This repository has been archived by the owner on Nov 21, 2022. It is now read-only.
forked from microsoft/WSL2-Linux-Kernel
-
Notifications
You must be signed in to change notification settings - Fork 21
request enable CONFIG_IO_URING #10
Comments
image build from tag wsl2-cbl-kernel-next-20201029-v53 instead of next branch works!! |
I have gone ahead and enabled it anyways. It will be in the next public release. |
nathanchance
pushed a commit
that referenced
this issue
Mar 2, 2021
The ubsan reported the following error. It was because sample's raw data missed u32 padding at the end. So it broke the alignment of the array after it. The raw data contains an u32 size prefix so the data size should have an u32 padding after 8-byte aligned data. 27: Sample parsing :util/synthetic-events.c:1539:4: runtime error: store to misaligned address 0x62100006b9bc for type '__u64' (aka 'unsigned long long'), which requires 8 byte alignment 0x62100006b9bc: note: pointer points here 00 00 00 00 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ #0 0x561532a9fc96 in perf_event__synthesize_sample util/synthetic-events.c:1539:13 #1 0x5615327f4a4f in do_test tests/sample-parsing.c:284:8 #2 0x5615327f3f50 in test__sample_parsing tests/sample-parsing.c:381:9 #3 0x56153279d3a1 in run_test tests/builtin-test.c:424:9 #4 0x56153279c836 in test_and_print tests/builtin-test.c:454:9 #5 0x56153279b7eb in __cmd_test tests/builtin-test.c:675:4 #6 0x56153279abf0 in cmd_test tests/builtin-test.c:821:9 #7 0x56153264e796 in run_builtin perf.c:312:11 #8 0x56153264cf03 in handle_internal_command perf.c:364:8 #9 0x56153264e47d in run_argv perf.c:408:2 #10 0x56153264c9a9 in main perf.c:538:3 #11 0x7f137ab6fbbc in __libc_start_main (/lib64/libc.so.6+0x38bbc) #12 0x561532596828 in _start ... SUMMARY: UndefinedBehaviorSanitizer: misaligned-pointer-use util/synthetic-events.c:1539:4 in Fixes: 045f8cd ("perf tests: Add a sample parsing test") Signed-off-by: Namhyung Kim <[email protected]> Acked-by: Adrian Hunter <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Andi Kleen <[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]> Cc: Stephane Eranian <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Mar 4, 2021
Calling btrfs_qgroup_reserve_meta_prealloc from btrfs_delayed_inode_reserve_metadata can result in flushing delalloc while holding a transaction and delayed node locks. This is deadlock prone. In the past multiple commits: * ae5e070 ("btrfs: qgroup: don't try to wait flushing if we're already holding a transaction") * 6f23277 ("btrfs: qgroup: don't commit transaction when we already hold the handle") Tried to solve various aspects of this but this was always a whack-a-mole game. Unfortunately those 2 fixes don't solve a deadlock scenario involving btrfs_delayed_node::mutex. Namely, one thread can call btrfs_dirty_inode as a result of reading a file and modifying its atime: PID: 6963 TASK: ffff8c7f3f94c000 CPU: 2 COMMAND: "test" #0 __schedule at ffffffffa529e07d #1 schedule at ffffffffa529e4ff #2 schedule_timeout at ffffffffa52a1bdd #3 wait_for_completion at ffffffffa529eeea <-- sleeps with delayed node mutex held #4 start_delalloc_inodes at ffffffffc0380db5 #5 btrfs_start_delalloc_snapshot at ffffffffc0393836 #6 try_flush_qgroup at ffffffffc03f04b2 #7 __btrfs_qgroup_reserve_meta at ffffffffc03f5bb6 <-- tries to reserve space and starts delalloc inodes. #8 btrfs_delayed_update_inode at ffffffffc03e31aa <-- acquires delayed node mutex #9 btrfs_update_inode at ffffffffc0385ba8 #10 btrfs_dirty_inode at ffffffffc038627b <-- TRANSACTIION OPENED #11 touch_atime at ffffffffa4cf0000 #12 generic_file_read_iter at ffffffffa4c1f123 #13 new_sync_read at ffffffffa4ccdc8a #14 vfs_read at ffffffffa4cd0849 #15 ksys_read at ffffffffa4cd0bd1 #16 do_syscall_64 at ffffffffa4a052eb #17 entry_SYSCALL_64_after_hwframe at ffffffffa540008c This will cause an asynchronous work to flush the delalloc inodes to happen which can try to acquire the same delayed_node mutex: PID: 455 TASK: ffff8c8085fa4000 CPU: 5 COMMAND: "kworker/u16:30" #0 __schedule at ffffffffa529e07d #1 schedule at ffffffffa529e4ff #2 schedule_preempt_disabled at ffffffffa529e80a #3 __mutex_lock at ffffffffa529fdcb <-- goes to sleep, never wakes up. #4 btrfs_delayed_update_inode at ffffffffc03e3143 <-- tries to acquire the mutex #5 btrfs_update_inode at ffffffffc0385ba8 <-- this is the same inode that pid 6963 is holding #6 cow_file_range_inline.constprop.78 at ffffffffc0386be7 #7 cow_file_range at ffffffffc03879c1 #8 btrfs_run_delalloc_range at ffffffffc038894c #9 writepage_delalloc at ffffffffc03a3c8f #10 __extent_writepage at ffffffffc03a4c01 #11 extent_write_cache_pages at ffffffffc03a500b #12 extent_writepages at ffffffffc03a6de2 #13 do_writepages at ffffffffa4c277eb #14 __filemap_fdatawrite_range at ffffffffa4c1e5bb #15 btrfs_run_delalloc_work at ffffffffc0380987 <-- starts running delayed nodes #16 normal_work_helper at ffffffffc03b706c #17 process_one_work at ffffffffa4aba4e4 #18 worker_thread at ffffffffa4aba6fd #19 kthread at ffffffffa4ac0a3d #20 ret_from_fork at ffffffffa54001ff To fully address those cases the complete fix is to never issue any flushing while holding the transaction or the delayed node lock. This patch achieves it by calling qgroup_reserve_meta directly which will either succeed without flushing or will fail and return -EDQUOT. In the latter case that return value is going to be propagated to btrfs_dirty_inode which will fallback to start a new transaction. That's fine as the majority of time we expect the inode will have BTRFS_DELAYED_NODE_INODE_DIRTY flag set which will result in directly copying the in-memory state. Fixes: c53e965 ("btrfs: qgroup: try to flush qgroup space when we get -EDQUOT") CC: [email protected] # 5.10+ Reviewed-by: Qu Wenruo <[email protected]> Signed-off-by: Nikolay Borisov <[email protected]> Signed-off-by: David Sterba <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Mar 7, 2021
[ 6684.493350] Unable to handle kernel paging request at virtual address ffff800011c5b0f0 [ 6684.498531] mmc0: card 0001 removed [ 6684.501556] Mem abort info: [ 6684.509681] ESR = 0x96000047 [ 6684.512786] EC = 0x25: DABT (current EL), IL = 32 bits [ 6684.518394] SET = 0, FnV = 0 [ 6684.521707] EA = 0, S1PTW = 0 [ 6684.524998] Data abort info: [ 6684.528236] ISV = 0, ISS = 0x00000047 [ 6684.532986] CM = 0, WnR = 1 [ 6684.536129] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000081b22000 [ 6684.543923] [ffff800011c5b0f0] pgd=00000000bffff003, p4d=00000000bffff003, pud=00000000bfffe003, pmd=00000000900e1003, pte=0000000000000000 [ 6684.557915] Internal error: Oops: 96000047 [#1] PREEMPT SMP [ 6684.564240] Modules linked in: sdhci_esdhc_imx(-) sdhci_pltfm sdhci cqhci mmc_block mmc_core fsl_jr_uio caam_jr caamkeyblob_desc caamhash_desc caamalg_desc crypto_engine rng_core authenc libdes crct10dif_ce flexcan can_dev caam error [last unloaded: mmc_core] [ 6684.587281] CPU: 0 PID: 79138 Comm: kworker/0:3H Not tainted 5.10.9-01410-g3ba33182767b-dirty #10 [ 6684.596160] Hardware name: Freescale i.MX8DXL EVK (DT) [ 6684.601320] Workqueue: kblockd blk_mq_run_work_fn [ 6684.606094] pstate: 40000005 (nZcv daif -PAN -UAO -TCO BTYPE=--) [ 6684.612286] pc : cqhci_request+0x148/0x4e8 [cqhci] ^GMessage from syslogd@ at Thu Jan 1 01:51:24 1970 ...[ 6684.617085] lr : cqhci_request+0x314/0x4e8 [cqhci] [ 6684.626734] sp : ffff80001243b9f0 [ 6684.630049] x29: ffff80001243b9f0 x28: ffff00002c3dd000 [ 6684.635367] x27: 0000000000000001 x26: 0000000000000001 [ 6684.640690] x25: ffff00002c451000 x24: 000000000000000f [ 6684.646007] x23: ffff000017e71c80 x22: ffff00002c451000 [ 6684.651326] x21: ffff00002c0f3550 x20: ffff00002c0f3550 [ 6684.656651] x19: ffff000017d46880 x18: ffff00002cea1500 [ 6684.661977] x17: 0000000000000000 x16: 0000000000000000 [ 6684.667294] x15: 000001ee628e3ed1 x14: 0000000000000278 [ 6684.672610] x13: 0000000000000001 x12: 0000000000000001 [ 6684.677927] x11: 0000000000000000 x10: 0000000000000000 [ 6684.683243] x9 : 000000000000002b x8 : 0000000000001000 [ 6684.688560] x7 : 0000000000000010 x6 : ffff00002c0f3678 [ 6684.693886] x5 : 000000000000000f x4 : ffff800011c5b000 [ 6684.699211] x3 : 000000000002d988 x2 : 0000000000000008 [ 6684.704537] x1 : 00000000000000f0 x0 : 0002d9880008102f [ 6684.709854] Call trace: [ 6684.712313] cqhci_request+0x148/0x4e8 [cqhci] [ 6684.716803] mmc_cqe_start_req+0x58/0x68 [mmc_core] [ 6684.721698] mmc_blk_mq_issue_rq+0x460/0x810 [mmc_block] [ 6684.727018] mmc_mq_queue_rq+0x118/0x2b0 [mmc_block] The problem occurs when cqhci_request() get called after cqhci_disable() as it leads to access of allocated memory that has already been freed. Let's fix the problem by calling cqhci_disable() a bit later in the remove path. Signed-off-by: Frank Li <[email protected]> Diagnosed-by: Adrian Hunter <[email protected]> Acked-by: Adrian Hunter <[email protected]> Link: https://lore.kernel.org/r/[email protected] Fixes: f690f44 ("mmc: mmc: Enable CQE's") Cc: [email protected] Signed-off-by: Ulf Hansson <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Mar 7, 2021
Calling btrfs_qgroup_reserve_meta_prealloc from btrfs_delayed_inode_reserve_metadata can result in flushing delalloc while holding a transaction and delayed node locks. This is deadlock prone. In the past multiple commits: * ae5e070 ("btrfs: qgroup: don't try to wait flushing if we're already holding a transaction") * 6f23277 ("btrfs: qgroup: don't commit transaction when we already hold the handle") Tried to solve various aspects of this but this was always a whack-a-mole game. Unfortunately those 2 fixes don't solve a deadlock scenario involving btrfs_delayed_node::mutex. Namely, one thread can call btrfs_dirty_inode as a result of reading a file and modifying its atime: PID: 6963 TASK: ffff8c7f3f94c000 CPU: 2 COMMAND: "test" #0 __schedule at ffffffffa529e07d #1 schedule at ffffffffa529e4ff #2 schedule_timeout at ffffffffa52a1bdd #3 wait_for_completion at ffffffffa529eeea <-- sleeps with delayed node mutex held #4 start_delalloc_inodes at ffffffffc0380db5 #5 btrfs_start_delalloc_snapshot at ffffffffc0393836 #6 try_flush_qgroup at ffffffffc03f04b2 #7 __btrfs_qgroup_reserve_meta at ffffffffc03f5bb6 <-- tries to reserve space and starts delalloc inodes. #8 btrfs_delayed_update_inode at ffffffffc03e31aa <-- acquires delayed node mutex #9 btrfs_update_inode at ffffffffc0385ba8 #10 btrfs_dirty_inode at ffffffffc038627b <-- TRANSACTIION OPENED #11 touch_atime at ffffffffa4cf0000 #12 generic_file_read_iter at ffffffffa4c1f123 #13 new_sync_read at ffffffffa4ccdc8a #14 vfs_read at ffffffffa4cd0849 #15 ksys_read at ffffffffa4cd0bd1 #16 do_syscall_64 at ffffffffa4a052eb #17 entry_SYSCALL_64_after_hwframe at ffffffffa540008c This will cause an asynchronous work to flush the delalloc inodes to happen which can try to acquire the same delayed_node mutex: PID: 455 TASK: ffff8c8085fa4000 CPU: 5 COMMAND: "kworker/u16:30" #0 __schedule at ffffffffa529e07d #1 schedule at ffffffffa529e4ff #2 schedule_preempt_disabled at ffffffffa529e80a #3 __mutex_lock at ffffffffa529fdcb <-- goes to sleep, never wakes up. #4 btrfs_delayed_update_inode at ffffffffc03e3143 <-- tries to acquire the mutex #5 btrfs_update_inode at ffffffffc0385ba8 <-- this is the same inode that pid 6963 is holding #6 cow_file_range_inline.constprop.78 at ffffffffc0386be7 #7 cow_file_range at ffffffffc03879c1 #8 btrfs_run_delalloc_range at ffffffffc038894c #9 writepage_delalloc at ffffffffc03a3c8f #10 __extent_writepage at ffffffffc03a4c01 #11 extent_write_cache_pages at ffffffffc03a500b #12 extent_writepages at ffffffffc03a6de2 #13 do_writepages at ffffffffa4c277eb #14 __filemap_fdatawrite_range at ffffffffa4c1e5bb #15 btrfs_run_delalloc_work at ffffffffc0380987 <-- starts running delayed nodes #16 normal_work_helper at ffffffffc03b706c #17 process_one_work at ffffffffa4aba4e4 #18 worker_thread at ffffffffa4aba6fd #19 kthread at ffffffffa4ac0a3d #20 ret_from_fork at ffffffffa54001ff To fully address those cases the complete fix is to never issue any flushing while holding the transaction or the delayed node lock. This patch achieves it by calling qgroup_reserve_meta directly which will either succeed without flushing or will fail and return -EDQUOT. In the latter case that return value is going to be propagated to btrfs_dirty_inode which will fallback to start a new transaction. That's fine as the majority of time we expect the inode will have BTRFS_DELAYED_NODE_INODE_DIRTY flag set which will result in directly copying the in-memory state. Fixes: c53e965 ("btrfs: qgroup: try to flush qgroup space when we get -EDQUOT") CC: [email protected] # 5.10+ Reviewed-by: Qu Wenruo <[email protected]> Signed-off-by: Nikolay Borisov <[email protected]> Signed-off-by: David Sterba <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Mar 10, 2021
The evlist has the maps with its own refcounts so we don't need to set the pointers to NULL. Otherwise following error was reported by Asan. # perf test -v 4 4: Read samples using the mmap interface : --- start --- test child forked, pid 139782 mmap size 528384B ================================================================= ==139782==ERROR: LeakSanitizer: detected memory leaks Direct leak of 40 byte(s) in 1 object(s) allocated from: #0 0x7f1f76daee8f in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145 #1 0x564ba21a0fea in cpu_map__trim_new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:79 #2 0x564ba21a1a0f in perf_cpu_map__read /home/namhyung/project/linux/tools/lib/perf/cpumap.c:149 #3 0x564ba21a21cf in cpu_map__read_all_cpu_map /home/namhyung/project/linux/tools/lib/perf/cpumap.c:166 #4 0x564ba21a21cf in perf_cpu_map__new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:181 #5 0x564ba1e48298 in test__basic_mmap tests/mmap-basic.c:55 #6 0x564ba1e278fb in run_test tests/builtin-test.c:428 #7 0x564ba1e278fb in test_and_print tests/builtin-test.c:458 #8 0x564ba1e29a53 in __cmd_test tests/builtin-test.c:679 #9 0x564ba1e29a53 in cmd_test tests/builtin-test.c:825 #10 0x564ba1e95cb4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313 #11 0x564ba1d1fa88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365 #12 0x564ba1d1fa88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409 #13 0x564ba1d1fa88 in main /home/namhyung/project/linux/tools/perf/perf.c:539 #14 0x7f1f768e4d09 in __libc_start_main ../csu/libc-start.c:308 ... test child finished with 1 ---- end ---- Read samples using the mmap interface: FAILED! failed to open shell test directory: /home/namhyung/libexec/perf-core/tests/shell Signed-off-by: Namhyung Kim <[email protected]> Acked-by: Jiri Olsa <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Stephane Eranian <[email protected]> Cc: Ian Rogers <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Leo Yan <[email protected]> Cc: Andi Kleen <[email protected]> Cc: Alexander Shishkin <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Mar 10, 2021
The evlist has the maps with its own refcounts so we don't need to set the pointers to NULL. Otherwise following error was reported by Asan. Also change the goto label since it doesn't need to have two. # perf test -v 24 24: Number of exit events of a simple workload : --- start --- test child forked, pid 145915 mmap size 528384B ================================================================= ==145915==ERROR: LeakSanitizer: detected memory leaks Direct leak of 32 byte(s) in 1 object(s) allocated from: #0 0x7fc44e50d1f8 in __interceptor_realloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:164 #1 0x561cf50f4d2e in perf_thread_map__realloc /home/namhyung/project/linux/tools/lib/perf/threadmap.c:23 #2 0x561cf4eeb949 in thread_map__new_by_tid util/thread_map.c:63 #3 0x561cf4db7fd2 in test__task_exit tests/task-exit.c:74 #4 0x561cf4d798fb in run_test tests/builtin-test.c:428 #5 0x561cf4d798fb in test_and_print tests/builtin-test.c:458 #6 0x561cf4d7ba53 in __cmd_test tests/builtin-test.c:679 #7 0x561cf4d7ba53 in cmd_test tests/builtin-test.c:825 #8 0x561cf4de7d04 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313 #9 0x561cf4c71a88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365 #10 0x561cf4c71a88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409 #11 0x561cf4c71a88 in main /home/namhyung/project/linux/tools/perf/perf.c:539 #12 0x7fc44e042d09 in __libc_start_main ../csu/libc-start.c:308 ... test child finished with 1 ---- end ---- Number of exit events of a simple workload: FAILED! Signed-off-by: Namhyung Kim <[email protected]> Acked-by: Jiri Olsa <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Andi Kleen <[email protected]> Cc: Ian Rogers <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Leo Yan <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Mar 10, 2021
The evlist has the maps with its own refcounts so we don't need to set the pointers to NULL. Otherwise following error was reported by Asan. Also change the goto label since it doesn't need to have two. # perf test -v 25 25: Software clock events period values : --- start --- test child forked, pid 149154 mmap size 528384B mmap size 528384B ================================================================= ==149154==ERROR: LeakSanitizer: detected memory leaks Direct leak of 32 byte(s) in 1 object(s) allocated from: #0 0x7fef5cd071f8 in __interceptor_realloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:164 #1 0x56260d5e8b8e in perf_thread_map__realloc /home/namhyung/project/linux/tools/lib/perf/threadmap.c:23 #2 0x56260d3df7a9 in thread_map__new_by_tid util/thread_map.c:63 #3 0x56260d2ac6b2 in __test__sw_clock_freq tests/sw-clock.c:65 #4 0x56260d26d8fb in run_test tests/builtin-test.c:428 #5 0x56260d26d8fb in test_and_print tests/builtin-test.c:458 #6 0x56260d26fa53 in __cmd_test tests/builtin-test.c:679 #7 0x56260d26fa53 in cmd_test tests/builtin-test.c:825 #8 0x56260d2dbb64 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313 #9 0x56260d165a88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365 #10 0x56260d165a88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409 #11 0x56260d165a88 in main /home/namhyung/project/linux/tools/perf/perf.c:539 #12 0x7fef5c83cd09 in __libc_start_main ../csu/libc-start.c:308 ... test child finished with 1 ---- end ---- Software clock events period values : FAILED! Signed-off-by: Namhyung Kim <[email protected]> Acked-by: Jiri Olsa <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Andi Kleen <[email protected]> Cc: Ian Rogers <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Leo Yan <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Mar 10, 2021
The evlist and the cpu/thread maps should be released together. Otherwise following error was reported by Asan. Note that this test still has memory leaks in DSOs so it still fails even after this change. I'll take a look at that too. # perf test -v 26 26: Object code reading : --- start --- test child forked, pid 154184 Looking at the vmlinux_path (8 entries long) symsrc__init: build id mismatch for vmlinux. symsrc__init: cannot get elf header. Using /proc/kcore for kernel data Using /proc/kallsyms for symbols Parsing event 'cycles' mmap size 528384B ... ================================================================= ==154184==ERROR: LeakSanitizer: detected memory leaks Direct leak of 439 byte(s) in 1 object(s) allocated from: #0 0x7fcb66e77037 in __interceptor_calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:154 #1 0x55ad9b7e821e in dso__new_id util/dso.c:1256 #2 0x55ad9b8cfd4a in __machine__addnew_vdso util/vdso.c:132 #3 0x55ad9b8cfd4a in machine__findnew_vdso util/vdso.c:347 #4 0x55ad9b845b7e in map__new util/map.c:176 #5 0x55ad9b8415a2 in machine__process_mmap2_event util/machine.c:1787 #6 0x55ad9b8fab16 in perf_tool__process_synth_event util/synthetic-events.c:64 #7 0x55ad9b8fab16 in perf_event__synthesize_mmap_events util/synthetic-events.c:499 #8 0x55ad9b8fbfdf in __event__synthesize_thread util/synthetic-events.c:741 #9 0x55ad9b8ff3e3 in perf_event__synthesize_thread_map util/synthetic-events.c:833 #10 0x55ad9b738585 in do_test_code_reading tests/code-reading.c:608 #11 0x55ad9b73b25d in test__code_reading tests/code-reading.c:722 #12 0x55ad9b6f28fb in run_test tests/builtin-test.c:428 #13 0x55ad9b6f28fb in test_and_print tests/builtin-test.c:458 #14 0x55ad9b6f4a53 in __cmd_test tests/builtin-test.c:679 #15 0x55ad9b6f4a53 in cmd_test tests/builtin-test.c:825 #16 0x55ad9b760cc4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313 #17 0x55ad9b5eaa88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365 #18 0x55ad9b5eaa88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409 #19 0x55ad9b5eaa88 in main /home/namhyung/project/linux/tools/perf/perf.c:539 #20 0x7fcb669acd09 in __libc_start_main ../csu/libc-start.c:308 ... SUMMARY: AddressSanitizer: 471 byte(s) leaked in 2 allocation(s). test child finished with 1 ---- end ---- Object code reading: FAILED! Signed-off-by: Namhyung Kim <[email protected]> Acked-by: Jiri Olsa <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Andi Kleen <[email protected]> Cc: Ian Rogers <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Leo Yan <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Mar 10, 2021
The evlist and the cpu/thread maps should be released together. Otherwise following error was reported by Asan. $ perf test -v 28 28: Use a dummy software event to keep tracking: --- start --- test child forked, pid 156810 mmap size 528384B ================================================================= ==156810==ERROR: LeakSanitizer: detected memory leaks Direct leak of 40 byte(s) in 1 object(s) allocated from: #0 0x7f637d2bce8f in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145 #1 0x55cc6295cffa in cpu_map__trim_new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:79 #2 0x55cc6295da1f in perf_cpu_map__read /home/namhyung/project/linux/tools/lib/perf/cpumap.c:149 #3 0x55cc6295e1df in cpu_map__read_all_cpu_map /home/namhyung/project/linux/tools/lib/perf/cpumap.c:166 #4 0x55cc6295e1df in perf_cpu_map__new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:181 #5 0x55cc626287cf in test__keep_tracking tests/keep-tracking.c:84 #6 0x55cc625e38fb in run_test tests/builtin-test.c:428 #7 0x55cc625e38fb in test_and_print tests/builtin-test.c:458 #8 0x55cc625e5a53 in __cmd_test tests/builtin-test.c:679 #9 0x55cc625e5a53 in cmd_test tests/builtin-test.c:825 #10 0x55cc62651cc4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313 #11 0x55cc624dba88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365 #12 0x55cc624dba88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409 #13 0x55cc624dba88 in main /home/namhyung/project/linux/tools/perf/perf.c:539 #14 0x7f637cdf2d09 in __libc_start_main ../csu/libc-start.c:308 SUMMARY: AddressSanitizer: 72 byte(s) leaked in 2 allocation(s). test child finished with 1 ---- end ---- Use a dummy software event to keep tracking: FAILED! Signed-off-by: Namhyung Kim <[email protected]> Acked-by: Jiri Olsa <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Andi Kleen <[email protected]> Cc: Ian Rogers <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Leo Yan <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Mar 10, 2021
The evlist and cpu/thread maps should be released together. Otherwise the following error was reported by Asan. $ perf test -v 35 35: Track with sched_switch : --- start --- test child forked, pid 159287 Using CPUID GenuineIntel-6-8E-C mmap size 528384B 1295 events recorded ================================================================= ==159287==ERROR: LeakSanitizer: detected memory leaks Direct leak of 40 byte(s) in 1 object(s) allocated from: #0 0x7fa28d9a2e8f in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145 #1 0x5652f5a5affa in cpu_map__trim_new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:79 #2 0x5652f5a5ba1f in perf_cpu_map__read /home/namhyung/project/linux/tools/lib/perf/cpumap.c:149 #3 0x5652f5a5c1df in cpu_map__read_all_cpu_map /home/namhyung/project/linux/tools/lib/perf/cpumap.c:166 #4 0x5652f5a5c1df in perf_cpu_map__new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:181 #5 0x5652f5723bbf in test__switch_tracking tests/switch-tracking.c:350 #6 0x5652f56e18fb in run_test tests/builtin-test.c:428 #7 0x5652f56e18fb in test_and_print tests/builtin-test.c:458 #8 0x5652f56e3a53 in __cmd_test tests/builtin-test.c:679 #9 0x5652f56e3a53 in cmd_test tests/builtin-test.c:825 #10 0x5652f574fcc4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313 #11 0x5652f55d9a88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365 #12 0x5652f55d9a88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409 #13 0x5652f55d9a88 in main /home/namhyung/project/linux/tools/perf/perf.c:539 #14 0x7fa28d4d8d09 in __libc_start_main ../csu/libc-start.c:308 SUMMARY: AddressSanitizer: 72 byte(s) leaked in 2 allocation(s). test child finished with 1 ---- end ---- Track with sched_switch: FAILED! Signed-off-by: Namhyung Kim <[email protected]> Acked-by: Jiri Olsa <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Andi Kleen <[email protected]> Cc: Ian Rogers <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Leo Yan <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Mar 10, 2021
It missed to call perf_thread_map__put() after using the map. $ perf test -v 43 43: Synthesize thread map : --- start --- test child forked, pid 162640 ================================================================= ==162640==ERROR: LeakSanitizer: detected memory leaks Direct leak of 32 byte(s) in 1 object(s) allocated from: #0 0x7fd48cdaa1f8 in __interceptor_realloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:164 #1 0x563e6d5f8d0e in perf_thread_map__realloc /home/namhyung/project/linux/tools/lib/perf/threadmap.c:23 #2 0x563e6d3ef69a in thread_map__new_by_pid util/thread_map.c:46 #3 0x563e6d2cec90 in test__thread_map_synthesize tests/thread-map.c:97 #4 0x563e6d27d8fb in run_test tests/builtin-test.c:428 #5 0x563e6d27d8fb in test_and_print tests/builtin-test.c:458 #6 0x563e6d27fa53 in __cmd_test tests/builtin-test.c:679 #7 0x563e6d27fa53 in cmd_test tests/builtin-test.c:825 #8 0x563e6d2ebce4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313 #9 0x563e6d175a88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365 #10 0x563e6d175a88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409 #11 0x563e6d175a88 in main /home/namhyung/project/linux/tools/perf/perf.c:539 #12 0x7fd48c8dfd09 in __libc_start_main ../csu/libc-start.c:308 SUMMARY: AddressSanitizer: 8224 byte(s) leaked in 2 allocation(s). test child finished with 1 ---- end ---- Synthesize thread map: FAILED! Signed-off-by: Namhyung Kim <[email protected]> Acked-by: Jiri Olsa <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Andi Kleen <[email protected]> Cc: Ian Rogers <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Leo Yan <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Mar 10, 2021
It should be released after printing the map. $ perf test -v 52 52: Print cpu map : --- start --- test child forked, pid 172233 ================================================================= ==172233==ERROR: LeakSanitizer: detected memory leaks Direct leak of 156 byte(s) in 1 object(s) allocated from: #0 0x7fc472518e8f in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145 #1 0x55e63b378f7a in cpu_map__trim_new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:79 #2 0x55e63b37a05c in perf_cpu_map__new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:237 #3 0x55e63b056d16 in cpu_map_print tests/cpumap.c:102 #4 0x55e63b056d16 in test__cpu_map_print tests/cpumap.c:120 #5 0x55e63afff8fb in run_test tests/builtin-test.c:428 #6 0x55e63afff8fb in test_and_print tests/builtin-test.c:458 #7 0x55e63b001a53 in __cmd_test tests/builtin-test.c:679 #8 0x55e63b001a53 in cmd_test tests/builtin-test.c:825 #9 0x55e63b06dc44 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313 #10 0x55e63aef7a88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365 #11 0x55e63aef7a88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409 #12 0x55e63aef7a88 in main /home/namhyung/project/linux/tools/perf/perf.c:539 #13 0x7fc47204ed09 in __libc_start_main ../csu/libc-start.c:308 ... SUMMARY: AddressSanitizer: 448 byte(s) leaked in 7 allocation(s). test child finished with 1 ---- end ---- Print cpu map: FAILED! Signed-off-by: Namhyung Kim <[email protected]> Acked-by: Jiri Olsa <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Andi Kleen <[email protected]> Cc: Ian Rogers <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Leo Yan <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Mar 10, 2021
It should release the maps at the end. $ perf test -v 71 71: Convert perf time to TSC : --- start --- test child forked, pid 178744 mmap size 528384B 1st event perf time 59207256505278 tsc 13187166645142 rdtsc time 59207256542151 tsc 13187166723020 2nd event perf time 59207256543749 tsc 13187166726393 ================================================================= ==178744==ERROR: LeakSanitizer: detected memory leaks Direct leak of 40 byte(s) in 1 object(s) allocated from: #0 0x7faf601f9e8f in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145 #1 0x55b620cfc00a in cpu_map__trim_new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:79 #2 0x55b620cfca2f in perf_cpu_map__read /home/namhyung/project/linux/tools/lib/perf/cpumap.c:149 #3 0x55b620cfd1ef in cpu_map__read_all_cpu_map /home/namhyung/project/linux/tools/lib/perf/cpumap.c:166 #4 0x55b620cfd1ef in perf_cpu_map__new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:181 #5 0x55b6209ef1b2 in test__perf_time_to_tsc tests/perf-time-to-tsc.c:73 #6 0x55b6209828fb in run_test tests/builtin-test.c:428 #7 0x55b6209828fb in test_and_print tests/builtin-test.c:458 #8 0x55b620984a53 in __cmd_test tests/builtin-test.c:679 #9 0x55b620984a53 in cmd_test tests/builtin-test.c:825 #10 0x55b6209f0cd4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313 #11 0x55b62087aa88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365 #12 0x55b62087aa88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409 #13 0x55b62087aa88 in main /home/namhyung/project/linux/tools/perf/perf.c:539 #14 0x7faf5fd2fd09 in __libc_start_main ../csu/libc-start.c:308 SUMMARY: AddressSanitizer: 72 byte(s) leaked in 2 allocation(s). test child finished with 1 ---- end ---- Convert perf time to TSC: FAILED! Signed-off-by: Namhyung Kim <[email protected]> Acked-by: Jiri Olsa <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Andi Kleen <[email protected]> Cc: Ian Rogers <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Leo Yan <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Mar 10, 2021
I got a segfault when using -r option with event groups. The option makes it run the workload multiple times and it will reuse the evlist and evsel for each run. While most of resources are allocated and freed properly, the id hash in the evlist was not and it resulted in the bug. You can see it with the address sanitizer like below: $ perf stat -r 100 -e '{cycles,instructions}' true ================================================================= ==693052==ERROR: AddressSanitizer: heap-use-after-free on address 0x6080000003d0 at pc 0x558c57732835 bp 0x7fff1526adb0 sp 0x7fff1526ada8 WRITE of size 8 at 0x6080000003d0 thread T0 #0 0x558c57732834 in hlist_add_head /home/namhyung/project/linux/tools/include/linux/list.h:644 #1 0x558c57732834 in perf_evlist__id_hash /home/namhyung/project/linux/tools/lib/perf/evlist.c:237 #2 0x558c57732834 in perf_evlist__id_add /home/namhyung/project/linux/tools/lib/perf/evlist.c:244 #3 0x558c57732834 in perf_evlist__id_add_fd /home/namhyung/project/linux/tools/lib/perf/evlist.c:285 #4 0x558c5747733e in store_evsel_ids util/evsel.c:2765 #5 0x558c5747733e in evsel__store_ids util/evsel.c:2782 #6 0x558c5730b717 in __run_perf_stat /home/namhyung/project/linux/tools/perf/builtin-stat.c:895 #7 0x558c5730b717 in run_perf_stat /home/namhyung/project/linux/tools/perf/builtin-stat.c:1014 #8 0x558c5730b717 in cmd_stat /home/namhyung/project/linux/tools/perf/builtin-stat.c:2446 #9 0x558c57427c24 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313 #10 0x558c572b1a48 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365 #11 0x558c572b1a48 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409 #12 0x558c572b1a48 in main /home/namhyung/project/linux/tools/perf/perf.c:539 #13 0x7fcadb9f7d09 in __libc_start_main ../csu/libc-start.c:308 #14 0x558c572b60f9 in _start (/home/namhyung/project/linux/tools/perf/perf+0x45d0f9) Actually the nodes in the hash table are struct perf_stream_id and they were freed in the previous run. Fix it by resetting the hash. Signed-off-by: Namhyung Kim <[email protected]> Acked-by: Jiri Olsa <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Ian Rogers <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Mar 10, 2021
[ 6684.493350] Unable to handle kernel paging request at virtual address ffff800011c5b0f0 [ 6684.498531] mmc0: card 0001 removed [ 6684.501556] Mem abort info: [ 6684.509681] ESR = 0x96000047 [ 6684.512786] EC = 0x25: DABT (current EL), IL = 32 bits [ 6684.518394] SET = 0, FnV = 0 [ 6684.521707] EA = 0, S1PTW = 0 [ 6684.524998] Data abort info: [ 6684.528236] ISV = 0, ISS = 0x00000047 [ 6684.532986] CM = 0, WnR = 1 [ 6684.536129] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000081b22000 [ 6684.543923] [ffff800011c5b0f0] pgd=00000000bffff003, p4d=00000000bffff003, pud=00000000bfffe003, pmd=00000000900e1003, pte=0000000000000000 [ 6684.557915] Internal error: Oops: 96000047 [#1] PREEMPT SMP [ 6684.564240] Modules linked in: sdhci_esdhc_imx(-) sdhci_pltfm sdhci cqhci mmc_block mmc_core fsl_jr_uio caam_jr caamkeyblob_desc caamhash_desc caamalg_desc crypto_engine rng_core authenc libdes crct10dif_ce flexcan can_dev caam error [last unloaded: mmc_core] [ 6684.587281] CPU: 0 PID: 79138 Comm: kworker/0:3H Not tainted 5.10.9-01410-g3ba33182767b-dirty #10 [ 6684.596160] Hardware name: Freescale i.MX8DXL EVK (DT) [ 6684.601320] Workqueue: kblockd blk_mq_run_work_fn [ 6684.606094] pstate: 40000005 (nZcv daif -PAN -UAO -TCO BTYPE=--) [ 6684.612286] pc : cqhci_request+0x148/0x4e8 [cqhci] ^GMessage from syslogd@ at Thu Jan 1 01:51:24 1970 ...[ 6684.617085] lr : cqhci_request+0x314/0x4e8 [cqhci] [ 6684.626734] sp : ffff80001243b9f0 [ 6684.630049] x29: ffff80001243b9f0 x28: ffff00002c3dd000 [ 6684.635367] x27: 0000000000000001 x26: 0000000000000001 [ 6684.640690] x25: ffff00002c451000 x24: 000000000000000f [ 6684.646007] x23: ffff000017e71c80 x22: ffff00002c451000 [ 6684.651326] x21: ffff00002c0f3550 x20: ffff00002c0f3550 [ 6684.656651] x19: ffff000017d46880 x18: ffff00002cea1500 [ 6684.661977] x17: 0000000000000000 x16: 0000000000000000 [ 6684.667294] x15: 000001ee628e3ed1 x14: 0000000000000278 [ 6684.672610] x13: 0000000000000001 x12: 0000000000000001 [ 6684.677927] x11: 0000000000000000 x10: 0000000000000000 [ 6684.683243] x9 : 000000000000002b x8 : 0000000000001000 [ 6684.688560] x7 : 0000000000000010 x6 : ffff00002c0f3678 [ 6684.693886] x5 : 000000000000000f x4 : ffff800011c5b000 [ 6684.699211] x3 : 000000000002d988 x2 : 0000000000000008 [ 6684.704537] x1 : 00000000000000f0 x0 : 0002d9880008102f [ 6684.709854] Call trace: [ 6684.712313] cqhci_request+0x148/0x4e8 [cqhci] [ 6684.716803] mmc_cqe_start_req+0x58/0x68 [mmc_core] [ 6684.721698] mmc_blk_mq_issue_rq+0x460/0x810 [mmc_block] [ 6684.727018] mmc_mq_queue_rq+0x118/0x2b0 [mmc_block] The problem occurs when cqhci_request() get called after cqhci_disable() as it leads to access of allocated memory that has already been freed. Let's fix the problem by calling cqhci_disable() a bit later in the remove path. Signed-off-by: Frank Li <[email protected]> Diagnosed-by: Adrian Hunter <[email protected]> Acked-by: Adrian Hunter <[email protected]> Link: https://lore.kernel.org/r/[email protected] Fixes: f690f44 ("mmc: mmc: Enable CQE's") Cc: [email protected] Signed-off-by: Ulf Hansson <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Mar 11, 2021
The original bcc pull request iovisor/bcc#3270 exposed a verifier failure with Clang 12/13 while Clang 4 works fine. Further investigation exposed two issues: Issue 1: LLVM may generate code which uses less refined value. The issue is fixed in LLVM patch: https://reviews.llvm.org/D97479 Issue 2: Spills with initial value 0 are marked as precise which makes later state pruning less effective. This is my rough initial analysis and further investigation is needed to find how to improve verifier pruning in such cases. With the above LLVM patch, for the new loop6.c test, which has smaller loop bound compared to original test, I got: $ test_progs -s -n 10/16 ... stack depth 64 processed 390735 insns (limit 1000000) max_states_per_insn 87 total_states 8658 peak_states 964 mark_read 6 #10/16 loop6.o:OK Use the original loop bound, i.e., commenting out "#define WORKAROUND", I got: $ test_progs -s -n 10/16 ... BPF program is too large. Processed 1000001 insn stack depth 64 processed 1000001 insns (limit 1000000) max_states_per_insn 91 total_states 23176 peak_states 5069 mark_read 6 ... #10/16 loop6.o:FAIL The purpose of this patch is to provide a regression test for the above LLVM fix and also provide a test case for further analyzing the verifier pruning issue. Signed-off-by: Yonghong Song <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Cc: Zhenwei Pi <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
nathanchance
pushed a commit
that referenced
this issue
Mar 26, 2021
Pablo Neira Ayuso says: ==================== netfilter: flowtable enhancements [ This is v2 that includes documentation enhancements, including existing limitations. This is a rebase on top on net-next. ] The following patchset augments the Netfilter flowtable fastpath to support for network topologies that combine IP forwarding, bridge, classic VLAN devices, bridge VLAN filtering, DSA and PPPoE. This includes support for the flowtable software and hardware datapaths. The following pictures provides an example scenario: fast path! .------------------------. / \ | IP forwarding | | / \ \/ | br0 wan ..... eth0 . / \ host C -> veth1 veth2 . switch/router . . eth0 host A The bridge master device 'br0' has an IP address and a DHCP server is also assumed to be running to provide connectivity to host A which reaches the Internet through 'br0' as default gateway. Then, packet enters the IP forwarding path and Netfilter is used to NAT the packets before they leave through the wan device. The general idea is to accelerate forwarding by building a fast path that takes packets from the ingress path of the bridge port and place them in the egress path of the wan device (and vice versa). Hence, skipping the classic bridge and IP stack paths. ** Patch from #1 to #6 add the infrastructure which describes the list of netdevice hops to reach a given destination MAC address in the local network topology. Patch #1 adds dev_fill_forward_path() and .ndo_fill_forward_path() to netdev_ops. Patch #2 adds .ndo_fill_forward_path for vlan devices, which provides the next device hop via vlan->real_dev, the vlan ID and the protocol. Patch #3 adds .ndo_fill_forward_path for bridge devices, which allows to make lookups to the FDB to locate the next device hop (bridge port) in the forwarding path. Patch #4 extends bridge .ndo_fill_forward_path to support for bridge VLAN filtering. Patch #5 adds .ndo_fill_forward_path for PPPoE devices. Patch #6 adds .ndo_fill_forward_path for DSA. Patches from #7 to #14 update the flowtable software datapath: Patch #7 adds the transmit path type field to the flow tuple. Two transmit paths are supported so far: the neighbour and the xfrm transmit paths. Patch #8 and #9 update the flowtable datapath to use dev_fill_forward_path() to obtain the real ingress/egress device for the flowtable datapath. This adds the new ethernet xmit direct path to the flowtable. Patch #10 adds native flowtable VLAN support (up to 2 VLAN tags) through dev_fill_forward_path(). The flowtable stores the VLAN id and protocol in the flow tuple. Patch #11 adds native flowtable bridge VLAN filter support through dev_fill_forward_path(). Patch #12 adds native flowtable bridge PPPoE through dev_fill_forward_path(). Patch #13 adds DSA support through dev_fill_forward_path(). Patch #14 extends flowtable selftests to cover for flowtable software datapath enhancements. ** Patches from #15 to #20 update the flowtable hardware offload datapath: Patch #15 extends the flowtable hardware offload to support for the direct ethernet xmit path. This also includes VLAN support. Patch #16 stores the egress real device in the flow tuple. The software flowtable datapath uses dev_hard_header() to transmit packets, hence it might refer to VLAN/DSA/PPPoE software device, not the real ethernet device. Patch #17 deals with switchdev PVID hardware offload to skip it on egress. Patch #18 adds FLOW_ACTION_PPPOE_PUSH to the flow_offload action API. Patch #19 extends the flowtable hardware offload to support for PPPoE Patch #20 adds TC_SETUP_FT support for DSA. ** Patches from #20 to #23: Felix Fietkau adds a new driver which support hardware offload for the mtk PPE engine through the existing flow offload API which supports for the flowtable enhancements coming in this batch. Patch #24 extends the documentation and describe existing limitations. Please, apply, thanks. ==================== Signed-off-by: David S. Miller <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Mar 26, 2021
Ido Schimmel says: ==================== mlxsw: Add support for resilient nexthop groups This patchset adds support for resilient nexthop groups in mlxsw. As far as the hardware is concerned, resilient groups are the same as regular groups. The differences lie in how mlxsw manages the individual adjacency entries (nexthop buckets) that make up the group. The first difference is that unlike regular groups the driver needs to periodically update the kernel about activity of nexthop buckets so that the kernel will not treat the buckets as idle, given traffic is offloaded from the CPU to the ASIC. This is similar to what mlxsw is already doing with respect to neighbour entries. The update interval is set to 1 second to allow for short idle timers. The second difference is that nexthop buckets that correspond to an unresolved neighbour must be programmed to the device, as the size of the group must remain fixed. This is achieved by programming such entries with trap action, in order to trigger neighbour resolution by the kernel. The third difference is atomic replacement of individual nexthop buckets. While the driver periodically updates the kernel about activity of nexthop buckets, it is possible for a bucket to become active just before the kernel decides to replace it with a different nexthop. To avoid such situations and connections being reset, the driver instructs the device to only replace an adjacency entry if it is inactive. Failures are propagated back to the nexthop code. Patchset overview: Patches #1-#7 gradually add support for resilient nexthop groups Patch #8 finally enables such groups to be programmed to the device Patches #9-#10 add mlxsw-specific selftests ==================== Signed-off-by: David S. Miller <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
May 18, 2021
Ido Schimmel says: ==================== mlxsw: Various updates This patchset contains various updates to the mlxsw driver and related selftests. Patches #1-#5 contain various updates to mlxsw selftests. The most significant change is the conversion of the DCB selftests to use the new iproute2 DCB support. Patches #6-#9 contain mostly trivial changes to the driver itself. No user facing changes. Patches #10-#11 remove support for SwitchX-2 and SwitchIB ASICs that did not see any updates in the last 4-5 years and will not see any in the future. See individual commit messages for detailed explanation as to why it is OK to remove these drivers from the kernel. ==================== Signed-off-by: David S. Miller <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
May 19, 2021
Ido Schimmel says: ==================== Add support for custom multipath hash This patchset adds support for custom multipath hash policy for both IPv4 and IPv6 traffic. The new policy allows user space to control the outer and inner packet fields used for the hash computation. Motivation ========== Linux currently supports different multipath hash policies for IPv4 and IPv6 traffic: * Layer 3 * Layer 4 * Layer 3 or inner layer 3, if present These policies hash on a fixed set of fields, which is inflexible and against operators' requirements to control the hash input: "The ability to control the inputs to the hash function should be a consideration in any load-balancing RFP" [1]. An example of this inflexibility can be seen by the fact that none of the current policies allows operators to use the standard 5-tuple and the flow label for multipath hash computation. Such a policy is useful in the following real-world example of a data center with the following types of traffic: * Anycast IPv6 TCP traffic towards layer 4 load balancers. Flow label is constant (zero) to avoid breaking established connections * Non-encapsulated IPv6 traffic. Flow label is used to re-route flows around problematic (congested / failed) paths [2] * IPv6 encapsulated traffic (IPv4-in-IPv6 or IPv6-in-IPv6). Outer flow label is generated from encapsulated packet * UDP encapsulated traffic. Outer source port is generated from encapsulated packet In the above example, using the inner flow information for hash computation in addition to the outer flow information is useful during failures of the BPF agent that selectively generates the flow label based on the traffic type. In such cases, the self-healing properties of the flow label are lost, but encapsulated flows are still load balanced. Control over the inner fields is even more critical when encapsulation is performed by hardware routers. For example, the Spectrum ASIC can only encode 8 bits of entropy in the outer flow label / outer UDP source port when performing IP / UDP encapsulation. In the case of IPv4 GRE encapsulation there is no outer field to encode the inner hash in. User interface ============== In accordance with existing multipath hash configuration, the new custom policy is added as a new option (3) to the net.ipv{4,6}.fib_multipath_hash_policy sysctls. When the new policy is used, the packet fields used for hash computation are determined by the net.ipv{4,6}.fib_multipath_hash_fields sysctls. These sysctls accept a bitmask according to the following table (from ip-sysctl.rst): ====== ============================ 0x0001 Source IP address 0x0002 Destination IP address 0x0004 IP protocol 0x0008 Flow Label 0x0010 Source port 0x0020 Destination port 0x0040 Inner source IP address 0x0080 Inner destination IP address 0x0100 Inner IP protocol 0x0200 Inner Flow Label 0x0400 Inner source port 0x0800 Inner destination port ====== ============================ For example, to allow IPv6 traffic to be hashed based on standard 5-tuple and flow label: # sysctl -wq net.ipv6.fib_multipath_hash_fields=0x0037 # sysctl -wq net.ipv6.fib_multipath_hash_policy=3 Implementation ============== As with existing policies, the new policy relies on the flow dissector to extract the packet fields for the hash computation. However, unlike existing policies that either use the outer or inner flow, the new policy might require both flows to be dissected. To avoid unnecessary invocations of the flow dissector, the data path skips dissection of the outer or inner flows if none of the outer or inner fields are required. In addition, inner flow dissection is not performed when no encapsulation was encountered (i.e., 'FLOW_DIS_ENCAPSULATION' not set by flow dissector) during dissection of the outer flow. Testing ======= Three new selftests are added with three different topologies that allow testing of following traffic combinations: * Non-encapsulated IPv4 / IPv6 traffic * IPv4 / IPv6 overlay over IPv4 underlay * IPv4 / IPv6 overlay over IPv6 underlay All three tests follow the same pattern. Each time a different packet field is used for hash computation. When the field changes in the packet stream, traffic is expected to be balanced across the two paths. When the field does not change, traffic is expected to be unbalanced across the two paths. Patchset overview ================= Patches #1-#3 add custom multipath hash support for IPv4 traffic Patches #4-#7 do the same for IPv6 Patches #8-#10 add selftests Future work =========== mlxsw support can be found here [3]. Changes since RFC v2 [4]: * Patch #2: Document that 0x0008 is used for Flow Label * Patch #2: Do not allow the bitmask to be zero * Patch #6: Do not allow the bitmask to be zero Changes since RFC v1 [5]: * Use a bitmask instead of a bitmap [1] https://blog.apnic.net/2018/01/11/ipv6-flow-label-misuse-hashing/ [2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3acf3ec3f4b0fd4263989f2e4227bbd1c42b5fe1 [3] https://github.com/idosch/linux/tree/submit/custom_hash_mlxsw_v2 [4] https://lore.kernel.org/netdev/[email protected]/ [5] https://lore.kernel.org/netdev/[email protected]/ ==================== Signed-off-by: David S. Miller <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
May 24, 2021
…tances As syzbot reported, there is an use-after-free issue during f2fs recovery: Use-after-free write at 0xffff88823bc16040 (in kfence-#10): kmem_cache_destroy+0x1f/0x120 mm/slab_common.c:486 f2fs_recover_fsync_data+0x75b0/0x8380 fs/f2fs/recovery.c:869 f2fs_fill_super+0x9393/0xa420 fs/f2fs/super.c:3945 mount_bdev+0x26c/0x3a0 fs/super.c:1367 legacy_get_tree+0xea/0x180 fs/fs_context.c:592 vfs_get_tree+0x86/0x270 fs/super.c:1497 do_new_mount fs/namespace.c:2905 [inline] path_mount+0x196f/0x2be0 fs/namespace.c:3235 do_mount fs/namespace.c:3248 [inline] __do_sys_mount fs/namespace.c:3456 [inline] __se_sys_mount+0x2f9/0x3b0 fs/namespace.c:3433 do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae The root cause is multi f2fs filesystem instances can race on accessing global fsync_entry_slab pointer, result in use-after-free issue of slab cache, fixes to init/destroy this slab cache only once during module init/destroy procedure to avoid this issue. Reported-by: [email protected] Signed-off-by: Chao Yu <[email protected]> Signed-off-by: Jaegeuk Kim <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Jun 8, 2021
ASan reported a memory leak caused by info_linear not being deallocated. The info_linear was allocated during in perf_event__synthesize_one_bpf_prog(). This patch adds the corresponding free() when bpf_prog_info_node is freed in perf_env__purge_bpf(). $ sudo ./perf record -- sleep 5 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.025 MB perf.data (8 samples) ] ================================================================= ==297735==ERROR: LeakSanitizer: detected memory leaks Direct leak of 7688 byte(s) in 19 object(s) allocated from: #0 0x4f420f in malloc (/home/user/linux/tools/perf/perf+0x4f420f) #1 0xc06a74 in bpf_program__get_prog_info_linear /home/user/linux/tools/lib/bpf/libbpf.c:11113:16 #2 0xb426fe in perf_event__synthesize_one_bpf_prog /home/user/linux/tools/perf/util/bpf-event.c:191:16 #3 0xb42008 in perf_event__synthesize_bpf_events /home/user/linux/tools/perf/util/bpf-event.c:410:9 #4 0x594596 in record__synthesize /home/user/linux/tools/perf/builtin-record.c:1490:8 #5 0x58c9ac in __cmd_record /home/user/linux/tools/perf/builtin-record.c:1798:8 #6 0x58990b in cmd_record /home/user/linux/tools/perf/builtin-record.c:2901:8 #7 0x7b2a20 in run_builtin /home/user/linux/tools/perf/perf.c:313:11 #8 0x7b12ff in handle_internal_command /home/user/linux/tools/perf/perf.c:365:8 #9 0x7b2583 in run_argv /home/user/linux/tools/perf/perf.c:409:2 #10 0x7b0d79 in main /home/user/linux/tools/perf/perf.c:539:3 #11 0x7fa357ef6b74 in __libc_start_main /usr/src/debug/glibc-2.33-8.fc34.x86_64/csu/../csu/libc-start.c:332:16 Signed-off-by: Riccardo Mancini <[email protected]> Acked-by: Ian Rogers <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Alexei Starovoitov <[email protected]> Cc: Andrii Nakryiko <[email protected]> Cc: Daniel Borkmann <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: John Fastabend <[email protected]> Cc: KP Singh <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Martin KaFai Lau <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Song Liu <[email protected]> Cc: Yonghong Song <[email protected]> Link: http://lore.kernel.org/lkml/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Jul 17, 2021
ASan reports a heap-buffer-overflow in elf_sec__is_text when using perf-top. The bug is caused by the fact that secstrs is built from runtime_ss, while shdr is built from syms_ss if shdr.sh_type != SHT_NOBITS. Therefore, they point to two different ELF files. This patch renames secstrs to secstrs_run and adds secstrs_sym, so that the correct secstrs is chosen depending on shdr.sh_type. $ ASAN_OPTIONS=abort_on_error=1:disable_coredump=0:unmap_shadow_on_exit=1 ./perf top ================================================================= ==363148==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x61300009add6 at pc 0x00000049875c bp 0x7f4f56446440 sp 0x7f4f56445bf0 READ of size 1 at 0x61300009add6 thread T6 #0 0x49875b in StrstrCheck(void*, char*, char const*, char const*) (/home/user/linux/tools/perf/perf+0x49875b) #1 0x4d13a2 in strstr (/home/user/linux/tools/perf/perf+0x4d13a2) #2 0xacae36 in elf_sec__is_text /home/user/linux/tools/perf/util/symbol-elf.c:176:9 #3 0xac3ec9 in elf_sec__filter /home/user/linux/tools/perf/util/symbol-elf.c:187:9 #4 0xac2c3d in dso__load_sym /home/user/linux/tools/perf/util/symbol-elf.c:1254:20 #5 0x883981 in dso__load /home/user/linux/tools/perf/util/symbol.c:1897:9 #6 0x8e6248 in map__load /home/user/linux/tools/perf/util/map.c:332:7 #7 0x8e66e5 in map__find_symbol /home/user/linux/tools/perf/util/map.c:366:6 #8 0x7f8278 in machine__resolve /home/user/linux/tools/perf/util/event.c:707:13 #9 0x5f3d1a in perf_event__process_sample /home/user/linux/tools/perf/builtin-top.c:773:6 #10 0x5f30e4 in deliver_event /home/user/linux/tools/perf/builtin-top.c:1197:3 #11 0x908a72 in do_flush /home/user/linux/tools/perf/util/ordered-events.c:244:9 #12 0x905fae in __ordered_events__flush /home/user/linux/tools/perf/util/ordered-events.c:323:8 #13 0x9058db in ordered_events__flush /home/user/linux/tools/perf/util/ordered-events.c:341:9 #14 0x5f19b1 in process_thread /home/user/linux/tools/perf/builtin-top.c:1109:7 #15 0x7f4f6a21a298 in start_thread /usr/src/debug/glibc-2.33-16.fc34.x86_64/nptl/pthread_create.c:481:8 #16 0x7f4f697d0352 in clone ../sysdeps/unix/sysv/linux/x86_64/clone.S:95 0x61300009add6 is located 10 bytes to the right of 332-byte region [0x61300009ac80,0x61300009adcc) allocated by thread T6 here: #0 0x4f3f7f in malloc (/home/user/linux/tools/perf/perf+0x4f3f7f) #1 0x7f4f6a0a88d9 (/lib64/libelf.so.1+0xa8d9) Thread T6 created by T0 here: #0 0x464856 in pthread_create (/home/user/linux/tools/perf/perf+0x464856) #1 0x5f06e0 in __cmd_top /home/user/linux/tools/perf/builtin-top.c:1309:6 #2 0x5ef19f in cmd_top /home/user/linux/tools/perf/builtin-top.c:1762:11 #3 0x7b28c0 in run_builtin /home/user/linux/tools/perf/perf.c:313:11 #4 0x7b119f in handle_internal_command /home/user/linux/tools/perf/perf.c:365:8 #5 0x7b2423 in run_argv /home/user/linux/tools/perf/perf.c:409:2 #6 0x7b0c19 in main /home/user/linux/tools/perf/perf.c:539:3 #7 0x7f4f696f7b74 in __libc_start_main /usr/src/debug/glibc-2.33-16.fc34.x86_64/csu/../csu/libc-start.c:332:16 SUMMARY: AddressSanitizer: heap-buffer-overflow (/home/user/linux/tools/perf/perf+0x49875b) in StrstrCheck(void*, char*, char const*, char const*) Shadow bytes around the buggy address: 0x0c268000b560: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c268000b570: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c268000b580: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c268000b590: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x0c268000b5a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 =>0x0c268000b5b0: 00 00 00 00 00 00 00 00 00 04[fa]fa fa fa fa fa 0x0c268000b5c0: fa fa fa fa fa fa fa fa 00 00 00 00 00 00 00 00 0x0c268000b5d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x0c268000b5e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x0c268000b5f0: 07 fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c268000b600: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd 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 ==363148==ABORTING Suggested-by: Jiri Slaby <[email protected]> Signed-off-by: Riccardo Mancini <[email protected]> Acked-by: Namhyung Kim <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Fabian Hemmer <[email protected]> Cc: Ian Rogers <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Jiri Slaby <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Remi Bernon <[email protected]> Link: http://lore.kernel.org/lkml/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Sep 13, 2021
… sample data Perf records IBS (Instruction Based Sampling) extra sample data when 'perf record --raw-samples' is used with an IBS-compatible event, on a machine that supports IBS. IBS support is indicated in CPUID_Fn80000001_ECX bit #10. Up until now, users have been able to see the extra sample data solely in raw hex format using 'perf report --dump-raw-trace'. From there, users could decode the data either manually, or by using an external script. Enable the built-in 'perf report --dump-raw-trace' to do the decoding of the extra sample data bits, so manual or external script decoding isn't necessary. Example usage: $ sudo perf record -c 10000001 -a --raw-samples -e ibs_fetch/rand_en=1/,ibs_op/cnt_ctl=1/ -C 0,1 taskset -c 0,1 7za b -mmt2 | perf report --dump-raw-trace Stdout contains IBS Fetch samples, e.g.: ibs_fetch_ctl: 02170007ffffffff MaxCnt 1048560 Cnt 1048560 Lat 7 En 1 Val 1 Comp 1 IcMiss 0 PhyAddrValid 1 L1TlbPgSz 4KB L1TlbMiss 0 L2TlbMiss 0 RandEn 1 L2Miss 0 IbsFetchLinAd: 000056016b2ead40 IbsFetchPhysAd: 000000115cedfd40 c_ibs_ext_ctl: 0000000000000000 IbsItlbRefillLat 0 ..and IBS Op samples, e.g.: ibs_op_ctl: 0000009e009e8968 MaxCnt 10000000 En 1 Val 1 CntCtl 1=uOps CurCnt 158 IbsOpRip: 000056016b2ea73d ibs_op_data: 00000000000b0002 CompToRetCtr 2 TagToRetCtr 11 BrnRet 0 RipInvalid 0 BrnFuse 0 Microcode 0 ibs_op_data2: 0000000000000002 CacheHitSt 0=M-state RmtNode 0 DataSrc 2=Local node cache ibs_op_data3: 0000000000c60002 LdOp 0 StOp 1 DcL1TlbMiss 0 DcL2TlbMiss 0 DcL1TlbHit2M 0 DcL1TlbHit1G 0 DcL2TlbHit2M 0 DcMiss 0 DcMisAcc 0 DcWcMemAcc 0 DcUcMemAcc 0 DcLockedOp 0 DcMissNoMabAlloc 0 DcLinAddrValid 1 DcPhyAddrValid 1 DcL2TlbHit1G 0 L2Miss 0 SwPf 0 OpMemWidth 4 bytes OpDcMissOpenMemReqs 0 DcMissLat 0 TlbRefillLat 0 IbsDCLinAd: 00007f133c319ce0 IbsDCPhysAd: 0000000270485ce0 Committer notes: Fixed up this: util/amd-sample-raw.c: In function ‘evlist__amd_sample_raw’: util/amd-sample-raw.c:125:42: error: ‘ bytes’ directive output may be truncated writing 6 bytes into a region of size between 4 and 7 [-Werror=format-truncation=] 125 | " OpMemWidth %2d bytes", 1 << (reg.op_mem_width - 1)); | ^~~~~~ In file included from /usr/include/stdio.h:866, from util/amd-sample-raw.c:7: /usr/include/bits/stdio2.h:71:10: note: ‘__builtin___snprintf_chk’ output between 21 and 24 bytes into a destination of size 21 71 | return __builtin___snprintf_chk (__s, __n, __USE_FORTIFY_LEVEL - 1, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 72 | __glibc_objsize (__s), __fmt, | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 73 | __va_arg_pack ()); | ~~~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors As that %2d won't limit the number of chars to 2, just state that 2 is the minimal width: $ cat printf.c #include <stdio.h> #include <stdlib.h> int main(int argc, char *argv[]) { char bf[64]; int len = snprintf(bf, sizeof(bf), "%2d", atoi(argv[1])); printf("strlen(%s): %u\n", bf, len); return 0; } $ ./printf 1 strlen( 1): 2 $ ./printf 12 strlen(12): 2 $ ./printf 123 strlen(123): 3 $ ./printf 1234 strlen(1234): 4 $ ./printf 12345 strlen(12345): 5 $ ./printf 123456 strlen(123456): 6 $ And since we probably don't want that output to be truncated, just assume the worst case, as the compiler did, and add a few more chars to that buffer. Also use sizeof(var) instead of sizeof(dup-of-wanted-format-string) to avoid bugs when changing one but not the other. I also had to change this: -#include <asm/amd-ibs.h> +#include "../../arch/x86/include/asm/amd-ibs.h" To make it build on other architectures, just like intel-pt does. Signed-off-by: Kim Phillips <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Boris Ostrovsky <[email protected]> Cc: Ian Rogers <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Joao Martins <[email protected]> Cc: Konrad Rzeszutek Wilk <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Michael Petlan <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Robert Richter <[email protected]> Cc: Stephane Eranian <[email protected]> Link: https //lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Sep 16, 2021
Ido Schimmel says: ==================== mlxsw: Add support for transceiver modules reset This patchset prepares mlxsw for future transceiver modules related [1] changes and adds reset support via the existing 'ETHTOOL_RESET' interface. Patches #1-#6 are relatively straightforward preparations. Patch #7 tracks the number of logical ports that are mapped to the transceiver module and the number of logical ports using it that are administratively up. Needed for both reset support and power mode policy support. Patches #8-#9 add required fields in device registers. Patch #10 implements support for ethtool_ops::reset in order to reset transceiver modules. [1] https://lore.kernel.org/netdev/[email protected]/ ==================== Signed-off-by: David S. Miller <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Sep 22, 2021
It's later supposed to be either a correct address or NULL. Without the initialization, it may contain an undefined value which results in the following segmentation fault: # perf top --sort comm -g --ignore-callees=do_idle terminates with: #0 0x00007ffff56b7685 in __strlen_avx2 () from /lib64/libc.so.6 #1 0x00007ffff55e3802 in strdup () from /lib64/libc.so.6 #2 0x00005555558cb139 in hist_entry__init (callchain_size=<optimized out>, sample_self=true, template=0x7fffde7fb110, he=0x7fffd801c250) at util/hist.c:489 #3 hist_entry__new (template=template@entry=0x7fffde7fb110, sample_self=sample_self@entry=true) at util/hist.c:564 #4 0x00005555558cb4ba in hists__findnew_entry (hists=hists@entry=0x5555561d9e38, entry=entry@entry=0x7fffde7fb110, al=al@entry=0x7fffde7fb420, sample_self=sample_self@entry=true) at util/hist.c:657 #5 0x00005555558cba1b in __hists__add_entry (hists=hists@entry=0x5555561d9e38, al=0x7fffde7fb420, sym_parent=<optimized out>, bi=bi@entry=0x0, mi=mi@entry=0x0, sample=sample@entry=0x7fffde7fb4b0, sample_self=true, ops=0x0, block_info=0x0) at util/hist.c:288 #6 0x00005555558cbb70 in hists__add_entry (sample_self=true, sample=0x7fffde7fb4b0, mi=0x0, bi=0x0, sym_parent=<optimized out>, al=<optimized out>, hists=0x5555561d9e38) at util/hist.c:1056 #7 iter_add_single_cumulative_entry (iter=0x7fffde7fb460, al=<optimized out>) at util/hist.c:1056 #8 0x00005555558cc8a4 in hist_entry_iter__add (iter=iter@entry=0x7fffde7fb460, al=al@entry=0x7fffde7fb420, max_stack_depth=<optimized out>, arg=arg@entry=0x7fffffff7db0) at util/hist.c:1231 #9 0x00005555557cdc9a in perf_event__process_sample (machine=<optimized out>, sample=0x7fffde7fb4b0, evsel=<optimized out>, event=<optimized out>, tool=0x7fffffff7db0) at builtin-top.c:842 #10 deliver_event (qe=<optimized out>, qevent=<optimized out>) at builtin-top.c:1202 #11 0x00005555558a9318 in do_flush (show_progress=false, oe=0x7fffffff80e0) at util/ordered-events.c:244 #12 __ordered_events__flush (oe=oe@entry=0x7fffffff80e0, how=how@entry=OE_FLUSH__TOP, timestamp=timestamp@entry=0) at util/ordered-events.c:323 #13 0x00005555558a9789 in __ordered_events__flush (timestamp=<optimized out>, how=<optimized out>, oe=<optimized out>) at util/ordered-events.c:339 #14 ordered_events__flush (how=OE_FLUSH__TOP, oe=0x7fffffff80e0) at util/ordered-events.c:341 #15 ordered_events__flush (oe=oe@entry=0x7fffffff80e0, how=how@entry=OE_FLUSH__TOP) at util/ordered-events.c:339 #16 0x00005555557cd631 in process_thread (arg=0x7fffffff7db0) at builtin-top.c:1114 #17 0x00007ffff7bb817a in start_thread () from /lib64/libpthread.so.0 #18 0x00007ffff5656dc3 in clone () from /lib64/libc.so.6 If you look at the frame #2, the code is: 488 if (he->srcline) { 489 he->srcline = strdup(he->srcline); 490 if (he->srcline == NULL) 491 goto err_rawdata; 492 } If he->srcline is not NULL (it is not NULL if it is uninitialized rubbish), it gets strdupped and strdupping a rubbish random string causes the problem. Also, if you look at the commit 1fb7d06, it adds the srcline property into the struct, but not initializing it everywhere needed. Committer notes: Now I see, when using --ignore-callees=do_idle we end up here at line 2189 in add_callchain_ip(): 2181 if (al.sym != NULL) { 2182 if (perf_hpp_list.parent && !*parent && 2183 symbol__match_regex(al.sym, &parent_regex)) 2184 *parent = al.sym; 2185 else if (have_ignore_callees && root_al && 2186 symbol__match_regex(al.sym, &ignore_callees_regex)) { 2187 /* Treat this symbol as the root, 2188 forgetting its callees. */ 2189 *root_al = al; 2190 callchain_cursor_reset(cursor); 2191 } 2192 } And the al that doesn't have the ->srcline field initialized will be copied to the root_al, so then, back to: 1211 int hist_entry_iter__add(struct hist_entry_iter *iter, struct addr_location *al, 1212 int max_stack_depth, void *arg) 1213 { 1214 int err, err2; 1215 struct map *alm = NULL; 1216 1217 if (al) 1218 alm = map__get(al->map); 1219 1220 err = sample__resolve_callchain(iter->sample, &callchain_cursor, &iter->parent, 1221 iter->evsel, al, max_stack_depth); 1222 if (err) { 1223 map__put(alm); 1224 return err; 1225 } 1226 1227 err = iter->ops->prepare_entry(iter, al); 1228 if (err) 1229 goto out; 1230 1231 err = iter->ops->add_single_entry(iter, al); 1232 if (err) 1233 goto out; 1234 That al at line 1221 is what hist_entry_iter__add() (called from sample__resolve_callchain()) saw as 'root_al', and then: iter->ops->add_single_entry(iter, al); will go on with al->srcline with a bogus value, I'll add the above sequence to the cset and apply, thanks! Signed-off-by: Michael Petlan <[email protected]> CC: Milian Wolff <[email protected]> Cc: Jiri Olsa <[email protected]> Fixes: 1fb7d06 ("perf report Use srcline from callchain for hist entries") Link: https //lore.kernel.org/r/[email protected] Reported-by: Juri Lelli <[email protected]> Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Sep 22, 2021
FD uses xyarray__entry that may return NULL if an index is out of bounds. If NULL is returned then a segv happens as FD unconditionally dereferences the pointer. This was happening in a case of with perf iostat as shown below. The fix is to make FD an "int*" rather than an int and handle the NULL case as either invalid input or a closed fd. $ sudo gdb --args perf stat --iostat list ... Breakpoint 1, perf_evsel__alloc_fd (evsel=0x5555560951a0, ncpus=1, nthreads=1) at evsel.c:50 50 { (gdb) bt #0 perf_evsel__alloc_fd (evsel=0x5555560951a0, ncpus=1, nthreads=1) at evsel.c:50 #1 0x000055555585c188 in evsel__open_cpu (evsel=0x5555560951a0, cpus=0x555556093410, threads=0x555556086fb0, start_cpu=0, end_cpu=1) at util/evsel.c:1792 #2 0x000055555585cfb2 in evsel__open (evsel=0x5555560951a0, cpus=0x0, threads=0x555556086fb0) at util/evsel.c:2045 #3 0x000055555585d0db in evsel__open_per_thread (evsel=0x5555560951a0, threads=0x555556086fb0) at util/evsel.c:2065 #4 0x00005555558ece64 in create_perf_stat_counter (evsel=0x5555560951a0, config=0x555555c34700 <stat_config>, target=0x555555c2f1c0 <target>, cpu=0) at util/stat.c:590 #5 0x000055555578e927 in __run_perf_stat (argc=1, argv=0x7fffffffe4a0, run_idx=0) at builtin-stat.c:833 #6 0x000055555578f3c6 in run_perf_stat (argc=1, argv=0x7fffffffe4a0, run_idx=0) at builtin-stat.c:1048 #7 0x0000555555792ee5 in cmd_stat (argc=1, argv=0x7fffffffe4a0) at builtin-stat.c:2534 #8 0x0000555555835ed3 in run_builtin (p=0x555555c3f540 <commands+288>, argc=3, argv=0x7fffffffe4a0) at perf.c:313 #9 0x0000555555836154 in handle_internal_command (argc=3, argv=0x7fffffffe4a0) at perf.c:365 #10 0x000055555583629f in run_argv (argcp=0x7fffffffe2ec, argv=0x7fffffffe2e0) at perf.c:409 #11 0x0000555555836692 in main (argc=3, argv=0x7fffffffe4a0) at perf.c:539 ... (gdb) c Continuing. Error: The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (uncore_iio_0/event=0x83,umask=0x04,ch_mask=0xF,fc_mask=0x07/). /bin/dmesg | grep -i perf may provide additional information. Program received signal SIGSEGV, Segmentation fault. 0x00005555559b03ea in perf_evsel__close_fd_cpu (evsel=0x5555560951a0, cpu=1) at evsel.c:166 166 if (FD(evsel, cpu, thread) >= 0) v3. fixes a bug in perf_evsel__run_ioctl where the sense of a branch was backward. Signed-off-by: Ian Rogers <[email protected]> Acked-by: Jiri Olsa <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: http://lore.kernel.org/lkml/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Sep 27, 2021
Ido Schimmel says: ==================== mlxsw: Add support for IP-in-IP with IPv6 underlay Currently, mlxsw only supports IP-in-IP with IPv4 underlay. Traffic routed through 'gre' netdevs is encapsulated with IPv4 and GRE headers. Similarly, incoming IPv4 GRE packets are decapsulated and routed in the overlay VRF (which can be the same as the underlay VRF). This patchset adds support for IPv6 underlay using the 'ip6gre' netdev. Due to architectural differences between Spectrum-1 and later ASICs, this functionality is only supported on Spectrum-2 onwards (the software data path is used for Spectrum-1). Patchset overview: Patches #1-#5 are preparations. Patches #6-#9 add and extend required device registers. Patches #10-#14 gradually add IPv6 underlay support. A follow-up patchset will add net/forwarding/ selftests. ==================== Signed-off-by: David S. Miller <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Oct 28, 2021
Attempting to defragment a Btrfs file containing a transparent huge page immediately deadlocks with the following stack trace: #0 context_switch (kernel/sched/core.c:4940:2) #1 __schedule (kernel/sched/core.c:6287:8) #2 schedule (kernel/sched/core.c:6366:3) #3 io_schedule (kernel/sched/core.c:8389:2) #4 wait_on_page_bit_common (mm/filemap.c:1356:4) #5 __lock_page (mm/filemap.c:1648:2) #6 lock_page (./include/linux/pagemap.h:625:3) #7 pagecache_get_page (mm/filemap.c:1910:4) #8 find_or_create_page (./include/linux/pagemap.h:420:9) #9 defrag_prepare_one_page (fs/btrfs/ioctl.c:1068:9) #10 defrag_one_range (fs/btrfs/ioctl.c:1326:14) #11 defrag_one_cluster (fs/btrfs/ioctl.c:1421:9) #12 btrfs_defrag_file (fs/btrfs/ioctl.c:1523:9) #13 btrfs_ioctl_defrag (fs/btrfs/ioctl.c:3117:9) #14 btrfs_ioctl (fs/btrfs/ioctl.c:4872:10) #15 vfs_ioctl (fs/ioctl.c:51:10) #16 __do_sys_ioctl (fs/ioctl.c:874:11) #17 __se_sys_ioctl (fs/ioctl.c:860:1) #18 __x64_sys_ioctl (fs/ioctl.c:860:1) #19 do_syscall_x64 (arch/x86/entry/common.c:50:14) #20 do_syscall_64 (arch/x86/entry/common.c:80:7) #21 entry_SYSCALL_64+0x7c/0x15b (arch/x86/entry/entry_64.S:113) A huge page is represented by a compound page, which consists of a struct page for each PAGE_SIZE page within the huge page. The first struct page is the "head page", and the remaining are "tail pages". Defragmentation attempts to lock each page in the range. However, lock_page() on a tail page actually locks the corresponding head page. So, if defragmentation tries to lock more than one struct page in a compound page, it tries to lock the same head page twice and deadlocks with itself. Ideally, we should be able to defragment transparent huge pages. However, THP for filesystems is currently read-only, so a lot of code is not ready to use huge pages for I/O. For now, let's just return ETXTBUSY. This can be reproduced with the following on a kernel with CONFIG_READ_ONLY_THP_FOR_FS=y: $ cat create_thp_file.c #include <fcntl.h> #include <stdbool.h> #include <stdio.h> #include <stdint.h> #include <stdlib.h> #include <unistd.h> #include <sys/mman.h> static const char zeroes[1024 * 1024]; static const size_t FILE_SIZE = 2 * 1024 * 1024; int main(int argc, char **argv) { if (argc != 2) { fprintf(stderr, "usage: %s PATH\n", argv[0]); return EXIT_FAILURE; } int fd = creat(argv[1], 0777); if (fd == -1) { perror("creat"); return EXIT_FAILURE; } size_t written = 0; while (written < FILE_SIZE) { ssize_t ret = write(fd, zeroes, sizeof(zeroes) < FILE_SIZE - written ? sizeof(zeroes) : FILE_SIZE - written); if (ret < 0) { perror("write"); return EXIT_FAILURE; } written += ret; } close(fd); fd = open(argv[1], O_RDONLY); if (fd == -1) { perror("open"); return EXIT_FAILURE; } /* * Reserve some address space so that we can align the file mapping to * the huge page size. */ void *placeholder_map = mmap(NULL, FILE_SIZE * 2, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); if (placeholder_map == MAP_FAILED) { perror("mmap (placeholder)"); return EXIT_FAILURE; } void *aligned_address = (void *)(((uintptr_t)placeholder_map + FILE_SIZE - 1) & ~(FILE_SIZE - 1)); void *map = mmap(aligned_address, FILE_SIZE, PROT_READ | PROT_EXEC, MAP_SHARED | MAP_FIXED, fd, 0); if (map == MAP_FAILED) { perror("mmap"); return EXIT_FAILURE; } if (madvise(map, FILE_SIZE, MADV_HUGEPAGE) < 0) { perror("madvise"); return EXIT_FAILURE; } char *line = NULL; size_t line_capacity = 0; FILE *smaps_file = fopen("/proc/self/smaps", "r"); if (!smaps_file) { perror("fopen"); return EXIT_FAILURE; } for (;;) { for (size_t off = 0; off < FILE_SIZE; off += 4096) ((volatile char *)map)[off]; ssize_t ret; bool this_mapping = false; while ((ret = getline(&line, &line_capacity, smaps_file)) > 0) { unsigned long start, end, huge; if (sscanf(line, "%lx-%lx", &start, &end) == 2) { this_mapping = (start <= (uintptr_t)map && (uintptr_t)map < end); } else if (this_mapping && sscanf(line, "FilePmdMapped: %ld", &huge) == 1 && huge > 0) { return EXIT_SUCCESS; } } sleep(6); rewind(smaps_file); fflush(smaps_file); } } $ ./create_thp_file huge $ btrfs fi defrag -czstd ./huge Reviewed-by: Josef Bacik <[email protected]> Signed-off-by: Omar Sandoval <[email protected]> Reviewed-by: David Sterba <[email protected]> Signed-off-by: David Sterba <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Nov 15, 2021
The exit function fixes a memory leak with the src field as detected by leak sanitizer. An example of which is: Indirect leak of 25133184 byte(s) in 207 object(s) allocated from: #0 0x7f199ecfe987 in __interceptor_calloc libsanitizer/asan/asan_malloc_linux.cpp:154 #1 0x55defe638224 in annotated_source__alloc_histograms util/annotate.c:803 #2 0x55defe6397e4 in symbol__hists util/annotate.c:952 #3 0x55defe639908 in symbol__inc_addr_samples util/annotate.c:968 #4 0x55defe63aa29 in hist_entry__inc_addr_samples util/annotate.c:1119 #5 0x55defe499a79 in hist_iter__report_callback tools/perf/builtin-report.c:182 #6 0x55defe7a859d in hist_entry_iter__add util/hist.c:1236 #7 0x55defe49aa63 in process_sample_event tools/perf/builtin-report.c:315 #8 0x55defe731bc8 in evlist__deliver_sample util/session.c:1473 #9 0x55defe731e38 in machines__deliver_event util/session.c:1510 #10 0x55defe732a23 in perf_session__deliver_event util/session.c:1590 #11 0x55defe72951e in ordered_events__deliver_event util/session.c:183 #12 0x55defe740082 in do_flush util/ordered-events.c:244 #13 0x55defe7407cb in __ordered_events__flush util/ordered-events.c:323 #14 0x55defe740a61 in ordered_events__flush util/ordered-events.c:341 #15 0x55defe73837f in __perf_session__process_events util/session.c:2390 #16 0x55defe7385ff in perf_session__process_events util/session.c:2420 ... Signed-off-by: Ian Rogers <[email protected]> Acked-by: Namhyung Kim <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: James Clark <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Kajol Jain <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Martin Liška <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Jan 14, 2022
If the key is already present then free the key used for lookup. Found with: $ perf stat -M IO_Read_BW /bin/true ==1749112==ERROR: LeakSanitizer: detected memory leaks Direct leak of 32 byte(s) in 4 object(s) allocated from: #0 0x7f6f6fa7d7cf in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145 #1 0x55acecd9d7a6 in check_per_pkg util/stat.c:343 #2 0x55acecd9d9c5 in process_counter_values util/stat.c:365 #3 0x55acecd9e0ab in process_counter_maps util/stat.c:421 #4 0x55acecd9e292 in perf_stat_process_counter util/stat.c:443 #5 0x55aceca8553e in read_counters ./tools/perf/builtin-stat.c:470 #6 0x55aceca88fe3 in __run_perf_stat ./tools/perf/builtin-stat.c:1023 #7 0x55aceca89146 in run_perf_stat ./tools/perf/builtin-stat.c:1048 #8 0x55aceca90858 in cmd_stat ./tools/perf/builtin-stat.c:2555 #9 0x55acecc05fa5 in run_builtin ./tools/perf/perf.c:313 #10 0x55acecc064fe in handle_internal_command ./tools/perf/perf.c:365 #11 0x55acecc068bb in run_argv ./tools/perf/perf.c:409 #12 0x55acecc070aa in main ./tools/perf/perf.c:539 Reviewed-by: James Clark <[email protected]> Signed-off-by: Ian Rogers <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Andi Kleen <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: John Garry <[email protected]> Cc: Kajol Jain <[email protected]> Cc: Kan Liang <[email protected]> Cc: Leo Yan <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Mathieu Poirier <[email protected]> Cc: Mike Leach <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Paul Clarke <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Riccardo Mancini <[email protected]> Cc: Stephane Eranian <[email protected]> Cc: Suzuki Poulouse <[email protected]> Cc: Vineet Singh <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Mar 4, 2022
Ido Schimmel says: ==================== HW counters for soft devices Petr says: Offloading switch device drivers may be able to collect statistics of the traffic taking place in the HW datapath that pertains to a certain soft netdevice, such as a VLAN. In this patch set, add the necessary infrastructure to allow exposing these statistics to the offloaded netdevice in question, and add mlxsw offload. Across HW platforms, the counter itself very likely constitutes a limited resource, and the act of counting may have a performance impact. Therefore this patch set makes the HW statistics collection opt-in and togglable from userspace on a per-netdevice basis. Additionally, HW devices may have various limiting conditions under which they can realize the counter. Therefore it is also possible to query whether the requested counter is realized by any driver. In TC parlance, which is to a degree reused in this patch set, two values are recognized: "request" tracks whether the user enabled collecting HW statistics, and "used" tracks whether any HW statistics are actually collected. In the past, this author has expressed the opinion that `a typical user doing "ip -s l sh", including various scripts, wants to see the full picture and not worry what's going on where'. While that would be nice, unfortunately it cannot work: - Packets that trap from the HW datapath to the SW datapath would be double counted. For a given netdevice, some traffic can be purely a SW artifact, and some may flow through the HW object corresponding to the netdevice. But some traffic can also get trapped to the SW datapath after bumping the HW counter. It is not clear how to make sure double-counting does not occur in the SW datapath in that case, while still making sure that possibly divergent SW forwarding path gets bumped as appropriate. So simply adding HW and SW stats may work roughly, most of the time, but there are scenarios where the result is nonsensical. - HW devices will have limitations as to what type of traffic they can count. In case of mlxsw, which is part of this patch set, there is no reasonable way to count all traffic going through a certain netdevice, such as a VLAN netdevice enslaved to a bridge. It is however very simple to count traffic flowing through an L3 object, such as a VLAN netdevice with an IP address. Similarly for physical netdevices, the L3 object at which the counter is installed is the subport carrying untagged traffic. These are not "just counters". It is important that the user understands what is being counted. It would be incorrect to conflate these statistics with another existing statistics suite. To that end, this patch set introduces a statistics suite called "L3 stats". This label should make it easy to understand what is being counted, and to decide whether a given device can or cannot implement this suite for some type of netdevice. At the same time, the code is written to make future extensions easy, should a device pop up that can implement a different flavor of statistics suite (say L2, or an address-family-specific suite). For example, using a work-in-progress iproute2[1], to turn on and then list the counters on a VLAN netdevice: # ip stats set dev swp1.200 l3_stats on # ip stats show dev swp1.200 group offload subgroup l3_stats 56: swp1.200: group offload subgroup l3_stats on used on RX: bytes packets errors dropped missed mcast 0 0 0 0 0 0 TX: bytes packets errors dropped carrier collsns 0 0 0 0 0 0 The patchset progresses as follows: - Patch #1 is a cleanup. - In patch #2, remove the assumption that all LINK_OFFLOAD_XSTATS are dev-backed. The only attribute defined under the nest is currently IFLA_OFFLOAD_XSTATS_CPU_HIT. L3_STATS differs from CPU_HIT in that the driver that supplies the statistics is not the same as the driver that implements the netdevice. Make the code compatible with this in patch #2. - In patch #3, add the possibility to filter inside nests. The filter_mask field of RTM_GETSTATS header determines which top-level attributes should be included in the netlink response. This saves processing time by only including the bits that the user cares about instead of always dumping everything. This is doubly important for HW-backed statistics that would typically require a trip to the device to fetch the stats. In this patch, the UAPI is extended to allow filtering inside IFLA_STATS_LINK_OFFLOAD_XSTATS in particular, but the scheme is easily extensible to other nests as well. - In patch #4, propagate extack where we need it. In patch #5, make it possible to propagate errors from drivers to the user. - In patch #6, add the in-kernel APIs for keeping track of the new stats suite, and the notifiers that the core uses to communicate with the drivers. - In patch #7, add UAPI for obtaining the new stats suite. - In patch #8, add a new UAPI message, RTM_SETSTATS, which will carry the message to toggle the newly-added stats suite. In patch #9, add the toggle itself. At this point the core is ready for drivers to add support for the new stats suite. - In patches #10, #11 and #12, apply small tweaks to mlxsw code. - In patch #13, add support for L3 stats, which are realized as RIF counters. - Finally in patch #14, a selftest is added to the net/forwarding directory. Technically this is a HW-specific test, in that without a HW implementing the counters, it just will not pass. But devices that support L3 statistics at all are likely to be able to reuse this selftest, so it seems appropriate to put it in the general forwarding directory. We also have a netdevsim implementation, and a corresponding selftest that verifies specifically some of the core code. We intend to contribute these later. Interested parties can take a look at the raw code at [2]. [1] https://github.com/pmachata/iproute2/commits/soft_counters [2] https://github.com/pmachata/linux_mlxsw/commits/petrm_soft_counters_2 v2: - Patch #3: - Do not declare strict_start_type at the new policies, since they are used with nla_parse_nested() (sans _deprecated). - Use NLA_POLICY_NESTED to declare what the nest contents should be - Use NLA_POLICY_MASK instead of BITFIELD32 for the filtering attribute. - Patch #6: - s/monotonous/monotonic/ in commit message - Use a newly-added struct rtnl_hw_stats64 for stats transfer - Patch #7: - Use a newly-added struct rtnl_hw_stats64 for stats transfer - Patch #8: - Do not declare strict_start_type at the new policies, since they are used with nla_parse_nested() (sans _deprecated). - Patch #13: - Use a newly-added struct rtnl_hw_stats64 for stats transfer ==================== Signed-off-by: David S. Miller <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Mar 22, 2022
In remove_phb_dynamic() we use &phb->io_resource, after we've called device_unregister(&host_bridge->dev). But the unregister may have freed phb, because pcibios_free_controller_deferred() is the release function for the host_bridge. If there are no outstanding references when we call device_unregister() then phb will be freed out from under us. This has gone mainly unnoticed, but with slub_debug and page_poison enabled it can lead to a crash: PID: 7574 TASK: c0000000d492cb80 CPU: 13 COMMAND: "drmgr" #0 [c0000000e4f075a0] crash_kexec at c00000000027d7dc #1 [c0000000e4f075d0] oops_end at c000000000029608 #2 [c0000000e4f07650] __bad_page_fault at c0000000000904b4 #3 [c0000000e4f076c0] do_bad_slb_fault at c00000000009a5a8 #4 [c0000000e4f076f0] data_access_slb_common_virt at c000000000008b30 Data SLB Access [380] exception frame: R0: c000000000167250 R1: c0000000e4f07a00 R2: c000000002a46100 R3: c000000002b39ce8 R4: 00000000000000c0 R5: 00000000000000a9 R6: 3894674d000000c0 R7: 0000000000000000 R8: 00000000000000ff R9: 0000000000000100 R10: 6b6b6b6b6b6b6b6b R11: 0000000000008000 R12: c00000000023da80 R13: c0000009ffd38b00 R14: 0000000000000000 R15: 000000011c87f0f0 R16: 0000000000000006 R17: 0000000000000003 R18: 0000000000000002 R19: 0000000000000004 R20: 0000000000000005 R21: 000000011c87ede8 R22: 000000011c87c5a8 R23: 000000011c87d3a0 R24: 0000000000000000 R25: 0000000000000001 R26: c0000000e4f07cc8 R27: c00000004d1cc400 R28: c0080000031d00e8 R29: c00000004d23d800 R30: c00000004d1d2400 R31: c00000004d1d2540 NIP: c000000000167258 MSR: 8000000000009033 OR3: c000000000e9f474 CTR: 0000000000000000 LR: c000000000167250 XER: 0000000020040003 CCR: 0000000024088420 MQ: 0000000000000000 DAR: 6b6b6b6b6b6b6ba3 DSISR: c0000000e4f07920 Syscall Result: fffffffffffffff2 [NIP : release_resource+56] [LR : release_resource+48] #5 [c0000000e4f07a00] release_resource at c000000000167258 (unreliable) #6 [c0000000e4f07a30] remove_phb_dynamic at c000000000105648 #7 [c0000000e4f07ab0] dlpar_remove_slot at c0080000031a09e8 [rpadlpar_io] #8 [c0000000e4f07b50] remove_slot_store at c0080000031a0b9c [rpadlpar_io] #9 [c0000000e4f07be0] kobj_attr_store at c000000000817d8c #10 [c0000000e4f07c00] sysfs_kf_write at c00000000063e504 #11 [c0000000e4f07c20] kernfs_fop_write_iter at c00000000063d868 #12 [c0000000e4f07c70] new_sync_write at c00000000054339c #13 [c0000000e4f07d10] vfs_write at c000000000546624 #14 [c0000000e4f07d60] ksys_write at c0000000005469f4 #15 [c0000000e4f07db0] system_call_exception at c000000000030840 #16 [c0000000e4f07e10] system_call_vectored_common at c00000000000c168 To avoid it, we can take a reference to the host_bridge->dev until we're done using phb. Then when we drop the reference the phb will be freed. Fixes: 2dd9c11 ("powerpc/pseries: use pci_host_bridge.release_fn() to kfree(phb)") Reported-by: David Dai <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Tested-by: Sachin Sant <[email protected]> Link: https://lore.kernel.org/r/[email protected]
nathanchance
pushed a commit
that referenced
this issue
Apr 5, 2022
This patch will address the following warning and style violations generated by ./scripts/checkpatch.pl in strict mode: WARNING: Use #include <linux/module.h> instead of <asm/module.h> #10: FILE: kernel/module/internal.h:10: +#include <asm/module.h> CHECK: spaces preferred around that '-' (ctx:VxV) #18: FILE: kernel/module/internal.h:18: +#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1)) CHECK: Please use a blank line after function/struct/union/enum declarations #69: FILE: kernel/module/internal.h:69: +} +static inline void module_decompress_cleanup(struct load_info *info) ^ CHECK: extern prototypes should be avoided in .h files #84: FILE: kernel/module/internal.h:84: +extern int mod_verify_sig(const void *mod, struct load_info *info); WARNING: Missing a blank line after declarations #116: FILE: kernel/module/decompress.c:116: + struct page *page = module_get_next_page(info); + if (!page) { WARNING: Missing a blank line after declarations #174: FILE: kernel/module/decompress.c:174: + struct page *page = module_get_next_page(info); + if (!page) { CHECK: Please use a blank line after function/struct/union/enum declarations #258: FILE: kernel/module/decompress.c:258: +} +static struct kobj_attribute module_compression_attr = __ATTR_RO(compression); Note: Fortunately, the multiple-include optimisation found in include/linux/module.h will prevent duplication/or inclusion more than once. Fixes: f314dfe ("modsign: log module name in the event of an error") Reviewed-by: Christophe Leroy <[email protected]> Signed-off-by: Aaron Tomlin <[email protected]> Signed-off-by: Luis Chamberlain <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Apr 5, 2022
…ne() failed Patch series "mm: COW fixes part 2: reliable GUP pins of anonymous pages", v3. This series is the result of the discussion on the previous approach [2]. More information on the general COW issues can be found there. It is based on latest linus/master (post v5.17, with relevant core-MM changes for v5.18-rc1). This series fixes memory corruptions when a GUP pin (FOLL_PIN) was taken on an anonymous page and COW logic fails to detect exclusivity of the page to then replacing the anonymous page by a copy in the page table: The GUP pin lost synchronicity with the pages mapped into the page tables. This issue, including other related COW issues, has been summarized in [3] under 3): " 3. Intra Process Memory Corruptions due to Wrong COW (FOLL_PIN) page_maybe_dma_pinned() is used to check if a page may be pinned for DMA (using FOLL_PIN instead of FOLL_GET). While false positives are tolerable, false negatives are problematic: pages that are pinned for DMA must not be added to the swapcache. If it happens, the (now pinned) page could be faulted back from the swapcache into page tables read-only. Future write-access would detect the pinning and COW the page, losing synchronicity. For the interested reader, this is nicely documented in feb889f ("mm: don't put pinned pages into the swap cache"). Peter reports [8] that page_maybe_dma_pinned() as used is racy in some cases and can result in a violation of the documented semantics: giving false negatives because of the race. There are cases where we call it without properly taking a per-process sequence lock, turning the usage of page_maybe_dma_pinned() racy. While one case (clear_refs SOFTDIRTY tracking, see below) seems to be easy to handle, there is especially one rmap case (shrink_page_list) that's hard to fix: in the rmap world, we're not limited to a single process. The shrink_page_list() issue is really subtle. If we race with someone pinning a page, we can trigger the same issue as in the FOLL_GET case. See the detail section at the end of this mail on a discussion how bad this can bite us with VFIO or other FOLL_PIN user. It's harder to reproduce, but I managed to modify the O_DIRECT reproducer to use io_uring fixed buffers [15] instead, which ends up using FOLL_PIN | FOLL_WRITE | FOLL_LONGTERM to pin buffer pages and can similarly trigger a loss of synchronicity and consequently a memory corruption. Again, the root issue is that a write-fault on a page that has additional references results in a COW and thereby a loss of synchronicity and consequently a memory corruption if two parties believe they are referencing the same page. " This series makes GUP pins (R/O and R/W) on anonymous pages fully reliable, especially also taking care of concurrent pinning via GUP-fast, for example, also fully fixing an issue reported regarding NUMA balancing [4] recently. While doing that, it further reduces "unnecessary COWs", especially when we don't fork()/KSM and don't swapout, and fixes the COW security for hugetlb for FOLL_PIN. In summary, we track via a pageflag (PG_anon_exclusive) whether a mapped anonymous page is exclusive. Exclusive anonymous pages that are mapped R/O can directly be mapped R/W by the COW logic in the write fault handler. Exclusive anonymous pages that want to be shared (fork(), KSM) first have to be marked shared -- which will fail if there are GUP pins on the page. GUP is only allowed to take a pin on anonymous pages that are exclusive. The PT lock is the primary mechanism to synchronize modifications of PG_anon_exclusive. We synchronize against GUP-fast either via the src_mm->write_protect_seq (during fork()) or via clear/invalidate+flush of the relevant page table entry. Special care has to be taken about swap, migration, and THPs (whereby a PMD-mapping can be converted to a PTE mapping and we have to track information for subpages). Besides these, we let the rmap code handle most magic. For reliable R/O pins of anonymous pages, we need FAULT_FLAG_UNSHARE logic as part of our previous approach [2], however, it's now 100% mapcount free and I further simplified it a bit. #1 is a fix #3-#10 are mostly rmap preparations for PG_anon_exclusive handling #11 introduces PG_anon_exclusive #12 uses PG_anon_exclusive and make R/W pins of anonymous pages reliable #13 is a preparation for reliable R/O pins #14 and #15 is reused/modified GUP-triggered unsharing for R/O GUP pins make R/O pins of anonymous pages reliable #16 adds sanity check when (un)pinning anonymous pages [1] https://lkml.kernel.org/r/[email protected] [2] https://lkml.kernel.org/r/[email protected] [3] https://lore.kernel.org/r/[email protected] [4] https://bugzilla.kernel.org/show_bug.cgi?id=215616 This patch (of 16): In case arch_unmap_one() fails, we already did a swap_duplicate(). let's undo that properly via swap_free(). Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Fixes: ca827d5 ("mm, swap: Add infrastructure for saving page metadata on swap") Signed-off-by: David Hildenbrand <[email protected]> Reviewed-by: Khalid Aziz <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: David Rientjes <[email protected]> Cc: Shakeel Butt <[email protected]> Cc: John Hubbard <[email protected]> Cc: Jason Gunthorpe <[email protected]> Cc: Mike Kravetz <[email protected]> Cc: Mike Rapoport <[email protected]> Cc: Yang Shi <[email protected]> Cc: "Kirill A. Shutemov" <[email protected]> Cc: Matthew Wilcox (Oracle) <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: Jann Horn <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Nadav Amit <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Andrea Arcangeli <[email protected]> Cc: Peter Xu <[email protected]> Cc: Don Dutile <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Jan Kara <[email protected]> Cc: Liang Zhang <[email protected]> Cc: Pedro Demarchi Gomes <[email protected]> Cc: Oded Gabbay <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Apr 6, 2022
This patch will address the following warning and style violations generated by ./scripts/checkpatch.pl in strict mode: WARNING: Use #include <linux/module.h> instead of <asm/module.h> #10: FILE: kernel/module/internal.h:10: +#include <asm/module.h> CHECK: spaces preferred around that '-' (ctx:VxV) #18: FILE: kernel/module/internal.h:18: +#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1)) CHECK: Please use a blank line after function/struct/union/enum declarations #69: FILE: kernel/module/internal.h:69: +} +static inline void module_decompress_cleanup(struct load_info *info) ^ CHECK: extern prototypes should be avoided in .h files #84: FILE: kernel/module/internal.h:84: +extern int mod_verify_sig(const void *mod, struct load_info *info); WARNING: Missing a blank line after declarations #116: FILE: kernel/module/decompress.c:116: + struct page *page = module_get_next_page(info); + if (!page) { WARNING: Missing a blank line after declarations #174: FILE: kernel/module/decompress.c:174: + struct page *page = module_get_next_page(info); + if (!page) { CHECK: Please use a blank line after function/struct/union/enum declarations #258: FILE: kernel/module/decompress.c:258: +} +static struct kobj_attribute module_compression_attr = __ATTR_RO(compression); Note: Fortunately, the multiple-include optimisation found in include/linux/module.h will prevent duplication/or inclusion more than once. Fixes: f314dfe ("modsign: log module name in the event of an error") Reviewed-by: Christophe Leroy <[email protected]> Signed-off-by: Aaron Tomlin <[email protected]> Signed-off-by: Luis Chamberlain <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Apr 6, 2022
…ne() failed Patch series "mm: COW fixes part 2: reliable GUP pins of anonymous pages", v3. This series is the result of the discussion on the previous approach [2]. More information on the general COW issues can be found there. It is based on latest linus/master (post v5.17, with relevant core-MM changes for v5.18-rc1). This series fixes memory corruptions when a GUP pin (FOLL_PIN) was taken on an anonymous page and COW logic fails to detect exclusivity of the page to then replacing the anonymous page by a copy in the page table: The GUP pin lost synchronicity with the pages mapped into the page tables. This issue, including other related COW issues, has been summarized in [3] under 3): " 3. Intra Process Memory Corruptions due to Wrong COW (FOLL_PIN) page_maybe_dma_pinned() is used to check if a page may be pinned for DMA (using FOLL_PIN instead of FOLL_GET). While false positives are tolerable, false negatives are problematic: pages that are pinned for DMA must not be added to the swapcache. If it happens, the (now pinned) page could be faulted back from the swapcache into page tables read-only. Future write-access would detect the pinning and COW the page, losing synchronicity. For the interested reader, this is nicely documented in feb889f ("mm: don't put pinned pages into the swap cache"). Peter reports [8] that page_maybe_dma_pinned() as used is racy in some cases and can result in a violation of the documented semantics: giving false negatives because of the race. There are cases where we call it without properly taking a per-process sequence lock, turning the usage of page_maybe_dma_pinned() racy. While one case (clear_refs SOFTDIRTY tracking, see below) seems to be easy to handle, there is especially one rmap case (shrink_page_list) that's hard to fix: in the rmap world, we're not limited to a single process. The shrink_page_list() issue is really subtle. If we race with someone pinning a page, we can trigger the same issue as in the FOLL_GET case. See the detail section at the end of this mail on a discussion how bad this can bite us with VFIO or other FOLL_PIN user. It's harder to reproduce, but I managed to modify the O_DIRECT reproducer to use io_uring fixed buffers [15] instead, which ends up using FOLL_PIN | FOLL_WRITE | FOLL_LONGTERM to pin buffer pages and can similarly trigger a loss of synchronicity and consequently a memory corruption. Again, the root issue is that a write-fault on a page that has additional references results in a COW and thereby a loss of synchronicity and consequently a memory corruption if two parties believe they are referencing the same page. " This series makes GUP pins (R/O and R/W) on anonymous pages fully reliable, especially also taking care of concurrent pinning via GUP-fast, for example, also fully fixing an issue reported regarding NUMA balancing [4] recently. While doing that, it further reduces "unnecessary COWs", especially when we don't fork()/KSM and don't swapout, and fixes the COW security for hugetlb for FOLL_PIN. In summary, we track via a pageflag (PG_anon_exclusive) whether a mapped anonymous page is exclusive. Exclusive anonymous pages that are mapped R/O can directly be mapped R/W by the COW logic in the write fault handler. Exclusive anonymous pages that want to be shared (fork(), KSM) first have to be marked shared -- which will fail if there are GUP pins on the page. GUP is only allowed to take a pin on anonymous pages that are exclusive. The PT lock is the primary mechanism to synchronize modifications of PG_anon_exclusive. We synchronize against GUP-fast either via the src_mm->write_protect_seq (during fork()) or via clear/invalidate+flush of the relevant page table entry. Special care has to be taken about swap, migration, and THPs (whereby a PMD-mapping can be converted to a PTE mapping and we have to track information for subpages). Besides these, we let the rmap code handle most magic. For reliable R/O pins of anonymous pages, we need FAULT_FLAG_UNSHARE logic as part of our previous approach [2], however, it's now 100% mapcount free and I further simplified it a bit. #1 is a fix #3-#10 are mostly rmap preparations for PG_anon_exclusive handling #11 introduces PG_anon_exclusive #12 uses PG_anon_exclusive and make R/W pins of anonymous pages reliable #13 is a preparation for reliable R/O pins #14 and #15 is reused/modified GUP-triggered unsharing for R/O GUP pins make R/O pins of anonymous pages reliable #16 adds sanity check when (un)pinning anonymous pages [1] https://lkml.kernel.org/r/[email protected] [2] https://lkml.kernel.org/r/[email protected] [3] https://lore.kernel.org/r/[email protected] [4] https://bugzilla.kernel.org/show_bug.cgi?id=215616 This patch (of 16): In case arch_unmap_one() fails, we already did a swap_duplicate(). let's undo that properly via swap_free(). Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Fixes: ca827d5 ("mm, swap: Add infrastructure for saving page metadata on swap") Signed-off-by: David Hildenbrand <[email protected]> Reviewed-by: Khalid Aziz <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: David Rientjes <[email protected]> Cc: Shakeel Butt <[email protected]> Cc: John Hubbard <[email protected]> Cc: Jason Gunthorpe <[email protected]> Cc: Mike Kravetz <[email protected]> Cc: Mike Rapoport <[email protected]> Cc: Yang Shi <[email protected]> Cc: "Kirill A. Shutemov" <[email protected]> Cc: Matthew Wilcox (Oracle) <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: Jann Horn <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Nadav Amit <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Andrea Arcangeli <[email protected]> Cc: Peter Xu <[email protected]> Cc: Don Dutile <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Jan Kara <[email protected]> Cc: Liang Zhang <[email protected]> Cc: Pedro Demarchi Gomes <[email protected]> Cc: Oded Gabbay <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Apr 12, 2022
…ne() failed Patch series "mm: COW fixes part 2: reliable GUP pins of anonymous pages", v3. This series is the result of the discussion on the previous approach [2]. More information on the general COW issues can be found there. It is based on latest linus/master (post v5.17, with relevant core-MM changes for v5.18-rc1). This series fixes memory corruptions when a GUP pin (FOLL_PIN) was taken on an anonymous page and COW logic fails to detect exclusivity of the page to then replacing the anonymous page by a copy in the page table: The GUP pin lost synchronicity with the pages mapped into the page tables. This issue, including other related COW issues, has been summarized in [3] under 3): " 3. Intra Process Memory Corruptions due to Wrong COW (FOLL_PIN) page_maybe_dma_pinned() is used to check if a page may be pinned for DMA (using FOLL_PIN instead of FOLL_GET). While false positives are tolerable, false negatives are problematic: pages that are pinned for DMA must not be added to the swapcache. If it happens, the (now pinned) page could be faulted back from the swapcache into page tables read-only. Future write-access would detect the pinning and COW the page, losing synchronicity. For the interested reader, this is nicely documented in feb889f ("mm: don't put pinned pages into the swap cache"). Peter reports [8] that page_maybe_dma_pinned() as used is racy in some cases and can result in a violation of the documented semantics: giving false negatives because of the race. There are cases where we call it without properly taking a per-process sequence lock, turning the usage of page_maybe_dma_pinned() racy. While one case (clear_refs SOFTDIRTY tracking, see below) seems to be easy to handle, there is especially one rmap case (shrink_page_list) that's hard to fix: in the rmap world, we're not limited to a single process. The shrink_page_list() issue is really subtle. If we race with someone pinning a page, we can trigger the same issue as in the FOLL_GET case. See the detail section at the end of this mail on a discussion how bad this can bite us with VFIO or other FOLL_PIN user. It's harder to reproduce, but I managed to modify the O_DIRECT reproducer to use io_uring fixed buffers [15] instead, which ends up using FOLL_PIN | FOLL_WRITE | FOLL_LONGTERM to pin buffer pages and can similarly trigger a loss of synchronicity and consequently a memory corruption. Again, the root issue is that a write-fault on a page that has additional references results in a COW and thereby a loss of synchronicity and consequently a memory corruption if two parties believe they are referencing the same page. " This series makes GUP pins (R/O and R/W) on anonymous pages fully reliable, especially also taking care of concurrent pinning via GUP-fast, for example, also fully fixing an issue reported regarding NUMA balancing [4] recently. While doing that, it further reduces "unnecessary COWs", especially when we don't fork()/KSM and don't swapout, and fixes the COW security for hugetlb for FOLL_PIN. In summary, we track via a pageflag (PG_anon_exclusive) whether a mapped anonymous page is exclusive. Exclusive anonymous pages that are mapped R/O can directly be mapped R/W by the COW logic in the write fault handler. Exclusive anonymous pages that want to be shared (fork(), KSM) first have to be marked shared -- which will fail if there are GUP pins on the page. GUP is only allowed to take a pin on anonymous pages that are exclusive. The PT lock is the primary mechanism to synchronize modifications of PG_anon_exclusive. We synchronize against GUP-fast either via the src_mm->write_protect_seq (during fork()) or via clear/invalidate+flush of the relevant page table entry. Special care has to be taken about swap, migration, and THPs (whereby a PMD-mapping can be converted to a PTE mapping and we have to track information for subpages). Besides these, we let the rmap code handle most magic. For reliable R/O pins of anonymous pages, we need FAULT_FLAG_UNSHARE logic as part of our previous approach [2], however, it's now 100% mapcount free and I further simplified it a bit. #1 is a fix #3-#10 are mostly rmap preparations for PG_anon_exclusive handling #11 introduces PG_anon_exclusive #12 uses PG_anon_exclusive and make R/W pins of anonymous pages reliable #13 is a preparation for reliable R/O pins #14 and #15 is reused/modified GUP-triggered unsharing for R/O GUP pins make R/O pins of anonymous pages reliable #16 adds sanity check when (un)pinning anonymous pages [1] https://lkml.kernel.org/r/[email protected] [2] https://lkml.kernel.org/r/[email protected] [3] https://lore.kernel.org/r/[email protected] [4] https://bugzilla.kernel.org/show_bug.cgi?id=215616 This patch (of 16): In case arch_unmap_one() fails, we already did a swap_duplicate(). let's undo that properly via swap_free(). Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Fixes: ca827d5 ("mm, swap: Add infrastructure for saving page metadata on swap") Signed-off-by: David Hildenbrand <[email protected]> Reviewed-by: Khalid Aziz <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: David Rientjes <[email protected]> Cc: Shakeel Butt <[email protected]> Cc: John Hubbard <[email protected]> Cc: Jason Gunthorpe <[email protected]> Cc: Mike Kravetz <[email protected]> Cc: Mike Rapoport <[email protected]> Cc: Yang Shi <[email protected]> Cc: "Kirill A. Shutemov" <[email protected]> Cc: Matthew Wilcox (Oracle) <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: Jann Horn <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Nadav Amit <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Andrea Arcangeli <[email protected]> Cc: Peter Xu <[email protected]> Cc: Don Dutile <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Jan Kara <[email protected]> Cc: Liang Zhang <[email protected]> Cc: Pedro Demarchi Gomes <[email protected]> Cc: Oded Gabbay <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Apr 13, 2022
…ne() failed Patch series "mm: COW fixes part 2: reliable GUP pins of anonymous pages", v3. This series is the result of the discussion on the previous approach [2]. More information on the general COW issues can be found there. It is based on latest linus/master (post v5.17, with relevant core-MM changes for v5.18-rc1). This series fixes memory corruptions when a GUP pin (FOLL_PIN) was taken on an anonymous page and COW logic fails to detect exclusivity of the page to then replacing the anonymous page by a copy in the page table: The GUP pin lost synchronicity with the pages mapped into the page tables. This issue, including other related COW issues, has been summarized in [3] under 3): " 3. Intra Process Memory Corruptions due to Wrong COW (FOLL_PIN) page_maybe_dma_pinned() is used to check if a page may be pinned for DMA (using FOLL_PIN instead of FOLL_GET). While false positives are tolerable, false negatives are problematic: pages that are pinned for DMA must not be added to the swapcache. If it happens, the (now pinned) page could be faulted back from the swapcache into page tables read-only. Future write-access would detect the pinning and COW the page, losing synchronicity. For the interested reader, this is nicely documented in feb889f ("mm: don't put pinned pages into the swap cache"). Peter reports [8] that page_maybe_dma_pinned() as used is racy in some cases and can result in a violation of the documented semantics: giving false negatives because of the race. There are cases where we call it without properly taking a per-process sequence lock, turning the usage of page_maybe_dma_pinned() racy. While one case (clear_refs SOFTDIRTY tracking, see below) seems to be easy to handle, there is especially one rmap case (shrink_page_list) that's hard to fix: in the rmap world, we're not limited to a single process. The shrink_page_list() issue is really subtle. If we race with someone pinning a page, we can trigger the same issue as in the FOLL_GET case. See the detail section at the end of this mail on a discussion how bad this can bite us with VFIO or other FOLL_PIN user. It's harder to reproduce, but I managed to modify the O_DIRECT reproducer to use io_uring fixed buffers [15] instead, which ends up using FOLL_PIN | FOLL_WRITE | FOLL_LONGTERM to pin buffer pages and can similarly trigger a loss of synchronicity and consequently a memory corruption. Again, the root issue is that a write-fault on a page that has additional references results in a COW and thereby a loss of synchronicity and consequently a memory corruption if two parties believe they are referencing the same page. " This series makes GUP pins (R/O and R/W) on anonymous pages fully reliable, especially also taking care of concurrent pinning via GUP-fast, for example, also fully fixing an issue reported regarding NUMA balancing [4] recently. While doing that, it further reduces "unnecessary COWs", especially when we don't fork()/KSM and don't swapout, and fixes the COW security for hugetlb for FOLL_PIN. In summary, we track via a pageflag (PG_anon_exclusive) whether a mapped anonymous page is exclusive. Exclusive anonymous pages that are mapped R/O can directly be mapped R/W by the COW logic in the write fault handler. Exclusive anonymous pages that want to be shared (fork(), KSM) first have to be marked shared -- which will fail if there are GUP pins on the page. GUP is only allowed to take a pin on anonymous pages that are exclusive. The PT lock is the primary mechanism to synchronize modifications of PG_anon_exclusive. We synchronize against GUP-fast either via the src_mm->write_protect_seq (during fork()) or via clear/invalidate+flush of the relevant page table entry. Special care has to be taken about swap, migration, and THPs (whereby a PMD-mapping can be converted to a PTE mapping and we have to track information for subpages). Besides these, we let the rmap code handle most magic. For reliable R/O pins of anonymous pages, we need FAULT_FLAG_UNSHARE logic as part of our previous approach [2], however, it's now 100% mapcount free and I further simplified it a bit. #1 is a fix #3-#10 are mostly rmap preparations for PG_anon_exclusive handling #11 introduces PG_anon_exclusive #12 uses PG_anon_exclusive and make R/W pins of anonymous pages reliable #13 is a preparation for reliable R/O pins #14 and #15 is reused/modified GUP-triggered unsharing for R/O GUP pins make R/O pins of anonymous pages reliable #16 adds sanity check when (un)pinning anonymous pages [1] https://lkml.kernel.org/r/[email protected] [2] https://lkml.kernel.org/r/[email protected] [3] https://lore.kernel.org/r/[email protected] [4] https://bugzilla.kernel.org/show_bug.cgi?id=215616 This patch (of 16): In case arch_unmap_one() fails, we already did a swap_duplicate(). let's undo that properly via swap_free(). Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Fixes: ca827d5 ("mm, swap: Add infrastructure for saving page metadata on swap") Signed-off-by: David Hildenbrand <[email protected]> Reviewed-by: Khalid Aziz <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: David Rientjes <[email protected]> Cc: Shakeel Butt <[email protected]> Cc: John Hubbard <[email protected]> Cc: Jason Gunthorpe <[email protected]> Cc: Mike Kravetz <[email protected]> Cc: Mike Rapoport <[email protected]> Cc: Yang Shi <[email protected]> Cc: "Kirill A. Shutemov" <[email protected]> Cc: Matthew Wilcox (Oracle) <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: Jann Horn <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Nadav Amit <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Andrea Arcangeli <[email protected]> Cc: Peter Xu <[email protected]> Cc: Don Dutile <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Jan Kara <[email protected]> Cc: Liang Zhang <[email protected]> Cc: Pedro Demarchi Gomes <[email protected]> Cc: Oded Gabbay <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Apr 19, 2022
…ne() failed Patch series "mm: COW fixes part 2: reliable GUP pins of anonymous pages", v3. This series is the result of the discussion on the previous approach [2]. More information on the general COW issues can be found there. It is based on latest linus/master (post v5.17, with relevant core-MM changes for v5.18-rc1). This series fixes memory corruptions when a GUP pin (FOLL_PIN) was taken on an anonymous page and COW logic fails to detect exclusivity of the page to then replacing the anonymous page by a copy in the page table: The GUP pin lost synchronicity with the pages mapped into the page tables. This issue, including other related COW issues, has been summarized in [3] under 3): " 3. Intra Process Memory Corruptions due to Wrong COW (FOLL_PIN) page_maybe_dma_pinned() is used to check if a page may be pinned for DMA (using FOLL_PIN instead of FOLL_GET). While false positives are tolerable, false negatives are problematic: pages that are pinned for DMA must not be added to the swapcache. If it happens, the (now pinned) page could be faulted back from the swapcache into page tables read-only. Future write-access would detect the pinning and COW the page, losing synchronicity. For the interested reader, this is nicely documented in feb889f ("mm: don't put pinned pages into the swap cache"). Peter reports [8] that page_maybe_dma_pinned() as used is racy in some cases and can result in a violation of the documented semantics: giving false negatives because of the race. There are cases where we call it without properly taking a per-process sequence lock, turning the usage of page_maybe_dma_pinned() racy. While one case (clear_refs SOFTDIRTY tracking, see below) seems to be easy to handle, there is especially one rmap case (shrink_page_list) that's hard to fix: in the rmap world, we're not limited to a single process. The shrink_page_list() issue is really subtle. If we race with someone pinning a page, we can trigger the same issue as in the FOLL_GET case. See the detail section at the end of this mail on a discussion how bad this can bite us with VFIO or other FOLL_PIN user. It's harder to reproduce, but I managed to modify the O_DIRECT reproducer to use io_uring fixed buffers [15] instead, which ends up using FOLL_PIN | FOLL_WRITE | FOLL_LONGTERM to pin buffer pages and can similarly trigger a loss of synchronicity and consequently a memory corruption. Again, the root issue is that a write-fault on a page that has additional references results in a COW and thereby a loss of synchronicity and consequently a memory corruption if two parties believe they are referencing the same page. " This series makes GUP pins (R/O and R/W) on anonymous pages fully reliable, especially also taking care of concurrent pinning via GUP-fast, for example, also fully fixing an issue reported regarding NUMA balancing [4] recently. While doing that, it further reduces "unnecessary COWs", especially when we don't fork()/KSM and don't swapout, and fixes the COW security for hugetlb for FOLL_PIN. In summary, we track via a pageflag (PG_anon_exclusive) whether a mapped anonymous page is exclusive. Exclusive anonymous pages that are mapped R/O can directly be mapped R/W by the COW logic in the write fault handler. Exclusive anonymous pages that want to be shared (fork(), KSM) first have to be marked shared -- which will fail if there are GUP pins on the page. GUP is only allowed to take a pin on anonymous pages that are exclusive. The PT lock is the primary mechanism to synchronize modifications of PG_anon_exclusive. We synchronize against GUP-fast either via the src_mm->write_protect_seq (during fork()) or via clear/invalidate+flush of the relevant page table entry. Special care has to be taken about swap, migration, and THPs (whereby a PMD-mapping can be converted to a PTE mapping and we have to track information for subpages). Besides these, we let the rmap code handle most magic. For reliable R/O pins of anonymous pages, we need FAULT_FLAG_UNSHARE logic as part of our previous approach [2], however, it's now 100% mapcount free and I further simplified it a bit. #1 is a fix #3-#10 are mostly rmap preparations for PG_anon_exclusive handling #11 introduces PG_anon_exclusive #12 uses PG_anon_exclusive and make R/W pins of anonymous pages reliable #13 is a preparation for reliable R/O pins #14 and #15 is reused/modified GUP-triggered unsharing for R/O GUP pins make R/O pins of anonymous pages reliable #16 adds sanity check when (un)pinning anonymous pages [1] https://lkml.kernel.org/r/[email protected] [2] https://lkml.kernel.org/r/[email protected] [3] https://lore.kernel.org/r/[email protected] [4] https://bugzilla.kernel.org/show_bug.cgi?id=215616 This patch (of 16): In case arch_unmap_one() fails, we already did a swap_duplicate(). let's undo that properly via swap_free(). Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Fixes: ca827d5 ("mm, swap: Add infrastructure for saving page metadata on swap") Signed-off-by: David Hildenbrand <[email protected]> Reviewed-by: Khalid Aziz <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: David Rientjes <[email protected]> Cc: Shakeel Butt <[email protected]> Cc: John Hubbard <[email protected]> Cc: Jason Gunthorpe <[email protected]> Cc: Mike Kravetz <[email protected]> Cc: Mike Rapoport <[email protected]> Cc: Yang Shi <[email protected]> Cc: "Kirill A. Shutemov" <[email protected]> Cc: Matthew Wilcox (Oracle) <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: Jann Horn <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Nadav Amit <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Andrea Arcangeli <[email protected]> Cc: Peter Xu <[email protected]> Cc: Don Dutile <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Jan Kara <[email protected]> Cc: Liang Zhang <[email protected]> Cc: Pedro Demarchi Gomes <[email protected]> Cc: Oded Gabbay <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Apr 29, 2022
…ne() failed Patch series "mm: COW fixes part 2: reliable GUP pins of anonymous pages", v4. This series is the result of the discussion on the previous approach [2]. More information on the general COW issues can be found there. It is based on latest linus/master (post v5.17, with relevant core-MM changes for v5.18-rc1). This series fixes memory corruptions when a GUP pin (FOLL_PIN) was taken on an anonymous page and COW logic fails to detect exclusivity of the page to then replacing the anonymous page by a copy in the page table: The GUP pin lost synchronicity with the pages mapped into the page tables. This issue, including other related COW issues, has been summarized in [3] under 3): " 3. Intra Process Memory Corruptions due to Wrong COW (FOLL_PIN) page_maybe_dma_pinned() is used to check if a page may be pinned for DMA (using FOLL_PIN instead of FOLL_GET). While false positives are tolerable, false negatives are problematic: pages that are pinned for DMA must not be added to the swapcache. If it happens, the (now pinned) page could be faulted back from the swapcache into page tables read-only. Future write-access would detect the pinning and COW the page, losing synchronicity. For the interested reader, this is nicely documented in feb889f ("mm: don't put pinned pages into the swap cache"). Peter reports [8] that page_maybe_dma_pinned() as used is racy in some cases and can result in a violation of the documented semantics: giving false negatives because of the race. There are cases where we call it without properly taking a per-process sequence lock, turning the usage of page_maybe_dma_pinned() racy. While one case (clear_refs SOFTDIRTY tracking, see below) seems to be easy to handle, there is especially one rmap case (shrink_page_list) that's hard to fix: in the rmap world, we're not limited to a single process. The shrink_page_list() issue is really subtle. If we race with someone pinning a page, we can trigger the same issue as in the FOLL_GET case. See the detail section at the end of this mail on a discussion how bad this can bite us with VFIO or other FOLL_PIN user. It's harder to reproduce, but I managed to modify the O_DIRECT reproducer to use io_uring fixed buffers [15] instead, which ends up using FOLL_PIN | FOLL_WRITE | FOLL_LONGTERM to pin buffer pages and can similarly trigger a loss of synchronicity and consequently a memory corruption. Again, the root issue is that a write-fault on a page that has additional references results in a COW and thereby a loss of synchronicity and consequently a memory corruption if two parties believe they are referencing the same page. " This series makes GUP pins (R/O and R/W) on anonymous pages fully reliable, especially also taking care of concurrent pinning via GUP-fast, for example, also fully fixing an issue reported regarding NUMA balancing [4] recently. While doing that, it further reduces "unnecessary COWs", especially when we don't fork()/KSM and don't swapout, and fixes the COW security for hugetlb for FOLL_PIN. In summary, we track via a pageflag (PG_anon_exclusive) whether a mapped anonymous page is exclusive. Exclusive anonymous pages that are mapped R/O can directly be mapped R/W by the COW logic in the write fault handler. Exclusive anonymous pages that want to be shared (fork(), KSM) first have to be marked shared -- which will fail if there are GUP pins on the page. GUP is only allowed to take a pin on anonymous pages that are exclusive. The PT lock is the primary mechanism to synchronize modifications of PG_anon_exclusive. We synchronize against GUP-fast either via the src_mm->write_protect_seq (during fork()) or via clear/invalidate+flush of the relevant page table entry. Special care has to be taken about swap, migration, and THPs (whereby a PMD-mapping can be converted to a PTE mapping and we have to track information for subpages). Besides these, we let the rmap code handle most magic. For reliable R/O pins of anonymous pages, we need FAULT_FLAG_UNSHARE logic as part of our previous approach [2], however, it's now 100% mapcount free and I further simplified it a bit. #1 is a fix #3-#10 are mostly rmap preparations for PG_anon_exclusive handling #11 introduces PG_anon_exclusive #12 uses PG_anon_exclusive and make R/W pins of anonymous pages reliable #13 is a preparation for reliable R/O pins #14 and #15 is reused/modified GUP-triggered unsharing for R/O GUP pins make R/O pins of anonymous pages reliable #16 adds sanity check when (un)pinning anonymous pages [1] https://lkml.kernel.org/r/[email protected] [2] https://lkml.kernel.org/r/[email protected] [3] https://lore.kernel.org/r/[email protected] [4] https://bugzilla.kernel.org/show_bug.cgi?id=215616 This patch (of 17): In case arch_unmap_one() fails, we already did a swap_duplicate(). let's undo that properly via swap_free(). Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Fixes: ca827d5 ("mm, swap: Add infrastructure for saving page metadata on swap") Signed-off-by: David Hildenbrand <[email protected]> Reviewed-by: Khalid Aziz <[email protected]> Acked-by: Vlastimil Babka <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: David Rientjes <[email protected]> Cc: Shakeel Butt <[email protected]> Cc: John Hubbard <[email protected]> Cc: Jason Gunthorpe <[email protected]> Cc: Mike Kravetz <[email protected]> Cc: Mike Rapoport <[email protected]> Cc: Yang Shi <[email protected]> Cc: "Kirill A. Shutemov" <[email protected]> Cc: "Matthew Wilcox (Oracle)" <[email protected]> Cc: Jann Horn <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Nadav Amit <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Andrea Arcangeli <[email protected]> Cc: Peter Xu <[email protected]> Cc: Don Dutile <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Jan Kara <[email protected]> Cc: Liang Zhang <[email protected]> Cc: Pedro Demarchi Gomes <[email protected]> Cc: Oded Gabbay <[email protected]> Cc: David Hildenbrand <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
May 2, 2022
…ne() failed Patch series "mm: COW fixes part 2: reliable GUP pins of anonymous pages", v4. This series is the result of the discussion on the previous approach [2]. More information on the general COW issues can be found there. It is based on latest linus/master (post v5.17, with relevant core-MM changes for v5.18-rc1). This series fixes memory corruptions when a GUP pin (FOLL_PIN) was taken on an anonymous page and COW logic fails to detect exclusivity of the page to then replacing the anonymous page by a copy in the page table: The GUP pin lost synchronicity with the pages mapped into the page tables. This issue, including other related COW issues, has been summarized in [3] under 3): " 3. Intra Process Memory Corruptions due to Wrong COW (FOLL_PIN) page_maybe_dma_pinned() is used to check if a page may be pinned for DMA (using FOLL_PIN instead of FOLL_GET). While false positives are tolerable, false negatives are problematic: pages that are pinned for DMA must not be added to the swapcache. If it happens, the (now pinned) page could be faulted back from the swapcache into page tables read-only. Future write-access would detect the pinning and COW the page, losing synchronicity. For the interested reader, this is nicely documented in feb889f ("mm: don't put pinned pages into the swap cache"). Peter reports [8] that page_maybe_dma_pinned() as used is racy in some cases and can result in a violation of the documented semantics: giving false negatives because of the race. There are cases where we call it without properly taking a per-process sequence lock, turning the usage of page_maybe_dma_pinned() racy. While one case (clear_refs SOFTDIRTY tracking, see below) seems to be easy to handle, there is especially one rmap case (shrink_page_list) that's hard to fix: in the rmap world, we're not limited to a single process. The shrink_page_list() issue is really subtle. If we race with someone pinning a page, we can trigger the same issue as in the FOLL_GET case. See the detail section at the end of this mail on a discussion how bad this can bite us with VFIO or other FOLL_PIN user. It's harder to reproduce, but I managed to modify the O_DIRECT reproducer to use io_uring fixed buffers [15] instead, which ends up using FOLL_PIN | FOLL_WRITE | FOLL_LONGTERM to pin buffer pages and can similarly trigger a loss of synchronicity and consequently a memory corruption. Again, the root issue is that a write-fault on a page that has additional references results in a COW and thereby a loss of synchronicity and consequently a memory corruption if two parties believe they are referencing the same page. " This series makes GUP pins (R/O and R/W) on anonymous pages fully reliable, especially also taking care of concurrent pinning via GUP-fast, for example, also fully fixing an issue reported regarding NUMA balancing [4] recently. While doing that, it further reduces "unnecessary COWs", especially when we don't fork()/KSM and don't swapout, and fixes the COW security for hugetlb for FOLL_PIN. In summary, we track via a pageflag (PG_anon_exclusive) whether a mapped anonymous page is exclusive. Exclusive anonymous pages that are mapped R/O can directly be mapped R/W by the COW logic in the write fault handler. Exclusive anonymous pages that want to be shared (fork(), KSM) first have to be marked shared -- which will fail if there are GUP pins on the page. GUP is only allowed to take a pin on anonymous pages that are exclusive. The PT lock is the primary mechanism to synchronize modifications of PG_anon_exclusive. We synchronize against GUP-fast either via the src_mm->write_protect_seq (during fork()) or via clear/invalidate+flush of the relevant page table entry. Special care has to be taken about swap, migration, and THPs (whereby a PMD-mapping can be converted to a PTE mapping and we have to track information for subpages). Besides these, we let the rmap code handle most magic. For reliable R/O pins of anonymous pages, we need FAULT_FLAG_UNSHARE logic as part of our previous approach [2], however, it's now 100% mapcount free and I further simplified it a bit. #1 is a fix #3-#10 are mostly rmap preparations for PG_anon_exclusive handling #11 introduces PG_anon_exclusive #12 uses PG_anon_exclusive and make R/W pins of anonymous pages reliable #13 is a preparation for reliable R/O pins #14 and #15 is reused/modified GUP-triggered unsharing for R/O GUP pins make R/O pins of anonymous pages reliable #16 adds sanity check when (un)pinning anonymous pages [1] https://lkml.kernel.org/r/[email protected] [2] https://lkml.kernel.org/r/[email protected] [3] https://lore.kernel.org/r/[email protected] [4] https://bugzilla.kernel.org/show_bug.cgi?id=215616 This patch (of 17): In case arch_unmap_one() fails, we already did a swap_duplicate(). let's undo that properly via swap_free(). Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Fixes: ca827d5 ("mm, swap: Add infrastructure for saving page metadata on swap") Signed-off-by: David Hildenbrand <[email protected]> Reviewed-by: Khalid Aziz <[email protected]> Acked-by: Vlastimil Babka <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: David Rientjes <[email protected]> Cc: Shakeel Butt <[email protected]> Cc: John Hubbard <[email protected]> Cc: Jason Gunthorpe <[email protected]> Cc: Mike Kravetz <[email protected]> Cc: Mike Rapoport <[email protected]> Cc: Yang Shi <[email protected]> Cc: "Kirill A. Shutemov" <[email protected]> Cc: "Matthew Wilcox (Oracle)" <[email protected]> Cc: Jann Horn <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Nadav Amit <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Andrea Arcangeli <[email protected]> Cc: Peter Xu <[email protected]> Cc: Don Dutile <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Jan Kara <[email protected]> Cc: Liang Zhang <[email protected]> Cc: Pedro Demarchi Gomes <[email protected]> Cc: Oded Gabbay <[email protected]> Cc: David Hildenbrand <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
May 11, 2022
…ne() failed Patch series "mm: COW fixes part 2: reliable GUP pins of anonymous pages", v4. This series is the result of the discussion on the previous approach [2]. More information on the general COW issues can be found there. It is based on latest linus/master (post v5.17, with relevant core-MM changes for v5.18-rc1). This series fixes memory corruptions when a GUP pin (FOLL_PIN) was taken on an anonymous page and COW logic fails to detect exclusivity of the page to then replacing the anonymous page by a copy in the page table: The GUP pin lost synchronicity with the pages mapped into the page tables. This issue, including other related COW issues, has been summarized in [3] under 3): " 3. Intra Process Memory Corruptions due to Wrong COW (FOLL_PIN) page_maybe_dma_pinned() is used to check if a page may be pinned for DMA (using FOLL_PIN instead of FOLL_GET). While false positives are tolerable, false negatives are problematic: pages that are pinned for DMA must not be added to the swapcache. If it happens, the (now pinned) page could be faulted back from the swapcache into page tables read-only. Future write-access would detect the pinning and COW the page, losing synchronicity. For the interested reader, this is nicely documented in feb889f ("mm: don't put pinned pages into the swap cache"). Peter reports [8] that page_maybe_dma_pinned() as used is racy in some cases and can result in a violation of the documented semantics: giving false negatives because of the race. There are cases where we call it without properly taking a per-process sequence lock, turning the usage of page_maybe_dma_pinned() racy. While one case (clear_refs SOFTDIRTY tracking, see below) seems to be easy to handle, there is especially one rmap case (shrink_page_list) that's hard to fix: in the rmap world, we're not limited to a single process. The shrink_page_list() issue is really subtle. If we race with someone pinning a page, we can trigger the same issue as in the FOLL_GET case. See the detail section at the end of this mail on a discussion how bad this can bite us with VFIO or other FOLL_PIN user. It's harder to reproduce, but I managed to modify the O_DIRECT reproducer to use io_uring fixed buffers [15] instead, which ends up using FOLL_PIN | FOLL_WRITE | FOLL_LONGTERM to pin buffer pages and can similarly trigger a loss of synchronicity and consequently a memory corruption. Again, the root issue is that a write-fault on a page that has additional references results in a COW and thereby a loss of synchronicity and consequently a memory corruption if two parties believe they are referencing the same page. " This series makes GUP pins (R/O and R/W) on anonymous pages fully reliable, especially also taking care of concurrent pinning via GUP-fast, for example, also fully fixing an issue reported regarding NUMA balancing [4] recently. While doing that, it further reduces "unnecessary COWs", especially when we don't fork()/KSM and don't swapout, and fixes the COW security for hugetlb for FOLL_PIN. In summary, we track via a pageflag (PG_anon_exclusive) whether a mapped anonymous page is exclusive. Exclusive anonymous pages that are mapped R/O can directly be mapped R/W by the COW logic in the write fault handler. Exclusive anonymous pages that want to be shared (fork(), KSM) first have to be marked shared -- which will fail if there are GUP pins on the page. GUP is only allowed to take a pin on anonymous pages that are exclusive. The PT lock is the primary mechanism to synchronize modifications of PG_anon_exclusive. We synchronize against GUP-fast either via the src_mm->write_protect_seq (during fork()) or via clear/invalidate+flush of the relevant page table entry. Special care has to be taken about swap, migration, and THPs (whereby a PMD-mapping can be converted to a PTE mapping and we have to track information for subpages). Besides these, we let the rmap code handle most magic. For reliable R/O pins of anonymous pages, we need FAULT_FLAG_UNSHARE logic as part of our previous approach [2], however, it's now 100% mapcount free and I further simplified it a bit. #1 is a fix #3-#10 are mostly rmap preparations for PG_anon_exclusive handling #11 introduces PG_anon_exclusive #12 uses PG_anon_exclusive and make R/W pins of anonymous pages reliable #13 is a preparation for reliable R/O pins #14 and #15 is reused/modified GUP-triggered unsharing for R/O GUP pins make R/O pins of anonymous pages reliable #16 adds sanity check when (un)pinning anonymous pages [1] https://lkml.kernel.org/r/[email protected] [2] https://lkml.kernel.org/r/[email protected] [3] https://lore.kernel.org/r/[email protected] [4] https://bugzilla.kernel.org/show_bug.cgi?id=215616 This patch (of 17): In case arch_unmap_one() fails, we already did a swap_duplicate(). let's undo that properly via swap_free(). Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Fixes: ca827d5 ("mm, swap: Add infrastructure for saving page metadata on swap") Signed-off-by: David Hildenbrand <[email protected]> Reviewed-by: Khalid Aziz <[email protected]> Acked-by: Vlastimil Babka <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: David Rientjes <[email protected]> Cc: Shakeel Butt <[email protected]> Cc: John Hubbard <[email protected]> Cc: Jason Gunthorpe <[email protected]> Cc: Mike Kravetz <[email protected]> Cc: Mike Rapoport <[email protected]> Cc: Yang Shi <[email protected]> Cc: "Kirill A. Shutemov" <[email protected]> Cc: "Matthew Wilcox (Oracle)" <[email protected]> Cc: Jann Horn <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Nadav Amit <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Andrea Arcangeli <[email protected]> Cc: Peter Xu <[email protected]> Cc: Don Dutile <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Jan Kara <[email protected]> Cc: Liang Zhang <[email protected]> Cc: Pedro Demarchi Gomes <[email protected]> Cc: Oded Gabbay <[email protected]> Cc: David Hildenbrand <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
May 11, 2022
The pty_write() invokes kmalloc() which may invoke a normal printk() to print failure message. This can cause a deadlock in the scenario reported by syz-bot below: CPU0 CPU1 CPU2 ---- ---- ---- lock(console_owner); lock(&port_lock_key); lock(&port->lock); lock(&port_lock_key); lock(&port->lock); lock(console_owner); As commit dbdda84 ("printk: Add console owner and waiter logic to load balance console writes") said, such deadlock can be prevented by using printk_deferred() in kmalloc() (which is invoked in the section guarded by the port->lock). But there are too many printk() on the kmalloc() path, and kmalloc() can be called from anywhere, so changing printk() to printk_deferred() is too complicated and inelegant. Therefore, this patch chooses to specify __GFP_NOWARN to kmalloc(), so that printk() will not be called, and this deadlock problem can be avoided. Syz-bot reported the following lockdep error: ====================================================== WARNING: possible circular locking dependency detected 5.4.143-00237-g08ccc19a-dirty #10 Not tainted ------------------------------------------------------ syz-executor.4/29420 is trying to acquire lock: ffffffff8aedb2a0 (console_owner){....}-{0:0}, at: console_trylock_spinning kernel/printk/printk.c:1752 [inline] ffffffff8aedb2a0 (console_owner){....}-{0:0}, at: vprintk_emit+0x2ca/0x470 kernel/printk/printk.c:2023 but task is already holding lock: ffff8880119c9158 (&port->lock){-.-.}-{2:2}, at: pty_write+0xf4/0x1f0 drivers/tty/pty.c:120 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&port->lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x35/0x50 kernel/locking/spinlock.c:159 tty_port_tty_get drivers/tty/tty_port.c:288 [inline] <-- lock(&port->lock); tty_port_default_wakeup+0x1d/0xb0 drivers/tty/tty_port.c:47 serial8250_tx_chars+0x530/0xa80 drivers/tty/serial/8250/8250_port.c:1767 serial8250_handle_irq.part.0+0x31f/0x3d0 drivers/tty/serial/8250/8250_port.c:1854 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1827 [inline] <-- lock(&port_lock_key); serial8250_default_handle_irq+0xb2/0x220 drivers/tty/serial/8250/8250_port.c:1870 serial8250_interrupt+0xfd/0x200 drivers/tty/serial/8250/8250_core.c:126 __handle_irq_event_percpu+0x109/0xa50 kernel/irq/handle.c:156 handle_irq_event_percpu+0x76/0x170 kernel/irq/handle.c:196 handle_irq_event+0xa1/0x130 kernel/irq/handle.c:213 handle_edge_irq+0x261/0xd00 kernel/irq/chip.c:833 generic_handle_irq_desc include/linux/irqdesc.h:156 [inline] do_IRQ+0xf2/0x2e0 arch/x86/kernel/irq.c:250 ret_from_intr+0x0/0x19 native_safe_halt arch/x86/include/asm/irqflags.h:60 [inline] arch_safe_halt arch/x86/include/asm/irqflags.h:103 [inline] default_idle+0x2c/0x1a0 arch/x86/kernel/process.c:572 cpuidle_idle_call kernel/sched/idle.c:184 [inline] do_idle+0x44c/0x590 kernel/sched/idle.c:294 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:386 start_secondary+0x2d1/0x3e0 arch/x86/kernel/smpboot.c:264 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241 -> #1 (&port_lock_key){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x35/0x50 kernel/locking/spinlock.c:159 serial8250_console_write+0x184/0xa40 drivers/tty/serial/8250/8250_port.c:3198 <-- lock(&port_lock_key); call_console_drivers kernel/printk/printk.c:1819 [inline] console_unlock+0x8cb/0xd00 kernel/printk/printk.c:2504 vprintk_emit+0x1b5/0x470 kernel/printk/printk.c:2024 <-- lock(console_owner); vprintk_func+0x8d/0x250 kernel/printk/printk_safe.c:394 printk+0xba/0xed kernel/printk/printk.c:2084 register_console+0x8b3/0xc10 kernel/printk/printk.c:2829 univ8250_console_init+0x3a/0x46 drivers/tty/serial/8250/8250_core.c:681 console_init+0x49d/0x6d3 kernel/printk/printk.c:2915 start_kernel+0x5e9/0x879 init/main.c:713 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241 -> #0 (console_owner){....}-{0:0}: check_prev_add kernel/locking/lockdep.c:2600 [inline] check_prevs_add kernel/locking/lockdep.c:2705 [inline] validate_chain kernel/locking/lockdep.c:3095 [inline] __lock_acquire+0x27e6/0x4cc0 kernel/locking/lockdep.c:4200 lock_acquire+0x127/0x340 kernel/locking/lockdep.c:4734 console_trylock_spinning kernel/printk/printk.c:1773 [inline] <-- lock(console_owner); vprintk_emit+0x307/0x470 kernel/printk/printk.c:2023 vprintk_func+0x8d/0x250 kernel/printk/printk_safe.c:394 printk+0xba/0xed kernel/printk/printk.c:2084 fail_dump lib/fault-inject.c:45 [inline] should_fail+0x67b/0x7c0 lib/fault-inject.c:144 __should_failslab+0x152/0x1c0 mm/failslab.c:33 should_failslab+0x5/0x10 mm/slab_common.c:1224 slab_pre_alloc_hook mm/slab.h:468 [inline] slab_alloc_node mm/slub.c:2723 [inline] slab_alloc mm/slub.c:2807 [inline] __kmalloc+0x72/0x300 mm/slub.c:3871 kmalloc include/linux/slab.h:582 [inline] tty_buffer_alloc+0x23f/0x2a0 drivers/tty/tty_buffer.c:175 __tty_buffer_request_room+0x156/0x2a0 drivers/tty/tty_buffer.c:273 tty_insert_flip_string_fixed_flag+0x93/0x250 drivers/tty/tty_buffer.c:318 tty_insert_flip_string include/linux/tty_flip.h:37 [inline] pty_write+0x126/0x1f0 drivers/tty/pty.c:122 <-- lock(&port->lock); n_tty_write+0xa7a/0xfc0 drivers/tty/n_tty.c:2356 do_tty_write drivers/tty/tty_io.c:961 [inline] tty_write+0x512/0x930 drivers/tty/tty_io.c:1045 __vfs_write+0x76/0x100 fs/read_write.c:494 vfs_write+0x268/0x5c0 fs/read_write.c:558 ksys_write+0x12d/0x250 fs/read_write.c:611 do_syscall_64+0xd7/0x380 arch/x86/entry/common.c:291 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Chain exists of: console_owner --> &port_lock_key --> &port->lock Link: https://lkml.kernel.org/r/[email protected] Fixes: b6da31b ("tty: Fix data race in tty_insert_flip_string_fixed_flag") Signed-off-by: Qi Zheng <[email protected]> Cc: Akinobu Mita <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: Jiri Slaby <[email protected]> Cc: Steven Rostedt (Google) <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
May 12, 2022
pty_write() invokes kmalloc() which may invoke a normal printk() to print failure message. This can cause a deadlock in the scenario reported by syz-bot below: CPU0 CPU1 CPU2 ---- ---- ---- lock(console_owner); lock(&port_lock_key); lock(&port->lock); lock(&port_lock_key); lock(&port->lock); lock(console_owner); As commit dbdda84 ("printk: Add console owner and waiter logic to load balance console writes") said, such deadlock can be prevented by using printk_deferred() in kmalloc() (which is invoked in the section guarded by the port->lock). But there are too many printk() on the kmalloc() path, and kmalloc() can be called from anywhere, so changing printk() to printk_deferred() is too complicated and inelegant. Therefore, this patch chooses to specify __GFP_NOWARN to kmalloc(), so that printk() will not be called, and this deadlock problem can be avoided. Syzbot reported the following lockdep error: ====================================================== WARNING: possible circular locking dependency detected 5.4.143-00237-g08ccc19a-dirty #10 Not tainted ------------------------------------------------------ syz-executor.4/29420 is trying to acquire lock: ffffffff8aedb2a0 (console_owner){....}-{0:0}, at: console_trylock_spinning kernel/printk/printk.c:1752 [inline] ffffffff8aedb2a0 (console_owner){....}-{0:0}, at: vprintk_emit+0x2ca/0x470 kernel/printk/printk.c:2023 but task is already holding lock: ffff8880119c9158 (&port->lock){-.-.}-{2:2}, at: pty_write+0xf4/0x1f0 drivers/tty/pty.c:120 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&port->lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x35/0x50 kernel/locking/spinlock.c:159 tty_port_tty_get drivers/tty/tty_port.c:288 [inline] <-- lock(&port->lock); tty_port_default_wakeup+0x1d/0xb0 drivers/tty/tty_port.c:47 serial8250_tx_chars+0x530/0xa80 drivers/tty/serial/8250/8250_port.c:1767 serial8250_handle_irq.part.0+0x31f/0x3d0 drivers/tty/serial/8250/8250_port.c:1854 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1827 [inline] <-- lock(&port_lock_key); serial8250_default_handle_irq+0xb2/0x220 drivers/tty/serial/8250/8250_port.c:1870 serial8250_interrupt+0xfd/0x200 drivers/tty/serial/8250/8250_core.c:126 __handle_irq_event_percpu+0x109/0xa50 kernel/irq/handle.c:156 [...] -> #1 (&port_lock_key){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x35/0x50 kernel/locking/spinlock.c:159 serial8250_console_write+0x184/0xa40 drivers/tty/serial/8250/8250_port.c:3198 <-- lock(&port_lock_key); call_console_drivers kernel/printk/printk.c:1819 [inline] console_unlock+0x8cb/0xd00 kernel/printk/printk.c:2504 vprintk_emit+0x1b5/0x470 kernel/printk/printk.c:2024 <-- lock(console_owner); vprintk_func+0x8d/0x250 kernel/printk/printk_safe.c:394 printk+0xba/0xed kernel/printk/printk.c:2084 register_console+0x8b3/0xc10 kernel/printk/printk.c:2829 univ8250_console_init+0x3a/0x46 drivers/tty/serial/8250/8250_core.c:681 console_init+0x49d/0x6d3 kernel/printk/printk.c:2915 start_kernel+0x5e9/0x879 init/main.c:713 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241 -> #0 (console_owner){....}-{0:0}: [...] lock_acquire+0x127/0x340 kernel/locking/lockdep.c:4734 console_trylock_spinning kernel/printk/printk.c:1773 [inline] <-- lock(console_owner); vprintk_emit+0x307/0x470 kernel/printk/printk.c:2023 vprintk_func+0x8d/0x250 kernel/printk/printk_safe.c:394 printk+0xba/0xed kernel/printk/printk.c:2084 fail_dump lib/fault-inject.c:45 [inline] should_fail+0x67b/0x7c0 lib/fault-inject.c:144 __should_failslab+0x152/0x1c0 mm/failslab.c:33 should_failslab+0x5/0x10 mm/slab_common.c:1224 slab_pre_alloc_hook mm/slab.h:468 [inline] slab_alloc_node mm/slub.c:2723 [inline] slab_alloc mm/slub.c:2807 [inline] __kmalloc+0x72/0x300 mm/slub.c:3871 kmalloc include/linux/slab.h:582 [inline] tty_buffer_alloc+0x23f/0x2a0 drivers/tty/tty_buffer.c:175 __tty_buffer_request_room+0x156/0x2a0 drivers/tty/tty_buffer.c:273 tty_insert_flip_string_fixed_flag+0x93/0x250 drivers/tty/tty_buffer.c:318 tty_insert_flip_string include/linux/tty_flip.h:37 [inline] pty_write+0x126/0x1f0 drivers/tty/pty.c:122 <-- lock(&port->lock); n_tty_write+0xa7a/0xfc0 drivers/tty/n_tty.c:2356 do_tty_write drivers/tty/tty_io.c:961 [inline] tty_write+0x512/0x930 drivers/tty/tty_io.c:1045 __vfs_write+0x76/0x100 fs/read_write.c:494 [...] other info that might help us debug this: Chain exists of: console_owner --> &port_lock_key --> &port->lock Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Fixes: b6da31b ("tty: Fix data race in tty_insert_flip_string_fixed_flag") Signed-off-by: Qi Zheng <[email protected]> Acked-by: Jiri Slaby <[email protected]> Acked-by: Greg Kroah-Hartman <[email protected]> Cc: Akinobu Mita <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: Steven Rostedt (Google) <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
May 20, 2022
Do not allow to write timestamps on RX rings if PF is being configured. When PF is being configured RX rings can be freed or rebuilt. If at the same time timestamps are updated, the kernel will crash by dereferencing null RX ring pointer. PID: 1449 TASK: ff187d28ed658040 CPU: 34 COMMAND: "ice-ptp-0000:51" #0 [ff1966a94a713bb0] machine_kexec at ffffffff9d05a0be #1 [ff1966a94a713c08] __crash_kexec at ffffffff9d192e9d #2 [ff1966a94a713cd0] crash_kexec at ffffffff9d1941bd #3 [ff1966a94a713ce8] oops_end at ffffffff9d01bd54 #4 [ff1966a94a713d08] no_context at ffffffff9d06bda4 #5 [ff1966a94a713d60] __bad_area_nosemaphore at ffffffff9d06c10c #6 [ff1966a94a713da8] do_page_fault at ffffffff9d06cae4 #7 [ff1966a94a713de0] page_fault at ffffffff9da0107e [exception RIP: ice_ptp_update_cached_phctime+91] RIP: ffffffffc076db8b RSP: ff1966a94a713e98 RFLAGS: 00010246 RAX: 16e3db9c6b7ccae4 RBX: ff187d269dd3c180 RCX: ff187d269cd4d018 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ff187d269cfcc644 R8: ff187d339b9641b0 R9: 0000000000000000 R10: 0000000000000002 R11: 0000000000000000 R12: ff187d269cfcc648 R13: ffffffff9f128784 R14: ffffffff9d101b70 R15: ff187d269cfcc640 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #8 [ff1966a94a713ea0] ice_ptp_periodic_work at ffffffffc076dbef [ice] #9 [ff1966a94a713ee0] kthread_worker_fn at ffffffff9d101c1b #10 [ff1966a94a713f10] kthread at ffffffff9d101b4d #11 [ff1966a94a713f50] ret_from_fork at ffffffff9da0023f Fixes: 77a7811 ("ice: enable receive hardware timestamping") Signed-off-by: Arkadiusz Kubalewski <[email protected]> Reviewed-by: Michal Schmidt <[email protected]> Tested-by: Dave Cain <[email protected]> Tested-by: Gurucharan <[email protected]> (A Contingent worker at Intel) Signed-off-by: Tony Nguyen <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
May 23, 2022
There's a locking issue with the per-netns list of calls in rxrpc. The pieces of code that add and remove a call from the list use write_lock() and the calls procfile uses read_lock() to access it. However, the timer callback function may trigger a removal by trying to queue a call for processing and finding that it's already queued - at which point it has a spare refcount that it has to do something with. Unfortunately, if it puts the call and this reduces the refcount to 0, the call will be removed from the list. Unfortunately, since the _bh variants of the locking functions aren't used, this can deadlock. ================================ WARNING: inconsistent lock state 5.18.0-rc3-build4+ #10 Not tainted -------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. ksoftirqd/2/25 [HC0[0]:SC1[1]:HE1:SE0] takes: ffff888107ac4038 (&rxnet->call_lock){+.?.}-{2:2}, at: rxrpc_put_call+0x103/0x14b {SOFTIRQ-ON-W} state was registered at: ... Possible unsafe locking scenario: CPU0 ---- lock(&rxnet->call_lock); <Interrupt> lock(&rxnet->call_lock); *** DEADLOCK *** 1 lock held by ksoftirqd/2/25: #0: ffff8881008ffdb0 ((&call->timer)){+.-.}-{0:0}, at: call_timer_fn+0x5/0x23d Changes ======= ver #2) - Changed to using list_next_rcu() rather than rcu_dereference() directly. Fixes: 17926a7 ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both") Signed-off-by: David Howells <[email protected]> cc: Marc Dionne <[email protected]> cc: [email protected] Signed-off-by: David S. Miller <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Jun 21, 2022
Ido Schimmel says: ==================== mlxsw: L3 HW stats improvements While testing L3 HW stats [1] on top of mlxsw, two issues were found: 1. Stats cannot be enabled for more than 205 netdevs. This was fixed in commit 4b7a632 ("mlxsw: spectrum_cnt: Reorder counter pools"). 2. ARP packets are counted as errors. Patch #1 takes care of that. See the commit message for details. The goal of the majority of the rest of the patches is to add selftests that would have discovered that only about 205 netdevs can have L3 HW stats supported, despite the HW supporting much more. The obvious place to plug this in is the scale test framework. The scale tests are currently testing two things: that some number of instances of a given resource can actually be created; and that when an attempt is made to create more than the supported amount, the failures are noted and handled gracefully. However the ability to allocate the resource does not mean that the resource actually works when passing traffic. For that, make it possible for a given scale to also test traffic. To that end, this patchset adds traffic tests. The goal of these is to run traffic and observe whether a sample of the allocated resource instances actually perform their task. Traffic tests are only run on the positive leg of the scale test (no point trying to pass traffic when the expected outcome is that the resource will not be allocated). They are opt-in, if a given test does not expose it, it is not run. The patchset proceeds as follows: - Patches #2 and #3 add to "devlink resource" support for number of allocated RIFs, and the capacity. This is necessary, because when evaluating how many L3 HW stats instances it should be possible to allocate, the limiting resource on Spectrum-2 and above currently is not the counters themselves, but actually the RIFs. - Patch #6 adds support for invocation of a traffic test, if a given scale tests exposes it. - Patch #7 adds support for skipping a given scale test. Because on Spectrum-2 and above, the limiting factor to L3 HW stats instances is actually the number of RIFs, there is no point in running the failing leg of a scale tests, because it would test exhaustion of RIFs, not of RIF counters. - With patch #8, the scale tests drivers pass the target number to the cleanup function of a scale test. - In patch #9, add a traffic test to the tc_flower selftests. This makes sure that the flow counters installed with the ACLs actually do count as they are supposed to. - In patch #10, add a new scale selftest for RIF counter scale, including a traffic test. - In patch #11, the scale target for the tc_flower selftest is dynamically set instead of being hard coded. [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ca0a53dcec9495d1dc5bbc369c810c520d728373 ==================== Signed-off-by: David S. Miller <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Jun 23, 2022
Ido Schimmel says: ==================== mlxsw: Unified bridge conversion - part 2/6 This is the second part of the conversion of mlxsw to the unified bridge model. Part 1 was merged in commit 4336487 ("Merge branch 'mlxsw-unified-bridge-conversion-part-1'") which includes details about the new model and the motivation behind the conversion. This patchset does not begin the conversion, but rather prepares the code base for it. Patchset overview: Patch #1 removes an unnecessary field from one of the FID families. Patches #2-#7 make various improvements in the layer 2 multicast code, making it more receptive towards upcoming changes. Patches #8-#10 prepare the CONFIG_PROFILE command for the unified bridge model. This command will be used to enable the new model in the last patchset. Patches #11-#13 perform small changes in the FID code, preparing it for upcoming changes. ==================== Signed-off-by: David S. Miller <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Jul 5, 2022
Ido Schimmel says: ==================== mlxsw: Unified bridge conversion - part 6/6 This is the sixth and final part of the conversion of mlxsw to the unified bridge model. It transitions the last bits of functionality that were under firmware's responsibility in the legacy model to the driver. The last patches flip the driver to the unified bridge model and clean up code that was used to make the conversion easier to review. Patchset overview: Patch #1 sets the egress VID for known unicast packets. For multicast packets, the egress VID is configured using the MPE table. See commit 8c2da08 ("mlxsw: spectrum_fid: Configure egress VID classification for multicast"). Patch #2 configures the VNI to FID classification that is used during decapsulation. Patch #3 configures ingress router interface (RIF) in FID classification records, so that when a packet reaches the router block, its ingress RIF is known. Care is taken to configure this in all the different flows (e.g., RIF set on a FID, {Port, VID} joins a FID that already has a RIF etc.). Patch #4 configures the egress VID for routed packets. For such packets, the egress VID is not set by the MPE table or by an FDB record at the egress bridge, but instead by a dedicated table that maps {Egress RIF, Egress port} to a VID. Patch #5 removes VID configuration from RIF creation as in the unified bridge model firmware no longer needs it. Patch #6 sets the egress FID to use in RIF configuration so that the device knows using which FID to bridge the packet after routing. Patches #7-#9 add a new 802.1Q family and associated VLAN RIFs. In the unified bridge model, we no longer need to emulate 802.1Q FIDs using 802.1D FIDs as VNI can be associated with both. Patches #10-#11 finally flip the driver to the unified bridge model. Patches #12-#13 clean up code that was used to make the conversion easier to review. v2: * Fix build failure [1] in patch #1. [1] https://lore.kernel.org/netdev/[email protected]/ ==================== Signed-off-by: David S. Miller <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Jul 21, 2022
…rr-reporting' Vincent Mailhol says: ==================== can: error: set of fixes and improvement on txerr and rxerr reporting This series is a collection of patches targeting the CAN error counter. The series is split in three blocks (with small relation to each other). Several drivers uses the data[6] and data[7] fields (both of type u8) of the CAN error frame to report those values. However, the maximum size an u8 can hold is 255 and the error counter can exceed this value if bus-off status occurs. As such, the first nine patches of this series make sure that no drivers try to report txerr or rxerr through the CAN error frame when bus-off status is reached. can_frame::data[5..7] are defined as being "controller specific". Controller specific behaviors are not something desirable (portability issue...) The tenth patch of this series specifies how can_frame::data[5..7] should be use and remove any "controller specific" freedom. The eleventh patch adds a flag to notify though can_frame::can_id that data[6..7] were populated (in order to be consistent with other fields). Finally, the twelfth and last patch add three macro values to specify the different error counter threshold with so far was hard-coded as magic numbers in the drivers. N.B.: * patches 1 to 10 are for net (stable). * patches 11 and 12 are for net-next (but depends on patches 1 to 10). ** Changelog ** v1 -> v2: https://lore.kernel.org/all/[email protected] * Fix typo in patch #10: data[7] of CAN error frames is for the RX error counter, not the TX one (this is litteraly a one byte change). ==================== As discussed take the whole series via can-next -> net-next. Link: https://lore.kernel.org/all/[email protected] Signed-off-by: Marc Kleine-Budde <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Jul 26, 2022
Ido Schimmel says: ==================== mlxsw: Spectrum-2 PTP preparations This patchset includes various preparations required for Spectrum-2 PTP support. Most of the changes are non-functional (e.g., renaming, adding registers). The only intentional user visible change is in patch #10 where the PHC time is initialized to zero in accordance with the recommendation of the PTP maintainer. ==================== Signed-off-by: David S. Miller <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Aug 22, 2022
A transaction of type BINDER_TYPE_WEAK_HANDLE can fail to increment the reference for a node. In this case, the target proc normally releases the failed reference upon close as expected. However, if the target is dying in parallel the call will race with binder_deferred_release(), so the target could have released all of its references by now leaving the cleanup of the new failed reference unhandled. The transaction then ends and the target proc gets released making the ref->proc now a dangling pointer. Later on, ref->node is closed and we attempt to take spin_lock(&ref->proc->inner_lock), which leads to the use-after-free bug reported below. Let's fix this by cleaning up the failed reference on the spot instead of relying on the target to do so. ================================================================== BUG: KASAN: use-after-free in _raw_spin_lock+0xa8/0x150 Write of size 4 at addr ffff5ca207094238 by task kworker/1:0/590 CPU: 1 PID: 590 Comm: kworker/1:0 Not tainted 5.19.0-rc8 #10 Hardware name: linux,dummy-virt (DT) Workqueue: events binder_deferred_func Call trace: dump_backtrace.part.0+0x1d0/0x1e0 show_stack+0x18/0x70 dump_stack_lvl+0x68/0x84 print_report+0x2e4/0x61c kasan_report+0xa4/0x110 kasan_check_range+0xfc/0x1a4 __kasan_check_write+0x3c/0x50 _raw_spin_lock+0xa8/0x150 binder_deferred_func+0x5e0/0x9b0 process_one_work+0x38c/0x5f0 worker_thread+0x9c/0x694 kthread+0x188/0x190 ret_from_fork+0x10/0x20 Acked-by: Christian Brauner (Microsoft) <[email protected]> Signed-off-by: Carlos Llamas <[email protected]> Cc: stable <[email protected]> # 4.14+ Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Aug 25, 2022
Fix the following scenario: 1. ethtool -L $IFACE rx 8 tx 96 2. xdpsock -q 10 -t -z Above refers to a case where user would like to attach XSK socket in txonly mode at a queue id that does not have a corresponding Rx queue. At this moment ice's XSK logic is tightly bound to act on a "queue pair", e.g. both Tx and Rx queues at a given queue id are disabled/enabled and both of them will get XSK pool assigned, which is broken for the presented queue configuration. This results in the splat included at the bottom, which is basically an OOB access to Rx ring array. To fix this, allow using the ids only in scope of "combined" queues reported by ethtool. However, logic should be rewritten to allow such configurations later on, which would end up as a complete rewrite of the control path, so let us go with this temporary fix. [420160.558008] BUG: kernel NULL pointer dereference, address: 0000000000000082 [420160.566359] #PF: supervisor read access in kernel mode [420160.572657] #PF: error_code(0x0000) - not-present page [420160.579002] PGD 0 P4D 0 [420160.582756] Oops: 0000 [#1] PREEMPT SMP NOPTI [420160.588396] CPU: 10 PID: 21232 Comm: xdpsock Tainted: G OE 5.19.0-rc7+ #10 [420160.597893] Hardware name: Intel Corporation S2600WFT/S2600WFT, BIOS SE5C620.86B.02.01.0008.031920191559 03/19/2019 [420160.609894] RIP: 0010:ice_xsk_pool_setup+0x44/0x7d0 [ice] [420160.616968] Code: f3 48 83 ec 40 48 8b 4f 20 48 8b 3f 65 48 8b 04 25 28 00 00 00 48 89 44 24 38 31 c0 48 8d 04 ed 00 00 00 00 48 01 c1 48 8b 11 <0f> b7 92 82 00 00 00 48 85 d2 0f 84 2d 75 00 00 48 8d 72 ff 48 85 [420160.639421] RSP: 0018:ffffc9002d2afd48 EFLAGS: 00010282 [420160.646650] RAX: 0000000000000050 RBX: ffff88811d8bdd00 RCX: ffff888112c14ff8 [420160.655893] RDX: 0000000000000000 RSI: ffff88811d8bdd00 RDI: ffff888109861000 [420160.665166] RBP: 000000000000000a R08: 000000000000000a R09: 0000000000000000 [420160.674493] R10: 000000000000889f R11: 0000000000000000 R12: 000000000000000a [420160.683833] R13: 000000000000000a R14: 0000000000000000 R15: ffff888117611828 [420160.693211] FS: 00007fa869fc1f80(0000) GS:ffff8897e0880000(0000) knlGS:0000000000000000 [420160.703645] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [420160.711783] CR2: 0000000000000082 CR3: 00000001d076c001 CR4: 00000000007706e0 [420160.721399] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [420160.731045] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [420160.740707] PKRU: 55555554 [420160.745960] Call Trace: [420160.750962] <TASK> [420160.755597] ? kmalloc_large_node+0x79/0x90 [420160.762703] ? __kmalloc_node+0x3f5/0x4b0 [420160.769341] xp_assign_dev+0xfd/0x210 [420160.775661] ? shmem_file_read_iter+0x29a/0x420 [420160.782896] xsk_bind+0x152/0x490 [420160.788943] __sys_bind+0xd0/0x100 [420160.795097] ? exit_to_user_mode_prepare+0x20/0x120 [420160.802801] __x64_sys_bind+0x16/0x20 [420160.809298] do_syscall_64+0x38/0x90 [420160.815741] entry_SYSCALL_64_after_hwframe+0x63/0xcd [420160.823731] RIP: 0033:0x7fa86a0dd2fb [420160.830264] Code: c3 66 0f 1f 44 00 00 48 8b 15 69 8b 0c 00 f7 d8 64 89 02 b8 ff ff ff ff eb bc 0f 1f 44 00 00 f3 0f 1e fa b8 31 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 3d 8b 0c 00 f7 d8 64 89 01 48 [420160.855410] RSP: 002b:00007ffc1146f618 EFLAGS: 00000246 ORIG_RAX: 0000000000000031 [420160.866366] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa86a0dd2fb [420160.876957] RDX: 0000000000000010 RSI: 00007ffc1146f680 RDI: 0000000000000003 [420160.887604] RBP: 000055d7113a0520 R08: 00007fa868fb8000 R09: 0000000080000000 [420160.898293] R10: 0000000000008001 R11: 0000000000000246 R12: 000055d7113a04e0 [420160.909038] R13: 000055d7113a0320 R14: 000000000000000a R15: 0000000000000000 [420160.919817] </TASK> [420160.925659] Modules linked in: ice(OE) af_packet binfmt_misc nls_iso8859_1 ipmi_ssif intel_rapl_msr intel_rapl_common x86_pkg_temp_thermal intel_powerclamp mei_me coretemp ioatdma mei ipmi_si wmi ipmi_msghandler acpi_pad acpi_power_meter ip_tables x_tables autofs4 ixgbe i40e crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel crypto_simd cryptd ahci mdio dca libahci lpc_ich [last unloaded: ice] [420160.977576] CR2: 0000000000000082 [420160.985037] ---[ end trace 0000000000000000 ]--- [420161.097724] RIP: 0010:ice_xsk_pool_setup+0x44/0x7d0 [ice] [420161.107341] Code: f3 48 83 ec 40 48 8b 4f 20 48 8b 3f 65 48 8b 04 25 28 00 00 00 48 89 44 24 38 31 c0 48 8d 04 ed 00 00 00 00 48 01 c1 48 8b 11 <0f> b7 92 82 00 00 00 48 85 d2 0f 84 2d 75 00 00 48 8d 72 ff 48 85 [420161.134741] RSP: 0018:ffffc9002d2afd48 EFLAGS: 00010282 [420161.144274] RAX: 0000000000000050 RBX: ffff88811d8bdd00 RCX: ffff888112c14ff8 [420161.155690] RDX: 0000000000000000 RSI: ffff88811d8bdd00 RDI: ffff888109861000 [420161.168088] RBP: 000000000000000a R08: 000000000000000a R09: 0000000000000000 [420161.179295] R10: 000000000000889f R11: 0000000000000000 R12: 000000000000000a [420161.190420] R13: 000000000000000a R14: 0000000000000000 R15: ffff888117611828 [420161.201505] FS: 00007fa869fc1f80(0000) GS:ffff8897e0880000(0000) knlGS:0000000000000000 [420161.213628] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [420161.223413] CR2: 0000000000000082 CR3: 00000001d076c001 CR4: 00000000007706e0 [420161.234653] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [420161.245893] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [420161.257052] PKRU: 55555554 Fixes: 2d4238f ("ice: Add support for AF_XDP") Signed-off-by: Maciej Fijalkowski <[email protected]> Tested-by: George Kuruvinakunnel <[email protected]> Signed-off-by: Tony Nguyen <[email protected]>
nathanchance
pushed a commit
that referenced
this issue
Oct 3, 2022
I found a null pointer reference in arch_prepare_kprobe(): # echo 'p cmdline_proc_show' > kprobe_events # echo 'p cmdline_proc_show+16' >> kprobe_events Kernel attempted to read user page (0) - exploit attempt? (uid: 0) BUG: Kernel NULL pointer dereference on read at 0x00000000 Faulting instruction address: 0xc000000000050bfc Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA PowerNV Modules linked in: CPU: 0 PID: 122 Comm: sh Not tainted 6.0.0-rc3-00007-gdcf8e5633e2e #10 NIP: c000000000050bfc LR: c000000000050bec CTR: 0000000000005bdc REGS: c0000000348475b0 TRAP: 0300 Not tainted (6.0.0-rc3-00007-gdcf8e5633e2e) MSR: 9000000000009033 <SF,HV,EE,ME,IR,DR,RI,LE> CR: 88002444 XER: 20040006 CFAR: c00000000022d100 DAR: 0000000000000000 DSISR: 40000000 IRQMASK: 0 ... NIP arch_prepare_kprobe+0x10c/0x2d0 LR arch_prepare_kprobe+0xfc/0x2d0 Call Trace: 0xc0000000012f77a0 (unreliable) register_kprobe+0x3c0/0x7a0 __register_trace_kprobe+0x140/0x1a0 __trace_kprobe_create+0x794/0x1040 trace_probe_create+0xc4/0xe0 create_or_delete_trace_kprobe+0x2c/0x80 trace_parse_run_command+0xf0/0x210 probes_write+0x20/0x40 vfs_write+0xfc/0x450 ksys_write+0x84/0x140 system_call_exception+0x17c/0x3a0 system_call_vectored_common+0xe8/0x278 --- interrupt: 3000 at 0x7fffa5682de0 NIP: 00007fffa5682de0 LR: 0000000000000000 CTR: 0000000000000000 REGS: c000000034847e80 TRAP: 3000 Not tainted (6.0.0-rc3-00007-gdcf8e5633e2e) MSR: 900000000280f033 <SF,HV,VEC,VSX,EE,PR,FP,ME,IR,DR,RI,LE> CR: 44002408 XER: 00000000 The address being probed has some special: cmdline_proc_show: Probe based on ftrace cmdline_proc_show+16: Probe for the next instruction at the ftrace location The ftrace-based kprobe does not generate kprobe::ainsn::insn, it gets set to NULL. In arch_prepare_kprobe() it will check for: ... prev = get_kprobe(p->addr - 1); preempt_enable_no_resched(); if (prev && ppc_inst_prefixed(ppc_inst_read(prev->ainsn.insn))) { ... If prev is based on ftrace, 'ppc_inst_read(prev->ainsn.insn)' will occur with a null pointer reference. At this point prev->addr will not be a prefixed instruction, so the check can be skipped. Check if prev is ftrace-based kprobe before reading 'prev->ainsn.insn' to fix this problem. Fixes: b4657f7 ("powerpc/kprobes: Don't allow breakpoints on suffixes") Signed-off-by: Li Huafei <[email protected]> [mpe: Trim oops] Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
nathanchance
pushed a commit
that referenced
this issue
Oct 20, 2022
ASAN reports an use-after-free in btf_dump_name_dups: ERROR: AddressSanitizer: heap-use-after-free on address 0xffff927006db at pc 0xaaaab5dfb618 bp 0xffffdd89b890 sp 0xffffdd89b928 READ of size 2 at 0xffff927006db thread T0 #0 0xaaaab5dfb614 in __interceptor_strcmp.part.0 (test_progs+0x21b614) #1 0xaaaab635f144 in str_equal_fn tools/lib/bpf/btf_dump.c:127 #2 0xaaaab635e3e0 in hashmap_find_entry tools/lib/bpf/hashmap.c:143 #3 0xaaaab635e72c in hashmap__find tools/lib/bpf/hashmap.c:212 #4 0xaaaab6362258 in btf_dump_name_dups tools/lib/bpf/btf_dump.c:1525 #5 0xaaaab636240c in btf_dump_resolve_name tools/lib/bpf/btf_dump.c:1552 #6 0xaaaab6362598 in btf_dump_type_name tools/lib/bpf/btf_dump.c:1567 #7 0xaaaab6360b48 in btf_dump_emit_struct_def tools/lib/bpf/btf_dump.c:912 #8 0xaaaab6360630 in btf_dump_emit_type tools/lib/bpf/btf_dump.c:798 #9 0xaaaab635f720 in btf_dump__dump_type tools/lib/bpf/btf_dump.c:282 #10 0xaaaab608523c in test_btf_dump_incremental tools/testing/selftests/bpf/prog_tests/btf_dump.c:236 #11 0xaaaab6097530 in test_btf_dump tools/testing/selftests/bpf/prog_tests/btf_dump.c:875 #12 0xaaaab6314ed0 in run_one_test tools/testing/selftests/bpf/test_progs.c:1062 #13 0xaaaab631a0a8 in main tools/testing/selftests/bpf/test_progs.c:1697 #14 0xffff9676d214 in __libc_start_main ../csu/libc-start.c:308 #15 0xaaaab5d65990 (test_progs+0x185990) 0xffff927006db is located 11 bytes inside of 16-byte region [0xffff927006d0,0xffff927006e0) freed by thread T0 here: #0 0xaaaab5e2c7c4 in realloc (test_progs+0x24c7c4) #1 0xaaaab634f4a0 in libbpf_reallocarray tools/lib/bpf/libbpf_internal.h:191 #2 0xaaaab634f840 in libbpf_add_mem tools/lib/bpf/btf.c:163 #3 0xaaaab636643c in strset_add_str_mem tools/lib/bpf/strset.c:106 #4 0xaaaab6366560 in strset__add_str tools/lib/bpf/strset.c:157 #5 0xaaaab6352d70 in btf__add_str tools/lib/bpf/btf.c:1519 #6 0xaaaab6353e10 in btf__add_field tools/lib/bpf/btf.c:2032 #7 0xaaaab6084fcc in test_btf_dump_incremental tools/testing/selftests/bpf/prog_tests/btf_dump.c:232 #8 0xaaaab6097530 in test_btf_dump tools/testing/selftests/bpf/prog_tests/btf_dump.c:875 #9 0xaaaab6314ed0 in run_one_test tools/testing/selftests/bpf/test_progs.c:1062 #10 0xaaaab631a0a8 in main tools/testing/selftests/bpf/test_progs.c:1697 #11 0xffff9676d214 in __libc_start_main ../csu/libc-start.c:308 #12 0xaaaab5d65990 (test_progs+0x185990) previously allocated by thread T0 here: #0 0xaaaab5e2c7c4 in realloc (test_progs+0x24c7c4) #1 0xaaaab634f4a0 in libbpf_reallocarray tools/lib/bpf/libbpf_internal.h:191 #2 0xaaaab634f840 in libbpf_add_mem tools/lib/bpf/btf.c:163 #3 0xaaaab636643c in strset_add_str_mem tools/lib/bpf/strset.c:106 #4 0xaaaab6366560 in strset__add_str tools/lib/bpf/strset.c:157 #5 0xaaaab6352d70 in btf__add_str tools/lib/bpf/btf.c:1519 #6 0xaaaab6353ff0 in btf_add_enum_common tools/lib/bpf/btf.c:2070 #7 0xaaaab6354080 in btf__add_enum tools/lib/bpf/btf.c:2102 #8 0xaaaab6082f50 in test_btf_dump_incremental tools/testing/selftests/bpf/prog_tests/btf_dump.c:162 #9 0xaaaab6097530 in test_btf_dump tools/testing/selftests/bpf/prog_tests/btf_dump.c:875 #10 0xaaaab6314ed0 in run_one_test tools/testing/selftests/bpf/test_progs.c:1062 #11 0xaaaab631a0a8 in main tools/testing/selftests/bpf/test_progs.c:1697 #12 0xffff9676d214 in __libc_start_main ../csu/libc-start.c:308 #13 0xaaaab5d65990 (test_progs+0x185990) The reason is that the key stored in hash table name_map is a string address, and the string memory is allocated by realloc() function, when the memory is resized by realloc() later, the old memory may be freed, so the address stored in name_map references to a freed memory, causing use-after-free. Fix it by storing duplicated string address in name_map. Fixes: 919d2b1 ("libbpf: Allow modification of BTF and add btf__add_str API") Signed-off-by: Xu Kuohai <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Acked-by: Martin KaFai Lau <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
nathanchance
pushed a commit
that referenced
this issue
Nov 11, 2022
Petr Machata says: ==================== mlxsw: Add 802.1X and MAB offload support This patchset adds 802.1X [1] and MAB [2] offload support in mlxsw. Patches #1-#3 add the required switchdev interfaces. Patches #4-#5 add the required packet traps for 802.1X. Patches #6-#10 are small preparations in mlxsw. Patch #11 adds locked bridge port support in mlxsw. Patches #12-#15 add mlxsw selftests. The patchset was also tested with the generic forwarding selftest ('bridge_locked_port.sh'). [1] https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/?id=a21d9a670d81103db7f788de1a4a4a6e4b891a0b [2] https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/?id=a35ec8e38cdd1766f29924ca391a01de20163931 ==================== Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jakub Kicinski <[email protected]>
Sign up for free
to subscribe to this conversation on GitHub.
Already have an account?
Sign in.
The image downloaded from release page works for me, but image built by myself does not work.
The text was updated successfully, but these errors were encountered: