Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Add DTS for Fujitsu M532 (chagall) #3

Closed
wants to merge 2 commits into from
Closed

Add DTS for Fujitsu M532 (chagall) #3

wants to merge 2 commits into from

Conversation

cunidev
Copy link

@cunidev cunidev commented Mar 9, 2020

Still WiP, although several things (USB, LCD panel, backlight, keys) already work. Forked from the Asus TF300T DTS

Still WiP, although several things (USB, LCD panel, backlight, keys) already work. Forked from the Asus TF300T DTS
@cunidev cunidev closed this Mar 9, 2020
okias pushed a commit that referenced this pull request Mar 11, 2020
Downstream kernel of ASUS TF300T sets r0 to #3. Unfortunately there is no
explanation in downstream code whether this is really needed. Some of T30
downstream kernels have and explicit comment that all arguments are
ignored by firmware. Let's take the safe side and replicate behaviour of
the TF300T downstream kernel.

Tested-by: Peter Geis <[email protected]>
Signed-off-by: Dmitry Osipenko <[email protected]>
okias pushed a commit that referenced this pull request Mar 14, 2020
Downstream kernel of ASUS TF300T sets r0 to #3. Unfortunately there is no
explanation in downstream code whether this is really needed. Some of T30
downstream kernels have and explicit comment that all arguments are
ignored by firmware. Let's take the safe side and replicate behaviour of
the TF300T downstream kernel.

Tested-by: Peter Geis <[email protected]>
Signed-off-by: Dmitry Osipenko <[email protected]>
okias pushed a commit that referenced this pull request Mar 19, 2020
Downstream kernel of ASUS TF300T sets r0 to #3. Unfortunately there is no
explanation in downstream code whether this is really needed. Some of T30
downstream kernels have and explicit comment that all arguments are
ignored by firmware. Let's take the safe side and replicate behaviour of
the TF300T downstream kernel.

Tested-by: Peter Geis <[email protected]>
Signed-off-by: Dmitry Osipenko <[email protected]>
okias pushed a commit that referenced this pull request Mar 21, 2020
swap_info_struct si.highest_bit, si.swap_map[offset] and si.flags could
be accessed concurrently separately as noticed by KCSAN,

=== si.highest_bit ===

 write to 0xffff8d5abccdc4d4 of 4 bytes by task 5353 on cpu 24:
  swap_range_alloc+0x81/0x130
  swap_range_alloc at mm/swapfile.c:681
  scan_swap_map_slots+0x371/0xb90
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0xf2/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1795/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

 read to 0xffff8d5abccdc4d4 of 4 bytes by task 6672 on cpu 70:
  scan_swap_map_slots+0x4a6/0xb90
  scan_swap_map_slots at mm/swapfile.c:892
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0xf2/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1795/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 70 PID: 6672 Comm: oom01 Tainted: G        W    L 5.5.0-next-20200205+ #3
 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019

=== si.swap_map[offset] ===

 write to 0xffffbc370c29a64c of 1 bytes by task 6856 on cpu 86:
  __swap_entry_free_locked+0x8c/0x100
  __swap_entry_free_locked at mm/swapfile.c:1209 (discriminator 4)
  __swap_entry_free.constprop.20+0x69/0xb0
  free_swap_and_cache+0x53/0xa0
  unmap_page_range+0x7f8/0x1d70
  unmap_single_vma+0xcd/0x170
  unmap_vmas+0x18b/0x220
  exit_mmap+0xee/0x220
  mmput+0x10e/0x270
  do_exit+0x59b/0xf40
  do_group_exit+0x8b/0x180

 read to 0xffffbc370c29a64c of 1 bytes by task 6855 on cpu 20:
  _swap_info_get+0x81/0xa0
  _swap_info_get at mm/swapfile.c:1140
  free_swap_and_cache+0x40/0xa0
  unmap_page_range+0x7f8/0x1d70
  unmap_single_vma+0xcd/0x170
  unmap_vmas+0x18b/0x220
  exit_mmap+0xee/0x220
  mmput+0x10e/0x270
  do_exit+0x59b/0xf40
  do_group_exit+0x8b/0x180

=== si.flags ===

 write to 0xffff956c8fc6c400 of 8 bytes by task 6087 on cpu 23:
  scan_swap_map_slots+0x6fe/0xb50
  scan_swap_map_slots at mm/swapfile.c:887
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0x377/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1795/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

 read to 0xffff956c8fc6c400 of 8 bytes by task 6207 on cpu 63:
  _swap_info_get+0x41/0xa0
  __swap_info_get at mm/swapfile.c:1114
  put_swap_page+0x84/0x490
  __remove_mapping+0x384/0x5f0
  shrink_page_list+0xff1/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

The writes are under si->lock but the reads are not. For si.highest_bit
and si.swap_map[offset], data race could trigger logic bugs, so fix them
by having WRITE_ONCE() for the writes and READ_ONCE() for the reads
except those isolated reads where they compare against zero which a data
race would cause no harm. Thus, annotate them as intentional data races
using the data_race() macro.

For si.flags, the readers are only interested in a single bit where a
data race there would cause no issue there.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Qian Cai <[email protected]>
Cc: Marco Elver <[email protected]>
Cc: Hugh Dickins <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Stephen Rothwell <[email protected]>
okias pushed a commit that referenced this pull request Apr 23, 2020
swap_info_struct si.highest_bit, si.swap_map[offset] and si.flags could
be accessed concurrently separately as noticed by KCSAN,

=== si.highest_bit ===

 write to 0xffff8d5abccdc4d4 of 4 bytes by task 5353 on cpu 24:
  swap_range_alloc+0x81/0x130
  swap_range_alloc at mm/swapfile.c:681
  scan_swap_map_slots+0x371/0xb90
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0xf2/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1795/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

 read to 0xffff8d5abccdc4d4 of 4 bytes by task 6672 on cpu 70:
  scan_swap_map_slots+0x4a6/0xb90
  scan_swap_map_slots at mm/swapfile.c:892
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0xf2/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1795/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 70 PID: 6672 Comm: oom01 Tainted: G        W    L 5.5.0-next-20200205+ #3
 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019

=== si.swap_map[offset] ===

 write to 0xffffbc370c29a64c of 1 bytes by task 6856 on cpu 86:
  __swap_entry_free_locked+0x8c/0x100
  __swap_entry_free_locked at mm/swapfile.c:1209 (discriminator 4)
  __swap_entry_free.constprop.20+0x69/0xb0
  free_swap_and_cache+0x53/0xa0
  unmap_page_range+0x7f8/0x1d70
  unmap_single_vma+0xcd/0x170
  unmap_vmas+0x18b/0x220
  exit_mmap+0xee/0x220
  mmput+0x10e/0x270
  do_exit+0x59b/0xf40
  do_group_exit+0x8b/0x180

 read to 0xffffbc370c29a64c of 1 bytes by task 6855 on cpu 20:
  _swap_info_get+0x81/0xa0
  _swap_info_get at mm/swapfile.c:1140
  free_swap_and_cache+0x40/0xa0
  unmap_page_range+0x7f8/0x1d70
  unmap_single_vma+0xcd/0x170
  unmap_vmas+0x18b/0x220
  exit_mmap+0xee/0x220
  mmput+0x10e/0x270
  do_exit+0x59b/0xf40
  do_group_exit+0x8b/0x180

=== si.flags ===

 write to 0xffff956c8fc6c400 of 8 bytes by task 6087 on cpu 23:
  scan_swap_map_slots+0x6fe/0xb50
  scan_swap_map_slots at mm/swapfile.c:887
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0x377/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1795/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

 read to 0xffff956c8fc6c400 of 8 bytes by task 6207 on cpu 63:
  _swap_info_get+0x41/0xa0
  __swap_info_get at mm/swapfile.c:1114
  put_swap_page+0x84/0x490
  __remove_mapping+0x384/0x5f0
  shrink_page_list+0xff1/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

The writes are under si->lock but the reads are not. For si.highest_bit
and si.swap_map[offset], data race could trigger logic bugs, so fix them
by having WRITE_ONCE() for the writes and READ_ONCE() for the reads
except those isolated reads where they compare against zero which a data
race would cause no harm. Thus, annotate them as intentional data races
using the data_race() macro.

For si.flags, the readers are only interested in a single bit where a
data race there would cause no issue there.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Qian Cai <[email protected]>
Cc: Marco Elver <[email protected]>
Cc: Hugh Dickins <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Stephen Rothwell <[email protected]>
okias pushed a commit that referenced this pull request Apr 23, 2020
Downstream kernel of ASUS TF300T sets r0 to #3. There is no explanation in
downstream code whether this is really needed and some of T30 downstream
kernels have and explicit comment telling that all arguments are ignored
by firmware. Let's take a safe side by replicating behavior of the TF300T
downstream kernel. This change works fine on Ouya and Nexus 7 devices.

Tested-by: Michał Mirosław <[email protected]>
Tested-by: Jasper Korten <[email protected]>
Tested-by: David Heidelberg <[email protected]>
Tested-by: Peter Geis <[email protected]>
Signed-off-by: Dmitry Osipenko <[email protected]>
okias pushed a commit that referenced this pull request May 2, 2020
…f fs_info::journal_info

[BUG]
One run of btrfs/063 triggered the following lockdep warning:
  ============================================
  WARNING: possible recursive locking detected
  5.6.0-rc7-custom+ grate-driver#48 Not tainted
  --------------------------------------------
  kworker/u24:0/7 is trying to acquire lock:
  ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs]

  but task is already holding lock:
  ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs]

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

         CPU0
         ----
    lock(sb_internal#2);
    lock(sb_internal#2);

   *** DEADLOCK ***

   May be due to missing lock nesting notation

  4 locks held by kworker/u24:0/7:
   #0: ffff88817b495948 ((wq_completion)btrfs-endio-write){+.+.}, at: process_one_work+0x557/0xb80
   #1: ffff888189ea7db8 ((work_completion)(&work->normal_work)){+.+.}, at: process_one_work+0x557/0xb80
   #2: ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs]
   #3: ffff888174ca4da8 (&fs_info->reloc_mutex){+.+.}, at: btrfs_record_root_in_trans+0x83/0xd0 [btrfs]

  stack backtrace:
  CPU: 0 PID: 7 Comm: kworker/u24:0 Not tainted 5.6.0-rc7-custom+ grate-driver#48
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
  Workqueue: btrfs-endio-write btrfs_work_helper [btrfs]
  Call Trace:
   dump_stack+0xc2/0x11a
   __lock_acquire.cold+0xce/0x214
   lock_acquire+0xe6/0x210
   __sb_start_write+0x14e/0x290
   start_transaction+0x66c/0x890 [btrfs]
   btrfs_join_transaction+0x1d/0x20 [btrfs]
   find_free_extent+0x1504/0x1a50 [btrfs]
   btrfs_reserve_extent+0xd5/0x1f0 [btrfs]
   btrfs_alloc_tree_block+0x1ac/0x570 [btrfs]
   btrfs_copy_root+0x213/0x580 [btrfs]
   create_reloc_root+0x3bd/0x470 [btrfs]
   btrfs_init_reloc_root+0x2d2/0x310 [btrfs]
   record_root_in_trans+0x191/0x1d0 [btrfs]
   btrfs_record_root_in_trans+0x90/0xd0 [btrfs]
   start_transaction+0x16e/0x890 [btrfs]
   btrfs_join_transaction+0x1d/0x20 [btrfs]
   btrfs_finish_ordered_io+0x55d/0xcd0 [btrfs]
   finish_ordered_fn+0x15/0x20 [btrfs]
   btrfs_work_helper+0x116/0x9a0 [btrfs]
   process_one_work+0x632/0xb80
   worker_thread+0x80/0x690
   kthread+0x1a3/0x1f0
   ret_from_fork+0x27/0x50

It's pretty hard to reproduce, only one hit so far.

[CAUSE]
This is because we're calling btrfs_join_transaction() without re-using
the current running one:

btrfs_finish_ordered_io()
|- btrfs_join_transaction()		<<< Call #1
   |- btrfs_record_root_in_trans()
      |- btrfs_reserve_extent()
	 |- btrfs_join_transaction()	<<< Call #2

Normally such btrfs_join_transaction() call should re-use the existing
one, without trying to re-start a transaction.

But the problem is, in btrfs_join_transaction() call #1, we call
btrfs_record_root_in_trans() before initializing current::journal_info.

And in btrfs_join_transaction() call #2, we're relying on
current::journal_info to avoid such deadlock.

[FIX]
Call btrfs_record_root_in_trans() after we have initialized
current::journal_info.

CC: [email protected] # 4.4+
Signed-off-by: Qu Wenruo <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
okias pushed a commit that referenced this pull request May 2, 2020
swap_info_struct si.highest_bit, si.swap_map[offset] and si.flags could
be accessed concurrently separately as noticed by KCSAN,

=== si.highest_bit ===

 write to 0xffff8d5abccdc4d4 of 4 bytes by task 5353 on cpu 24:
  swap_range_alloc+0x81/0x130
  swap_range_alloc at mm/swapfile.c:681
  scan_swap_map_slots+0x371/0xb90
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0xf2/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1795/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

 read to 0xffff8d5abccdc4d4 of 4 bytes by task 6672 on cpu 70:
  scan_swap_map_slots+0x4a6/0xb90
  scan_swap_map_slots at mm/swapfile.c:892
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0xf2/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1795/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 70 PID: 6672 Comm: oom01 Tainted: G        W    L 5.5.0-next-20200205+ #3
 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019

=== si.swap_map[offset] ===

 write to 0xffffbc370c29a64c of 1 bytes by task 6856 on cpu 86:
  __swap_entry_free_locked+0x8c/0x100
  __swap_entry_free_locked at mm/swapfile.c:1209 (discriminator 4)
  __swap_entry_free.constprop.20+0x69/0xb0
  free_swap_and_cache+0x53/0xa0
  unmap_page_range+0x7f8/0x1d70
  unmap_single_vma+0xcd/0x170
  unmap_vmas+0x18b/0x220
  exit_mmap+0xee/0x220
  mmput+0x10e/0x270
  do_exit+0x59b/0xf40
  do_group_exit+0x8b/0x180

 read to 0xffffbc370c29a64c of 1 bytes by task 6855 on cpu 20:
  _swap_info_get+0x81/0xa0
  _swap_info_get at mm/swapfile.c:1140
  free_swap_and_cache+0x40/0xa0
  unmap_page_range+0x7f8/0x1d70
  unmap_single_vma+0xcd/0x170
  unmap_vmas+0x18b/0x220
  exit_mmap+0xee/0x220
  mmput+0x10e/0x270
  do_exit+0x59b/0xf40
  do_group_exit+0x8b/0x180

=== si.flags ===

 write to 0xffff956c8fc6c400 of 8 bytes by task 6087 on cpu 23:
  scan_swap_map_slots+0x6fe/0xb50
  scan_swap_map_slots at mm/swapfile.c:887
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0x377/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1795/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

 read to 0xffff956c8fc6c400 of 8 bytes by task 6207 on cpu 63:
  _swap_info_get+0x41/0xa0
  __swap_info_get at mm/swapfile.c:1114
  put_swap_page+0x84/0x490
  __remove_mapping+0x384/0x5f0
  shrink_page_list+0xff1/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

The writes are under si->lock but the reads are not. For si.highest_bit
and si.swap_map[offset], data race could trigger logic bugs, so fix them
by having WRITE_ONCE() for the writes and READ_ONCE() for the reads
except those isolated reads where they compare against zero which a data
race would cause no harm. Thus, annotate them as intentional data races
using the data_race() macro.

For si.flags, the readers are only interested in a single bit where a
data race there would cause no issue there.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Qian Cai <[email protected]>
Cc: Marco Elver <[email protected]>
Cc: Hugh Dickins <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Stephen Rothwell <[email protected]>
okias pushed a commit that referenced this pull request May 11, 2020
swap_info_struct si.highest_bit, si.swap_map[offset] and si.flags could
be accessed concurrently separately as noticed by KCSAN,

=== si.highest_bit ===

 write to 0xffff8d5abccdc4d4 of 4 bytes by task 5353 on cpu 24:
  swap_range_alloc+0x81/0x130
  swap_range_alloc at mm/swapfile.c:681
  scan_swap_map_slots+0x371/0xb90
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0xf2/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1795/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

 read to 0xffff8d5abccdc4d4 of 4 bytes by task 6672 on cpu 70:
  scan_swap_map_slots+0x4a6/0xb90
  scan_swap_map_slots at mm/swapfile.c:892
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0xf2/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1795/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 70 PID: 6672 Comm: oom01 Tainted: G        W    L 5.5.0-next-20200205+ #3
 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019

=== si.swap_map[offset] ===

 write to 0xffffbc370c29a64c of 1 bytes by task 6856 on cpu 86:
  __swap_entry_free_locked+0x8c/0x100
  __swap_entry_free_locked at mm/swapfile.c:1209 (discriminator 4)
  __swap_entry_free.constprop.20+0x69/0xb0
  free_swap_and_cache+0x53/0xa0
  unmap_page_range+0x7f8/0x1d70
  unmap_single_vma+0xcd/0x170
  unmap_vmas+0x18b/0x220
  exit_mmap+0xee/0x220
  mmput+0x10e/0x270
  do_exit+0x59b/0xf40
  do_group_exit+0x8b/0x180

 read to 0xffffbc370c29a64c of 1 bytes by task 6855 on cpu 20:
  _swap_info_get+0x81/0xa0
  _swap_info_get at mm/swapfile.c:1140
  free_swap_and_cache+0x40/0xa0
  unmap_page_range+0x7f8/0x1d70
  unmap_single_vma+0xcd/0x170
  unmap_vmas+0x18b/0x220
  exit_mmap+0xee/0x220
  mmput+0x10e/0x270
  do_exit+0x59b/0xf40
  do_group_exit+0x8b/0x180

=== si.flags ===

 write to 0xffff956c8fc6c400 of 8 bytes by task 6087 on cpu 23:
  scan_swap_map_slots+0x6fe/0xb50
  scan_swap_map_slots at mm/swapfile.c:887
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0x377/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1795/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

 read to 0xffff956c8fc6c400 of 8 bytes by task 6207 on cpu 63:
  _swap_info_get+0x41/0xa0
  __swap_info_get at mm/swapfile.c:1114
  put_swap_page+0x84/0x490
  __remove_mapping+0x384/0x5f0
  shrink_page_list+0xff1/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

The writes are under si->lock but the reads are not. For si.highest_bit
and si.swap_map[offset], data race could trigger logic bugs, so fix them
by having WRITE_ONCE() for the writes and READ_ONCE() for the reads
except those isolated reads where they compare against zero which a data
race would cause no harm. Thus, annotate them as intentional data races
using the data_race() macro.

For si.flags, the readers are only interested in a single bit where a
data race there would cause no issue there.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Qian Cai <[email protected]>
Cc: Marco Elver <[email protected]>
Cc: Hugh Dickins <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Stephen Rothwell <[email protected]>
okias pushed a commit that referenced this pull request May 11, 2020
Downstream kernel of ASUS TF300T sets r0 to #3. There is no explanation in
downstream code whether this is really needed and some of T30 downstream
kernels have and explicit comment telling that all arguments are ignored
by firmware. Let's take a safe side by replicating behavior of the TF300T
downstream kernel. This change works fine on Ouya and Nexus 7 devices.

Tested-by: Michał Mirosław <[email protected]>
Tested-by: Jasper Korten <[email protected]>
Tested-by: David Heidelberg <[email protected]>
Tested-by: Peter Geis <[email protected]>
Signed-off-by: Dmitry Osipenko <[email protected]>
okias pushed a commit that referenced this pull request May 12, 2020
Huazhong Tan says:

====================
net: hns3: misc updates for -next

This patchset includes some misc updates for the HNS3 ethernet driver.

 #1 & #2 add two cleanups.
 #3 provides an interface for the client to query the CMDQ's status.
 #4 adds a little optimization about debugfs.
 #5 prevents 1000M auto-negotiation off setting.
====================

Signed-off-by: Jakub Kicinski <[email protected]>
okias pushed a commit that referenced this pull request May 12, 2020
swap_info_struct si.highest_bit, si.swap_map[offset] and si.flags could
be accessed concurrently separately as noticed by KCSAN,

=== si.highest_bit ===

 write to 0xffff8d5abccdc4d4 of 4 bytes by task 5353 on cpu 24:
  swap_range_alloc+0x81/0x130
  swap_range_alloc at mm/swapfile.c:681
  scan_swap_map_slots+0x371/0xb90
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0xf2/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1795/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

 read to 0xffff8d5abccdc4d4 of 4 bytes by task 6672 on cpu 70:
  scan_swap_map_slots+0x4a6/0xb90
  scan_swap_map_slots at mm/swapfile.c:892
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0xf2/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1795/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 70 PID: 6672 Comm: oom01 Tainted: G        W    L 5.5.0-next-20200205+ #3
 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019

=== si.swap_map[offset] ===

 write to 0xffffbc370c29a64c of 1 bytes by task 6856 on cpu 86:
  __swap_entry_free_locked+0x8c/0x100
  __swap_entry_free_locked at mm/swapfile.c:1209 (discriminator 4)
  __swap_entry_free.constprop.20+0x69/0xb0
  free_swap_and_cache+0x53/0xa0
  unmap_page_range+0x7f8/0x1d70
  unmap_single_vma+0xcd/0x170
  unmap_vmas+0x18b/0x220
  exit_mmap+0xee/0x220
  mmput+0x10e/0x270
  do_exit+0x59b/0xf40
  do_group_exit+0x8b/0x180

 read to 0xffffbc370c29a64c of 1 bytes by task 6855 on cpu 20:
  _swap_info_get+0x81/0xa0
  _swap_info_get at mm/swapfile.c:1140
  free_swap_and_cache+0x40/0xa0
  unmap_page_range+0x7f8/0x1d70
  unmap_single_vma+0xcd/0x170
  unmap_vmas+0x18b/0x220
  exit_mmap+0xee/0x220
  mmput+0x10e/0x270
  do_exit+0x59b/0xf40
  do_group_exit+0x8b/0x180

=== si.flags ===

 write to 0xffff956c8fc6c400 of 8 bytes by task 6087 on cpu 23:
  scan_swap_map_slots+0x6fe/0xb50
  scan_swap_map_slots at mm/swapfile.c:887
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0x377/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1795/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

 read to 0xffff956c8fc6c400 of 8 bytes by task 6207 on cpu 63:
  _swap_info_get+0x41/0xa0
  __swap_info_get at mm/swapfile.c:1114
  put_swap_page+0x84/0x490
  __remove_mapping+0x384/0x5f0
  shrink_page_list+0xff1/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

The writes are under si->lock but the reads are not. For si.highest_bit
and si.swap_map[offset], data race could trigger logic bugs, so fix them
by having WRITE_ONCE() for the writes and READ_ONCE() for the reads
except those isolated reads where they compare against zero which a data
race would cause no harm. Thus, annotate them as intentional data races
using the data_race() macro.

For si.flags, the readers are only interested in a single bit where a
data race there would cause no issue there.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Qian Cai <[email protected]>
Cc: Marco Elver <[email protected]>
Cc: Hugh Dickins <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Stephen Rothwell <[email protected]>
okias pushed a commit that referenced this pull request May 14, 2020
When we increase hardware queue count, blk_mq_update_queue_map will
reset the mapping between cpu and hardware queue base on the hardware
queue count(set->nr_hw_queues). The mapping cannot be reset if it
encounters error in blk_mq_realloc_hw_ctxs, but the fallback flow will
continue using it, then blk_mq_map_swqueue will touch a invalid memory,
because the mapping points to a wrong hctx.

blktest block/030:

null_blk: module loaded
Increasing nr_hw_queues to 8 fails, fallback to 1
==================================================================
BUG: KASAN: null-ptr-deref in blk_mq_map_swqueue+0x2f2/0x830
Read of size 8 at addr 0000000000000128 by task nproc/8541

CPU: 5 PID: 8541 Comm: nproc Not tainted 5.7.0-rc4-dbg+ #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.13.0-0-gf21b5a4-rebuilt.opensuse.org 04/01/2014
Call Trace:
dump_stack+0xa5/0xe6
__kasan_report.cold+0x65/0xbb
kasan_report+0x45/0x60
check_memory_region+0x15e/0x1c0
__kasan_check_read+0x15/0x20
blk_mq_map_swqueue+0x2f2/0x830
__blk_mq_update_nr_hw_queues+0x3df/0x690
blk_mq_update_nr_hw_queues+0x32/0x50
nullb_device_submit_queues_store+0xde/0x160 [null_blk]
configfs_write_file+0x1c4/0x250 [configfs]
__vfs_write+0x4c/0x90
vfs_write+0x14b/0x2d0
ksys_write+0xdd/0x180
__x64_sys_write+0x47/0x50
do_syscall_64+0x6f/0x310
entry_SYSCALL_64_after_hwframe+0x49/0xb3

Signed-off-by: Weiping Zhang <[email protected]>
Tested-by: Bart van Assche <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
okias pushed a commit that referenced this pull request May 14, 2020
We need to check mddev->del_work before flush workqueu since the purpose
of flush is to ensure the previous md is disappeared. Otherwise the similar
deadlock appeared if LOCKDEP is enabled, it is due to md_open holds the
bdev->bd_mutex before flush workqueue.

kernel: [  154.522645] ======================================================
kernel: [  154.522647] WARNING: possible circular locking dependency detected
kernel: [  154.522650] 5.6.0-rc7-lp151.27-default grate-driver#25 Tainted: G           O
kernel: [  154.522651] ------------------------------------------------------
kernel: [  154.522653] mdadm/2482 is trying to acquire lock:
kernel: [  154.522655] ffff888078529128 ((wq_completion)md_misc){+.+.}, at: flush_workqueue+0x84/0x4b0
kernel: [  154.522673]
kernel: [  154.522673] but task is already holding lock:
kernel: [  154.522675] ffff88804efa9338 (&bdev->bd_mutex){+.+.}, at: __blkdev_get+0x79/0x590
kernel: [  154.522691]
kernel: [  154.522691] which lock already depends on the new lock.
kernel: [  154.522691]
kernel: [  154.522694]
kernel: [  154.522694] the existing dependency chain (in reverse order) is:
kernel: [  154.522696]
kernel: [  154.522696] -> #4 (&bdev->bd_mutex){+.+.}:
kernel: [  154.522704]        __mutex_lock+0x87/0x950
kernel: [  154.522706]        __blkdev_get+0x79/0x590
kernel: [  154.522708]        blkdev_get+0x65/0x140
kernel: [  154.522709]        blkdev_get_by_dev+0x2f/0x40
kernel: [  154.522716]        lock_rdev+0x3d/0x90 [md_mod]
kernel: [  154.522719]        md_import_device+0xd6/0x1b0 [md_mod]
kernel: [  154.522723]        new_dev_store+0x15e/0x210 [md_mod]
kernel: [  154.522728]        md_attr_store+0x7a/0xc0 [md_mod]
kernel: [  154.522732]        kernfs_fop_write+0x117/0x1b0
kernel: [  154.522735]        vfs_write+0xad/0x1a0
kernel: [  154.522737]        ksys_write+0xa4/0xe0
kernel: [  154.522745]        do_syscall_64+0x64/0x2b0
kernel: [  154.522748]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
kernel: [  154.522749]
kernel: [  154.522749] -> #3 (&mddev->reconfig_mutex){+.+.}:
kernel: [  154.522752]        __mutex_lock+0x87/0x950
kernel: [  154.522756]        new_dev_store+0xc9/0x210 [md_mod]
kernel: [  154.522759]        md_attr_store+0x7a/0xc0 [md_mod]
kernel: [  154.522761]        kernfs_fop_write+0x117/0x1b0
kernel: [  154.522763]        vfs_write+0xad/0x1a0
kernel: [  154.522765]        ksys_write+0xa4/0xe0
kernel: [  154.522767]        do_syscall_64+0x64/0x2b0
kernel: [  154.522769]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
kernel: [  154.522770]
kernel: [  154.522770] -> #2 (kn->count#253){++++}:
kernel: [  154.522775]        __kernfs_remove+0x253/0x2c0
kernel: [  154.522778]        kernfs_remove+0x1f/0x30
kernel: [  154.522780]        kobject_del+0x28/0x60
kernel: [  154.522783]        mddev_delayed_delete+0x24/0x30 [md_mod]
kernel: [  154.522786]        process_one_work+0x2a7/0x5f0
kernel: [  154.522788]        worker_thread+0x2d/0x3d0
kernel: [  154.522793]        kthread+0x117/0x130
kernel: [  154.522795]        ret_from_fork+0x3a/0x50
kernel: [  154.522796]
kernel: [  154.522796] -> #1 ((work_completion)(&mddev->del_work)){+.+.}:
kernel: [  154.522800]        process_one_work+0x27e/0x5f0
kernel: [  154.522802]        worker_thread+0x2d/0x3d0
kernel: [  154.522804]        kthread+0x117/0x130
kernel: [  154.522806]        ret_from_fork+0x3a/0x50
kernel: [  154.522807]
kernel: [  154.522807] -> #0 ((wq_completion)md_misc){+.+.}:
kernel: [  154.522813]        __lock_acquire+0x1392/0x1690
kernel: [  154.522816]        lock_acquire+0xb4/0x1a0
kernel: [  154.522818]        flush_workqueue+0xab/0x4b0
kernel: [  154.522821]        md_open+0xb6/0xc0 [md_mod]
kernel: [  154.522823]        __blkdev_get+0xea/0x590
kernel: [  154.522825]        blkdev_get+0x65/0x140
kernel: [  154.522828]        do_dentry_open+0x1d1/0x380
kernel: [  154.522831]        path_openat+0x567/0xcc0
kernel: [  154.522834]        do_filp_open+0x9b/0x110
kernel: [  154.522836]        do_sys_openat2+0x201/0x2a0
kernel: [  154.522838]        do_sys_open+0x57/0x80
kernel: [  154.522840]        do_syscall_64+0x64/0x2b0
kernel: [  154.522842]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
kernel: [  154.522844]
kernel: [  154.522844] other info that might help us debug this:
kernel: [  154.522844]
kernel: [  154.522846] Chain exists of:
kernel: [  154.522846]   (wq_completion)md_misc --> &mddev->reconfig_mutex --> &bdev->bd_mutex
kernel: [  154.522846]
kernel: [  154.522850]  Possible unsafe locking scenario:
kernel: [  154.522850]
kernel: [  154.522852]        CPU0                    CPU1
kernel: [  154.522853]        ----                    ----
kernel: [  154.522854]   lock(&bdev->bd_mutex);
kernel: [  154.522856]                                lock(&mddev->reconfig_mutex);
kernel: [  154.522858]                                lock(&bdev->bd_mutex);
kernel: [  154.522860]   lock((wq_completion)md_misc);
kernel: [  154.522861]
kernel: [  154.522861]  *** DEADLOCK ***
kernel: [  154.522861]
kernel: [  154.522864] 1 lock held by mdadm/2482:
kernel: [  154.522865]  #0: ffff88804efa9338 (&bdev->bd_mutex){+.+.}, at: __blkdev_get+0x79/0x590
kernel: [  154.522868]
kernel: [  154.522868] stack backtrace:
kernel: [  154.522873] CPU: 1 PID: 2482 Comm: mdadm Tainted: G           O      5.6.0-rc7-lp151.27-default grate-driver#25
kernel: [  154.522875] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
kernel: [  154.522878] Call Trace:
kernel: [  154.522881]  dump_stack+0x8f/0xcb
kernel: [  154.522884]  check_noncircular+0x194/0x1b0
kernel: [  154.522888]  ? __lock_acquire+0x1392/0x1690
kernel: [  154.522890]  __lock_acquire+0x1392/0x1690
kernel: [  154.522893]  lock_acquire+0xb4/0x1a0
kernel: [  154.522895]  ? flush_workqueue+0x84/0x4b0
kernel: [  154.522898]  flush_workqueue+0xab/0x4b0
kernel: [  154.522900]  ? flush_workqueue+0x84/0x4b0
kernel: [  154.522905]  ? md_open+0xb6/0xc0 [md_mod]
kernel: [  154.522908]  md_open+0xb6/0xc0 [md_mod]
kernel: [  154.522910]  __blkdev_get+0xea/0x590
kernel: [  154.522912]  ? bd_acquire+0xc0/0xc0
kernel: [  154.522914]  blkdev_get+0x65/0x140
kernel: [  154.522916]  ? bd_acquire+0xc0/0xc0
kernel: [  154.522918]  do_dentry_open+0x1d1/0x380
kernel: [  154.522921]  path_openat+0x567/0xcc0
kernel: [  154.522923]  ? __lock_acquire+0x380/0x1690
kernel: [  154.522926]  do_filp_open+0x9b/0x110
kernel: [  154.522929]  ? __alloc_fd+0xe5/0x1f0
kernel: [  154.522935]  ? kmem_cache_alloc+0x28c/0x630
kernel: [  154.522939]  ? do_sys_openat2+0x201/0x2a0
kernel: [  154.522941]  do_sys_openat2+0x201/0x2a0
kernel: [  154.522944]  do_sys_open+0x57/0x80
kernel: [  154.522946]  do_syscall_64+0x64/0x2b0
kernel: [  154.522948]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
kernel: [  154.522951] RIP: 0033:0x7f98d279d9ae

And md_alloc also flushed the same workqueue, but the thing is different
here. Because all the paths call md_alloc don't hold bdev->bd_mutex, and
the flush is necessary to avoid race condition, so leave it as it is.

Signed-off-by: Guoqing Jiang <[email protected]>
Signed-off-by: Song Liu <[email protected]>
okias pushed a commit that referenced this pull request May 14, 2020
Andrii Nakryiko says:

====================
Add generic benchmark runner framework which simplifies writing various
performance benchmarks in a consistent fashion.  This framework will be used
in follow up patches to test performance of perf buffer and ring buffer as
well.

Patch #1 extracts parse_num_list to be re-used between test_progs and bench.

Patch #2 adds generic runner implementation and atomic counter benchmarks to
validate benchmark runner's behavior.

Patch #3 implements test_overhead benchmark as part of bench runner. It also
add fmod_ret BPF program type to a set of benchmarks.

Patch #4 tests faster alternatives to set_task_comm() approach, tested in
test_overhead, in search for minimal-overhead way to trigger BPF program
execution from user-space on demand.

v2->v3:
  - added --prod-affinity and --cons-affinity (Yonghong);
  - removed ringbuf-related options leftovers (Yonghong);
  - added more benchmarking results for test_overhead performance discrepancies;
v1->v2:
  - moved benchmarks into benchs/ subdir (John);
  - added benchmark "suite" scripts (John);
  - few small clean ups, change defaults, etc.
====================

Signed-off-by: Alexei Starovoitov <[email protected]>
okias pushed a commit that referenced this pull request May 14, 2020
swap_info_struct si.highest_bit, si.swap_map[offset] and si.flags could
be accessed concurrently separately as noticed by KCSAN,

=== si.highest_bit ===

 write to 0xffff8d5abccdc4d4 of 4 bytes by task 5353 on cpu 24:
  swap_range_alloc+0x81/0x130
  swap_range_alloc at mm/swapfile.c:681
  scan_swap_map_slots+0x371/0xb90
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0xf2/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1795/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

 read to 0xffff8d5abccdc4d4 of 4 bytes by task 6672 on cpu 70:
  scan_swap_map_slots+0x4a6/0xb90
  scan_swap_map_slots at mm/swapfile.c:892
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0xf2/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1795/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 70 PID: 6672 Comm: oom01 Tainted: G        W    L 5.5.0-next-20200205+ #3
 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019

=== si.swap_map[offset] ===

 write to 0xffffbc370c29a64c of 1 bytes by task 6856 on cpu 86:
  __swap_entry_free_locked+0x8c/0x100
  __swap_entry_free_locked at mm/swapfile.c:1209 (discriminator 4)
  __swap_entry_free.constprop.20+0x69/0xb0
  free_swap_and_cache+0x53/0xa0
  unmap_page_range+0x7f8/0x1d70
  unmap_single_vma+0xcd/0x170
  unmap_vmas+0x18b/0x220
  exit_mmap+0xee/0x220
  mmput+0x10e/0x270
  do_exit+0x59b/0xf40
  do_group_exit+0x8b/0x180

 read to 0xffffbc370c29a64c of 1 bytes by task 6855 on cpu 20:
  _swap_info_get+0x81/0xa0
  _swap_info_get at mm/swapfile.c:1140
  free_swap_and_cache+0x40/0xa0
  unmap_page_range+0x7f8/0x1d70
  unmap_single_vma+0xcd/0x170
  unmap_vmas+0x18b/0x220
  exit_mmap+0xee/0x220
  mmput+0x10e/0x270
  do_exit+0x59b/0xf40
  do_group_exit+0x8b/0x180

=== si.flags ===

 write to 0xffff956c8fc6c400 of 8 bytes by task 6087 on cpu 23:
  scan_swap_map_slots+0x6fe/0xb50
  scan_swap_map_slots at mm/swapfile.c:887
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0x377/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1795/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

 read to 0xffff956c8fc6c400 of 8 bytes by task 6207 on cpu 63:
  _swap_info_get+0x41/0xa0
  __swap_info_get at mm/swapfile.c:1114
  put_swap_page+0x84/0x490
  __remove_mapping+0x384/0x5f0
  shrink_page_list+0xff1/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

The writes are under si->lock but the reads are not. For si.highest_bit
and si.swap_map[offset], data race could trigger logic bugs, so fix them
by having WRITE_ONCE() for the writes and READ_ONCE() for the reads
except those isolated reads where they compare against zero which a data
race would cause no harm. Thus, annotate them as intentional data races
using the data_race() macro.

For si.flags, the readers are only interested in a single bit where a
data race there would cause no issue there.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Qian Cai <[email protected]>
Cc: Marco Elver <[email protected]>
Cc: Hugh Dickins <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Stephen Rothwell <[email protected]>
okias pushed a commit that referenced this pull request May 22, 2020
This BUG halt was reported a while back, but the patch somehow got
missed:

PID: 2879   TASK: c16adaa0  CPU: 1   COMMAND: "sctpn"
 #0 [f418dd28] crash_kexec at c04a7d8c
 #1 [f418dd7c] oops_end at c0863e02
 #2 [f418dd90] do_invalid_op at c040aaca
 #3 [f418de28] error_code (via invalid_op) at c08631a5
    EAX: f34baac0  EBX: 00000090  ECX: f418deb0  EDX: f5542950  EBP: 00000000
    DS:  007b      ESI: f34ba800  ES:  007b      EDI: f418dea0  GS:  00e0
    CS:  0060      EIP: c046fa5e  ERR: ffffffff  EFLAGS: 00010286
 #4 [f418de5c] add_timer at c046fa5e
 #5 [f418de68] sctp_do_sm at f8db8c77 [sctp]
 #6 [f418df30] sctp_primitive_SHUTDOWN at f8dcc1b5 [sctp]
 #7 [f418df48] inet_shutdown at c080baf9
 #8 [f418df5c] sys_shutdown at c079eedf
 grate-driver#9 [f418df70] sys_socketcall at c079fe88
    EAX: ffffffda  EBX: 0000000d  ECX: bfceea90  EDX: 0937af98
    DS:  007b      ESI: 0000000c  ES:  007b      EDI: b7150ae4
    SS:  007b      ESP: bfceea7c  EBP: bfceeaa8  GS:  0033
    CS:  0073      EIP: b775c424  ERR: 00000066  EFLAGS: 00000282

It appears that the side effect that starts the shutdown timer was processed
multiple times, which can happen as multiple paths can trigger it.  This of
course leads to the BUG halt in add_timer getting called.

Fix seems pretty straightforward, just check before the timer is added if its
already been started.  If it has mod the timer instead to min(current
expiration, new expiration)

Its been tested but not confirmed to fix the problem, as the issue has only
occured in production environments where test kernels are enjoined from being
installed.  It appears to be a sane fix to me though.  Also, recentely,
Jere found a reproducer posted on list to confirm that this resolves the
issues

Signed-off-by: Neil Horman <[email protected]>
CC: Vlad Yasevich <[email protected]>
CC: "David S. Miller" <[email protected]>
CC: [email protected]
CC: [email protected]
CC: [email protected]
Acked-by: Marcelo Ricardo Leitner <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
okias pushed a commit that referenced this pull request May 22, 2020
swap_info_struct si.highest_bit, si.swap_map[offset] and si.flags could
be accessed concurrently separately as noticed by KCSAN,

=== si.highest_bit ===

 write to 0xffff8d5abccdc4d4 of 4 bytes by task 5353 on cpu 24:
  swap_range_alloc+0x81/0x130
  swap_range_alloc at mm/swapfile.c:681
  scan_swap_map_slots+0x371/0xb90
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0xf2/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1795/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

 read to 0xffff8d5abccdc4d4 of 4 bytes by task 6672 on cpu 70:
  scan_swap_map_slots+0x4a6/0xb90
  scan_swap_map_slots at mm/swapfile.c:892
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0xf2/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1795/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 70 PID: 6672 Comm: oom01 Tainted: G        W    L 5.5.0-next-20200205+ #3
 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019

=== si.swap_map[offset] ===

 write to 0xffffbc370c29a64c of 1 bytes by task 6856 on cpu 86:
  __swap_entry_free_locked+0x8c/0x100
  __swap_entry_free_locked at mm/swapfile.c:1209 (discriminator 4)
  __swap_entry_free.constprop.20+0x69/0xb0
  free_swap_and_cache+0x53/0xa0
  unmap_page_range+0x7f8/0x1d70
  unmap_single_vma+0xcd/0x170
  unmap_vmas+0x18b/0x220
  exit_mmap+0xee/0x220
  mmput+0x10e/0x270
  do_exit+0x59b/0xf40
  do_group_exit+0x8b/0x180

 read to 0xffffbc370c29a64c of 1 bytes by task 6855 on cpu 20:
  _swap_info_get+0x81/0xa0
  _swap_info_get at mm/swapfile.c:1140
  free_swap_and_cache+0x40/0xa0
  unmap_page_range+0x7f8/0x1d70
  unmap_single_vma+0xcd/0x170
  unmap_vmas+0x18b/0x220
  exit_mmap+0xee/0x220
  mmput+0x10e/0x270
  do_exit+0x59b/0xf40
  do_group_exit+0x8b/0x180

=== si.flags ===

 write to 0xffff956c8fc6c400 of 8 bytes by task 6087 on cpu 23:
  scan_swap_map_slots+0x6fe/0xb50
  scan_swap_map_slots at mm/swapfile.c:887
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0x377/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1795/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

 read to 0xffff956c8fc6c400 of 8 bytes by task 6207 on cpu 63:
  _swap_info_get+0x41/0xa0
  __swap_info_get at mm/swapfile.c:1114
  put_swap_page+0x84/0x490
  __remove_mapping+0x384/0x5f0
  shrink_page_list+0xff1/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

The writes are under si->lock but the reads are not. For si.highest_bit
and si.swap_map[offset], data race could trigger logic bugs, so fix them
by having WRITE_ONCE() for the writes and READ_ONCE() for the reads
except those isolated reads where they compare against zero which a data
race would cause no harm. Thus, annotate them as intentional data races
using the data_race() macro.

For si.flags, the readers are only interested in a single bit where a
data race there would cause no issue there.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Qian Cai <[email protected]>
Cc: Marco Elver <[email protected]>
Cc: Hugh Dickins <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Stephen Rothwell <[email protected]>
okias pushed a commit that referenced this pull request May 23, 2020
The reclaim code that balances between swapping and cache reclaim tries to
predict likely reuse based on in-memory reference patterns alone.  This
works in many cases, but when it fails it cannot detect when the cache is
thrashing pathologically, or when we're in the middle of a swap storm.

The high seek cost of rotational drives under which the algorithm evolved
also meant that mistakes could quickly result in lockups from too
aggressive swapping (which is predominantly random IO).  As a result, the
balancing code has been tuned over time to a point where it mostly goes
for page cache and defers swapping until the VM is under significant
memory pressure.

The resulting strategy doesn't make optimal caching decisions - where
optimal is the least amount of IO required to execute the workload.

The proliferation of fast random IO devices such as SSDs, in-memory
compression such as zswap, and persistent memory technologies on the
horizon, has made this undesirable behavior very noticable: Even in the
presence of large amounts of cold anonymous memory and a capable swap
device, the VM refuses to even seriously scan these pages, and can leave
the page cache thrashing needlessly.

This series sets out to address this.  Since commit ("a528910e12ec mm:
thrash detection-based file cache sizing") we have exact tracking of
refault IO - the ultimate cost of reclaiming the wrong pages.  This allows
us to use an IO cost based balancing model that is more aggressive about
scanning anonymous memory when the cache is thrashing, while being able to
avoid unnecessary swap storms.

These patches base the LRU balance on the rate of refaults on each list,
times the relative IO cost between swap device and filesystem
(swappiness), in order to optimize reclaim for least IO cost incurred.

	History

I floated these changes in 2016.  At the time they were incomplete and
full of workarounds due to a lack of infrastructure in the reclaim code:
We didn't have PageWorkingset, we didn't have hierarchical cgroup
statistics, and problems with the cgroup swap controller.  As swapping
wasn't too high a priority then, the patches stalled out.  With all
dependencies in place now, here we are again with much cleaner,
feature-complete patches.

I kept the acks for patches that stayed materially the same :-)

Below is a series of test results that demonstrate certain problematic
behavior of the current code, as well as showcase the new code's more
predictable and appropriate balancing decisions.

	Test #1: No convergence

This test shows an edge case where the VM currently doesn't converge at
all on a new file workingset with a stale anon/tmpfs set.

The test sets up a cold anon set the size of 3/4 RAM, then tries to
establish a new file set half the size of RAM (flat access pattern).

The vanilla kernel refuses to even scan anon pages and never converges.
The file set is perpetually served from the filesystem.

The first test kernel is with the series up to the workingset patch
applied.  This allows thrashing page cache to challenge the anonymous
workingset.  The VM then scans the lists based on the current
scanned/rotated balancing algorithm.  It converges on a stable state where
all cold anon pages are pushed out and the fileset is served entirely from
cache:

			    noconverge/5.7-rc5-mm	noconverge/5.7-rc5-mm-workingset
Scanned			417719308.00 (    +0.00%)		64091155.00 (   -84.66%)
Reclaimed		417711094.00 (    +0.00%)		61640308.00 (   -85.24%)
Reclaim efficiency %	      100.00 (    +0.00%)		      96.18 (    -3.78%)
Scanned file		417719308.00 (    +0.00%)		59211118.00 (   -85.83%)
Scanned anon			0.00 (    +0.00%)	         4880037.00 (          )
Swapouts			0.00 (    +0.00%)	         2439957.00 (          )
Swapins				0.00 (    +0.00%)		     257.00 (          )
Refaults		415246605.00 (    +0.00%)		59183722.00 (   -85.75%)
Restore refaults		0.00 (    +0.00%)	        54988252.00 (          )

The second test kernel is with the full patch series applied, which
replaces the scanned/rotated ratios with refault/swapin rate-based
balancing.  It evicts the cold anon pages more aggressively in the
presence of a thrashing cache and the absence of swapins, and so converges
with about 60% of the IO and reclaim activity:

			noconverge/5.7-rc5-mm-workingset	noconverge/5.7-rc5-mm-lrubalance
Scanned				64091155.00 (    +0.00%)		37579741.00 (   -41.37%)
Reclaimed			61640308.00 (    +0.00%)		35129293.00 (   -43.01%)
Reclaim efficiency %		      96.18 (    +0.00%)		      93.48 (    -2.78%)
Scanned file			59211118.00 (    +0.00%)		32708385.00 (   -44.76%)
Scanned anon			 4880037.00 (    +0.00%)		 4871356.00 (    -0.18%)
Swapouts			 2439957.00 (    +0.00%)		 2435565.00 (    -0.18%)
Swapins				     257.00 (    +0.00%)		     262.00 (    +1.94%)
Refaults			59183722.00 (    +0.00%)		32675667.00 (   -44.79%)
Restore refaults		54988252.00 (    +0.00%)		28480430.00 (   -48.21%)

We're triggering this case in host sideloading scenarios: When a host's
primary workload is not saturating the machine (primary load is usually
driven by user activity), we can optimistically sideload a batch job; if
user activity picks up and the primary workload needs the whole host
during this time, we freeze the sideload and rely on it getting pushed to
swap.  Frequently that swapping doesn't happen and the completely inactive
sideload simply stays resident while the expanding primary worklad is
struggling to gain ground.

	Test #2: Kernel build

This test is a a kernel build that is slightly memory-restricted (make -j4
inside a 400M cgroup).

Despite the very aggressive swapping of cold anon pages in test #1, this
test shows that the new kernel carefully balances swap against cache
refaults when both the file and the cache set are pressured.

It shows the patched kernel to be slightly better at finding the coldest
memory from the combined anon and file set to evict under pressure.  The
result is lower aggregate reclaim and paging activity:

z				    5.7-rc5-mm	5.7-rc5-mm-lrubalance
Real time		   210.60 (    +0.00%)	   210.97 (    +0.18%)
User time		   745.42 (    +0.00%)	   746.48 (    +0.14%)
System time		    69.78 (    +0.00%)	    69.79 (    +0.02%)
Scanned file		354682.00 (    +0.00%)	293661.00 (   -17.20%)
Scanned anon		465381.00 (    +0.00%)	378144.00 (   -18.75%)
Swapouts		185920.00 (    +0.00%)	147801.00 (   -20.50%)
Swapins			 34583.00 (    +0.00%)	 32491.00 (    -6.05%)
Refaults		212664.00 (    +0.00%)	172409.00 (   -18.93%)
Restore refaults	 48861.00 (    +0.00%)	 80091.00 (   +63.91%)
Total paging IO		433167.00 (    +0.00%)	352701.00 (   -18.58%)

	Test #3: Overload

This next test is not about performance, but rather about the
predictability of the algorithm.  The current balancing behavior doesn't
always lead to comprehensible results, which makes performance analysis
and parameter tuning (swappiness e.g.) very difficult.

The test shows the balancing behavior under equivalent anon and file
input.  Anon and file sets are created of equal size (3/4 RAM), have the
same access patterns (a hot-cold gradient), and synchronized access rates.
Swappiness is raised from the default of 60 to 100 to indicate equal IO
cost between swap and cache.

With the vanilla balancing code, anon scans make up around 9% of the total
pages scanned, or a ~1:10 ratio.  This is a surprisingly skewed ratio, and
it's an outcome that is hard to explain given the input parameters to the
VM.

The new balancing model targets a 1:2 balance: All else being equal,
reclaiming a file page costs one page IO - the refault; reclaiming an anon
page costs two IOs - the swapout and the swapin.  In the test we observe a
~1:3 balance.

The scanned and paging IO numbers indicate that the anon LRU algorithm we
have in place right now does a slightly worse job at picking the coldest
pages compared to the file algorithm.  There is ongoing work to improve
this, like Joonsoo's anon workingset patches; however, it's difficult to
compare the two aging strategies when the balancing between them is
behaving unintuitively.

The slightly less efficient anon reclaim results in a deviation from the
optimal 1:2 scan ratio we would like to see here - however, 1:3 is much
closer to what we'd want to see in this test than the vanilla kernel's
aging of 10+ cache pages for every anonymous one:

			overload-100/5.7-rc5-mm-workingset	overload-100/5.7-rc5-mm-lrubalance-realfile
Scanned				 533633725.00 (    +0.00%)			  595687785.00 (   +11.63%)
Reclaimed			 494325440.00 (    +0.00%)			  518154380.00 (    +4.82%)
Reclaim efficiency %			92.63 (    +0.00%)				 86.98 (    -6.03%)
Scanned file			 484532894.00 (    +0.00%)			  456937722.00 (    -5.70%)
Scanned anon			  49100831.00 (    +0.00%)			  138750063.00 (  +182.58%)
Swapouts			   8096423.00 (    +0.00%)			   48982142.00 (  +504.98%)
Swapins				  10027384.00 (    +0.00%)			   62325044.00 (  +521.55%)
Refaults			 479819973.00 (    +0.00%)			  451309483.00 (    -5.94%)
Restore refaults		 426422087.00 (    +0.00%)			  399914067.00 (    -6.22%)
Total paging IO			 497943780.00 (    +0.00%)			  562616669.00 (   +12.99%)

	Test #4: Parallel IO

It's important to note that these patches only affect the situation where
the kernel has to reclaim workingset memory, which is usually a
transitionary period.  The vast majority of page reclaim occuring in a
system is from trimming the ever-expanding page cache.

These patches don't affect cache trimming behavior.  We never swap as long
as we only have use-once cache moving through the file LRU, we only
consider swapping when the cache is actively thrashing.

The following test demonstrates this.  It has an anon workingset that
takes up half of RAM and then writes a file that is twice the size of RAM
out to disk.

As the cache is funneled through the inactive file list, no anon pages are
scanned (aside from apparently some background noise of 10 pages):

					  5.7-rc5-mm		          5.7-rc5-mm-lrubalance
Scanned			    10714722.00 (    +0.00%)		       10723445.00 (    +0.08%)
Reclaimed		    10703596.00 (    +0.00%)		       10712166.00 (    +0.08%)
Reclaim efficiency %		  99.90 (    +0.00%)			     99.89 (    -0.00%)
Scanned file		    10714722.00 (    +0.00%)		       10723435.00 (    +0.08%)
Scanned anon			   0.00 (    +0.00%)			     10.00 (          )
Swapouts			   0.00 (    +0.00%)			      7.00 (          )
Swapins				   0.00 (    +0.00%)			      0.00 (    +0.00%)
Refaults			  92.00 (    +0.00%)			     41.00 (   -54.84%)
Restore refaults		   0.00 (    +0.00%)			      0.00 (    +0.00%)
Total paging IO			  92.00 (    +0.00%)			     48.00 (   -47.31%)

This patch (of 14):

Currently, THP are counted as single pages until they are split right
before being swapped out.  However, at that point the VM is already in the
middle of reclaim, and adjusting the LRU balance then is useless.

Always account THP by the number of basepages, and remove the fixup from
the splitting path.

Link: http://lkml.kernel.org/r/[email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Johannes Weiner <[email protected]>
Reviewed-by: Rik van Riel <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Acked-by: Minchan Kim <[email protected]>
Cc: Joonsoo Kim <[email protected]>,
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Stephen Rothwell <[email protected]>
okias pushed a commit that referenced this pull request May 23, 2020
swap_info_struct si.highest_bit, si.swap_map[offset] and si.flags could
be accessed concurrently separately as noticed by KCSAN,

=== si.highest_bit ===

 write to 0xffff8d5abccdc4d4 of 4 bytes by task 5353 on cpu 24:
  swap_range_alloc+0x81/0x130
  swap_range_alloc at mm/swapfile.c:681
  scan_swap_map_slots+0x371/0xb90
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0xf2/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1795/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

 read to 0xffff8d5abccdc4d4 of 4 bytes by task 6672 on cpu 70:
  scan_swap_map_slots+0x4a6/0xb90
  scan_swap_map_slots at mm/swapfile.c:892
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0xf2/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1795/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 70 PID: 6672 Comm: oom01 Tainted: G        W    L 5.5.0-next-20200205+ #3
 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019

=== si.swap_map[offset] ===

 write to 0xffffbc370c29a64c of 1 bytes by task 6856 on cpu 86:
  __swap_entry_free_locked+0x8c/0x100
  __swap_entry_free_locked at mm/swapfile.c:1209 (discriminator 4)
  __swap_entry_free.constprop.20+0x69/0xb0
  free_swap_and_cache+0x53/0xa0
  unmap_page_range+0x7f8/0x1d70
  unmap_single_vma+0xcd/0x170
  unmap_vmas+0x18b/0x220
  exit_mmap+0xee/0x220
  mmput+0x10e/0x270
  do_exit+0x59b/0xf40
  do_group_exit+0x8b/0x180

 read to 0xffffbc370c29a64c of 1 bytes by task 6855 on cpu 20:
  _swap_info_get+0x81/0xa0
  _swap_info_get at mm/swapfile.c:1140
  free_swap_and_cache+0x40/0xa0
  unmap_page_range+0x7f8/0x1d70
  unmap_single_vma+0xcd/0x170
  unmap_vmas+0x18b/0x220
  exit_mmap+0xee/0x220
  mmput+0x10e/0x270
  do_exit+0x59b/0xf40
  do_group_exit+0x8b/0x180

=== si.flags ===

 write to 0xffff956c8fc6c400 of 8 bytes by task 6087 on cpu 23:
  scan_swap_map_slots+0x6fe/0xb50
  scan_swap_map_slots at mm/swapfile.c:887
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0x377/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1795/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

 read to 0xffff956c8fc6c400 of 8 bytes by task 6207 on cpu 63:
  _swap_info_get+0x41/0xa0
  __swap_info_get at mm/swapfile.c:1114
  put_swap_page+0x84/0x490
  __remove_mapping+0x384/0x5f0
  shrink_page_list+0xff1/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

The writes are under si->lock but the reads are not. For si.highest_bit
and si.swap_map[offset], data race could trigger logic bugs, so fix them
by having WRITE_ONCE() for the writes and READ_ONCE() for the reads
except those isolated reads where they compare against zero which a data
race would cause no harm. Thus, annotate them as intentional data races
using the data_race() macro.

For si.flags, the readers are only interested in a single bit where a
data race there would cause no issue there.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Qian Cai <[email protected]>
Cc: Marco Elver <[email protected]>
Cc: Hugh Dickins <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Stephen Rothwell <[email protected]>
okias pushed a commit that referenced this pull request Jun 15, 2020
swap_info_struct si.highest_bit, si.swap_map[offset] and si.flags could
be accessed concurrently separately as noticed by KCSAN,

=== si.highest_bit ===

 write to 0xffff8d5abccdc4d4 of 4 bytes by task 5353 on cpu 24:
  swap_range_alloc+0x81/0x130
  swap_range_alloc at mm/swapfile.c:681
  scan_swap_map_slots+0x371/0xb90
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0xf2/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1795/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

 read to 0xffff8d5abccdc4d4 of 4 bytes by task 6672 on cpu 70:
  scan_swap_map_slots+0x4a6/0xb90
  scan_swap_map_slots at mm/swapfile.c:892
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0xf2/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1795/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 70 PID: 6672 Comm: oom01 Tainted: G        W    L 5.5.0-next-20200205+ #3
 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019

=== si.swap_map[offset] ===

 write to 0xffffbc370c29a64c of 1 bytes by task 6856 on cpu 86:
  __swap_entry_free_locked+0x8c/0x100
  __swap_entry_free_locked at mm/swapfile.c:1209 (discriminator 4)
  __swap_entry_free.constprop.20+0x69/0xb0
  free_swap_and_cache+0x53/0xa0
  unmap_page_range+0x7f8/0x1d70
  unmap_single_vma+0xcd/0x170
  unmap_vmas+0x18b/0x220
  exit_mmap+0xee/0x220
  mmput+0x10e/0x270
  do_exit+0x59b/0xf40
  do_group_exit+0x8b/0x180

 read to 0xffffbc370c29a64c of 1 bytes by task 6855 on cpu 20:
  _swap_info_get+0x81/0xa0
  _swap_info_get at mm/swapfile.c:1140
  free_swap_and_cache+0x40/0xa0
  unmap_page_range+0x7f8/0x1d70
  unmap_single_vma+0xcd/0x170
  unmap_vmas+0x18b/0x220
  exit_mmap+0xee/0x220
  mmput+0x10e/0x270
  do_exit+0x59b/0xf40
  do_group_exit+0x8b/0x180

=== si.flags ===

 write to 0xffff956c8fc6c400 of 8 bytes by task 6087 on cpu 23:
  scan_swap_map_slots+0x6fe/0xb50
  scan_swap_map_slots at mm/swapfile.c:887
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0x377/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1795/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

 read to 0xffff956c8fc6c400 of 8 bytes by task 6207 on cpu 63:
  _swap_info_get+0x41/0xa0
  __swap_info_get at mm/swapfile.c:1114
  put_swap_page+0x84/0x490
  __remove_mapping+0x384/0x5f0
  shrink_page_list+0xff1/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

The writes are under si->lock but the reads are not. For si.highest_bit
and si.swap_map[offset], data race could trigger logic bugs, so fix them
by having WRITE_ONCE() for the writes and READ_ONCE() for the reads
except those isolated reads where they compare against zero which a data
race would cause no harm. Thus, annotate them as intentional data races
using the data_race() macro.

For si.flags, the readers are only interested in a single bit where a
data race there would cause no issue there.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Qian Cai <[email protected]>
Cc: Marco Elver <[email protected]>
Cc: Hugh Dickins <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Stephen Rothwell <[email protected]>
okias pushed a commit that referenced this pull request Jun 23, 2020
swap_info_struct si.highest_bit, si.swap_map[offset] and si.flags could
be accessed concurrently separately as noticed by KCSAN,

=== si.highest_bit ===

 write to 0xffff8d5abccdc4d4 of 4 bytes by task 5353 on cpu 24:
  swap_range_alloc+0x81/0x130
  swap_range_alloc at mm/swapfile.c:681
  scan_swap_map_slots+0x371/0xb90
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0xf2/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1795/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

 read to 0xffff8d5abccdc4d4 of 4 bytes by task 6672 on cpu 70:
  scan_swap_map_slots+0x4a6/0xb90
  scan_swap_map_slots at mm/swapfile.c:892
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0xf2/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1795/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 70 PID: 6672 Comm: oom01 Tainted: G        W    L 5.5.0-next-20200205+ #3
 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019

=== si.swap_map[offset] ===

 write to 0xffffbc370c29a64c of 1 bytes by task 6856 on cpu 86:
  __swap_entry_free_locked+0x8c/0x100
  __swap_entry_free_locked at mm/swapfile.c:1209 (discriminator 4)
  __swap_entry_free.constprop.20+0x69/0xb0
  free_swap_and_cache+0x53/0xa0
  unmap_page_range+0x7f8/0x1d70
  unmap_single_vma+0xcd/0x170
  unmap_vmas+0x18b/0x220
  exit_mmap+0xee/0x220
  mmput+0x10e/0x270
  do_exit+0x59b/0xf40
  do_group_exit+0x8b/0x180

 read to 0xffffbc370c29a64c of 1 bytes by task 6855 on cpu 20:
  _swap_info_get+0x81/0xa0
  _swap_info_get at mm/swapfile.c:1140
  free_swap_and_cache+0x40/0xa0
  unmap_page_range+0x7f8/0x1d70
  unmap_single_vma+0xcd/0x170
  unmap_vmas+0x18b/0x220
  exit_mmap+0xee/0x220
  mmput+0x10e/0x270
  do_exit+0x59b/0xf40
  do_group_exit+0x8b/0x180

=== si.flags ===

 write to 0xffff956c8fc6c400 of 8 bytes by task 6087 on cpu 23:
  scan_swap_map_slots+0x6fe/0xb50
  scan_swap_map_slots at mm/swapfile.c:887
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0x377/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1795/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

 read to 0xffff956c8fc6c400 of 8 bytes by task 6207 on cpu 63:
  _swap_info_get+0x41/0xa0
  __swap_info_get at mm/swapfile.c:1114
  put_swap_page+0x84/0x490
  __remove_mapping+0x384/0x5f0
  shrink_page_list+0xff1/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290

The writes are under si->lock but the reads are not. For si.highest_bit
and si.swap_map[offset], data race could trigger logic bugs, so fix them
by having WRITE_ONCE() for the writes and READ_ONCE() for the reads
except those isolated reads where they compare against zero which a data
race would cause no harm. Thus, annotate them as intentional data races
using the data_race() macro.

For si.flags, the readers are only interested in a single bit where a
data race there would cause no issue there.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Qian Cai <[email protected]>
Cc: Marco Elver <[email protected]>
Cc: Hugh Dickins <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Stephen Rothwell <[email protected]>
okias pushed a commit that referenced this pull request Sep 3, 2020
I got the following lockdep splat while testing:

  ======================================================
  WARNING: possible circular locking dependency detected
  5.8.0-rc7-00172-g021118712e59 #932 Not tainted
  ------------------------------------------------------
  btrfs/229626 is trying to acquire lock:
  ffffffff828513f0 (cpu_hotplug_lock){++++}-{0:0}, at: alloc_workqueue+0x378/0x450

  but task is already holding lock:
  ffff889dd3889518 (&fs_info->scrub_lock){+.+.}-{3:3}, at: btrfs_scrub_dev+0x11c/0x630

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #7 (&fs_info->scrub_lock){+.+.}-{3:3}:
	 __mutex_lock+0x9f/0x930
	 btrfs_scrub_dev+0x11c/0x630
	 btrfs_dev_replace_by_ioctl.cold.21+0x10a/0x1d4
	 btrfs_ioctl+0x2799/0x30a0
	 ksys_ioctl+0x83/0xc0
	 __x64_sys_ioctl+0x16/0x20
	 do_syscall_64+0x50/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #6 (&fs_devs->device_list_mutex){+.+.}-{3:3}:
	 __mutex_lock+0x9f/0x930
	 btrfs_run_dev_stats+0x49/0x480
	 commit_cowonly_roots+0xb5/0x2a0
	 btrfs_commit_transaction+0x516/0xa60
	 sync_filesystem+0x6b/0x90
	 generic_shutdown_super+0x22/0x100
	 kill_anon_super+0xe/0x30
	 btrfs_kill_super+0x12/0x20
	 deactivate_locked_super+0x29/0x60
	 cleanup_mnt+0xb8/0x140
	 task_work_run+0x6d/0xb0
	 __prepare_exit_to_usermode+0x1cc/0x1e0
	 do_syscall_64+0x5c/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #5 (&fs_info->tree_log_mutex){+.+.}-{3:3}:
	 __mutex_lock+0x9f/0x930
	 btrfs_commit_transaction+0x4bb/0xa60
	 sync_filesystem+0x6b/0x90
	 generic_shutdown_super+0x22/0x100
	 kill_anon_super+0xe/0x30
	 btrfs_kill_super+0x12/0x20
	 deactivate_locked_super+0x29/0x60
	 cleanup_mnt+0xb8/0x140
	 task_work_run+0x6d/0xb0
	 __prepare_exit_to_usermode+0x1cc/0x1e0
	 do_syscall_64+0x5c/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #4 (&fs_info->reloc_mutex){+.+.}-{3:3}:
	 __mutex_lock+0x9f/0x930
	 btrfs_record_root_in_trans+0x43/0x70
	 start_transaction+0xd1/0x5d0
	 btrfs_dirty_inode+0x42/0xd0
	 touch_atime+0xa1/0xd0
	 btrfs_file_mmap+0x3f/0x60
	 mmap_region+0x3a4/0x640
	 do_mmap+0x376/0x580
	 vm_mmap_pgoff+0xd5/0x120
	 ksys_mmap_pgoff+0x193/0x230
	 do_syscall_64+0x50/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #3 (&mm->mmap_lock#2){++++}-{3:3}:
	 __might_fault+0x68/0x90
	 _copy_to_user+0x1e/0x80
	 perf_read+0x141/0x2c0
	 vfs_read+0xad/0x1b0
	 ksys_read+0x5f/0xe0
	 do_syscall_64+0x50/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #2 (&cpuctx_mutex){+.+.}-{3:3}:
	 __mutex_lock+0x9f/0x930
	 perf_event_init_cpu+0x88/0x150
	 perf_event_init+0x1db/0x20b
	 start_kernel+0x3ae/0x53c
	 secondary_startup_64+0xa4/0xb0

  -> #1 (pmus_lock){+.+.}-{3:3}:
	 __mutex_lock+0x9f/0x930
	 perf_event_init_cpu+0x4f/0x150
	 cpuhp_invoke_callback+0xb1/0x900
	 _cpu_up.constprop.26+0x9f/0x130
	 cpu_up+0x7b/0xc0
	 bringup_nonboot_cpus+0x4f/0x60
	 smp_init+0x26/0x71
	 kernel_init_freeable+0x110/0x258
	 kernel_init+0xa/0x103
	 ret_from_fork+0x1f/0x30

  -> #0 (cpu_hotplug_lock){++++}-{0:0}:
	 __lock_acquire+0x1272/0x2310
	 lock_acquire+0x9e/0x360
	 cpus_read_lock+0x39/0xb0
	 alloc_workqueue+0x378/0x450
	 __btrfs_alloc_workqueue+0x15d/0x200
	 btrfs_alloc_workqueue+0x51/0x160
	 scrub_workers_get+0x5a/0x170
	 btrfs_scrub_dev+0x18c/0x630
	 btrfs_dev_replace_by_ioctl.cold.21+0x10a/0x1d4
	 btrfs_ioctl+0x2799/0x30a0
	 ksys_ioctl+0x83/0xc0
	 __x64_sys_ioctl+0x16/0x20
	 do_syscall_64+0x50/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  other info that might help us debug this:

  Chain exists of:
    cpu_hotplug_lock --> &fs_devs->device_list_mutex --> &fs_info->scrub_lock

   Possible unsafe locking scenario:

	 CPU0                    CPU1
	 ----                    ----
    lock(&fs_info->scrub_lock);
				 lock(&fs_devs->device_list_mutex);
				 lock(&fs_info->scrub_lock);
    lock(cpu_hotplug_lock);

   *** DEADLOCK ***

  2 locks held by btrfs/229626:
   #0: ffff88bfe8bb86e0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: btrfs_scrub_dev+0xbd/0x630
   #1: ffff889dd3889518 (&fs_info->scrub_lock){+.+.}-{3:3}, at: btrfs_scrub_dev+0x11c/0x630

  stack backtrace:
  CPU: 15 PID: 229626 Comm: btrfs Kdump: loaded Not tainted 5.8.0-rc7-00172-g021118712e59 #932
  Hardware name: Quanta Tioga Pass Single Side 01-0030993006/Tioga Pass Single Side, BIOS F08_3A18 12/20/2018
  Call Trace:
   dump_stack+0x78/0xa0
   check_noncircular+0x165/0x180
   __lock_acquire+0x1272/0x2310
   lock_acquire+0x9e/0x360
   ? alloc_workqueue+0x378/0x450
   cpus_read_lock+0x39/0xb0
   ? alloc_workqueue+0x378/0x450
   alloc_workqueue+0x378/0x450
   ? rcu_read_lock_sched_held+0x52/0x80
   __btrfs_alloc_workqueue+0x15d/0x200
   btrfs_alloc_workqueue+0x51/0x160
   scrub_workers_get+0x5a/0x170
   btrfs_scrub_dev+0x18c/0x630
   ? start_transaction+0xd1/0x5d0
   btrfs_dev_replace_by_ioctl.cold.21+0x10a/0x1d4
   btrfs_ioctl+0x2799/0x30a0
   ? do_sigaction+0x102/0x250
   ? lockdep_hardirqs_on_prepare+0xca/0x160
   ? _raw_spin_unlock_irq+0x24/0x30
   ? trace_hardirqs_on+0x1c/0xe0
   ? _raw_spin_unlock_irq+0x24/0x30
   ? do_sigaction+0x102/0x250
   ? ksys_ioctl+0x83/0xc0
   ksys_ioctl+0x83/0xc0
   __x64_sys_ioctl+0x16/0x20
   do_syscall_64+0x50/0x90
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

This happens because we're allocating the scrub workqueues under the
scrub and device list mutex, which brings in a whole host of other
dependencies.

Because the work queue allocation is done with GFP_KERNEL, it can
trigger reclaim, which can lead to a transaction commit, which in turns
needs the device_list_mutex, it can lead to a deadlock. A different
problem for which this fix is a solution.

Fix this by moving the actual allocation outside of the
scrub lock, and then only take the lock once we're ready to actually
assign them to the fs_info.  We'll now have to cleanup the workqueues in
a few more places, so I've added a helper to do the refcount dance to
safely free the workqueues.

CC: [email protected] # 5.4+
Reviewed-by: Filipe Manana <[email protected]>
Signed-off-by: Josef Bacik <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
okias pushed a commit that referenced this pull request Sep 3, 2020
…s metrics" test

Linux 5.9 introduced perf test case "Parse and process metrics" and
on s390 this test case always dumps core:

  [root@t35lp67 perf]# ./perf test -vvvv -F 67
  67: Parse and process metrics                             :
  --- start ---
  metric expr inst_retired.any / cpu_clk_unhalted.thread for IPC
  parsing metric: inst_retired.any / cpu_clk_unhalted.thread
  Segmentation fault (core dumped)
  [root@t35lp67 perf]#

I debugged this core dump and gdb shows this call chain:

  (gdb) where
   #0  0x000003ffabc3192a in __strnlen_c_1 () from /lib64/libc.so.6
   #1  0x000003ffabc293de in strcasestr () from /lib64/libc.so.6
   #2  0x0000000001102ba2 in match_metric(list=0x1e6ea20 "inst_retired.any",
            n=<optimized out>)
       at util/metricgroup.c:368
   #3  find_metric (map=<optimized out>, map=<optimized out>,
           metric=0x1e6ea20 "inst_retired.any")
      at util/metricgroup.c:765
   #4  __resolve_metric (ids=0x0, map=<optimized out>, metric_list=0x0,
           metric_no_group=<optimized out>, m=<optimized out>)
      at util/metricgroup.c:844
   #5  resolve_metric (ids=0x0, map=0x0, metric_list=0x0,
          metric_no_group=<optimized out>)
      at util/metricgroup.c:881
   #6  metricgroup__add_metric (metric=<optimized out>,
        metric_no_group=metric_no_group@entry=false, events=<optimized out>,
        events@entry=0x3ffd84fb878, metric_list=0x0,
        metric_list@entry=0x3ffd84fb868, map=0x0)
      at util/metricgroup.c:943
   #7  0x00000000011034ae in metricgroup__add_metric_list (map=0x13f9828 <map>,
        metric_list=0x3ffd84fb868, events=0x3ffd84fb878,
        metric_no_group=<optimized out>, list=<optimized out>)
      at util/metricgroup.c:988
   #8  parse_groups (perf_evlist=perf_evlist@entry=0x1e70260,
          str=str@entry=0x12f34b2 "IPC", metric_no_group=<optimized out>,
          metric_no_merge=<optimized out>,
          fake_pmu=fake_pmu@entry=0x1462f18 <perf_pmu.fake>,
          metric_events=0x3ffd84fba58, map=0x1)
      at util/metricgroup.c:1040
   grate-driver#9  0x0000000001103eb2 in metricgroup__parse_groups_test(
  	evlist=evlist@entry=0x1e70260, map=map@entry=0x13f9828 <map>,
  	str=str@entry=0x12f34b2 "IPC",
  	metric_no_group=metric_no_group@entry=false,
  	metric_no_merge=metric_no_merge@entry=false,
  	metric_events=0x3ffd84fba58)
      at util/metricgroup.c:1082
   grate-driver#10 0x00000000010c84d8 in __compute_metric (ratio2=0x0, name2=0x0,
          ratio1=<synthetic pointer>, name1=0x12f34b2 "IPC",
  	vals=0x3ffd84fbad8, name=0x12f34b2 "IPC")
      at tests/parse-metric.c:159
   grate-driver#11 compute_metric (ratio=<synthetic pointer>, vals=0x3ffd84fbad8,
  	name=0x12f34b2 "IPC")
      at tests/parse-metric.c:189
   grate-driver#12 test_ipc () at tests/parse-metric.c:208
.....
..... omitted many more lines

This test case was added with
commit 218ca91 ("perf tests: Add parse metric test for frontend metric").

When I compile with make DEBUG=y it works fine and I do not get a core dump.

It turned out that the above listed function call chain worked on a struct
pmu_event array which requires a trailing element with zeroes which was
missing. The marco map_for_each_event() loops over that array tests for members
metric_expr/metric_name/metric_group being non-NULL. Adding this element fixes
the issue.

Output after:

  [root@t35lp46 perf]# ./perf test 67
  67: Parse and process metrics                             : Ok
  [root@t35lp46 perf]#

Committer notes:

As Ian remarks, this is not s390 specific:

<quote Ian>
  This also shows up with address sanitizer on all architectures
  (perhaps change the patch title) and perhaps add a "Fixes: <commit>"
  tag.

  =================================================================
  ==4718==ERROR: AddressSanitizer: global-buffer-overflow on address
  0x55c93b4d59e8 at pc 0x55c93a1541e2 bp 0x7ffd24327c60 sp
  0x7ffd24327c58
  READ of size 8 at 0x55c93b4d59e8 thread T0
      #0 0x55c93a1541e1 in find_metric tools/perf/util/metricgroup.c:764:2
      #1 0x55c93a153e6c in __resolve_metric tools/perf/util/metricgroup.c:844:9
      #2 0x55c93a152f18 in resolve_metric tools/perf/util/metricgroup.c:881:9
      #3 0x55c93a1528db in metricgroup__add_metric
  tools/perf/util/metricgroup.c:943:9
      #4 0x55c93a151996 in metricgroup__add_metric_list
  tools/perf/util/metricgroup.c:988:9
      #5 0x55c93a1511b9 in parse_groups tools/perf/util/metricgroup.c:1040:8
      #6 0x55c93a1513e1 in metricgroup__parse_groups_test
  tools/perf/util/metricgroup.c:1082:9
      #7 0x55c93a0108ae in __compute_metric tools/perf/tests/parse-metric.c:159:8
      #8 0x55c93a010744 in compute_metric tools/perf/tests/parse-metric.c:189:9
      grate-driver#9 0x55c93a00f5ee in test_ipc tools/perf/tests/parse-metric.c:208:2
      grate-driver#10 0x55c93a00f1e8 in test__parse_metric
  tools/perf/tests/parse-metric.c:345:2
      grate-driver#11 0x55c939fd7202 in run_test tools/perf/tests/builtin-test.c:410:9
      grate-driver#12 0x55c939fd6736 in test_and_print tools/perf/tests/builtin-test.c:440:9
      grate-driver#13 0x55c939fd58c3 in __cmd_test tools/perf/tests/builtin-test.c:661:4
      grate-driver#14 0x55c939fd4e02 in cmd_test tools/perf/tests/builtin-test.c:807:9
      grate-driver#15 0x55c939e4763d in run_builtin tools/perf/perf.c:313:11
      grate-driver#16 0x55c939e46475 in handle_internal_command tools/perf/perf.c:365:8
      grate-driver#17 0x55c939e4737e in run_argv tools/perf/perf.c:409:2
      grate-driver#18 0x55c939e45f7e in main tools/perf/perf.c:539:3

  0x55c93b4d59e8 is located 0 bytes to the right of global variable
  'pme_test' defined in 'tools/perf/tests/parse-metric.c:17:25'
  (0x55c93b4d54a0) of size 1352
  SUMMARY: AddressSanitizer: global-buffer-overflow
  tools/perf/util/metricgroup.c:764:2 in find_metric
  Shadow bytes around the buggy address:
    0x0ab9a7692ae0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ab9a7692af0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ab9a7692b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ab9a7692b10: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ab9a7692b20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  =>0x0ab9a7692b30: 00 00 00 00 00 00 00 00 00 00 00 00 00[f9]f9 f9
    0x0ab9a7692b40: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
    0x0ab9a7692b50: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
    0x0ab9a7692b60: f9 f9 f9 f9 f9 f9 f9 f9 00 00 00 00 00 00 00 00
    0x0ab9a7692b70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ab9a7692b80: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
  Shadow byte legend (one shadow byte represents 8 application bytes):
    Addressable:           00
    Partially addressable: 01 02 03 04 05 06 07
    Heap left redzone:	   fa
    Freed heap region:	   fd
    Stack left redzone:	   f1
    Stack mid redzone:	   f2
    Stack right redzone:     f3
    Stack after return:	   f5
    Stack use after scope:   f8
    Global redzone:          f9
    Global init order:	   f6
    Poisoned by user:        f7
    Container overflow:	   fc
    Array cookie:            ac
    Intra object redzone:    bb
    ASan internal:           fe
    Left alloca redzone:     ca
    Right alloca redzone:    cb
    Shadow gap:              cc
</quote>

I'm also adding the missing "Fixes" tag and setting just .name to NULL,
as doing it that way is more compact (the compiler will zero out
everything else) and the table iterators look for .name being NULL as
the sentinel marking the end of the table.

Fixes: 0a507af ("perf tests: Add parse metric test for ipc metric")
Signed-off-by: Thomas Richter <[email protected]>
Reviewed-by: Sumanth Korikkar <[email protected]>
Acked-by: Ian Rogers <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
okias pushed a commit that referenced this pull request Feb 3, 2021
While testing the error paths in relocation, I hit the following lockdep
splat:

  ======================================================
  WARNING: possible circular locking dependency detected
  5.10.0-rc3+ #206 Not tainted
  ------------------------------------------------------
  btrfs-balance/1571 is trying to acquire lock:
  ffff8cdbcc8f77d0 (&head_ref->mutex){+.+.}-{3:3}, at: btrfs_lookup_extent_info+0x156/0x3b0

  but task is already holding lock:
  ffff8cdbc54adbf8 (btrfs-tree-00){++++}-{3:3}, at: __btrfs_tree_lock+0x27/0x100

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #2 (btrfs-tree-00){++++}-{3:3}:
	 down_write_nested+0x43/0x80
	 __btrfs_tree_lock+0x27/0x100
	 btrfs_search_slot+0x248/0x890
	 relocate_tree_blocks+0x490/0x650
	 relocate_block_group+0x1ba/0x5d0
	 kretprobe_trampoline+0x0/0x50

  -> #1 (btrfs-csum-01){++++}-{3:3}:
	 down_read_nested+0x43/0x130
	 __btrfs_tree_read_lock+0x27/0x100
	 btrfs_read_lock_root_node+0x31/0x40
	 btrfs_search_slot+0x5ab/0x890
	 btrfs_del_csums+0x10b/0x3c0
	 __btrfs_free_extent+0x49d/0x8e0
	 __btrfs_run_delayed_refs+0x283/0x11f0
	 btrfs_run_delayed_refs+0x86/0x220
	 btrfs_start_dirty_block_groups+0x2ba/0x520
	 kretprobe_trampoline+0x0/0x50

  -> #0 (&head_ref->mutex){+.+.}-{3:3}:
	 __lock_acquire+0x1167/0x2150
	 lock_acquire+0x116/0x3e0
	 __mutex_lock+0x7e/0x7b0
	 btrfs_lookup_extent_info+0x156/0x3b0
	 walk_down_proc+0x1c3/0x280
	 walk_down_tree+0x64/0xe0
	 btrfs_drop_subtree+0x182/0x260
	 do_relocation+0x52e/0x660
	 relocate_tree_blocks+0x2ae/0x650
	 relocate_block_group+0x1ba/0x5d0
	 kretprobe_trampoline+0x0/0x50

  other info that might help us debug this:

  Chain exists of:
    &head_ref->mutex --> btrfs-csum-01 --> btrfs-tree-00

   Possible unsafe locking scenario:

	 CPU0                    CPU1
	 ----                    ----
    lock(btrfs-tree-00);
				 lock(btrfs-csum-01);
				 lock(btrfs-tree-00);
    lock(&head_ref->mutex);

   *** DEADLOCK ***

  5 locks held by btrfs-balance/1571:
   #0: ffff8cdb89749ff8 (&fs_info->delete_unused_bgs_mutex){+.+.}-{3:3}, at: btrfs_balance+0x563/0xf40
   #1: ffff8cdb89748838 (&fs_info->cleaner_mutex){+.+.}-{3:3}, at: btrfs_relocate_block_group+0x156/0x300
   #2: ffff8cdbc2c16650 (sb_internal#2){.+.+}-{0:0}, at: start_transaction+0x413/0x5c0
   #3: ffff8cdbc135f538 (btrfs-treloc-01){+.+.}-{3:3}, at: __btrfs_tree_lock+0x27/0x100
   #4: ffff8cdbc54adbf8 (btrfs-tree-00){++++}-{3:3}, at: __btrfs_tree_lock+0x27/0x100

  stack backtrace:
  CPU: 1 PID: 1571 Comm: btrfs-balance Not tainted 5.10.0-rc3+ #206
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
  Call Trace:
   dump_stack+0x8b/0xb0
   check_noncircular+0xcf/0xf0
   ? trace_call_bpf+0x139/0x260
   __lock_acquire+0x1167/0x2150
   lock_acquire+0x116/0x3e0
   ? btrfs_lookup_extent_info+0x156/0x3b0
   __mutex_lock+0x7e/0x7b0
   ? btrfs_lookup_extent_info+0x156/0x3b0
   ? btrfs_lookup_extent_info+0x156/0x3b0
   ? release_extent_buffer+0x124/0x170
   ? _raw_spin_unlock+0x1f/0x30
   ? release_extent_buffer+0x124/0x170
   btrfs_lookup_extent_info+0x156/0x3b0
   walk_down_proc+0x1c3/0x280
   walk_down_tree+0x64/0xe0
   btrfs_drop_subtree+0x182/0x260
   do_relocation+0x52e/0x660
   relocate_tree_blocks+0x2ae/0x650
   ? add_tree_block+0x149/0x1b0
   relocate_block_group+0x1ba/0x5d0
   elfcorehdr_read+0x40/0x40
   ? elfcorehdr_read+0x40/0x40
   ? btrfs_balance+0x796/0xf40
   ? __kthread_parkme+0x66/0x90
   ? btrfs_balance+0xf40/0xf40
   ? balance_kthread+0x37/0x50
   ? kthread+0x137/0x150
   ? __kthread_bind_mask+0x60/0x60
   ? ret_from_fork+0x1f/0x30

As you can see this is bogus, we never take another tree's lock under
the csum lock.  This happens because sometimes we have to read tree
blocks from disk without knowing which root they belong to during
relocation.  We defaulted to an owner of 0, which translates to an fs
tree.  This is fine as all fs trees have the same class, but obviously
isn't fine if the block belongs to a COW only tree.

Thankfully COW only trees only have their owners root as a reference to
them, and since we already look up the extent information during
relocation, go ahead and check and see if this block might belong to a
COW only tree, and if so save the owner in the tree_block struct.  This
allows us to read_tree_block with the proper owner, which gets rid of
this lockdep splat.

Signed-off-by: Josef Bacik <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
okias pushed a commit that referenced this pull request Feb 3, 2021
Add 3 new tests for tag-based KASAN modes:

1. Check that match-all pointer tag is not assigned randomly.
2. Check that 0xff works as a match-all pointer tag.
3. Check that there are no match-all memory tags.

Note, that test #3 causes a significant number (255) of KASAN reports
to be printed during execution for the SW_TAGS mode.

Link: https://linux-review.googlesource.com/id/I78f1375efafa162b37f3abcb2c5bc2f3955dfd8e
Link: https://lkml.kernel.org/r/da841a5408e2204bf25f3b23f70540a65844e8a4.1610733117.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Reviewed-by: Marco Elver <[email protected]>
Reviewed-by: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Branislav Rankov <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Evgenii Stepanov <[email protected]>
Cc: Kevin Brodsky <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Stephen Rothwell <[email protected]>
okias pushed a commit that referenced this pull request Feb 23, 2021
Add 3 new tests for tag-based KASAN modes:

1. Check that match-all pointer tag is not assigned randomly.
2. Check that 0xff works as a match-all pointer tag.
3. Check that there are no match-all memory tags.

Note, that test #3 causes a significant number (255) of KASAN reports
to be printed during execution for the SW_TAGS mode.

Link: https://linux-review.googlesource.com/id/I78f1375efafa162b37f3abcb2c5bc2f3955dfd8e
Link: https://lkml.kernel.org/r/da841a5408e2204bf25f3b23f70540a65844e8a4.1610733117.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Reviewed-by: Marco Elver <[email protected]>
Reviewed-by: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Branislav Rankov <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Evgenii Stepanov <[email protected]>
Cc: Kevin Brodsky <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Stephen Rothwell <[email protected]>
okias pushed a commit that referenced this pull request Feb 6, 2022
…_work

[ Upstream commit ed05c7c ]

When enable debug config, it print below warning while shut down wlan
interface shuh as run "ifconfig wlan0 down".

The reason is because ar->regd_update_work is ran once, and it is will
call wiphy_lock(ar->hw->wiphy) in function ath11k_regd_update() which
is running in workqueue of ieee80211_local queued by ieee80211_queue_work().
Another thread from "ifconfig wlan0 down" will also accuqire the lock
by wiphy_lock(sdata->local->hw.wiphy) in function ieee80211_stop(), and
then it call ieee80211_stop_device() to flush_workqueue(local->workqueue),
this will wait the workqueue of ieee80211_local finished. Then deadlock
will happen easily if the two thread run meanwhile.

Below warning disappeared after this change.

[  914.088798] ath11k_pci 0000:05:00.0: mac remove interface (vdev 0)
[  914.088806] ath11k_pci 0000:05:00.0: mac stop 11d scan
[  914.088810] ath11k_pci 0000:05:00.0: mac stop 11d vdev id 0
[  914.088827] ath11k_pci 0000:05:00.0: htc ep 2 consumed 1 credits (total 0)
[  914.088841] ath11k_pci 0000:05:00.0: send 11d scan stop vdev id 0
[  914.088849] ath11k_pci 0000:05:00.0: htc insufficient credits ep 2 required 1 available 0
[  914.088856] ath11k_pci 0000:05:00.0: htc insufficient credits ep 2 required 1 available 0
[  914.096434] ath11k_pci 0000:05:00.0: rx ce pipe 2 len 16
[  914.096442] ath11k_pci 0000:05:00.0: htc ep 2 got 1 credits (total 1)
[  914.096481] ath11k_pci 0000:05:00.0: htc ep 2 consumed 1 credits (total 0)
[  914.096491] ath11k_pci 0000:05:00.0: WMI vdev delete id 0
[  914.111598] ath11k_pci 0000:05:00.0: rx ce pipe 2 len 16
[  914.111628] ath11k_pci 0000:05:00.0: htc ep 2 got 1 credits (total 1)
[  914.114659] ath11k_pci 0000:05:00.0: rx ce pipe 2 len 20
[  914.114742] ath11k_pci 0000:05:00.0: htc rx completion ep 2 skb         pK-error
[  914.115977] ath11k_pci 0000:05:00.0: vdev delete resp for vdev id 0
[  914.116685] ath11k_pci 0000:05:00.0: vdev 00:03:7f:29:61:11 deleted, vdev_id 0

[  914.117583] ======================================================
[  914.117592] WARNING: possible circular locking dependency detected
[  914.117600] 5.16.0-rc1-wt-ath+ #1 Tainted: G           OE
[  914.117611] ------------------------------------------------------
[  914.117618] ifconfig/2805 is trying to acquire lock:
[  914.117628] ffff9c00a62bb548 ((wq_completion)phy0){+.+.}-{0:0}, at: flush_workqueue+0x87/0x470
[  914.117674]
               but task is already holding lock:
[  914.117682] ffff9c00baea07d0 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: ieee80211_stop+0x38/0x180 [mac80211]
[  914.117872]
               which lock already depends on the new lock.

[  914.117880]
               the existing dependency chain (in reverse order) is:
[  914.117888]
               -> #3 (&rdev->wiphy.mtx){+.+.}-{4:4}:
[  914.117910]        __mutex_lock+0xa0/0x9c0
[  914.117930]        mutex_lock_nested+0x1b/0x20
[  914.117944]        reg_process_self_managed_hints+0x3a/0xb0 [cfg80211]
[  914.118093]        wiphy_regulatory_register+0x47/0x80 [cfg80211]
[  914.118229]        wiphy_register+0x84f/0x9c0 [cfg80211]
[  914.118353]        ieee80211_register_hw+0x6b1/0xd90 [mac80211]
[  914.118486]        ath11k_mac_register+0x6af/0xb60 [ath11k]
[  914.118550]        ath11k_core_qmi_firmware_ready+0x383/0x4a0 [ath11k]
[  914.118598]        ath11k_qmi_driver_event_work+0x347/0x4a0 [ath11k]
[  914.118656]        process_one_work+0x228/0x670
[  914.118669]        worker_thread+0x4d/0x440
[  914.118680]        kthread+0x16d/0x1b0
[  914.118697]        ret_from_fork+0x22/0x30
[  914.118714]
               -> #2 (rtnl_mutex){+.+.}-{4:4}:
[  914.118736]        __mutex_lock+0xa0/0x9c0
[  914.118751]        mutex_lock_nested+0x1b/0x20
[  914.118767]        rtnl_lock+0x17/0x20
[  914.118783]        ath11k_regd_update+0x15a/0x260 [ath11k]
[  914.118841]        ath11k_regd_update_work+0x15/0x20 [ath11k]
[  914.118897]        process_one_work+0x228/0x670
[  914.118909]        worker_thread+0x4d/0x440
[  914.118920]        kthread+0x16d/0x1b0
[  914.118934]        ret_from_fork+0x22/0x30
[  914.118948]
               -> #1 ((work_completion)(&ar->regd_update_work)){+.+.}-{0:0}:
[  914.118972]        process_one_work+0x1fa/0x670
[  914.118984]        worker_thread+0x4d/0x440
[  914.118996]        kthread+0x16d/0x1b0
[  914.119010]        ret_from_fork+0x22/0x30
[  914.119023]
               -> #0 ((wq_completion)phy0){+.+.}-{0:0}:
[  914.119045]        __lock_acquire+0x146d/0x1cf0
[  914.119057]        lock_acquire+0x19b/0x360
[  914.119067]        flush_workqueue+0xae/0x470
[  914.119084]        ieee80211_stop_device+0x3b/0x50 [mac80211]
[  914.119260]        ieee80211_do_stop+0x5d7/0x830 [mac80211]
[  914.119409]        ieee80211_stop+0x45/0x180 [mac80211]
[  914.119557]        __dev_close_many+0xb3/0x120
[  914.119573]        __dev_change_flags+0xc3/0x1d0
[  914.119590]        dev_change_flags+0x29/0x70
[  914.119605]        devinet_ioctl+0x653/0x810
[  914.119620]        inet_ioctl+0x193/0x1e0
[  914.119631]        sock_do_ioctl+0x4d/0xf0
[  914.119649]        sock_ioctl+0x262/0x340
[  914.119665]        __x64_sys_ioctl+0x96/0xd0
[  914.119678]        do_syscall_64+0x3d/0xd0
[  914.119694]        entry_SYSCALL_64_after_hwframe+0x44/0xae
[  914.119709]
               other info that might help us debug this:

[  914.119717] Chain exists of:
                 (wq_completion)phy0 --> rtnl_mutex --> &rdev->wiphy.mtx

[  914.119745]  Possible unsafe locking scenario:

[  914.119752]        CPU0                    CPU1
[  914.119758]        ----                    ----
[  914.119765]   lock(&rdev->wiphy.mtx);
[  914.119778]                                lock(rtnl_mutex);
[  914.119792]                                lock(&rdev->wiphy.mtx);
[  914.119807]   lock((wq_completion)phy0);
[  914.119819]
                *** DEADLOCK ***

[  914.119827] 2 locks held by ifconfig/2805:
[  914.119837]  #0: ffffffffba3dc010 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock+0x17/0x20
[  914.119872]  #1: ffff9c00baea07d0 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: ieee80211_stop+0x38/0x180 [mac80211]
[  914.120039]
               stack backtrace:
[  914.120048] CPU: 0 PID: 2805 Comm: ifconfig Tainted: G           OE     5.16.0-rc1-wt-ath+ #1
[  914.120064] Hardware name: LENOVO 418065C/418065C, BIOS 83ET63WW (1.33 ) 07/29/2011
[  914.120074] Call Trace:
[  914.120084]  <TASK>
[  914.120094]  dump_stack_lvl+0x73/0xa4
[  914.120119]  dump_stack+0x10/0x12
[  914.120135]  print_circular_bug.isra.44+0x221/0x2e0
[  914.120165]  check_noncircular+0x106/0x150
[  914.120203]  __lock_acquire+0x146d/0x1cf0
[  914.120215]  ? __lock_acquire+0x146d/0x1cf0
[  914.120245]  lock_acquire+0x19b/0x360
[  914.120259]  ? flush_workqueue+0x87/0x470
[  914.120286]  ? lockdep_init_map_type+0x6b/0x250
[  914.120310]  flush_workqueue+0xae/0x470
[  914.120327]  ? flush_workqueue+0x87/0x470
[  914.120344]  ? lockdep_hardirqs_on+0xd7/0x150
[  914.120391]  ieee80211_stop_device+0x3b/0x50 [mac80211]
[  914.120565]  ? ieee80211_stop_device+0x3b/0x50 [mac80211]
[  914.120736]  ieee80211_do_stop+0x5d7/0x830 [mac80211]
[  914.120906]  ieee80211_stop+0x45/0x180 [mac80211]
[  914.121060]  __dev_close_many+0xb3/0x120
[  914.121081]  __dev_change_flags+0xc3/0x1d0
[  914.121109]  dev_change_flags+0x29/0x70
[  914.121131]  devinet_ioctl+0x653/0x810
[  914.121149]  ? __might_fault+0x77/0x80
[  914.121179]  inet_ioctl+0x193/0x1e0
[  914.121194]  ? inet_ioctl+0x193/0x1e0
[  914.121218]  ? __might_fault+0x77/0x80
[  914.121238]  ? _copy_to_user+0x68/0x80
[  914.121266]  sock_do_ioctl+0x4d/0xf0
[  914.121283]  ? inet_stream_connect+0x60/0x60
[  914.121297]  ? sock_do_ioctl+0x4d/0xf0
[  914.121329]  sock_ioctl+0x262/0x340
[  914.121347]  ? sock_ioctl+0x262/0x340
[  914.121362]  ? exit_to_user_mode_prepare+0x13b/0x280
[  914.121388]  ? syscall_enter_from_user_mode+0x20/0x50
[  914.121416]  __x64_sys_ioctl+0x96/0xd0
[  914.121430]  ? br_ioctl_call+0x90/0x90
[  914.121445]  ? __x64_sys_ioctl+0x96/0xd0
[  914.121465]  do_syscall_64+0x3d/0xd0
[  914.121482]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[  914.121497] RIP: 0033:0x7f0ed051737b
[  914.121513] Code: 0f 1e fa 48 8b 05 15 3b 0d 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e5 3a 0d 00 f7 d8 64 89 01 48
[  914.121527] RSP: 002b:00007fff7be38b98 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
[  914.121544] RAX: ffffffffffffffda RBX: 00007fff7be38ba0 RCX: 00007f0ed051737b
[  914.121555] RDX: 00007fff7be38ba0 RSI: 0000000000008914 RDI: 0000000000000004
[  914.121566] RBP: 00007fff7be38c60 R08: 000000000000000a R09: 0000000000000001
[  914.121576] R10: 0000000000000000 R11: 0000000000000202 R12: 00000000fffffffe
[  914.121586] R13: 0000000000000004 R14: 0000000000000000 R15: 0000000000000000
[  914.121620]  </TASK>

Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-01720.1-QCAHSPSWPL_V1_V2_SILICONZ_LITE-1

Signed-off-by: Wen Gong <[email protected]>
Signed-off-by: Kalle Valo <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sasha Levin <[email protected]>
okias pushed a commit that referenced this pull request Jul 31, 2023
[ Upstream commit 99d4850 ]

Found by leak sanitizer:
```
==1632594==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 21 byte(s) in 1 object(s) allocated from:
    #0 0x7f2953a7077b in __interceptor_strdup ../../../../src/libsanitizer/asan/asan_interceptors.cpp:439
    #1 0x556701d6fbbf in perf_env__read_cpuid util/env.c:369
    #2 0x556701d70589 in perf_env__cpuid util/env.c:465
    #3 0x55670204bba2 in x86__is_amd_cpu arch/x86/util/env.c:14
    #4 0x5567020487a2 in arch__post_evsel_config arch/x86/util/evsel.c:83
    #5 0x556701d8f78b in evsel__config util/evsel.c:1366
    #6 0x556701ef5872 in evlist__config util/record.c:108
    #7 0x556701cd6bcd in test__PERF_RECORD tests/perf-record.c:112
    #8 0x556701cacd07 in run_test tests/builtin-test.c:236
    grate-driver#9 0x556701cacfac in test_and_print tests/builtin-test.c:265
    grate-driver#10 0x556701cadddb in __cmd_test tests/builtin-test.c:402
    grate-driver#11 0x556701caf2aa in cmd_test tests/builtin-test.c:559
    grate-driver#12 0x556701d3b557 in run_builtin tools/perf/perf.c:323
    grate-driver#13 0x556701d3bac8 in handle_internal_command tools/perf/perf.c:377
    grate-driver#14 0x556701d3be90 in run_argv tools/perf/perf.c:421
    grate-driver#15 0x556701d3c3f8 in main tools/perf/perf.c:537
    grate-driver#16 0x7f2952a46189 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58

SUMMARY: AddressSanitizer: 21 byte(s) leaked in 1 allocation(s).
```

Fixes: f7b58cb ("perf mem/c2c: Add load store event mappings for AMD")
Signed-off-by: Ian Rogers <[email protected]>
Acked-by: Ravi Bangoria <[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: Ravi Bangoria <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
okias pushed a commit that referenced this pull request Jul 31, 2023
[ Upstream commit b684c09 ]

ppc_save_regs() skips one stack frame while saving the CPU register states.
Instead of saving current R1, it pulls the previous stack frame pointer.

When vmcores caused by direct panic call (such as `echo c >
/proc/sysrq-trigger`), are debugged with gdb, gdb fails to show the
backtrace correctly. On further analysis, it was found that it was because
of mismatch between r1 and NIP.

GDB uses NIP to get current function symbol and uses corresponding debug
info of that function to unwind previous frames, but due to the
mismatching r1 and NIP, the unwinding does not work, and it fails to
unwind to the 2nd frame and hence does not show the backtrace.

GDB backtrace with vmcore of kernel without this patch:

---------
(gdb) bt
 #0  0xc0000000002a53e8 in crash_setup_regs (oldregs=<optimized out>,
    newregs=0xc000000004f8f8d8) at ./arch/powerpc/include/asm/kexec.h:69
 #1  __crash_kexec (regs=<optimized out>) at kernel/kexec_core.c:974
 #2  0x0000000000000063 in ?? ()
 #3  0xc000000003579320 in ?? ()
---------

Further analysis revealed that the mismatch occurred because
"ppc_save_regs" was saving the previous stack's SP instead of the current
r1. This patch fixes this by storing current r1 in the saved pt_regs.

GDB backtrace with vmcore of patched kernel:

--------
(gdb) bt
 #0  0xc0000000002a53e8 in crash_setup_regs (oldregs=0x0, newregs=0xc00000000670b8d8)
    at ./arch/powerpc/include/asm/kexec.h:69
 #1  __crash_kexec (regs=regs@entry=0x0) at kernel/kexec_core.c:974
 #2  0xc000000000168918 in panic (fmt=fmt@entry=0xc000000001654a60 "sysrq triggered crash\n")
    at kernel/panic.c:358
 #3  0xc000000000b735f8 in sysrq_handle_crash (key=<optimized out>) at drivers/tty/sysrq.c:155
 #4  0xc000000000b742cc in __handle_sysrq (key=key@entry=99, check_mask=check_mask@entry=false)
    at drivers/tty/sysrq.c:602
 #5  0xc000000000b7506c in write_sysrq_trigger (file=<optimized out>, buf=<optimized out>,
    count=2, ppos=<optimized out>) at drivers/tty/sysrq.c:1163
 #6  0xc00000000069a7bc in pde_write (ppos=<optimized out>, count=<optimized out>,
    buf=<optimized out>, file=<optimized out>, pde=0xc00000000362cb40) at fs/proc/inode.c:340
 #7  proc_reg_write (file=<optimized out>, buf=<optimized out>, count=<optimized out>,
    ppos=<optimized out>) at fs/proc/inode.c:352
 #8  0xc0000000005b3bbc in vfs_write (file=file@entry=0xc000000006aa6b00,
    buf=buf@entry=0x61f498b4f60 <error: Cannot access memory at address 0x61f498b4f60>,
    count=count@entry=2, pos=pos@entry=0xc00000000670bda0) at fs/read_write.c:582
 grate-driver#9  0xc0000000005b4264 in ksys_write (fd=<optimized out>,
    buf=0x61f498b4f60 <error: Cannot access memory at address 0x61f498b4f60>, count=2)
    at fs/read_write.c:637
 grate-driver#10 0xc00000000002ea2c in system_call_exception (regs=0xc00000000670be80, r0=<optimized out>)
    at arch/powerpc/kernel/syscall.c:171
 grate-driver#11 0xc00000000000c270 in system_call_vectored_common ()
    at arch/powerpc/kernel/interrupt_64.S:192
--------

Nick adds:
  So this now saves regs as though it was an interrupt taken in the
  caller, at the instruction after the call to ppc_save_regs, whereas
  previously the NIP was there, but R1 came from the caller's caller and
  that mismatch is what causes gdb's dwarf unwinder to go haywire.

Signed-off-by: Aditya Gupta <[email protected]>
Fixes: d16a58f ("powerpc: Improve ppc_save_regs()")
Reivewed-by: Nicholas Piggin <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://msgid.link/[email protected]
Signed-off-by: Sasha Levin <[email protected]>
okias pushed a commit that referenced this pull request Dec 4, 2023
When scanning namespaces, it is possible to get valid data from the first
call to nvme_identify_ns() in nvme_alloc_ns(), but not from the second
call in nvme_update_ns_info_block().  In particular, if the NSID becomes
inactive between the two commands, a storage device may return a buffer
filled with zero as per 4.1.5.1.  In this case, we can get a kernel crash
due to a divide-by-zero in blk_stack_limits() because ns->lba_shift will
be set to zero.

PID: 326      TASK: ffff95fec3cd8000  CPU: 29   COMMAND: "kworker/u98:10"
 #0 [ffffad8f8702f9e0] machine_kexec at ffffffff91c76ec7
 #1 [ffffad8f8702fa38] __crash_kexec at ffffffff91dea4fa
 #2 [ffffad8f8702faf8] crash_kexec at ffffffff91deb788
 #3 [ffffad8f8702fb00] oops_end at ffffffff91c2e4bb
 #4 [ffffad8f8702fb20] do_trap at ffffffff91c2a4ce
 #5 [ffffad8f8702fb70] do_error_trap at ffffffff91c2a595
 #6 [ffffad8f8702fbb0] exc_divide_error at ffffffff928506e6
 #7 [ffffad8f8702fbd0] asm_exc_divide_error at ffffffff92a00926
    [exception RIP: blk_stack_limits+434]
    RIP: ffffffff92191872  RSP: ffffad8f8702fc80  RFLAGS: 00010246
    RAX: 0000000000000000  RBX: ffff95efa0c91800  RCX: 0000000000000001
    RDX: 0000000000000000  RSI: 0000000000000001  RDI: 0000000000000001
    RBP: 00000000ffffffff   R8: ffff95fec7df35a8   R9: 0000000000000000
    R10: 0000000000000000  R11: 0000000000000001  R12: 0000000000000000
    R13: 0000000000000000  R14: 0000000000000000  R15: ffff95fed33c09a8
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #8 [ffffad8f8702fce0] nvme_update_ns_info_block at ffffffffc06d3533 [nvme_core]
 grate-driver#9 [ffffad8f8702fd18] nvme_scan_ns at ffffffffc06d6fa7 [nvme_core]

This happened when the check for valid data was moved out of nvme_identify_ns()
into one of the callers.  Fix this by checking in both callers.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=218186
Fixes: 0dd6fff ("nvme: bring back auto-removal of deleted namespaces during sequential scan")
Cc: [email protected]
Signed-off-by: Ewan D. Milne <[email protected]>
Signed-off-by: Keith Busch <[email protected]>
okias pushed a commit that referenced this pull request Dec 4, 2023
Currently DP driver is executed independent of PM runtime framework.
This leads msm eDP panel can not being detected by edp_panel driver
during generic_edp_panel_probe() due to AUX DPCD read failed at
edp panel driver. Incorporate PM runtime framework into DP driver so
that host controller's power and clocks are enable/disable through
PM runtime mechanism.  Once PM runtime framework is incorporated into
DP driver, waking up device from power up path is not necessary. Hence
remove it.

After incorporating pm_runtime framework into eDP/DP driver,
dp_pm_suspend() to handle power off both DP phy and controller during
suspend and dp_pm_resume() to handle power on both DP phy and controller
during resume are not necessary. Therefore both dp_pm_suspend() and
dp_pm_resume() are dropped and replace with dp_pm_runtime_suspend() and
dp_pm_runtime_resume() respectively.

Changes in v9:
-- silent compiler warning message at dp_power_init() and dp_power_deinit()
   with W1 flag

Changes in v7:
-- add comments to dp_pm_runtime_resume()
-- add comments to dp_bridge_hpd_enable()
-- delete dp->hpd_state = ST_DISCONNECTED from dp_bridge_hpd_notify()

Changes in v6:
-- delete dp_power_client_deinit(dp->power);
-- remove if (!dp->dp_display.is_edp) condition checkout at plug_handle()
-- remove if (!dp->dp_display.is_edp) condition checkout at unplug_handle()
-- add IRQF_NO_AUTOEN to devm_request_irq()
-- add enable_irq() and disable_irq() to pm_runtime_resume()/suspend()
-- del dp->hpd_state = ST_DISCONNECTED from dp_bridge_hpd_disable()

Changes in v5:
-- remove pm_runtime_put_autosuspend feature, use pm_runtime_put_sync()
-- squash add pm_runtime_force_suspend()/resume() patch into this patch

Changes in v4:
-- reworded commit text to explain why pm_framework is required for
   edp panel
-- reworded commit text to explain autosuspend is choiced
-- delete EV_POWER_PM_GET and PM_EV_POWER_PUT from changes #3
-- delete dp_display_pm_get() and dp_display_pm_Put() from changes #3
-- return value from pm_runtime_resume_and_get() directly
-- check return value of devm_pm_runtime_enable()
-- delete pm_runtime_xxx from dp_display_remove()
-- drop dp_display_host_init() from EV_HPD_INIT_SETUP
-- drop both dp_pm_prepare() and dp_pm_compete() from this change
-- delete ST_SUSPENDED state
-- rewording commit text to add more details regrading the purpose
   of this change

Changes in v3:
-- incorporate removing pm_runtime_xx() from dp_pwer.c to this patch
-- use pm_runtime_resume_and_get() instead of pm_runtime_get()
-- error checking pm_runtime_resume_and_get() return value
-- add EV_POWER_PM_GET and PM_EV_POWER_PUT to handle HPD_GPIO case
-- replace dp_pm_suspend() with pm_runtime_force_suspend()
-- replace dp_pm_resume() with pm_runtime_force_resume()

Signed-off-by: Kuogee Hsieh <[email protected]>
Reviewed-by: Dmitry Baryshkov <[email protected]>
okias pushed a commit that referenced this pull request Dec 18, 2023
Petr Machata says:

====================
mlxsw: CFF flood mode: NVE underlay configuration

Recently, support for CFF flood mode (for Compressed FID Flooding) was
added to the mlxsw driver. The most recent patchset has a detailed coverage
of what CFF is and what has changed and how:

    https://lore.kernel.org/netdev/[email protected]/

In CFF flood mode, each FID allocates a handful (in our implementation two
or three) consecutive PGT entries. One entry holds the flood vector for
unknown-UC traffic, one for MC, one for BC.

To determine how to look up flood vectors, the CFF flood mode uses a
concept of flood profiles, which are IDs that reference mappings from
traffic types to offsets. In the case of CFF flood mode, the offset in
question is applied to the PGT address configured at a FID. The same
mechanism is used by NVE underlay for flooding. Again the profile ID and
the traffic type determine the offset to apply, this time to KVD address
used to look up flooding entries. Since mlxsw configures NVE underlay flood
the same regardless of traffic type, only one offset was ever needed: the
zero, which is the default, and thus no explicit configuration was needed.

Now that CFF uses profiles as well, it would be better to configure the
profile used by NVE explicitly, to make the configuration visible in the
source code.

In this patchset, add the register support (in patch #1), add a new traffic
type to refer to "any traffic at all" (in patch #2) and finally configure
the NVE profile explicitly for FIDs (in patch #3).

So far, the implicitly configured flood profile was the ID 0. With this
patchset, it changes to 3, leaving the 0 free to allow us to spot missed
configuration.
====================

Signed-off-by: David S. Miller <[email protected]>
okias pushed a commit that referenced this pull request Dec 18, 2023
syzbot found a potential circular dependency leading to a deadlock:
    -> #3 (&hdev->req_lock){+.+.}-{3:3}:
    __mutex_lock_common+0x1b6/0x1bc2 kernel/locking/mutex.c:599
    __mutex_lock kernel/locking/mutex.c:732 [inline]
    mutex_lock_nested+0x17/0x1c kernel/locking/mutex.c:784
    hci_dev_do_close+0x3f/0x9f net/bluetooth/hci_core.c:551
    hci_rfkill_set_block+0x130/0x1ac net/bluetooth/hci_core.c:935
    rfkill_set_block+0x1e6/0x3b8 net/rfkill/core.c:345
    rfkill_fop_write+0x2d8/0x672 net/rfkill/core.c:1274
    vfs_write+0x277/0xcf5 fs/read_write.c:594
    ksys_write+0x19b/0x2bd fs/read_write.c:650
    do_syscall_x64 arch/x86/entry/common.c:55 [inline]
    do_syscall_64+0x51/0xba arch/x86/entry/common.c:93
    entry_SYSCALL_64_after_hwframe+0x61/0xcb

    -> #2 (rfkill_global_mutex){+.+.}-{3:3}:
    __mutex_lock_common+0x1b6/0x1bc2 kernel/locking/mutex.c:599
    __mutex_lock kernel/locking/mutex.c:732 [inline]
    mutex_lock_nested+0x17/0x1c kernel/locking/mutex.c:784
    rfkill_register+0x30/0x7e3 net/rfkill/core.c:1045
    hci_register_dev+0x48f/0x96d net/bluetooth/hci_core.c:2622
    __vhci_create_device drivers/bluetooth/hci_vhci.c:341 [inline]
    vhci_create_device+0x3ad/0x68f drivers/bluetooth/hci_vhci.c:374
    vhci_get_user drivers/bluetooth/hci_vhci.c:431 [inline]
    vhci_write+0x37b/0x429 drivers/bluetooth/hci_vhci.c:511
    call_write_iter include/linux/fs.h:2109 [inline]
    new_sync_write fs/read_write.c:509 [inline]
    vfs_write+0xaa8/0xcf5 fs/read_write.c:596
    ksys_write+0x19b/0x2bd fs/read_write.c:650
    do_syscall_x64 arch/x86/entry/common.c:55 [inline]
    do_syscall_64+0x51/0xba arch/x86/entry/common.c:93
    entry_SYSCALL_64_after_hwframe+0x61/0xcb

    -> #1 (&data->open_mutex){+.+.}-{3:3}:
    __mutex_lock_common+0x1b6/0x1bc2 kernel/locking/mutex.c:599
    __mutex_lock kernel/locking/mutex.c:732 [inline]
    mutex_lock_nested+0x17/0x1c kernel/locking/mutex.c:784
    vhci_send_frame+0x68/0x9c drivers/bluetooth/hci_vhci.c:75
    hci_send_frame+0x1cc/0x2ff net/bluetooth/hci_core.c:2989
    hci_sched_acl_pkt net/bluetooth/hci_core.c:3498 [inline]
    hci_sched_acl net/bluetooth/hci_core.c:3583 [inline]
    hci_tx_work+0xb94/0x1a60 net/bluetooth/hci_core.c:3654
    process_one_work+0x901/0xfb8 kernel/workqueue.c:2310
    worker_thread+0xa67/0x1003 kernel/workqueue.c:2457
    kthread+0x36a/0x430 kernel/kthread.c:319
    ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

    -> #0 ((work_completion)(&hdev->tx_work)){+.+.}-{0:0}:
    check_prev_add kernel/locking/lockdep.c:3053 [inline]
    check_prevs_add kernel/locking/lockdep.c:3172 [inline]
    validate_chain kernel/locking/lockdep.c:3787 [inline]
    __lock_acquire+0x2d32/0x77fa kernel/locking/lockdep.c:5011
    lock_acquire+0x273/0x4d5 kernel/locking/lockdep.c:5622
    __flush_work+0xee/0x19f kernel/workqueue.c:3090
    hci_dev_close_sync+0x32f/0x1113 net/bluetooth/hci_sync.c:4352
    hci_dev_do_close+0x47/0x9f net/bluetooth/hci_core.c:553
    hci_rfkill_set_block+0x130/0x1ac net/bluetooth/hci_core.c:935
    rfkill_set_block+0x1e6/0x3b8 net/rfkill/core.c:345
    rfkill_fop_write+0x2d8/0x672 net/rfkill/core.c:1274
    vfs_write+0x277/0xcf5 fs/read_write.c:594
    ksys_write+0x19b/0x2bd fs/read_write.c:650
    do_syscall_x64 arch/x86/entry/common.c:55 [inline]
    do_syscall_64+0x51/0xba arch/x86/entry/common.c:93
    entry_SYSCALL_64_after_hwframe+0x61/0xcb

This change removes the need for acquiring the open_mutex in
vhci_send_frame, thus eliminating the potential deadlock while
maintaining the required packet ordering.

Fixes: 92d4abd ("Bluetooth: vhci: Fix race when opening vhci device")
Signed-off-by: Ying Hsu <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
okias pushed a commit that referenced this pull request Dec 18, 2023
Patch series "Multi-size THP for anonymous memory", v9.

A series to implement multi-size THP (mTHP) for anonymous memory
(previously called "small-sized THP" and "large anonymous folios").

The objective of this is to improve performance by allocating larger
chunks of memory during anonymous page faults:

1) Since SW (the kernel) is dealing with larger chunks of memory than base
   pages, there are efficiency savings to be had; fewer page faults, batched PTE
   and RMAP manipulation, reduced lru list, etc. In short, we reduce kernel
   overhead. This should benefit all architectures.
2) Since we are now mapping physically contiguous chunks of memory, we can take
   advantage of HW TLB compression techniques. A reduction in TLB pressure
   speeds up kernel and user space. arm64 systems have 2 mechanisms to coalesce
   TLB entries; "the contiguous bit" (architectural) and HPA (uarch).

This version incorporates David's feedback on the core patches (#3, #4)
and adds some RB and TB tags (see change log for details).

By default, the existing behaviour (and performance) is maintained.  The
user must explicitly enable multi-size THP to see the performance benefit.
This is done via a new sysfs interface (as recommended by David
Hildenbrand - thanks to David for the suggestion)!  This interface is
inspired by the existing per-hugepage-size sysfs interface used by
hugetlb, provides full backwards compatibility with the existing PMD-size
THP interface, and provides a base for future extensibility.  See [9] for
detailed discussion of the interface.

This series is based on mm-unstable (715b67adf4c8).


Prerequisites
=============

I'm removing this section on the basis that I don't believe what we were
previously calling prerequisites are really prerequisites anymore.  We
originally defined them when mTHP was a compile-time feature.  There is
now a runtime control to opt-in to mTHP; when disabled, correctness and
performance are as before.  When enabled, the code is still
correct/robust, but in the absence of the one remaining item (compaction)
there may be a performance impact in some corners.  See the old list in
the v8 cover letter at [8].  And a longer explanation of my thinking here
[10].

SUMMARY: I don't think we should hold this series up, waiting for the
items on the prerequisites list.  I believe this series should be ready
now so hopefully can be added to mm-unstable for some testing, then
fingers crossed for v6.8.


Testing
=======

The series includes patches for mm selftests to enlighten the cow and
khugepaged tests to explicitly test with multi-size THP, in the same way
that PMD-sized THP is tested.  The new tests all pass, and no regressions
are observed in the mm selftest suite.  I've also run my usual kernel
compilation and java script benchmarks without any issues.

Refer to my performance numbers posted with v6 [6].  (These are for
multi-size THP only - they do not include the arm64 contpte follow-on
series).

John Hubbard at Nvidia has indicated dramatic 10x performance improvements
for some workloads at [11].  (Observed using v6 of this series as well as
the arm64 contpte series).

Kefeng Wang at Huawei has also indicated he sees improvements at [12] although
there are some latency regressions also.

I've also checked that there is no regression in the write fault path when
mTHP is disabled using a microbenchmark.  I ran it for a baseline kernel,
as well as v8 and v9.  I repeated on Ampere Altra (bare metal) and Apple
M2 (VM):

|              |        m2 vm        |        altra        |
|--------------|---------------------|---------------------|
| kernel       |     mean |  std_rel |     mean |  std_rel |
|--------------|----------|----------|----------|----------|
| baseline     |   0.000% |   0.341% |   0.000% |   3.581% |
| anonfolio-v8 |   0.005% |   0.272% |   5.068% |   1.128% |
| anonfolio-v9 |  -0.013% |   0.442% |   0.107% |   1.788% |

There is no measurable difference on M2, but altra has a slow down in v8
which is fixed in v9 by moving the THP order check to be inline within
thp_vma_allowable_orders(), as suggested by David.


This patch (of 10):

In preparation for the introduction of anonymous multi-size THP, we would
like to be able to split them when they have unmapped subpages, in order
to free those unused pages under memory pressure.  So remove the
artificial requirement that the large folio needed to be at least
PMD-sized.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ryan Roberts <[email protected]>
Reviewed-by: Yu Zhao <[email protected]>
Reviewed-by: Yin Fengwei <[email protected]>
Reviewed-by: Matthew Wilcox (Oracle) <[email protected]>
Reviewed-by: David Hildenbrand <[email protected]>
Reviewed-by: Barry Song <[email protected]>
Tested-by: Kefeng Wang <[email protected]>
Tested-by: John Hubbard <[email protected]>
Cc: Alistair Popple <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: "Huang, Ying" <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Itaru Kitayama <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Cc: Luis Chamberlain <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Yang Shi <[email protected]>
Cc: Zi Yan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
okias pushed a commit that referenced this pull request Dec 18, 2023
Calling led_trigger_register() when attaching a PHY located on an SFP
module potentially (and practically) leads into a deadlock.
Fix this by not calling led_trigger_register() for PHYs localted on SFP
modules as such modules actually never got any LEDs.

======================================================
WARNING: possible circular locking dependency detected
6.7.0-rc4-next-20231208+ #0 Tainted: G           O
------------------------------------------------------
kworker/u8:2/43 is trying to acquire lock:
ffffffc08108c4e8 (triggers_list_lock){++++}-{3:3}, at: led_trigger_register+0x4c/0x1a8

but task is already holding lock:
ffffff80c5c6f318 (&sfp->sm_mutex){+.+.}-{3:3}, at: cleanup_module+0x2ba8/0x3120 [sfp]

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #3 (&sfp->sm_mutex){+.+.}-{3:3}:
       __mutex_lock+0x88/0x7a0
       mutex_lock_nested+0x20/0x28
       cleanup_module+0x2ae0/0x3120 [sfp]
       sfp_register_bus+0x5c/0x9c
       sfp_register_socket+0x48/0xd4
       cleanup_module+0x271c/0x3120 [sfp]
       platform_probe+0x64/0xb8
       really_probe+0x17c/0x3c0
       __driver_probe_device+0x78/0x164
       driver_probe_device+0x3c/0xd4
       __driver_attach+0xec/0x1f0
       bus_for_each_dev+0x60/0xa0
       driver_attach+0x20/0x28
       bus_add_driver+0x108/0x208
       driver_register+0x5c/0x118
       __platform_driver_register+0x24/0x2c
       init_module+0x28/0xa7c [sfp]
       do_one_initcall+0x70/0x2ec
       do_init_module+0x54/0x1e4
       load_module+0x1b78/0x1c8c
       __do_sys_init_module+0x1bc/0x2cc
       __arm64_sys_init_module+0x18/0x20
       invoke_syscall.constprop.0+0x4c/0xdc
       do_el0_svc+0x3c/0xbc
       el0_svc+0x34/0x80
       el0t_64_sync_handler+0xf8/0x124
       el0t_64_sync+0x150/0x154

-> #2 (rtnl_mutex){+.+.}-{3:3}:
       __mutex_lock+0x88/0x7a0
       mutex_lock_nested+0x20/0x28
       rtnl_lock+0x18/0x20
       set_device_name+0x30/0x130
       netdev_trig_activate+0x13c/0x1ac
       led_trigger_set+0x118/0x234
       led_trigger_write+0x104/0x17c
       sysfs_kf_bin_write+0x64/0x80
       kernfs_fop_write_iter+0x128/0x1b4
       vfs_write+0x178/0x2a4
       ksys_write+0x58/0xd4
       __arm64_sys_write+0x18/0x20
       invoke_syscall.constprop.0+0x4c/0xdc
       do_el0_svc+0x3c/0xbc
       el0_svc+0x34/0x80
       el0t_64_sync_handler+0xf8/0x124
       el0t_64_sync+0x150/0x154

-> #1 (&led_cdev->trigger_lock){++++}-{3:3}:
       down_write+0x4c/0x13c
       led_trigger_write+0xf8/0x17c
       sysfs_kf_bin_write+0x64/0x80
       kernfs_fop_write_iter+0x128/0x1b4
       vfs_write+0x178/0x2a4
       ksys_write+0x58/0xd4
       __arm64_sys_write+0x18/0x20
       invoke_syscall.constprop.0+0x4c/0xdc
       do_el0_svc+0x3c/0xbc
       el0_svc+0x34/0x80
       el0t_64_sync_handler+0xf8/0x124
       el0t_64_sync+0x150/0x154

-> #0 (triggers_list_lock){++++}-{3:3}:
       __lock_acquire+0x12a0/0x2014
       lock_acquire+0x100/0x2ac
       down_write+0x4c/0x13c
       led_trigger_register+0x4c/0x1a8
       phy_led_triggers_register+0x9c/0x214
       phy_attach_direct+0x154/0x36c
       phylink_attach_phy+0x30/0x60
       phylink_sfp_connect_phy+0x140/0x510
       sfp_add_phy+0x34/0x50
       init_module+0x15c/0xa7c [sfp]
       cleanup_module+0x1d94/0x3120 [sfp]
       cleanup_module+0x2bb4/0x3120 [sfp]
       process_one_work+0x1f8/0x4ec
       worker_thread+0x1e8/0x3d8
       kthread+0x104/0x110
       ret_from_fork+0x10/0x20

other info that might help us debug this:

Chain exists of:
  triggers_list_lock --> rtnl_mutex --> &sfp->sm_mutex

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&sfp->sm_mutex);
                               lock(rtnl_mutex);
                               lock(&sfp->sm_mutex);
  lock(triggers_list_lock);

 *** DEADLOCK ***

4 locks held by kworker/u8:2/43:
 #0: ffffff80c000f938 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x150/0x4ec
 #1: ffffffc08214bde8 ((work_completion)(&(&sfp->timeout)->work)){+.+.}-{0:0}, at: process_one_work+0x150/0x4ec
 #2: ffffffc0810902f8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x18/0x20
 #3: ffffff80c5c6f318 (&sfp->sm_mutex){+.+.}-{3:3}, at: cleanup_module+0x2ba8/0x3120 [sfp]

stack backtrace:
CPU: 0 PID: 43 Comm: kworker/u8:2 Tainted: G           O       6.7.0-rc4-next-20231208+ #0
Hardware name: Bananapi BPI-R4 (DT)
Workqueue: events_power_efficient cleanup_module [sfp]
Call trace:
 dump_backtrace+0xa8/0x10c
 show_stack+0x14/0x1c
 dump_stack_lvl+0x5c/0xa0
 dump_stack+0x14/0x1c
 print_circular_bug+0x328/0x430
 check_noncircular+0x124/0x134
 __lock_acquire+0x12a0/0x2014
 lock_acquire+0x100/0x2ac
 down_write+0x4c/0x13c
 led_trigger_register+0x4c/0x1a8
 phy_led_triggers_register+0x9c/0x214
 phy_attach_direct+0x154/0x36c
 phylink_attach_phy+0x30/0x60
 phylink_sfp_connect_phy+0x140/0x510
 sfp_add_phy+0x34/0x50
 init_module+0x15c/0xa7c [sfp]
 cleanup_module+0x1d94/0x3120 [sfp]
 cleanup_module+0x2bb4/0x3120 [sfp]
 process_one_work+0x1f8/0x4ec
 worker_thread+0x1e8/0x3d8
 kthread+0x104/0x110
 ret_from_fork+0x10/0x20

Signed-off-by: Daniel Golle <[email protected]>
Fixes: 01e5b72 ("net: phy: Add a binding for PHY LEDs")
Link: https://lore.kernel.org/r/102a9dce38bdf00215735d04cd4704458273ad9c.1702339354.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <[email protected]>
okias pushed a commit that referenced this pull request Dec 27, 2023
syzbot found a potential circular dependency leading to a deadlock:
    -> #3 (&hdev->req_lock){+.+.}-{3:3}:
    __mutex_lock_common+0x1b6/0x1bc2 kernel/locking/mutex.c:599
    __mutex_lock kernel/locking/mutex.c:732 [inline]
    mutex_lock_nested+0x17/0x1c kernel/locking/mutex.c:784
    hci_dev_do_close+0x3f/0x9f net/bluetooth/hci_core.c:551
    hci_rfkill_set_block+0x130/0x1ac net/bluetooth/hci_core.c:935
    rfkill_set_block+0x1e6/0x3b8 net/rfkill/core.c:345
    rfkill_fop_write+0x2d8/0x672 net/rfkill/core.c:1274
    vfs_write+0x277/0xcf5 fs/read_write.c:594
    ksys_write+0x19b/0x2bd fs/read_write.c:650
    do_syscall_x64 arch/x86/entry/common.c:55 [inline]
    do_syscall_64+0x51/0xba arch/x86/entry/common.c:93
    entry_SYSCALL_64_after_hwframe+0x61/0xcb

    -> #2 (rfkill_global_mutex){+.+.}-{3:3}:
    __mutex_lock_common+0x1b6/0x1bc2 kernel/locking/mutex.c:599
    __mutex_lock kernel/locking/mutex.c:732 [inline]
    mutex_lock_nested+0x17/0x1c kernel/locking/mutex.c:784
    rfkill_register+0x30/0x7e3 net/rfkill/core.c:1045
    hci_register_dev+0x48f/0x96d net/bluetooth/hci_core.c:2622
    __vhci_create_device drivers/bluetooth/hci_vhci.c:341 [inline]
    vhci_create_device+0x3ad/0x68f drivers/bluetooth/hci_vhci.c:374
    vhci_get_user drivers/bluetooth/hci_vhci.c:431 [inline]
    vhci_write+0x37b/0x429 drivers/bluetooth/hci_vhci.c:511
    call_write_iter include/linux/fs.h:2109 [inline]
    new_sync_write fs/read_write.c:509 [inline]
    vfs_write+0xaa8/0xcf5 fs/read_write.c:596
    ksys_write+0x19b/0x2bd fs/read_write.c:650
    do_syscall_x64 arch/x86/entry/common.c:55 [inline]
    do_syscall_64+0x51/0xba arch/x86/entry/common.c:93
    entry_SYSCALL_64_after_hwframe+0x61/0xcb

    -> #1 (&data->open_mutex){+.+.}-{3:3}:
    __mutex_lock_common+0x1b6/0x1bc2 kernel/locking/mutex.c:599
    __mutex_lock kernel/locking/mutex.c:732 [inline]
    mutex_lock_nested+0x17/0x1c kernel/locking/mutex.c:784
    vhci_send_frame+0x68/0x9c drivers/bluetooth/hci_vhci.c:75
    hci_send_frame+0x1cc/0x2ff net/bluetooth/hci_core.c:2989
    hci_sched_acl_pkt net/bluetooth/hci_core.c:3498 [inline]
    hci_sched_acl net/bluetooth/hci_core.c:3583 [inline]
    hci_tx_work+0xb94/0x1a60 net/bluetooth/hci_core.c:3654
    process_one_work+0x901/0xfb8 kernel/workqueue.c:2310
    worker_thread+0xa67/0x1003 kernel/workqueue.c:2457
    kthread+0x36a/0x430 kernel/kthread.c:319
    ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

    -> #0 ((work_completion)(&hdev->tx_work)){+.+.}-{0:0}:
    check_prev_add kernel/locking/lockdep.c:3053 [inline]
    check_prevs_add kernel/locking/lockdep.c:3172 [inline]
    validate_chain kernel/locking/lockdep.c:3787 [inline]
    __lock_acquire+0x2d32/0x77fa kernel/locking/lockdep.c:5011
    lock_acquire+0x273/0x4d5 kernel/locking/lockdep.c:5622
    __flush_work+0xee/0x19f kernel/workqueue.c:3090
    hci_dev_close_sync+0x32f/0x1113 net/bluetooth/hci_sync.c:4352
    hci_dev_do_close+0x47/0x9f net/bluetooth/hci_core.c:553
    hci_rfkill_set_block+0x130/0x1ac net/bluetooth/hci_core.c:935
    rfkill_set_block+0x1e6/0x3b8 net/rfkill/core.c:345
    rfkill_fop_write+0x2d8/0x672 net/rfkill/core.c:1274
    vfs_write+0x277/0xcf5 fs/read_write.c:594
    ksys_write+0x19b/0x2bd fs/read_write.c:650
    do_syscall_x64 arch/x86/entry/common.c:55 [inline]
    do_syscall_64+0x51/0xba arch/x86/entry/common.c:93
    entry_SYSCALL_64_after_hwframe+0x61/0xcb

This change removes the need for acquiring the open_mutex in
vhci_send_frame, thus eliminating the potential deadlock while
maintaining the required packet ordering.

Fixes: 92d4abd ("Bluetooth: vhci: Fix race when opening vhci device")
Signed-off-by: Ying Hsu <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
okias pushed a commit that referenced this pull request Dec 27, 2023
Jiri Pirko says:

====================
devlink: introduce notifications filtering

From: Jiri Pirko <[email protected]>

Currently the user listening on a socket for devlink notifications
gets always all messages for all existing devlink instances and objects,
even if he is interested only in one of those. That may cause
unnecessary overhead on setups with thousands of instances present.

User is currently able to narrow down the devlink objects replies
to dump commands by specifying select attributes.

Allow similar approach for notifications providing user a new
notify-filter-set command to select attributes with values
the notification message has to match. In that case, it is delivered
to the socket.

Note that the filtering is done per-socket, so multiple users may
specify different selection of attributes with values.

This patchset initially introduces support for following attributes:
DEVLINK_ATTR_BUS_NAME
DEVLINK_ATTR_DEV_NAME
DEVLINK_ATTR_PORT_INDEX

Patches #1 - #4 are preparations in devlink code, patch #3 is
                an optimization done on the way.
Patches #5 - #7 are preparations in netlink and generic netlink code.
Patch #8 is the main one in this set implementing of
         the notify-filter-set command and the actual
         per-socket filtering.
Patch grate-driver#9 extends the infrastructure allowing to filter according
         to a port index.

Example:
$ devlink mon port pci/0000:08:00.0/32768
[port,new] pci/0000:08:00.0/32768: type notset flavour pcisf controller 0 pfnum 0 sfnum 107 splittable false
  function:
    hw_addr 00:00:00:00:00:00 state inactive opstate detached roce enable
[port,new] pci/0000:08:00.0/32768: type eth flavour pcisf controller 0 pfnum 0 sfnum 107 splittable false
  function:
    hw_addr 00:00:00:00:00:00 state inactive opstate detached roce enable
[port,new] pci/0000:08:00.0/32768: type eth netdev eth3 flavour pcisf controller 0 pfnum 0 sfnum 107 splittable false
  function:
    hw_addr 00:00:00:00:00:00 state inactive opstate detached roce enable
[port,new] pci/0000:08:00.0/32768: type eth netdev eth3 flavour pcisf controller 0 pfnum 0 sfnum 107 splittable false
  function:
    hw_addr 00:00:00:00:00:00 state inactive opstate detached roce enable
[port,new] pci/0000:08:00.0/32768: type eth flavour pcisf controller 0 pfnum 0 sfnum 107 splittable false
  function:
    hw_addr 00:00:00:00:00:00 state inactive opstate detached roce enable
[port,new] pci/0000:08:00.0/32768: type notset flavour pcisf controller 0 pfnum 0 sfnum 107 splittable false
  function:
    hw_addr 00:00:00:00:00:00 state inactive opstate detached roce enable
[port,del] pci/0000:08:00.0/32768: type notset flavour pcisf controller 0 pfnum 0 sfnum 107 splittable false
  function:
    hw_addr 00:00:00:00:00:00 state inactive opstate detached roce enable
====================

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
okias pushed a commit that referenced this pull request Dec 27, 2023
syzbot found a potential circular dependency leading to a deadlock:
    -> #3 (&hdev->req_lock){+.+.}-{3:3}:
    __mutex_lock_common+0x1b6/0x1bc2 kernel/locking/mutex.c:599
    __mutex_lock kernel/locking/mutex.c:732 [inline]
    mutex_lock_nested+0x17/0x1c kernel/locking/mutex.c:784
    hci_dev_do_close+0x3f/0x9f net/bluetooth/hci_core.c:551
    hci_rfkill_set_block+0x130/0x1ac net/bluetooth/hci_core.c:935
    rfkill_set_block+0x1e6/0x3b8 net/rfkill/core.c:345
    rfkill_fop_write+0x2d8/0x672 net/rfkill/core.c:1274
    vfs_write+0x277/0xcf5 fs/read_write.c:594
    ksys_write+0x19b/0x2bd fs/read_write.c:650
    do_syscall_x64 arch/x86/entry/common.c:55 [inline]
    do_syscall_64+0x51/0xba arch/x86/entry/common.c:93
    entry_SYSCALL_64_after_hwframe+0x61/0xcb

    -> #2 (rfkill_global_mutex){+.+.}-{3:3}:
    __mutex_lock_common+0x1b6/0x1bc2 kernel/locking/mutex.c:599
    __mutex_lock kernel/locking/mutex.c:732 [inline]
    mutex_lock_nested+0x17/0x1c kernel/locking/mutex.c:784
    rfkill_register+0x30/0x7e3 net/rfkill/core.c:1045
    hci_register_dev+0x48f/0x96d net/bluetooth/hci_core.c:2622
    __vhci_create_device drivers/bluetooth/hci_vhci.c:341 [inline]
    vhci_create_device+0x3ad/0x68f drivers/bluetooth/hci_vhci.c:374
    vhci_get_user drivers/bluetooth/hci_vhci.c:431 [inline]
    vhci_write+0x37b/0x429 drivers/bluetooth/hci_vhci.c:511
    call_write_iter include/linux/fs.h:2109 [inline]
    new_sync_write fs/read_write.c:509 [inline]
    vfs_write+0xaa8/0xcf5 fs/read_write.c:596
    ksys_write+0x19b/0x2bd fs/read_write.c:650
    do_syscall_x64 arch/x86/entry/common.c:55 [inline]
    do_syscall_64+0x51/0xba arch/x86/entry/common.c:93
    entry_SYSCALL_64_after_hwframe+0x61/0xcb

    -> #1 (&data->open_mutex){+.+.}-{3:3}:
    __mutex_lock_common+0x1b6/0x1bc2 kernel/locking/mutex.c:599
    __mutex_lock kernel/locking/mutex.c:732 [inline]
    mutex_lock_nested+0x17/0x1c kernel/locking/mutex.c:784
    vhci_send_frame+0x68/0x9c drivers/bluetooth/hci_vhci.c:75
    hci_send_frame+0x1cc/0x2ff net/bluetooth/hci_core.c:2989
    hci_sched_acl_pkt net/bluetooth/hci_core.c:3498 [inline]
    hci_sched_acl net/bluetooth/hci_core.c:3583 [inline]
    hci_tx_work+0xb94/0x1a60 net/bluetooth/hci_core.c:3654
    process_one_work+0x901/0xfb8 kernel/workqueue.c:2310
    worker_thread+0xa67/0x1003 kernel/workqueue.c:2457
    kthread+0x36a/0x430 kernel/kthread.c:319
    ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

    -> #0 ((work_completion)(&hdev->tx_work)){+.+.}-{0:0}:
    check_prev_add kernel/locking/lockdep.c:3053 [inline]
    check_prevs_add kernel/locking/lockdep.c:3172 [inline]
    validate_chain kernel/locking/lockdep.c:3787 [inline]
    __lock_acquire+0x2d32/0x77fa kernel/locking/lockdep.c:5011
    lock_acquire+0x273/0x4d5 kernel/locking/lockdep.c:5622
    __flush_work+0xee/0x19f kernel/workqueue.c:3090
    hci_dev_close_sync+0x32f/0x1113 net/bluetooth/hci_sync.c:4352
    hci_dev_do_close+0x47/0x9f net/bluetooth/hci_core.c:553
    hci_rfkill_set_block+0x130/0x1ac net/bluetooth/hci_core.c:935
    rfkill_set_block+0x1e6/0x3b8 net/rfkill/core.c:345
    rfkill_fop_write+0x2d8/0x672 net/rfkill/core.c:1274
    vfs_write+0x277/0xcf5 fs/read_write.c:594
    ksys_write+0x19b/0x2bd fs/read_write.c:650
    do_syscall_x64 arch/x86/entry/common.c:55 [inline]
    do_syscall_64+0x51/0xba arch/x86/entry/common.c:93
    entry_SYSCALL_64_after_hwframe+0x61/0xcb

This change removes the need for acquiring the open_mutex in
vhci_send_frame, thus eliminating the potential deadlock while
maintaining the required packet ordering.

Fixes: 92d4abd ("Bluetooth: vhci: Fix race when opening vhci device")
Signed-off-by: Ying Hsu <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
okias pushed a commit that referenced this pull request Dec 27, 2023
Ido Schimmel says:

====================
Add MDB bulk deletion support

This patchset adds MDB bulk deletion support, allowing user space to
request the deletion of matching entries instead of dumping the entire
MDB and issuing a separate deletion request for each matching entry.
Support is added in both the bridge and VXLAN drivers in a similar
fashion to the existing FDB bulk deletion support.

The parameters according to which bulk deletion can be performed are
similar to the FDB ones, namely: Destination port, VLAN ID, state (e.g.,
"permanent"), routing protocol, source / destination VNI, destination IP
and UDP port. Flushing based on flags (e.g., "offload", "fast_leave",
"added_by_star_ex", "blocked") is not currently supported, but can be
added in the future, if a use case arises.

Patch #1 adds a new uAPI attribute to allow specifying the state mask
according to which bulk deletion will be performed, if any.

Patch #2 adds a new policy according to which bulk deletion requests
(with 'NLM_F_BULK' flag set) will be parsed.

Patches #3-#4 add a new NDO for MDB bulk deletion and invoke it from the
rtnetlink code when a bulk deletion request is made.

Patches #5-#6 implement the MDB bulk deletion NDO in the bridge and
VXLAN drivers, respectively.

Patch #7 allows user space to issue MDB bulk deletion requests by no
longer rejecting the 'NLM_F_BULK' flag when it is set in 'RTM_DELMDB'
requests.

Patches #8-grate-driver#9 add selftests for both drivers, for both good and bad
flows.

iproute2 changes can be found here [1].

https://github.com/idosch/iproute2/tree/submit/mdb_flush_v1
====================

Signed-off-by: David S. Miller <[email protected]>
okias pushed a commit that referenced this pull request Dec 27, 2023
Patch series "Multi-size THP for anonymous memory", v9.

A series to implement multi-size THP (mTHP) for anonymous memory
(previously called "small-sized THP" and "large anonymous folios").

The objective of this is to improve performance by allocating larger
chunks of memory during anonymous page faults:

1) Since SW (the kernel) is dealing with larger chunks of memory than base
   pages, there are efficiency savings to be had; fewer page faults, batched PTE
   and RMAP manipulation, reduced lru list, etc. In short, we reduce kernel
   overhead. This should benefit all architectures.
2) Since we are now mapping physically contiguous chunks of memory, we can take
   advantage of HW TLB compression techniques. A reduction in TLB pressure
   speeds up kernel and user space. arm64 systems have 2 mechanisms to coalesce
   TLB entries; "the contiguous bit" (architectural) and HPA (uarch).

This version incorporates David's feedback on the core patches (#3, #4)
and adds some RB and TB tags (see change log for details).

By default, the existing behaviour (and performance) is maintained.  The
user must explicitly enable multi-size THP to see the performance benefit.
This is done via a new sysfs interface (as recommended by David
Hildenbrand - thanks to David for the suggestion)!  This interface is
inspired by the existing per-hugepage-size sysfs interface used by
hugetlb, provides full backwards compatibility with the existing PMD-size
THP interface, and provides a base for future extensibility.  See [9] for
detailed discussion of the interface.

This series is based on mm-unstable (715b67adf4c8).


Prerequisites
=============

I'm removing this section on the basis that I don't believe what we were
previously calling prerequisites are really prerequisites anymore.  We
originally defined them when mTHP was a compile-time feature.  There is
now a runtime control to opt-in to mTHP; when disabled, correctness and
performance are as before.  When enabled, the code is still
correct/robust, but in the absence of the one remaining item (compaction)
there may be a performance impact in some corners.  See the old list in
the v8 cover letter at [8].  And a longer explanation of my thinking here
[10].

SUMMARY: I don't think we should hold this series up, waiting for the
items on the prerequisites list.  I believe this series should be ready
now so hopefully can be added to mm-unstable for some testing, then
fingers crossed for v6.8.


Testing
=======

The series includes patches for mm selftests to enlighten the cow and
khugepaged tests to explicitly test with multi-size THP, in the same way
that PMD-sized THP is tested.  The new tests all pass, and no regressions
are observed in the mm selftest suite.  I've also run my usual kernel
compilation and java script benchmarks without any issues.

Refer to my performance numbers posted with v6 [6].  (These are for
multi-size THP only - they do not include the arm64 contpte follow-on
series).

John Hubbard at Nvidia has indicated dramatic 10x performance improvements
for some workloads at [11].  (Observed using v6 of this series as well as
the arm64 contpte series).

Kefeng Wang at Huawei has also indicated he sees improvements at [12] although
there are some latency regressions also.

I've also checked that there is no regression in the write fault path when
mTHP is disabled using a microbenchmark.  I ran it for a baseline kernel,
as well as v8 and v9.  I repeated on Ampere Altra (bare metal) and Apple
M2 (VM):

|              |        m2 vm        |        altra        |
|--------------|---------------------|---------------------|
| kernel       |     mean |  std_rel |     mean |  std_rel |
|--------------|----------|----------|----------|----------|
| baseline     |   0.000% |   0.341% |   0.000% |   3.581% |
| anonfolio-v8 |   0.005% |   0.272% |   5.068% |   1.128% |
| anonfolio-v9 |  -0.013% |   0.442% |   0.107% |   1.788% |

There is no measurable difference on M2, but altra has a slow down in v8
which is fixed in v9 by moving the THP order check to be inline within
thp_vma_allowable_orders(), as suggested by David.


This patch (of 10):

In preparation for the introduction of anonymous multi-size THP, we would
like to be able to split them when they have unmapped subpages, in order
to free those unused pages under memory pressure.  So remove the
artificial requirement that the large folio needed to be at least
PMD-sized.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ryan Roberts <[email protected]>
Reviewed-by: Yu Zhao <[email protected]>
Reviewed-by: Yin Fengwei <[email protected]>
Reviewed-by: Matthew Wilcox (Oracle) <[email protected]>
Reviewed-by: David Hildenbrand <[email protected]>
Reviewed-by: Barry Song <[email protected]>
Tested-by: Kefeng Wang <[email protected]>
Tested-by: John Hubbard <[email protected]>
Cc: Alistair Popple <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: "Huang, Ying" <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Itaru Kitayama <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Cc: Luis Chamberlain <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Yang Shi <[email protected]>
Cc: Zi Yan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
okias pushed a commit that referenced this pull request Dec 27, 2023
Trying to suspend to RAM on SAMA5D27 EVK leads to the following lockdep
warning:

 ============================================
 WARNING: possible recursive locking detected
 6.7.0-rc5-wt+ #532 Not tainted
 --------------------------------------------
 sh/92 is trying to acquire lock:
 c3cf306c (&irq_desc_lock_class){-.-.}-{2:2}, at: __irq_get_desc_lock+0xe8/0x100

 but task is already holding lock:
 c3d7c46c (&irq_desc_lock_class){-.-.}-{2:2}, at: __irq_get_desc_lock+0xe8/0x100

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

        CPU0
        ----
   lock(&irq_desc_lock_class);
   lock(&irq_desc_lock_class);

  *** DEADLOCK ***

  May be due to missing lock nesting notation

 6 locks held by sh/92:
  #0: c3aa0258 (sb_writers#6){.+.+}-{0:0}, at: ksys_write+0xd8/0x178
  #1: c4c2df44 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x138/0x284
  #2: c32684a0 (kn->active){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x148/0x284
  #3: c232b6d4 (system_transition_mutex){+.+.}-{3:3}, at: pm_suspend+0x13c/0x4e8
  #4: c387b088 (&dev->mutex){....}-{3:3}, at: __device_suspend+0x1e8/0x91c
  #5: c3d7c46c (&irq_desc_lock_class){-.-.}-{2:2}, at: __irq_get_desc_lock+0xe8/0x100

 stack backtrace:
 CPU: 0 PID: 92 Comm: sh Not tainted 6.7.0-rc5-wt+ #532
 Hardware name: Atmel SAMA5
  unwind_backtrace from show_stack+0x18/0x1c
  show_stack from dump_stack_lvl+0x34/0x48
  dump_stack_lvl from __lock_acquire+0x19ec/0x3a0c
  __lock_acquire from lock_acquire.part.0+0x124/0x2d0
  lock_acquire.part.0 from _raw_spin_lock_irqsave+0x5c/0x78
  _raw_spin_lock_irqsave from __irq_get_desc_lock+0xe8/0x100
  __irq_get_desc_lock from irq_set_irq_wake+0xa8/0x204
  irq_set_irq_wake from atmel_gpio_irq_set_wake+0x58/0xb4
  atmel_gpio_irq_set_wake from irq_set_irq_wake+0x100/0x204
  irq_set_irq_wake from gpio_keys_suspend+0xec/0x2b8
  gpio_keys_suspend from dpm_run_callback+0xe4/0x248
  dpm_run_callback from __device_suspend+0x234/0x91c
  __device_suspend from dpm_suspend+0x224/0x43c
  dpm_suspend from dpm_suspend_start+0x9c/0xa8
  dpm_suspend_start from suspend_devices_and_enter+0x1e0/0xa84
  suspend_devices_and_enter from pm_suspend+0x460/0x4e8
  pm_suspend from state_store+0x78/0xe4
  state_store from kernfs_fop_write_iter+0x1a0/0x284
  kernfs_fop_write_iter from vfs_write+0x38c/0x6f4
  vfs_write from ksys_write+0xd8/0x178
  ksys_write from ret_fast_syscall+0x0/0x1c
 Exception stack(0xc52b3fa8 to 0xc52b3ff0)
 3fa0:                   00000004 005a0ae8 00000001 005a0ae8 00000004 00000001
 3fc0: 00000004 005a0ae8 00000001 00000004 00000004 b6c616c0 00000020 0059d190
 3fe0: 00000004 b6c61678 aec5a041 aebf1a26

This warning is raised because pinctrl-at91-pio4 uses chained IRQ. Whenever
a wake up source configures an IRQ through irq_set_irq_wake, it will
lock the corresponding IRQ desc, and then call irq_set_irq_wake on "parent"
IRQ which will do the same on its own IRQ desc, but since those two locks
share the same class, lockdep reports this as an issue.

Fix lockdep false positive by setting a different class for parent and
children IRQ

Fixes: 7761808 ("pinctrl: introduce driver for Atmel PIO4 controller")
Signed-off-by: Alexis Lothoré <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Linus Walleij <[email protected]>
okias pushed a commit that referenced this pull request Dec 27, 2023
An issue occurred while reading an ELF file in libbpf.c during fuzzing:

	Program received signal SIGSEGV, Segmentation fault.
	0x0000000000958e97 in bpf_object.collect_prog_relos () at libbpf.c:4206
	4206 in libbpf.c
	(gdb) bt
	#0 0x0000000000958e97 in bpf_object.collect_prog_relos () at libbpf.c:4206
	#1 0x000000000094f9d6 in bpf_object.collect_relos () at libbpf.c:6706
	#2 0x000000000092bef3 in bpf_object_open () at libbpf.c:7437
	#3 0x000000000092c046 in bpf_object.open_mem () at libbpf.c:7497
	#4 0x0000000000924afa in LLVMFuzzerTestOneInput () at fuzz/bpf-object-fuzzer.c:16
	#5 0x000000000060be11 in testblitz_engine::fuzzer::Fuzzer::run_one ()
	#6 0x000000000087ad92 in tracing::span::Span::in_scope ()
	#7 0x00000000006078aa in testblitz_engine::fuzzer::util::walkdir ()
	#8 0x00000000005f3217 in testblitz_engine::entrypoint::main::{{closure}} ()
	grate-driver#9 0x00000000005f2601 in main ()
	(gdb)

scn_data was null at this code(tools/lib/bpf/src/libbpf.c):

	if (rel->r_offset % BPF_INSN_SZ || rel->r_offset >= scn_data->d_size) {

The scn_data is derived from the code above:

	scn = elf_sec_by_idx(obj, sec_idx);
	scn_data = elf_sec_data(obj, scn);

	relo_sec_name = elf_sec_str(obj, shdr->sh_name);
	sec_name = elf_sec_name(obj, scn);
	if (!relo_sec_name || !sec_name)// don't check whether scn_data is NULL
		return -EINVAL;

In certain special scenarios, such as reading a malformed ELF file,
it is possible that scn_data may be a null pointer

Signed-off-by: Mingyi Zhang <[email protected]>
Signed-off-by: Xin Liu <[email protected]>
Signed-off-by: Changye Wu <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Acked-by: Daniel Borkmann <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
okias pushed a commit that referenced this pull request Dec 27, 2023
During ieee80211_set_active_links() we do (among the others):
1. Call drv_change_vif_links() with both old_active and new_active
2. Unassign the chanctx for the removed link(s) (if any)
3. Assign chanctx to the added link(s) (if any)
4. Call drv_change_vif_links() with the new_active links bitmap

The problem here is that during step #1 the driver doesn't know whether
we will activate multiple links simultaneously or are just doing a link
switch, so it can't check there if multiple links are supported/enabled.
(Some of the drivers might enable/disable this option dynamically)

And during step #3, in which the driver already knows that,
returning an error code (for example when multiple links are not
supported or disabled), will cause a warning, and we will still complete
the transition to the new_active links.
(It is hard to undo things in that stage, since we released channels etc.)

Therefore add a driver callback to check if the desired new_active links
will be supported by the driver or not. This callback will be called
in the beginning of ieee80211_set_active_links() so we won't do anything
before we are sure it is supported.

Signed-off-by: Miri Korenblit <[email protected]>
Reviewed-by: Gregory Greenman <[email protected]>
Reviewed-by: Johannes Berg <[email protected]>
Link: https://msgid.link/20231220133549.64c4d70b33b8.I79708619be76b8ecd4ef3975205b8f903e24a2cd@changeid
Signed-off-by: Johannes Berg <[email protected]>
okias pushed a commit that referenced this pull request Jan 7, 2024
[ Upstream commit a84fbf2 ]

Generating metrics llc_code_read_mpi_demand_plus_prefetch,
llc_data_read_mpi_demand_plus_prefetch,
llc_miss_local_memory_bandwidth_read,
llc_miss_local_memory_bandwidth_write,
nllc_miss_remote_memory_bandwidth_read, memory_bandwidth_read,
memory_bandwidth_write, uncore_frequency, upi_data_transmit_bw,
C2_Pkg_Residency, C3_Core_Residency, C3_Pkg_Residency,
C6_Core_Residency, C6_Pkg_Residency, C7_Core_Residency,
C7_Pkg_Residency, UNCORE_FREQ and tma_info_system_socket_clks would
trigger an address sanitizer heap-buffer-overflows on a SkylakeX.

```
==2567752==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x5020003ed098 at pc 0x5621a816654e bp 0x7fffb55d4da0 sp 0x7fffb55d4d98
READ of size 4 at 0x5020003eee78 thread T0
    #0 0x558265d6654d in aggr_cpu_id__is_empty tools/perf/util/cpumap.c:694:12
    #1 0x558265c914da in perf_stat__get_aggr tools/perf/builtin-stat.c:1490:6
    #2 0x558265c914da in perf_stat__get_global_cached tools/perf/builtin-stat.c:1530:9
    #3 0x558265e53290 in should_skip_zero_counter tools/perf/util/stat-display.c:947:31
    #4 0x558265e53290 in print_counter_aggrdata tools/perf/util/stat-display.c:985:18
    #5 0x558265e51931 in print_counter tools/perf/util/stat-display.c:1110:3
    #6 0x558265e51931 in evlist__print_counters tools/perf/util/stat-display.c:1571:5
    #7 0x558265c8ec87 in print_counters tools/perf/builtin-stat.c:981:2
    #8 0x558265c8cc71 in cmd_stat tools/perf/builtin-stat.c:2837:3
    grate-driver#9 0x558265bb9bd4 in run_builtin tools/perf/perf.c:323:11
    grate-driver#10 0x558265bb98eb in handle_internal_command tools/perf/perf.c:377:8
    grate-driver#11 0x558265bb9389 in run_argv tools/perf/perf.c:421:2
    grate-driver#12 0x558265bb9389 in main tools/perf/perf.c:537:3
```

The issue was the use of testing a cpumap with NULL rather than using
empty, as a map containing the dummy value isn't NULL and the -1
results in an empty aggr map being allocated which legitimately
overflows when any member is accessed.

Fixes: 8a96f45 ("perf stat: Avoid SEGV if core.cpus isn't set")
Signed-off-by: Ian Rogers <[email protected]>
Acked-by: Namhyung Kim <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
okias pushed a commit that referenced this pull request Jan 7, 2024
[ Upstream commit ede72dc ]

Fuzzing found that an invalid tracepoint name would create a memory
leak with an address sanitizer build:
```
$ perf stat -e '*:o/' true
event syntax error: '*:o/'
                       \___ parser error
Run 'perf list' for a list of valid events

 Usage: perf stat [<options>] [<command>]

    -e, --event <event>   event selector. use 'perf list' to list available events

=================================================================
==59380==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 4 byte(s) in 2 object(s) allocated from:
    #0 0x7f38ac07077b in __interceptor_strdup ../../../../src/libsanitizer/asan/asan_interceptors.cpp:439
    #1 0x55f2f41be73b in str util/parse-events.l:49
    #2 0x55f2f41d08e8 in parse_events_lex util/parse-events.l:338
    #3 0x55f2f41dc3b1 in parse_events_parse util/parse-events-bison.c:1464
    #4 0x55f2f410b8b3 in parse_events__scanner util/parse-events.c:1822
    #5 0x55f2f410d1b9 in __parse_events util/parse-events.c:2094
    #6 0x55f2f410e57f in parse_events_option util/parse-events.c:2279
    #7 0x55f2f4427b56 in get_value tools/lib/subcmd/parse-options.c:251
    #8 0x55f2f4428d98 in parse_short_opt tools/lib/subcmd/parse-options.c:351
    grate-driver#9 0x55f2f4429d80 in parse_options_step tools/lib/subcmd/parse-options.c:539
    grate-driver#10 0x55f2f442acb9 in parse_options_subcommand tools/lib/subcmd/parse-options.c:654
    grate-driver#11 0x55f2f3ec99fc in cmd_stat tools/perf/builtin-stat.c:2501
    grate-driver#12 0x55f2f4093289 in run_builtin tools/perf/perf.c:322
    grate-driver#13 0x55f2f40937f5 in handle_internal_command tools/perf/perf.c:375
    grate-driver#14 0x55f2f4093bbd in run_argv tools/perf/perf.c:419
    grate-driver#15 0x55f2f409412b in main tools/perf/perf.c:535

SUMMARY: AddressSanitizer: 4 byte(s) leaked in 2 allocation(s).
```
Fix by adding the missing destructor.

Fixes: 865582c ("perf tools: Adds the tracepoint name parsing support")
Signed-off-by: Ian Rogers <[email protected]>
Cc: He Kuang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Namhyung Kim <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
okias pushed a commit that referenced this pull request Jan 7, 2024
[ Upstream commit d45c4b4 ]

A thread started via eg. user_mode_thread() runs in the kernel to begin
with and then may later return to userspace. While it's running in the
kernel it has a pt_regs at the base of its kernel stack, but that
pt_regs is all zeroes.

If the thread oopses in that state, it leads to an ugly stack trace with
a big block of zero GPRs, as reported by Joel:

  Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.5.0-rc7-00004-gf7757129e3de-dirty #3
  Hardware name: IBM PowerNV (emulated by qemu) POWER9 0x4e1200 opal:v7.0 PowerNV
  Call Trace:
  [c0000000036afb00] [c0000000010dd058] dump_stack_lvl+0x6c/0x9c (unreliable)
  [c0000000036afb30] [c00000000013c524] panic+0x178/0x424
  [c0000000036afbd0] [c000000002005100] mount_root_generic+0x250/0x324
  [c0000000036afca0] [c0000000020057d0] prepare_namespace+0x2d4/0x344
  [c0000000036afd20] [c0000000020049c0] kernel_init_freeable+0x358/0x3ac
  [c0000000036afdf0] [c0000000000111b0] kernel_init+0x30/0x1a0
  [c0000000036afe50] [c00000000000debc] ret_from_kernel_user_thread+0x14/0x1c
  --- interrupt: 0 at 0x0
  NIP:  0000000000000000 LR: 0000000000000000 CTR: 0000000000000000
  REGS: c0000000036afe80 TRAP: 0000   Not tainted  (6.5.0-rc7-00004-gf7757129e3de-dirty)
  MSR:  0000000000000000 <>  CR: 00000000  XER: 00000000
  CFAR: 0000000000000000 IRQMASK: 0
  GPR00: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR04: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR08: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR12: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR24: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR28: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  NIP [0000000000000000] 0x0
  LR [0000000000000000] 0x0
  --- interrupt: 0

The all-zero pt_regs looks ugly and conveys no useful information, other
than its presence. So detect that case and just show the presence of the
frame by printing the interrupt marker, eg:

  Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.5.0-rc3-00126-g18e9506562a0-dirty #301
  Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1202 0xf000005 of:SLOF,HEAD hv:linux,kvm pSeries
  Call Trace:
  [c000000003aabb00] [c000000001143db8] dump_stack_lvl+0x6c/0x9c (unreliable)
  [c000000003aabb30] [c00000000014c624] panic+0x178/0x424
  [c000000003aabbd0] [c0000000020050fc] mount_root_generic+0x250/0x324
  [c000000003aabca0] [c0000000020057cc] prepare_namespace+0x2d4/0x344
  [c000000003aabd20] [c0000000020049bc] kernel_init_freeable+0x358/0x3ac
  [c000000003aabdf0] [c0000000000111b0] kernel_init+0x30/0x1a0
  [c000000003aabe50] [c00000000000debc] ret_from_kernel_user_thread+0x14/0x1c
  --- interrupt: 0 at 0x0

To avoid ever suppressing a valid pt_regs make sure the pt_regs has a
zero MSR and TRAP value, and is located at the very base of the stack.

Fixes: 6895dfc ("powerpc: copy_thread fill in interrupt frame marker and back chain")
Reported-by: Joel Stanley <[email protected]>
Reported-by: Nicholas Piggin <[email protected]>
Reviewed-by: Joel Stanley <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://msgid.link/[email protected]
Signed-off-by: Sasha Levin <[email protected]>
okias pushed a commit that referenced this pull request Jan 7, 2024
[ Upstream commit 34c4eff ]

KMSAN reported the following uninit-value access issue:

=====================================================
BUG: KMSAN: uninit-value in virtio_transport_recv_pkt+0x1dfb/0x26a0 net/vmw_vsock/virtio_transport_common.c:1421
 virtio_transport_recv_pkt+0x1dfb/0x26a0 net/vmw_vsock/virtio_transport_common.c:1421
 vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120
 process_one_work kernel/workqueue.c:2630 [inline]
 process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703
 worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784
 kthread+0x3cc/0x520 kernel/kthread.c:388
 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

Uninit was stored to memory at:
 virtio_transport_space_update net/vmw_vsock/virtio_transport_common.c:1274 [inline]
 virtio_transport_recv_pkt+0x1ee8/0x26a0 net/vmw_vsock/virtio_transport_common.c:1415
 vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120
 process_one_work kernel/workqueue.c:2630 [inline]
 process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703
 worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784
 kthread+0x3cc/0x520 kernel/kthread.c:388
 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

Uninit was created at:
 slab_post_alloc_hook+0x105/0xad0 mm/slab.h:767
 slab_alloc_node mm/slub.c:3478 [inline]
 kmem_cache_alloc_node+0x5a2/0xaf0 mm/slub.c:3523
 kmalloc_reserve+0x13c/0x4a0 net/core/skbuff.c:559
 __alloc_skb+0x2fd/0x770 net/core/skbuff.c:650
 alloc_skb include/linux/skbuff.h:1286 [inline]
 virtio_vsock_alloc_skb include/linux/virtio_vsock.h:66 [inline]
 virtio_transport_alloc_skb+0x90/0x11e0 net/vmw_vsock/virtio_transport_common.c:58
 virtio_transport_reset_no_sock net/vmw_vsock/virtio_transport_common.c:957 [inline]
 virtio_transport_recv_pkt+0x1279/0x26a0 net/vmw_vsock/virtio_transport_common.c:1387
 vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120
 process_one_work kernel/workqueue.c:2630 [inline]
 process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703
 worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784
 kthread+0x3cc/0x520 kernel/kthread.c:388
 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

CPU: 1 PID: 10664 Comm: kworker/1:5 Not tainted 6.6.0-rc3-00146-g9f3ebbef746f #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-1.fc38 04/01/2014
Workqueue: vsock-loopback vsock_loopback_work
=====================================================

The following simple reproducer can cause the issue described above:

int main(void)
{
  int sock;
  struct sockaddr_vm addr = {
    .svm_family = AF_VSOCK,
    .svm_cid = VMADDR_CID_ANY,
    .svm_port = 1234,
  };

  sock = socket(AF_VSOCK, SOCK_STREAM, 0);
  connect(sock, (struct sockaddr *)&addr, sizeof(addr));
  return 0;
}

This issue occurs because the `buf_alloc` and `fwd_cnt` fields of the
`struct virtio_vsock_hdr` are not initialized when a new skb is allocated
in `virtio_transport_init_hdr()`. This patch resolves the issue by
initializing these fields during allocation.

Fixes: 71dc9ec ("virtio/vsock: replace virtio_vsock_pkt with sk_buff")
Reported-and-tested-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=0c8ce1da0ac31abbadcd
Signed-off-by: Shigeru Yoshida <[email protected]>
Reviewed-by: Stefano Garzarella <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
okias pushed a commit that referenced this pull request Jan 7, 2024
commit dd976a9 upstream.

The smp_processor_id() shouldn't be called from preemptible code.
Instead use get_cpu() and put_cpu() which disables preemption in
addition to getting the processor id. Enable preemption back after
calling schedule_work() to make sure that the work gets scheduled on all
cores other than the current core. We want to avoid a scenario where
current core's stack trace is printed multiple times and one core's
stack trace isn't printed because of scheduling of current task.

This fixes the following bug:

[  119.143590] sysrq: Show backtrace of all active CPUs
[  119.143902] BUG: using smp_processor_id() in preemptible [00000000] code: bash/873
[  119.144586] caller is debug_smp_processor_id+0x20/0x30
[  119.144827] CPU: 6 PID: 873 Comm: bash Not tainted 5.10.124-dirty #3
[  119.144861] Hardware name: QEMU QEMU Virtual Machine, BIOS 2023.05-1 07/22/2023
[  119.145053] Call trace:
[  119.145093]  dump_backtrace+0x0/0x1a0
[  119.145122]  show_stack+0x18/0x70
[  119.145141]  dump_stack+0xc4/0x11c
[  119.145159]  check_preemption_disabled+0x100/0x110
[  119.145175]  debug_smp_processor_id+0x20/0x30
[  119.145195]  sysrq_handle_showallcpus+0x20/0xc0
[  119.145211]  __handle_sysrq+0x8c/0x1a0
[  119.145227]  write_sysrq_trigger+0x94/0x12c
[  119.145247]  proc_reg_write+0xa8/0xe4
[  119.145266]  vfs_write+0xec/0x280
[  119.145282]  ksys_write+0x6c/0x100
[  119.145298]  __arm64_sys_write+0x20/0x30
[  119.145315]  el0_svc_common.constprop.0+0x78/0x1e4
[  119.145332]  do_el0_svc+0x24/0x8c
[  119.145348]  el0_svc+0x10/0x20
[  119.145364]  el0_sync_handler+0x134/0x140
[  119.145381]  el0_sync+0x180/0x1c0

Cc: [email protected]
Cc: [email protected]
Fixes: 47cab6a ("debug lockups: Improve lockup detection, fix generic arch fallback")
Signed-off-by: Muhammad Usama Anjum <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
okias pushed a commit that referenced this pull request Jan 7, 2024
commit 807252f upstream.

Running smb2.rename test from Samba smbtorture suite against a kernel built
with lockdep triggers a "possible recursive locking detected" warning.

This is because mnt_want_write() is called twice with no mnt_drop_write()
in between:
  -> ksmbd_vfs_mkdir()
    -> ksmbd_vfs_kern_path_create()
       -> kern_path_create()
          -> filename_create()
            -> mnt_want_write()
       -> mnt_want_write()

Fix this by removing the mnt_want_write/mnt_drop_write calls from vfs
helpers that call kern_path_create().

Full lockdep trace below:

============================================
WARNING: possible recursive locking detected
6.6.0-rc5 #775 Not tainted
--------------------------------------------
kworker/1:1/32 is trying to acquire lock:
ffff888005ac83f8 (sb_writers#5){.+.+}-{0:0}, at: ksmbd_vfs_mkdir+0xe1/0x410

but task is already holding lock:
ffff888005ac83f8 (sb_writers#5){.+.+}-{0:0}, at: filename_create+0xb6/0x260

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

       CPU0
       ----
  lock(sb_writers#5);
  lock(sb_writers#5);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

4 locks held by kworker/1:1/32:
 #0: ffff8880064e4138 ((wq_completion)ksmbd-io){+.+.}-{0:0}, at: process_one_work+0x40e/0x980
 #1: ffff888005b0fdd0 ((work_completion)(&work->work)){+.+.}-{0:0}, at: process_one_work+0x40e/0x980
 #2: ffff888005ac83f8 (sb_writers#5){.+.+}-{0:0}, at: filename_create+0xb6/0x260
 #3: ffff8880057ce760 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: filename_create+0x123/0x260

Cc: [email protected]
Fixes: 40b268d ("ksmbd: add mnt_want_write to ksmbd vfs functions")
Signed-off-by: Marios Makassikis <[email protected]>
Acked-by: Namjae Jeon <[email protected]>
Signed-off-by: Steve French <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
okias pushed a commit that referenced this pull request Jan 7, 2024
commit 5a22fbc upstream.

When LAN9303 is MDIO-connected two callchains exist into
mdio->bus->write():

1. switch ports 1&2 ("physical" PHYs):

virtual (switch-internal) MDIO bus (lan9303_switch_ops->phy_{read|write})->
  lan9303_mdio_phy_{read|write} -> mdiobus_{read|write}_nested

2. LAN9303 virtual PHY:

virtual MDIO bus (lan9303_phy_{read|write}) ->
  lan9303_virt_phy_reg_{read|write} -> regmap -> lan9303_mdio_{read|write}

If the latter functions just take
mutex_lock(&sw_dev->device->bus->mdio_lock) it triggers a LOCKDEP
false-positive splat. It's false-positive because the first
mdio_lock in the second callchain above belongs to virtual MDIO bus, the
second mdio_lock belongs to physical MDIO bus.

Consequent annotation in lan9303_mdio_{read|write} as nested lock
(similar to lan9303_mdio_phy_{read|write}, it's the same physical MDIO bus)
prevents the following splat:

WARNING: possible circular locking dependency detected
5.15.71 #1 Not tainted
------------------------------------------------------
kworker/u4:3/609 is trying to acquire lock:
ffff000011531c68 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}, at: regmap_lock_mutex
but task is already holding lock:
ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&bus->mdio_lock){+.+.}-{3:3}:
       lock_acquire
       __mutex_lock
       mutex_lock_nested
       lan9303_mdio_read
       _regmap_read
       regmap_read
       lan9303_probe
       lan9303_mdio_probe
       mdio_probe
       really_probe
       __driver_probe_device
       driver_probe_device
       __device_attach_driver
       bus_for_each_drv
       __device_attach
       device_initial_probe
       bus_probe_device
       deferred_probe_work_func
       process_one_work
       worker_thread
       kthread
       ret_from_fork
-> #0 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}:
       __lock_acquire
       lock_acquire.part.0
       lock_acquire
       __mutex_lock
       mutex_lock_nested
       regmap_lock_mutex
       regmap_read
       lan9303_phy_read
       dsa_slave_phy_read
       __mdiobus_read
       mdiobus_read
       get_phy_device
       mdiobus_scan
       __mdiobus_register
       dsa_register_switch
       lan9303_probe
       lan9303_mdio_probe
       mdio_probe
       really_probe
       __driver_probe_device
       driver_probe_device
       __device_attach_driver
       bus_for_each_drv
       __device_attach
       device_initial_probe
       bus_probe_device
       deferred_probe_work_func
       process_one_work
       worker_thread
       kthread
       ret_from_fork
other info that might help us debug this:
 Possible unsafe locking scenario:
       CPU0                    CPU1
       ----                    ----
  lock(&bus->mdio_lock);
                               lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock);
                               lock(&bus->mdio_lock);
  lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock);
*** DEADLOCK ***
5 locks held by kworker/u4:3/609:
 #0: ffff000002842938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work
 #1: ffff80000bacbd60 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work
 #2: ffff000007645178 (&dev->mutex){....}-{3:3}, at: __device_attach
 #3: ffff8000096e6e78 (dsa2_mutex){+.+.}-{3:3}, at: dsa_register_switch
 #4: ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read
stack backtrace:
CPU: 1 PID: 609 Comm: kworker/u4:3 Not tainted 5.15.71 #1
Workqueue: events_unbound deferred_probe_work_func
Call trace:
 dump_backtrace
 show_stack
 dump_stack_lvl
 dump_stack
 print_circular_bug
 check_noncircular
 __lock_acquire
 lock_acquire.part.0
 lock_acquire
 __mutex_lock
 mutex_lock_nested
 regmap_lock_mutex
 regmap_read
 lan9303_phy_read
 dsa_slave_phy_read
 __mdiobus_read
 mdiobus_read
 get_phy_device
 mdiobus_scan
 __mdiobus_register
 dsa_register_switch
 lan9303_probe
 lan9303_mdio_probe
...

Cc: [email protected]
Fixes: dc70058 ("net: dsa: LAN9303: add MDIO managed mode support")
Signed-off-by: Alexander Sverdlin <[email protected]>
Reviewed-by: Andrew Lunn <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
okias pushed a commit that referenced this pull request Jan 7, 2024
commit d8b90d6 upstream.

When scanning namespaces, it is possible to get valid data from the first
call to nvme_identify_ns() in nvme_alloc_ns(), but not from the second
call in nvme_update_ns_info_block().  In particular, if the NSID becomes
inactive between the two commands, a storage device may return a buffer
filled with zero as per 4.1.5.1.  In this case, we can get a kernel crash
due to a divide-by-zero in blk_stack_limits() because ns->lba_shift will
be set to zero.

PID: 326      TASK: ffff95fec3cd8000  CPU: 29   COMMAND: "kworker/u98:10"
 #0 [ffffad8f8702f9e0] machine_kexec at ffffffff91c76ec7
 #1 [ffffad8f8702fa38] __crash_kexec at ffffffff91dea4fa
 #2 [ffffad8f8702faf8] crash_kexec at ffffffff91deb788
 #3 [ffffad8f8702fb00] oops_end at ffffffff91c2e4bb
 #4 [ffffad8f8702fb20] do_trap at ffffffff91c2a4ce
 #5 [ffffad8f8702fb70] do_error_trap at ffffffff91c2a595
 #6 [ffffad8f8702fbb0] exc_divide_error at ffffffff928506e6
 #7 [ffffad8f8702fbd0] asm_exc_divide_error at ffffffff92a00926
    [exception RIP: blk_stack_limits+434]
    RIP: ffffffff92191872  RSP: ffffad8f8702fc80  RFLAGS: 00010246
    RAX: 0000000000000000  RBX: ffff95efa0c91800  RCX: 0000000000000001
    RDX: 0000000000000000  RSI: 0000000000000001  RDI: 0000000000000001
    RBP: 00000000ffffffff   R8: ffff95fec7df35a8   R9: 0000000000000000
    R10: 0000000000000000  R11: 0000000000000001  R12: 0000000000000000
    R13: 0000000000000000  R14: 0000000000000000  R15: ffff95fed33c09a8
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #8 [ffffad8f8702fce0] nvme_update_ns_info_block at ffffffffc06d3533 [nvme_core]
 grate-driver#9 [ffffad8f8702fd18] nvme_scan_ns at ffffffffc06d6fa7 [nvme_core]

This happened when the check for valid data was moved out of nvme_identify_ns()
into one of the callers.  Fix this by checking in both callers.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=218186
Fixes: 0dd6fff ("nvme: bring back auto-removal of deleted namespaces during sequential scan")
Cc: [email protected]
Signed-off-by: Ewan D. Milne <[email protected]>
Signed-off-by: Keith Busch <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
okias pushed a commit that referenced this pull request Jan 7, 2024
[ Upstream commit a2e36cd ]

This allows it to break the following circular locking dependency.

Aug 10 07:01:29 dg1test kernel: ======================================================
Aug 10 07:01:29 dg1test kernel: WARNING: possible circular locking dependency detected
Aug 10 07:01:29 dg1test kernel: 6.4.0-rc7+ grate-driver#10 Not tainted
Aug 10 07:01:29 dg1test kernel: ------------------------------------------------------
Aug 10 07:01:29 dg1test kernel: wireplumber/2236 is trying to acquire lock:
Aug 10 07:01:29 dg1test kernel: ffff8fca5320da18 (&fctx->lock){-...}-{2:2}, at: nouveau_fence_wait_uevent_handler+0x2b/0x100 [nouveau]
Aug 10 07:01:29 dg1test kernel:
                                but task is already holding lock:
Aug 10 07:01:29 dg1test kernel: ffff8fca41208610 (&event->list_lock#2){-...}-{2:2}, at: nvkm_event_ntfy+0x50/0xf0 [nouveau]
Aug 10 07:01:29 dg1test kernel:
                                which lock already depends on the new lock.
Aug 10 07:01:29 dg1test kernel:
                                the existing dependency chain (in reverse order) is:
Aug 10 07:01:29 dg1test kernel:
                                -> #3 (&event->list_lock#2){-...}-{2:2}:
Aug 10 07:01:29 dg1test kernel:        _raw_spin_lock_irqsave+0x4b/0x70
Aug 10 07:01:29 dg1test kernel:        nvkm_event_ntfy+0x50/0xf0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        ga100_fifo_nonstall_intr+0x24/0x30 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_intr+0x12c/0x240 [nouveau]
Aug 10 07:01:29 dg1test kernel:        __handle_irq_event_percpu+0x88/0x240
Aug 10 07:01:29 dg1test kernel:        handle_irq_event+0x38/0x80
Aug 10 07:01:29 dg1test kernel:        handle_edge_irq+0xa3/0x240
Aug 10 07:01:29 dg1test kernel:        __common_interrupt+0x72/0x160
Aug 10 07:01:29 dg1test kernel:        common_interrupt+0x60/0xe0
Aug 10 07:01:29 dg1test kernel:        asm_common_interrupt+0x26/0x40
Aug 10 07:01:29 dg1test kernel:
                                -> #2 (&device->intr.lock){-...}-{2:2}:
Aug 10 07:01:29 dg1test kernel:        _raw_spin_lock_irqsave+0x4b/0x70
Aug 10 07:01:29 dg1test kernel:        nvkm_inth_allow+0x2c/0x80 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_event_ntfy_state+0x181/0x250 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_event_ntfy_allow+0x63/0xd0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_uevent_mthd+0x4d/0x70 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_ioctl+0x10b/0x250 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvif_object_mthd+0xa8/0x1f0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvif_event_allow+0x2a/0xa0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nouveau_fence_enable_signaling+0x78/0x80 [nouveau]
Aug 10 07:01:29 dg1test kernel:        __dma_fence_enable_signaling+0x5e/0x100
Aug 10 07:01:29 dg1test kernel:        dma_fence_add_callback+0x4b/0xd0
Aug 10 07:01:29 dg1test kernel:        nouveau_cli_work_queue+0xae/0x110 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nouveau_gem_object_close+0x1d1/0x2a0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        drm_gem_handle_delete+0x70/0xe0 [drm]
Aug 10 07:01:29 dg1test kernel:        drm_ioctl_kernel+0xa5/0x150 [drm]
Aug 10 07:01:29 dg1test kernel:        drm_ioctl+0x256/0x490 [drm]
Aug 10 07:01:29 dg1test kernel:        nouveau_drm_ioctl+0x5a/0xb0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        __x64_sys_ioctl+0x91/0xd0
Aug 10 07:01:29 dg1test kernel:        do_syscall_64+0x3c/0x90
Aug 10 07:01:29 dg1test kernel:        entry_SYSCALL_64_after_hwframe+0x72/0xdc
Aug 10 07:01:29 dg1test kernel:
                                -> #1 (&event->refs_lock#4){....}-{2:2}:
Aug 10 07:01:29 dg1test kernel:        _raw_spin_lock_irqsave+0x4b/0x70
Aug 10 07:01:29 dg1test kernel:        nvkm_event_ntfy_state+0x37/0x250 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_event_ntfy_allow+0x63/0xd0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_uevent_mthd+0x4d/0x70 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_ioctl+0x10b/0x250 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvif_object_mthd+0xa8/0x1f0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvif_event_allow+0x2a/0xa0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nouveau_fence_enable_signaling+0x78/0x80 [nouveau]
Aug 10 07:01:29 dg1test kernel:        __dma_fence_enable_signaling+0x5e/0x100
Aug 10 07:01:29 dg1test kernel:        dma_fence_add_callback+0x4b/0xd0
Aug 10 07:01:29 dg1test kernel:        nouveau_cli_work_queue+0xae/0x110 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nouveau_gem_object_close+0x1d1/0x2a0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        drm_gem_handle_delete+0x70/0xe0 [drm]
Aug 10 07:01:29 dg1test kernel:        drm_ioctl_kernel+0xa5/0x150 [drm]
Aug 10 07:01:29 dg1test kernel:        drm_ioctl+0x256/0x490 [drm]
Aug 10 07:01:29 dg1test kernel:        nouveau_drm_ioctl+0x5a/0xb0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        __x64_sys_ioctl+0x91/0xd0
Aug 10 07:01:29 dg1test kernel:        do_syscall_64+0x3c/0x90
Aug 10 07:01:29 dg1test kernel:        entry_SYSCALL_64_after_hwframe+0x72/0xdc
Aug 10 07:01:29 dg1test kernel:
                                -> #0 (&fctx->lock){-...}-{2:2}:
Aug 10 07:01:29 dg1test kernel:        __lock_acquire+0x14e3/0x2240
Aug 10 07:01:29 dg1test kernel:        lock_acquire+0xc8/0x2a0
Aug 10 07:01:29 dg1test kernel:        _raw_spin_lock_irqsave+0x4b/0x70
Aug 10 07:01:29 dg1test kernel:        nouveau_fence_wait_uevent_handler+0x2b/0x100 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_client_event+0xf/0x20 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_event_ntfy+0x9b/0xf0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        ga100_fifo_nonstall_intr+0x24/0x30 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_intr+0x12c/0x240 [nouveau]
Aug 10 07:01:29 dg1test kernel:        __handle_irq_event_percpu+0x88/0x240
Aug 10 07:01:29 dg1test kernel:        handle_irq_event+0x38/0x80
Aug 10 07:01:29 dg1test kernel:        handle_edge_irq+0xa3/0x240
Aug 10 07:01:29 dg1test kernel:        __common_interrupt+0x72/0x160
Aug 10 07:01:29 dg1test kernel:        common_interrupt+0x60/0xe0
Aug 10 07:01:29 dg1test kernel:        asm_common_interrupt+0x26/0x40
Aug 10 07:01:29 dg1test kernel:
                                other info that might help us debug this:
Aug 10 07:01:29 dg1test kernel: Chain exists of:
                                  &fctx->lock --> &device->intr.lock --> &event->list_lock#2
Aug 10 07:01:29 dg1test kernel:  Possible unsafe locking scenario:
Aug 10 07:01:29 dg1test kernel:        CPU0                    CPU1
Aug 10 07:01:29 dg1test kernel:        ----                    ----
Aug 10 07:01:29 dg1test kernel:   lock(&event->list_lock#2);
Aug 10 07:01:29 dg1test kernel:                                lock(&device->intr.lock);
Aug 10 07:01:29 dg1test kernel:                                lock(&event->list_lock#2);
Aug 10 07:01:29 dg1test kernel:   lock(&fctx->lock);
Aug 10 07:01:29 dg1test kernel:
                                 *** DEADLOCK ***
Aug 10 07:01:29 dg1test kernel: 2 locks held by wireplumber/2236:
Aug 10 07:01:29 dg1test kernel:  #0: ffff8fca53177bf8 (&device->intr.lock){-...}-{2:2}, at: nvkm_intr+0x29/0x240 [nouveau]
Aug 10 07:01:29 dg1test kernel:  #1: ffff8fca41208610 (&event->list_lock#2){-...}-{2:2}, at: nvkm_event_ntfy+0x50/0xf0 [nouveau]
Aug 10 07:01:29 dg1test kernel:
                                stack backtrace:
Aug 10 07:01:29 dg1test kernel: CPU: 6 PID: 2236 Comm: wireplumber Not tainted 6.4.0-rc7+ grate-driver#10
Aug 10 07:01:29 dg1test kernel: Hardware name: Gigabyte Technology Co., Ltd. Z390 I AORUS PRO WIFI/Z390 I AORUS PRO WIFI-CF, BIOS F8 11/05/2021
Aug 10 07:01:29 dg1test kernel: Call Trace:
Aug 10 07:01:29 dg1test kernel:  <TASK>
Aug 10 07:01:29 dg1test kernel:  dump_stack_lvl+0x5b/0x90
Aug 10 07:01:29 dg1test kernel:  check_noncircular+0xe2/0x110
Aug 10 07:01:29 dg1test kernel:  __lock_acquire+0x14e3/0x2240
Aug 10 07:01:29 dg1test kernel:  lock_acquire+0xc8/0x2a0
Aug 10 07:01:29 dg1test kernel:  ? nouveau_fence_wait_uevent_handler+0x2b/0x100 [nouveau]
Aug 10 07:01:29 dg1test kernel:  ? lock_acquire+0xc8/0x2a0
Aug 10 07:01:29 dg1test kernel:  _raw_spin_lock_irqsave+0x4b/0x70
Aug 10 07:01:29 dg1test kernel:  ? nouveau_fence_wait_uevent_handler+0x2b/0x100 [nouveau]
Aug 10 07:01:29 dg1test kernel:  nouveau_fence_wait_uevent_handler+0x2b/0x100 [nouveau]
Aug 10 07:01:29 dg1test kernel:  nvkm_client_event+0xf/0x20 [nouveau]
Aug 10 07:01:29 dg1test kernel:  nvkm_event_ntfy+0x9b/0xf0 [nouveau]
Aug 10 07:01:29 dg1test kernel:  ga100_fifo_nonstall_intr+0x24/0x30 [nouveau]
Aug 10 07:01:29 dg1test kernel:  nvkm_intr+0x12c/0x240 [nouveau]
Aug 10 07:01:29 dg1test kernel:  __handle_irq_event_percpu+0x88/0x240
Aug 10 07:01:29 dg1test kernel:  handle_irq_event+0x38/0x80
Aug 10 07:01:29 dg1test kernel:  handle_edge_irq+0xa3/0x240
Aug 10 07:01:29 dg1test kernel:  __common_interrupt+0x72/0x160
Aug 10 07:01:29 dg1test kernel:  common_interrupt+0x60/0xe0
Aug 10 07:01:29 dg1test kernel:  asm_common_interrupt+0x26/0x40
Aug 10 07:01:29 dg1test kernel: RIP: 0033:0x7fb66174d700
Aug 10 07:01:29 dg1test kernel: Code: c1 e2 05 29 ca 8d 0c 10 0f be 07 84 c0 75 eb 89 c8 c3 0f 1f 84 00 00 00 00 00 f3 0f 1e fa e9 d7 0f fc ff 0f 1f 80 00 00 00 00 <f3> 0f 1e fa e9 c7 0f fc>
Aug 10 07:01:29 dg1test kernel: RSP: 002b:00007ffdd3c48438 EFLAGS: 00000206
Aug 10 07:01:29 dg1test kernel: RAX: 000055bb758763c0 RBX: 000055bb758752c0 RCX: 00000000000028b0
Aug 10 07:01:29 dg1test kernel: RDX: 000055bb758752c0 RSI: 000055bb75887490 RDI: 000055bb75862950
Aug 10 07:01:29 dg1test kernel: RBP: 00007ffdd3c48490 R08: 000055bb75873b10 R09: 0000000000000001
Aug 10 07:01:29 dg1test kernel: R10: 0000000000000004 R11: 000055bb7587f000 R12: 000055bb75887490
Aug 10 07:01:29 dg1test kernel: R13: 000055bb757f6280 R14: 000055bb758875c0 R15: 000055bb757f6280
Aug 10 07:01:29 dg1test kernel:  </TASK>

Signed-off-by: Dave Airlie <[email protected]>
Tested-by: Danilo Krummrich <[email protected]>
Reviewed-by: Danilo Krummrich <[email protected]>
Signed-off-by: Danilo Krummrich <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
Signed-off-by: Sasha Levin <[email protected]>
okias pushed a commit that referenced this pull request Jan 7, 2024
[ Upstream commit e3e82fc ]

When creating ceq_0 during probing irdma, cqp.sc_cqp will be sent as a
cqp_request to cqp->sc_cqp.sq_ring. If the request is pending when
removing the irdma driver or unplugging its aux device, cqp.sc_cqp will be
dereferenced as wrong struct in irdma_free_pending_cqp_request().

  PID: 3669   TASK: ffff88aef892c000  CPU: 28  COMMAND: "kworker/28:0"
   #0 [fffffe0000549e38] crash_nmi_callback at ffffffff810e3a34
   #1 [fffffe0000549e40] nmi_handle at ffffffff810788b2
   #2 [fffffe0000549ea0] default_do_nmi at ffffffff8107938f
   #3 [fffffe0000549eb8] do_nmi at ffffffff81079582
   #4 [fffffe0000549ef0] end_repeat_nmi at ffffffff82e016b4
      [exception RIP: native_queued_spin_lock_slowpath+1291]
      RIP: ffffffff8127e72b  RSP: ffff88aa841ef778  RFLAGS: 00000046
      RAX: 0000000000000000  RBX: ffff88b01f849700  RCX: ffffffff8127e47e
      RDX: 0000000000000000  RSI: 0000000000000004  RDI: ffffffff83857ec0
      RBP: ffff88afe3e4efc8   R8: ffffed15fc7c9dfa   R9: ffffed15fc7c9dfa
      R10: 0000000000000001  R11: ffffed15fc7c9df9  R12: 0000000000740000
      R13: ffff88b01f849708  R14: 0000000000000003  R15: ffffed1603f092e1
      ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0000
  -- <NMI exception stack> --
   #5 [ffff88aa841ef778] native_queued_spin_lock_slowpath at ffffffff8127e72b
   #6 [ffff88aa841ef7b0] _raw_spin_lock_irqsave at ffffffff82c22aa4
   #7 [ffff88aa841ef7c8] __wake_up_common_lock at ffffffff81257363
   #8 [ffff88aa841ef888] irdma_free_pending_cqp_request at ffffffffa0ba12cc [irdma]
   grate-driver#9 [ffff88aa841ef958] irdma_cleanup_pending_cqp_op at ffffffffa0ba1469 [irdma]
   grate-driver#10 [ffff88aa841ef9c0] irdma_ctrl_deinit_hw at ffffffffa0b2989f [irdma]
   grate-driver#11 [ffff88aa841efa28] irdma_remove at ffffffffa0b252df [irdma]
   grate-driver#12 [ffff88aa841efae8] auxiliary_bus_remove at ffffffff8219afdb
   grate-driver#13 [ffff88aa841efb00] device_release_driver_internal at ffffffff821882e6
   grate-driver#14 [ffff88aa841efb38] bus_remove_device at ffffffff82184278
   grate-driver#15 [ffff88aa841efb88] device_del at ffffffff82179d23
   grate-driver#16 [ffff88aa841efc48] ice_unplug_aux_dev at ffffffffa0eb1c14 [ice]
   grate-driver#17 [ffff88aa841efc68] ice_service_task at ffffffffa0d88201 [ice]
   grate-driver#18 [ffff88aa841efde8] process_one_work at ffffffff811c589a
   grate-driver#19 [ffff88aa841efe60] worker_thread at ffffffff811c71ff
   grate-driver#20 [ffff88aa841eff10] kthread at ffffffff811d87a0
   grate-driver#21 [ffff88aa841eff50] ret_from_fork at ffffffff82e0022f

Fixes: 44d9e52 ("RDMA/irdma: Implement device initialization definitions")
Link: https://lore.kernel.org/r/[email protected]
Suggested-by: "Ismail, Mustafa" <[email protected]>
Signed-off-by: Shifeng Li <[email protected]>
Reviewed-by: Shiraz Saleem <[email protected]>
Signed-off-by: Jason Gunthorpe <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
okias pushed a commit that referenced this pull request Jan 7, 2024
commit fe2b122 upstream.

When working on LED support for r8169 I got the following lockdep
warning. Easiest way to prevent this scenario seems to be to take
the RTNL lock before the trigger_data lock in set_device_name().

======================================================
WARNING: possible circular locking dependency detected
6.7.0-rc2-next-20231124+ #2 Not tainted
------------------------------------------------------
bash/383 is trying to acquire lock:
ffff888103aa1c68 (&trigger_data->lock){+.+.}-{3:3}, at: netdev_trig_notify+0xec/0x190 [ledtrig_netdev]

but task is already holding lock:
ffffffff8cddf808 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x12/0x20

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (rtnl_mutex){+.+.}-{3:3}:
       __mutex_lock+0x9b/0xb50
       mutex_lock_nested+0x16/0x20
       rtnl_lock+0x12/0x20
       set_device_name+0xa9/0x120 [ledtrig_netdev]
       netdev_trig_activate+0x1a1/0x230 [ledtrig_netdev]
       led_trigger_set+0x172/0x2c0
       led_trigger_write+0xf1/0x140
       sysfs_kf_bin_write+0x5d/0x80
       kernfs_fop_write_iter+0x15d/0x210
       vfs_write+0x1f0/0x510
       ksys_write+0x6c/0xf0
       __x64_sys_write+0x14/0x20
       do_syscall_64+0x3f/0xf0
       entry_SYSCALL_64_after_hwframe+0x6c/0x74

-> #0 (&trigger_data->lock){+.+.}-{3:3}:
       __lock_acquire+0x1459/0x25a0
       lock_acquire+0xc8/0x2d0
       __mutex_lock+0x9b/0xb50
       mutex_lock_nested+0x16/0x20
       netdev_trig_notify+0xec/0x190 [ledtrig_netdev]
       call_netdevice_register_net_notifiers+0x5a/0x100
       register_netdevice_notifier+0x85/0x120
       netdev_trig_activate+0x1d4/0x230 [ledtrig_netdev]
       led_trigger_set+0x172/0x2c0
       led_trigger_write+0xf1/0x140
       sysfs_kf_bin_write+0x5d/0x80
       kernfs_fop_write_iter+0x15d/0x210
       vfs_write+0x1f0/0x510
       ksys_write+0x6c/0xf0
       __x64_sys_write+0x14/0x20
       do_syscall_64+0x3f/0xf0
       entry_SYSCALL_64_after_hwframe+0x6c/0x74

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(rtnl_mutex);
                               lock(&trigger_data->lock);
                               lock(rtnl_mutex);
  lock(&trigger_data->lock);

 *** DEADLOCK ***

8 locks held by bash/383:
 #0: ffff888103ff33f0 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x6c/0xf0
 #1: ffff888103aa1e88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x114/0x210
 #2: ffff8881036f1890 (kn->active#82){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x11d/0x210
 #3: ffff888108e2c358 (&led_cdev->led_access){+.+.}-{3:3}, at: led_trigger_write+0x30/0x140
 #4: ffffffff8cdd9e10 (triggers_list_lock){++++}-{3:3}, at: led_trigger_write+0x75/0x140
 #5: ffff888108e2c270 (&led_cdev->trigger_lock){++++}-{3:3}, at: led_trigger_write+0xe3/0x140
 #6: ffffffff8cdde3d0 (pernet_ops_rwsem){++++}-{3:3}, at: register_netdevice_notifier+0x1c/0x120
 #7: ffffffff8cddf808 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x12/0x20

stack backtrace:
CPU: 0 PID: 383 Comm: bash Not tainted 6.7.0-rc2-next-20231124+ #2
Hardware name: Default string Default string/Default string, BIOS ADLN.M6.SODIMM.ZB.CY.015 08/08/2023
Call Trace:
 <TASK>
 dump_stack_lvl+0x5c/0xd0
 dump_stack+0x10/0x20
 print_circular_bug+0x2dd/0x410
 check_noncircular+0x131/0x150
 __lock_acquire+0x1459/0x25a0
 lock_acquire+0xc8/0x2d0
 ? netdev_trig_notify+0xec/0x190 [ledtrig_netdev]
 __mutex_lock+0x9b/0xb50
 ? netdev_trig_notify+0xec/0x190 [ledtrig_netdev]
 ? __this_cpu_preempt_check+0x13/0x20
 ? netdev_trig_notify+0xec/0x190 [ledtrig_netdev]
 ? __cancel_work_timer+0x11c/0x1b0
 ? __mutex_lock+0x123/0xb50
 mutex_lock_nested+0x16/0x20
 ? mutex_lock_nested+0x16/0x20
 netdev_trig_notify+0xec/0x190 [ledtrig_netdev]
 call_netdevice_register_net_notifiers+0x5a/0x100
 register_netdevice_notifier+0x85/0x120
 netdev_trig_activate+0x1d4/0x230 [ledtrig_netdev]
 led_trigger_set+0x172/0x2c0
 ? preempt_count_add+0x49/0xc0
 led_trigger_write+0xf1/0x140
 sysfs_kf_bin_write+0x5d/0x80
 kernfs_fop_write_iter+0x15d/0x210
 vfs_write+0x1f0/0x510
 ksys_write+0x6c/0xf0
 __x64_sys_write+0x14/0x20
 do_syscall_64+0x3f/0xf0
 entry_SYSCALL_64_after_hwframe+0x6c/0x74
RIP: 0033:0x7f269055d034
Code: c7 00 16 00 00 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 80 3d 35 c3 0d 00 00 74 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 48 83 ec 28 48 89 54 24 18 48
RSP: 002b:00007ffddb7ef748 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 00007f269055d034
RDX: 0000000000000007 RSI: 000055bf5f4af3c0 RDI: 0000000000000001
RBP: 000055bf5f4af3c0 R08: 0000000000000073 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000007
R13: 00007f26906325c0 R14: 00007f269062ff20 R15: 0000000000000000
 </TASK>

Fixes: d5e0126 ("leds: trigger: netdev: add additional specific link speed mode")
Cc: [email protected]
Signed-off-by: Heiner Kallweit <[email protected]>
Reviewed-by: Andrew Lunn <[email protected]>
Acked-by: Lee Jones <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
okias pushed a commit that referenced this pull request Jan 11, 2024
The test_tag test triggers an unhandled page fault:

  # ./test_tag
  [  130.640218] CPU 0 Unable to handle kernel paging request at virtual address ffff80001b898004, era == 9000000003137f7c, ra == 9000000003139e70
  [  130.640501] Oops[#3]:
  [  130.640553] CPU: 0 PID: 1326 Comm: test_tag Tainted: G      D    O       6.7.0-rc4-loong-devel-gb62ab1a397cf grate-driver#47 61985c1d94084daa2432f771daa45b56b10d8d2a
  [  130.640764] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
  [  130.640874] pc 9000000003137f7c ra 9000000003139e70 tp 9000000104cb4000 sp 9000000104cb7a40
  [  130.641001] a0 ffff80001b894000 a1 ffff80001b897ff8 a2 000000006ba210be a3 0000000000000000
  [  130.641128] a4 000000006ba210be a5 00000000000000f1 a6 00000000000000b3 a7 0000000000000000
  [  130.641256] t0 0000000000000000 t1 00000000000007f6 t2 0000000000000000 t3 9000000004091b70
  [  130.641387] t4 000000006ba210be t5 0000000000000004 t6 fffffffffffffff0 t7 90000000040913e0
  [  130.641512] t8 0000000000000005 u0 0000000000000dc0 s9 0000000000000009 s0 9000000104cb7ae0
  [  130.641641] s1 00000000000007f6 s2 0000000000000009 s3 0000000000000095 s4 0000000000000000
  [  130.641771] s5 ffff80001b894000 s6 ffff80001b897fb0 s7 9000000004090c50 s8 0000000000000000
  [  130.641900]    ra: 9000000003139e70 build_body+0x1fcc/0x4988
  [  130.642007]   ERA: 9000000003137f7c build_body+0xd8/0x4988
  [  130.642112]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
  [  130.642261]  PRMD: 00000004 (PPLV0 +PIE -PWE)
  [  130.642353]  EUEN: 00000003 (+FPE +SXE -ASXE -BTE)
  [  130.642458]  ECFG: 00071c1c (LIE=2-4,10-12 VS=7)
  [  130.642554] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
  [  130.642658]  BADV: ffff80001b898004
  [  130.642719]  PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)
  [  130.642815] Modules linked in: [last unloaded: bpf_testmod(O)]
  [  130.642924] Process test_tag (pid: 1326, threadinfo=00000000f7f4015f, task=000000006499f9fd)
  [  130.643062] Stack : 0000000000000000 9000000003380724 0000000000000000 0000000104cb7be8
  [  130.643213]         0000000000000000 25af8d9b6e600558 9000000106250ea0 9000000104cb7ae0
  [  130.643378]         0000000000000000 0000000000000000 9000000104cb7be8 90000000049f6000
  [  130.643538]         0000000000000090 9000000106250ea0 ffff80001b894000 ffff80001b894000
  [  130.643685]         00007ffffb917790 900000000313ca94 0000000000000000 0000000000000000
  [  130.643831]         ffff80001b894000 0000000000000ff7 0000000000000000 9000000100468000
  [  130.643983]         0000000000000000 0000000000000000 0000000000000040 25af8d9b6e600558
  [  130.644131]         0000000000000bb7 ffff80001b894048 0000000000000000 0000000000000000
  [  130.644276]         9000000104cb7be8 90000000049f6000 0000000000000090 9000000104cb7bdc
  [  130.644423]         ffff80001b894000 0000000000000000 00007ffffb917790 90000000032acfb0
  [  130.644572]         ...
  [  130.644629] Call Trace:
  [  130.644641] [<9000000003137f7c>] build_body+0xd8/0x4988
  [  130.644785] [<900000000313ca94>] bpf_int_jit_compile+0x228/0x4ec
  [  130.644891] [<90000000032acfb0>] bpf_prog_select_runtime+0x158/0x1b0
  [  130.645003] [<90000000032b3504>] bpf_prog_load+0x760/0xb44
  [  130.645089] [<90000000032b6744>] __sys_bpf+0xbb8/0x2588
  [  130.645175] [<90000000032b8388>] sys_bpf+0x20/0x2c
  [  130.645259] [<9000000003f6ab38>] do_syscall+0x7c/0x94
  [  130.645369] [<9000000003121c5c>] handle_syscall+0xbc/0x158
  [  130.645507]
  [  130.645539] Code: 380839f6  380831f9  28412bae <24000ca6> 004081ad  0014cb50  004083e8  02bff34c  58008e91
  [  130.645729]
  [  130.646418] ---[ end trace 0000000000000000 ]---

On my machine, which has CONFIG_PAGE_SIZE_16KB=y, the test failed at
loading a BPF prog with 2039 instructions:

  prog = (struct bpf_prog *)ffff80001b894000
  insn = (struct bpf_insn *)(prog->insnsi)ffff80001b894048
  insn + 2039 = (struct bpf_insn *)ffff80001b898000 <- end of the page

In the build_insn() function, we are trying to access next instruction
unconditionally, i.e. `(insn + 1)->imm`. The address lies in the next
page and can be not owned by the current process, thus an page fault is
inevitable and then segfault.

So, let's access next instruction only under `dst = imm64` context.

With this fix, we have:

  # ./test_tag
  test_tag: OK (40945 tests)

Fixes: bbfddb9 ("LoongArch: BPF: Avoid declare variables in switch-case")
Tested-by: Tiezhu Yang <[email protected]>
Signed-off-by: Hengqi Chen <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>
okias pushed a commit that referenced this pull request Jan 11, 2024
======================================================
WARNING: possible circular locking dependency detected
6.5.0-kfd-yangp #2289 Not tainted
------------------------------------------------------
kworker/0:2/996 is trying to acquire lock:
        (srcu){.+.+}-{0:0}, at: __synchronize_srcu+0x5/0x1a0

but task is already holding lock:
        ((work_completion)(&svms->deferred_list_work)){+.+.}-{0:0}, at:
	process_one_work+0x211/0x560

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #3 ((work_completion)(&svms->deferred_list_work)){+.+.}-{0:0}:
        __flush_work+0x88/0x4f0
        svm_range_list_lock_and_flush_work+0x3d/0x110 [amdgpu]
        svm_range_set_attr+0xd6/0x14c0 [amdgpu]
        kfd_ioctl+0x1d1/0x630 [amdgpu]
        __x64_sys_ioctl+0x88/0xc0

-> #2 (&info->lock#2){+.+.}-{3:3}:
        __mutex_lock+0x99/0xc70
        amdgpu_amdkfd_gpuvm_restore_process_bos+0x54/0x740 [amdgpu]
        restore_process_helper+0x22/0x80 [amdgpu]
        restore_process_worker+0x2d/0xa0 [amdgpu]
        process_one_work+0x29b/0x560
        worker_thread+0x3d/0x3d0

-> #1 ((work_completion)(&(&process->restore_work)->work)){+.+.}-{0:0}:
        __flush_work+0x88/0x4f0
        __cancel_work_timer+0x12c/0x1c0
        kfd_process_notifier_release_internal+0x37/0x1f0 [amdgpu]
        __mmu_notifier_release+0xad/0x240
        exit_mmap+0x6a/0x3a0
        mmput+0x6a/0x120
        do_exit+0x322/0xb90
        do_group_exit+0x37/0xa0
        __x64_sys_exit_group+0x18/0x20
        do_syscall_64+0x38/0x80

-> #0 (srcu){.+.+}-{0:0}:
        __lock_acquire+0x1521/0x2510
        lock_sync+0x5f/0x90
        __synchronize_srcu+0x4f/0x1a0
        __mmu_notifier_release+0x128/0x240
        exit_mmap+0x6a/0x3a0
        mmput+0x6a/0x120
        svm_range_deferred_list_work+0x19f/0x350 [amdgpu]
        process_one_work+0x29b/0x560
        worker_thread+0x3d/0x3d0

other info that might help us debug this:
Chain exists of:
  srcu --> &info->lock#2 --> (work_completion)(&svms->deferred_list_work)

Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
        lock((work_completion)(&svms->deferred_list_work));
                        lock(&info->lock#2);
			lock((work_completion)(&svms->deferred_list_work));
        sync(srcu);

Signed-off-by: Philip Yang <[email protected]>
Reviewed-by: Felix Kuehling <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

Successfully merging this pull request may close these issues.

1 participant