist.c:761
  #5  0x00005555557ef71f in hists__add_entry (hists=0x555556039d60, al=0x7fffffffa8c0, sym_parent=0x0, bi=0x0, mi=0x0, ki=0x0,
      sample=0x7fffffffaa90, sample_self=true) at util/hist.c:779
  #6  0x00005555557f00fb in iter_add_single_normal_entry (iter=0x7fffffffa900, al=0x7fffffffa8c0) at util/hist.c:1015
  #7  0x00005555557f09a7 in hist_entry_iter__add (iter=0x7fffffffa900, al=0x7fffffffa8c0, max_stack_depth=127, arg=0x7fffffffbce0)
      at util/hist.c:1260
  #8  0x00005555555ba7ce in process_sample_event (tool=0x7fffffffbce0, event=0x7ffff7c14128, sample=0x7fffffffaa90, evsel=0x555556039ad0,
      machine=0x5555560388e8) at builtin-report.c:334
  #9  0x00005555557b30c8 in evlist__deliver_sample (evlist=0x555556039010, tool=0x7fffffffbce0, event=0x7ffff7c14128,
      sample=0x7fffffffaa90, evsel=0x555556039ad0, machine=0x5555560388e8) at util/session.c:1232
  #10 0x00005555557b32bc in machines__deliver_event (machines=0x5555560388e8, evlist=0x555556039010, event=0x7ffff7c14128,
      sample=0x7fffffffaa90, tool=0x7fffffffbce0, file_offset=110888, file_path=0x555556038ff0 "perf.data") at util/session.c:1271
  #11 0x00005555557b3848 in perf_session__deliver_event (session=0x5555560386d0, event=0x7ffff7c14128, tool=0x7fffffffbce0,
      file_offset=110888, file_path=0x555556038ff0 "perf.data") at util/session.c:1354
  #12 0x00005555557affaf in ordered_events__deliver_event (oe=0x555556038e60, event=0x555556135aa0) at util/session.c:132
  #13 0x00005555557bb605 in do_flush (oe=0x555556038e60, show_progress=false) at util/ordered-events.c:245
  #14 0x00005555557bb95c in __ordered_events__flush (oe=0x555556038e60, how=OE_FLUSH__ROUND, timestamp=0) at util/ordered-events.c:324
  #15 0x00005555557bba46 in ordered_events__flush (oe=0x555556038e60, how=OE_FLUSH__ROUND) at util/ordered-events.c:342
  #16 0x00005555557b1b3b in perf_event__process_finished_round (tool=0x7fffffffbce0, event=0x7ffff7c15bb8, oe=0x555556038e60)
      at util/session.c:780
  #17 0x00005555557b3b27 in perf_session__process_user_event (session=0x5555560386d0, event=0x7ffff7c15bb8, file_offset=117688,
      file_path=0x555556038ff0 "perf.data") at util/session.c:1406

As you can see the entry->ms.map was NULL even if he->ms.map has a
value.  This is because 'sym' sort key is not given, so it cannot assume
whether he->ms.sym and entry->ms.sym is the same.  I only checked the
'sym' sort key here as it implies 'dso' behavior (so maps are the same).

Fixes: ac01c8c ("perf hist: Update hist symbol when updating maps")
Signed-off-by: Namhyung Kim <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Matt Fleming <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
frank-w pushed a commit that referenced this issue Sep 30, 2024
Use a dedicated mutex to guard kvm_usage_count to fix a potential deadlock
on x86 due to a chain of locks and SRCU synchronizations.  Translating the
below lockdep splat, CPU1 #6 will wait on CPU0 #1, CPU0 #8 will wait on
CPU2 #3, and CPU2 #7 will wait on CPU1 #4 (if there's a writer, due to the
fairness of r/w semaphores).

    CPU0                     CPU1                     CPU2
1   lock(&kvm->slots_lock);
2                                                     lock(&vcpu->mutex);
3                                                     lock(&kvm->srcu);
4                            lock(cpu_hotplug_lock);
5                            lock(kvm_lock);
6                            lock(&kvm->slots_lock);
7                                                     lock(cpu_hotplug_lock);
8   sync(&kvm->srcu);

Note, there are likely more potential deadlocks in KVM x86, e.g. the same
pattern of taking cpu_hotplug_lock outside of kvm_lock likely exists with
__kvmclock_cpufreq_notifier():

  cpuhp_cpufreq_online()
  |
  -> cpufreq_online()
     |
     -> cpufreq_gov_performance_limits()
        |
        -> __cpufreq_driver_target()
           |
           -> __target_index()
              |
              -> cpufreq_freq_transition_begin()
                 |
                 -> cpufreq_notify_transition()
                    |
                    -> ... __kvmclock_cpufreq_notifier()

But, actually triggering such deadlocks is beyond rare due to the
combination of dependencies and timings involved.  E.g. the cpufreq
notifier is only used on older CPUs without a constant TSC, mucking with
the NX hugepage mitigation while VMs are running is very uncommon, and
doing so while also onlining/offlining a CPU (necessary to generate
contention on cpu_hotplug_lock) would be even more unusual.

The most robust solution to the general cpu_hotplug_lock issue is likely
to switch vm_list to be an RCU-protected list, e.g. so that x86's cpufreq
notifier doesn't to take kvm_lock.  For now, settle for fixing the most
blatant deadlock, as switching to an RCU-protected list is a much more
involved change, but add a comment in locking.rst to call out that care
needs to be taken when walking holding kvm_lock and walking vm_list.

  ======================================================
  WARNING: possible circular locking dependency detected
  6.10.0-smp--c257535a0c9d-pip #330 Tainted: G S         O
  ------------------------------------------------------
  tee/35048 is trying to acquire lock:
  ff6a80eced71e0a8 (&kvm->slots_lock){+.+.}-{3:3}, at: set_nx_huge_pages+0x179/0x1e0 [kvm]

  but task is already holding lock:
  ffffffffc07abb08 (kvm_lock){+.+.}-{3:3}, at: set_nx_huge_pages+0x14a/0x1e0 [kvm]

  which lock already depends on the new lock.

   the existing dependency chain (in reverse order) is:

  -> #3 (kvm_lock){+.+.}-{3:3}:
         __mutex_lock+0x6a/0xb40
         mutex_lock_nested+0x1f/0x30
         kvm_dev_ioctl+0x4fb/0xe50 [kvm]
         __se_sys_ioctl+0x7b/0xd0
         __x64_sys_ioctl+0x21/0x30
         x64_sys_call+0x15d0/0x2e60
         do_syscall_64+0x83/0x160
         entry_SYSCALL_64_after_hwframe+0x76/0x7e

  -> #2 (cpu_hotplug_lock){++++}-{0:0}:
         cpus_read_lock+0x2e/0xb0
         static_key_slow_inc+0x16/0x30
         kvm_lapic_set_base+0x6a/0x1c0 [kvm]
         kvm_set_apic_base+0x8f/0xe0 [kvm]
         kvm_set_msr_common+0x9ae/0xf80 [kvm]
         vmx_set_msr+0xa54/0xbe0 [kvm_intel]
         __kvm_set_msr+0xb6/0x1a0 [kvm]
         kvm_arch_vcpu_ioctl+0xeca/0x10c0 [kvm]
         kvm_vcpu_ioctl+0x485/0x5b0 [kvm]
         __se_sys_ioctl+0x7b/0xd0
         __x64_sys_ioctl+0x21/0x30
         x64_sys_call+0x15d0/0x2e60
         do_syscall_64+0x83/0x160
         entry_SYSCALL_64_after_hwframe+0x76/0x7e

  -> #1 (&kvm->srcu){.+.+}-{0:0}:
         __synchronize_srcu+0x44/0x1a0
         synchronize_srcu_expedited+0x21/0x30
         kvm_swap_active_memslots+0x110/0x1c0 [kvm]
         kvm_set_memslot+0x360/0x620 [kvm]
         __kvm_set_memory_region+0x27b/0x300 [kvm]
         kvm_vm_ioctl_set_memory_region+0x43/0x60 [kvm]
         kvm_vm_ioctl+0x295/0x650 [kvm]
         __se_sys_ioctl+0x7b/0xd0
         __x64_sys_ioctl+0x21/0x30
         x64_sys_call+0x15d0/0x2e60
         do_syscall_64+0x83/0x160
         entry_SYSCALL_64_after_hwframe+0x76/0x7e

  -> #0 (&kvm->slots_lock){+.+.}-{3:3}:
         __lock_acquire+0x15ef/0x2e30
         lock_acquire+0xe0/0x260
         __mutex_lock+0x6a/0xb40
         mutex_lock_nested+0x1f/0x30
         set_nx_huge_pages+0x179/0x1e0 [kvm]
         param_attr_store+0x93/0x100
         module_attr_store+0x22/0x40
         sysfs_kf_write+0x81/0xb0
         kernfs_fop_write_iter+0x133/0x1d0
         vfs_write+0x28d/0x380
         ksys_write+0x70/0xe0
         __x64_sys_write+0x1f/0x30
         x64_sys_call+0x281b/0x2e60
         do_syscall_64+0x83/0x160
         entry_SYSCALL_64_after_hwframe+0x76/0x7e

Cc: Chao Gao <[email protected]>
Fixes: 0bf5049 ("KVM: Drop kvm_count_lock and instead protect kvm_usage_count with kvm_lock")
Cc: [email protected]
Reviewed-by: Kai Huang <[email protected]>
Acked-by: Kai Huang <[email protected]>
Tested-by: Farrah Chen <[email protected]>
Signed-off-by: Sean Christopherson <[email protected]>
Message-ID: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>
BtbN pushed a commit to BtbN/BPI-Router-Linux that referenced this issue Oct 4, 2024
commit 44d1745 upstream.

Use a dedicated mutex to guard kvm_usage_count to fix a potential deadlock
on x86 due to a chain of locks and SRCU synchronizations.  Translating the
below lockdep splat, CPU1 frank-w#6 will wait on CPU0 frank-w#1, CPU0 frank-w#8 will wait on
CPU2 frank-w#3, and CPU2 frank-w#7 will wait on CPU1 frank-w#4 (if there's a writer, due to the
fairness of r/w semaphores).

    CPU0                     CPU1                     CPU2
1   lock(&kvm->slots_lock);
2                                                     lock(&vcpu->mutex);
3                                                     lock(&kvm->srcu);
4                            lock(cpu_hotplug_lock);
5                            lock(kvm_lock);
6                            lock(&kvm->slots_lock);
7                                                     lock(cpu_hotplug_lock);
8   sync(&kvm->srcu);

Note, there are likely more potential deadlocks in KVM x86, e.g. the same
pattern of taking cpu_hotplug_lock outside of kvm_lock likely exists with
__kvmclock_cpufreq_notifier():

  cpuhp_cpufreq_online()
  |
  -> cpufreq_online()
     |
     -> cpufreq_gov_performance_limits()
        |
        -> __cpufreq_driver_target()
           |
           -> __target_index()
              |
              -> cpufreq_freq_transition_begin()
                 |
                 -> cpufreq_notify_transition()
                    |
                    -> ... __kvmclock_cpufreq_notifier()

But, actually triggering such deadlocks is beyond rare due to the
combination of dependencies and timings involved.  E.g. the cpufreq
notifier is only used on older CPUs without a constant TSC, mucking with
the NX hugepage mitigation while VMs are running is very uncommon, and
doing so while also onlining/offlining a CPU (necessary to generate
contention on cpu_hotplug_lock) would be even more unusual.

The most robust solution to the general cpu_hotplug_lock issue is likely
to switch vm_list to be an RCU-protected list, e.g. so that x86's cpufreq
notifier doesn't to take kvm_lock.  For now, settle for fixing the most
blatant deadlock, as switching to an RCU-protected list is a much more
involved change, but add a comment in locking.rst to call out that care
needs to be taken when walking holding kvm_lock and walking vm_list.

  ======================================================
  WARNING: possible circular locking dependency detected
  6.10.0-smp--c257535a0c9d-pip #330 Tainted: G S         O
  ------------------------------------------------------
  tee/35048 is trying to acquire lock:
  ff6a80eced71e0a8 (&kvm->slots_lock){+.+.}-{3:3}, at: set_nx_huge_pages+0x179/0x1e0 [kvm]

  but task is already holding lock:
  ffffffffc07abb08 (kvm_lock){+.+.}-{3:3}, at: set_nx_huge_pages+0x14a/0x1e0 [kvm]

  which lock already depends on the new lock.

   the existing dependency chain (in reverse order) is:

  -> frank-w#3 (kvm_lock){+.+.}-{3:3}:
         __mutex_lock+0x6a/0xb40
         mutex_lock_nested+0x1f/0x30
         kvm_dev_ioctl+0x4fb/0xe50 [kvm]
         __se_sys_ioctl+0x7b/0xd0
         __x64_sys_ioctl+0x21/0x30
         x64_sys_call+0x15d0/0x2e60
         do_syscall_64+0x83/0x160
         entry_SYSCALL_64_after_hwframe+0x76/0x7e

  -> frank-w#2 (cpu_hotplug_lock){++++}-{0:0}:
         cpus_read_lock+0x2e/0xb0
         static_key_slow_inc+0x16/0x30
         kvm_lapic_set_base+0x6a/0x1c0 [kvm]
         kvm_set_apic_base+0x8f/0xe0 [kvm]
         kvm_set_msr_common+0x9ae/0xf80 [kvm]
         vmx_set_msr+0xa54/0xbe0 [kvm_intel]
         __kvm_set_msr+0xb6/0x1a0 [kvm]
         kvm_arch_vcpu_ioctl+0xeca/0x10c0 [kvm]
         kvm_vcpu_ioctl+0x485/0x5b0 [kvm]
         __se_sys_ioctl+0x7b/0xd0
         __x64_sys_ioctl+0x21/0x30
         x64_sys_call+0x15d0/0x2e60
         do_syscall_64+0x83/0x160
         entry_SYSCALL_64_after_hwframe+0x76/0x7e

  -> frank-w#1 (&kvm->srcu){.+.+}-{0:0}:
         __synchronize_srcu+0x44/0x1a0
         synchronize_srcu_expedited+0x21/0x30
         kvm_swap_active_memslots+0x110/0x1c0 [kvm]
         kvm_set_memslot+0x360/0x620 [kvm]
         __kvm_set_memory_region+0x27b/0x300 [kvm]
         kvm_vm_ioctl_set_memory_region+0x43/0x60 [kvm]
         kvm_vm_ioctl+0x295/0x650 [kvm]
         __se_sys_ioctl+0x7b/0xd0
         __x64_sys_ioctl+0x21/0x30
         x64_sys_call+0x15d0/0x2e60
         do_syscall_64+0x83/0x160
         entry_SYSCALL_64_after_hwframe+0x76/0x7e

  -> #0 (&kvm->slots_lock){+.+.}-{3:3}:
         __lock_acquire+0x15ef/0x2e30
         lock_acquire+0xe0/0x260
         __mutex_lock+0x6a/0xb40
         mutex_lock_nested+0x1f/0x30
         set_nx_huge_pages+0x179/0x1e0 [kvm]
         param_attr_store+0x93/0x100
         module_attr_store+0x22/0x40
         sysfs_kf_write+0x81/0xb0
         kernfs_fop_write_iter+0x133/0x1d0
         vfs_write+0x28d/0x380
         ksys_write+0x70/0xe0
         __x64_sys_write+0x1f/0x30
         x64_sys_call+0x281b/0x2e60
         do_syscall_64+0x83/0x160
         entry_SYSCALL_64_after_hwframe+0x76/0x7e

Cc: Chao Gao <[email protected]>
Fixes: 0bf5049 ("KVM: Drop kvm_count_lock and instead protect kvm_usage_count with kvm_lock")
Cc: [email protected]
Reviewed-by: Kai Huang <[email protected]>
Acked-by: Kai Huang <[email protected]>
Tested-by: Farrah Chen <[email protected]>
Signed-off-by: Sean Christopherson <[email protected]>
Message-ID: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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