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Litespi cs handling #4

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@mczerski mczerski commented Mar 18, 2021

spi: litespi: fix litespi cs handling for bulk transfers

For bulk transfers it is essential to keep cs asserted for all transfers in a block. This is done by the higher level api trough set_cs callback.
Changes in this commit require changes in the HDL part (https://github.com/enjoy-digital/litex) in the SPIMaster module, namely CS register must directly drive the cs pin.

HDL related changes are in enjoy-digital/litex#852.

gsomlo pushed a commit that referenced this pull request Mar 22, 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
 torvalds#14  vfs_read at ffffffffa4cd0849
 #15  ksys_read at ffffffffa4cd0bd1
 #16  do_syscall_64 at ffffffffa4a052eb
 torvalds#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
 torvalds#14  __filemap_fdatawrite_range at ffffffffa4c1e5bb
 #15  btrfs_run_delalloc_work at ffffffffc0380987         <-- starts running delayed nodes
 #16  normal_work_helper at ffffffffc03b706c
 torvalds#17  process_one_work at ffffffffa4aba4e4
 torvalds#18  worker_thread at ffffffffa4aba6fd
 torvalds#19  kthread at ffffffffa4ac0a3d
 torvalds#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]>
gsomlo pushed a commit that referenced this pull request Mar 22, 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
    torvalds#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]>
gsomlo pushed a commit that referenced this pull request Mar 22, 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]>
gsomlo pushed a commit that referenced this pull request Mar 22, 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]>
gsomlo pushed a commit that referenced this pull request Mar 22, 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
    torvalds#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
    torvalds#17 0x55ad9b5eaa88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365
    torvalds#18 0x55ad9b5eaa88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409
    torvalds#19 0x55ad9b5eaa88 in main /home/namhyung/project/linux/tools/perf/perf.c:539
    torvalds#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]>
gsomlo pushed a commit that referenced this pull request Mar 22, 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
    torvalds#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]>
gsomlo pushed a commit that referenced this pull request Mar 22, 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
    torvalds#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]>
gsomlo pushed a commit that referenced this pull request Mar 22, 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]>
gsomlo pushed a commit that referenced this pull request Mar 22, 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]>
gsomlo pushed a commit that referenced this pull request Mar 22, 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
    torvalds#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]>
gsomlo pushed a commit that referenced this pull request Mar 22, 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
    torvalds#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]>
gsomlo pushed a commit that referenced this pull request Mar 22, 2021
The digital input subdevice supports Comedi asynchronous commands that
read interrupt status information.  This uses 16-bit Comedi samples (of
which only the bottom 8 bits contain status information).  However, the
interrupt handler is calling `comedi_buf_write_samples()` with the
address of a 32-bit variable `unsigned int status`.  On a bigendian
machine, this will copy 2 bytes from the wrong end of the variable.  Fix
it by changing the type of the variable to `unsigned short`.

Fixes: a8c66b6 ("staging: comedi: addi_apci_1500: rewrite the subdevice support functions")
Cc: <[email protected]> #4.0+
Signed-off-by: Ian Abbott <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
@mczerski mczerski force-pushed the litespi_cs_handling branch from 5e3d0bd to e941368 Compare March 26, 2021 20:10
shenki and others added 16 commits March 26, 2021 20:21
Original author: Joel Stanley <[email protected]>
Added to linux-on-litex-vexriscv by David Shah <[email protected]>
Polling mode support by Antony Pavlov <[email protected]>
Updated for 32-bit CSRs and 64bit CPUs by Gabriel Somlo <[email protected]>
BE fixes & unset-MAC detection by Stafford Horne <[email protected]>
unused 'struct liteeth *priv' warning by kernel test robot <[email protected]>

Signed-off-by: Joel Stanley <[email protected]>
Signed-off-by: Gabriel Somlo <[email protected]>
Original author: Filip Kokosinski <[email protected]>
Cleanup, 32-bit CSR, 64-bit CPU update: Gabriel Somlo <[email protected]>

Signed-off-by: Filip Kokosinski <[email protected]>
Signed-off-by: Gabriel Somlo <[email protected]>
Original author: Kamil Rakoczy <[email protected]>
Updated for DMA transfers: Maciej Dudek <[email protected]>
Clenaup, 32bit CSR, eject support: Gabriel Somlo <[email protected]>

Signed-off-by: Kamil Rakoczy <[email protected]>
Signed-off-by: Maciej Dudek <[email protected]>
Signed-off-by: Gabriel Somlo <[email protected]>
Add defconfig for LiteX SoC with RocketChip CPU, LiteETH, LiteSDCard,
and optional support for spi-mode SDCard.

Signed-off-by: Gabriel Somlo <[email protected]>
Signed-off-by: Robert Winkler <[email protected]>

FIXME: not updated or tested for 32-bit CSR data width, 64-bit CPU (gls)
FIXME: if possible, replace calls to '_litex_[get|set]_reg()' with
the appropriate 'litex_[read|write][8|16|32|64]()'. If the size of
a LiteX CSR access can't be determined at compile time, we should
make available a set of public 'litex_[get|set]_reg()' methods that
add 'BUG_ON(reg_size > sizeof(u64) || reg_size < 1)' on top of the
call to '_litex_[get|set]_reg()'.
Signed-off-by: Robert Winkler <[email protected]>

FIXME: not updated or tested for 32-bit CSR data width, 64-bit CPU (gls)
NOTE (gls): this SHOULD work on 32-bit CSRs and/or 64-bit CPUs, but
has not been tested under those conditions.
Signed-off-by: Robert Winkler <[email protected]>

FIXME: not updated or tested for 32-bit CSR data width, 64-bit CPU (gls)
FIXME: still needs register offsets re-calculated based on subreg width!
Signed-off-by: Daniel Craviee <[email protected]>

FIXME: not updated or tested for 32-bit CSR data width, 64-bit CPU (gls)
FIXME: still needs register offsets re-calculated based on subreg width!
Signed-off-by: Daniel Craviee <[email protected]>

FIXME: not updated or tested for 32-bit CSR data width, 64-bit CPU (gls)
NOTE (gls): this SHOULD work on 32-bit CSRs and/or 64-bit CPUs, but
has not been tested under those conditions.
  - Fix $id to match file path,
  - Include spi-controller.yaml,
  - Document flash subnode,
  - Add missing "unevaluatedProperties: false",
  - Fix indentation of example,
  - Use "spi" from generic node names recommendation,
  - Add missing #{address,size}-cells to example,
  - Fix reg property of flash subnode.

Signed-off-by: Geert Uytterhoeven <[email protected]>
Signed-off-by: Robert Winkler <[email protected]>

FIXME: not updated or tested for 32-bit CSR data width, 64-bit CPU (gls)
gsomlo pushed a commit that referenced this pull request Aug 24, 2024
UBSAN reports the following 'subtraction overflow' error when booting
in a virtual machine on Android:

 | Internal error: UBSAN: integer subtraction overflow: 00000000f2005515 [#1] PREEMPT SMP
 | Modules linked in:
 | CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.10.0-00006-g3cbe9e5abd46-dirty #4
 | Hardware name: linux,dummy-virt (DT)
 | pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 | pc : cancel_delayed_work+0x34/0x44
 | lr : cancel_delayed_work+0x2c/0x44
 | sp : ffff80008002ba60
 | x29: ffff80008002ba60 x28: 0000000000000000 x27: 0000000000000000
 | x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000
 | x23: 0000000000000000 x22: 0000000000000000 x21: ffff1f65014cd3c0
 | x20: ffffc0e84c9d0da0 x19: ffffc0e84cab3558 x18: ffff800080009058
 | x17: 00000000247ee1f8 x16: 00000000247ee1f8 x15: 00000000bdcb279d
 | x14: 0000000000000001 x13: 0000000000000075 x12: 00000a0000000000
 | x11: ffff1f6501499018 x10: 00984901651fffff x9 : ffff5e7cc35af000
 | x8 : 0000000000000001 x7 : 3d4d455453595342 x6 : 000000004e514553
 | x5 : ffff1f6501499265 x4 : ffff1f650ff60b10 x3 : 0000000000000620
 | x2 : ffff80008002ba78 x1 : 0000000000000000 x0 : 0000000000000000
 | Call trace:
 |  cancel_delayed_work+0x34/0x44
 |  deferred_probe_extend_timeout+0x20/0x70
 |  driver_register+0xa8/0x110
 |  __platform_driver_register+0x28/0x3c
 |  syscon_init+0x24/0x38
 |  do_one_initcall+0xe4/0x338
 |  do_initcall_level+0xac/0x178
 |  do_initcalls+0x5c/0xa0
 |  do_basic_setup+0x20/0x30
 |  kernel_init_freeable+0x8c/0xf8
 |  kernel_init+0x28/0x1b4
 |  ret_from_fork+0x10/0x20
 | Code: f9000fbf 97fffa2f 39400268 37100048 (d42aa2a0)
 | ---[ end trace 0000000000000000 ]---
 | Kernel panic - not syncing: UBSAN: integer subtraction overflow: Fatal exception

This is due to shift_and_mask() using a signed immediate to construct
the mask and being called with a shift of 31 (WORK_OFFQ_POOL_SHIFT) so
that it ends up decrementing from INT_MIN.

Use an unsigned constant '1U' to generate the mask in shift_and_mask().

Cc: Tejun Heo <[email protected]>
Cc: Lai Jiangshan <[email protected]>
Fixes: 1211f3b ("workqueue: Preserve OFFQ bits in cancel[_sync] paths")
Signed-off-by: Will Deacon <[email protected]>
Signed-off-by: Tejun Heo <[email protected]>
gsomlo pushed a commit that referenced this pull request Oct 1, 2024
Use a dedicated mutex to guard kvm_usage_count to fix a potential deadlock
on x86 due to a chain of locks and SRCU synchronizations.  Translating the
below lockdep splat, CPU1 #6 will wait on CPU0 #1, CPU0 #8 will wait on
CPU2 #3, and CPU2 #7 will wait on CPU1 #4 (if there's a writer, due to the
fairness of r/w semaphores).

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

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

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

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

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

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

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

  which lock already depends on the new lock.

   the existing dependency chain (in reverse order) is:

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

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

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

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

Cc: Chao Gao <[email protected]>
Fixes: 0bf5049 ("KVM: Drop kvm_count_lock and instead protect kvm_usage_count with kvm_lock")
Cc: [email protected]
Reviewed-by: Kai Huang <[email protected]>
Acked-by: Kai Huang <[email protected]>
Tested-by: Farrah Chen <[email protected]>
Signed-off-by: Sean Christopherson <[email protected]>
Message-ID: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>
gsomlo pushed a commit that referenced this pull request Oct 12, 2024
On the node of an NFS client, some files saved in the mountpoint of the
NFS server were copied to another location of the same NFS server.
Accidentally, the nfs42_complete_copies() got a NULL-pointer dereference
crash with the following syslog:

[232064.838881] NFSv4: state recovery failed for open file nfs/pvc-12b5200d-cd0f-46a3-b9f0-af8f4fe0ef64.qcow2, error = -116
[232064.839360] NFSv4: state recovery failed for open file nfs/pvc-12b5200d-cd0f-46a3-b9f0-af8f4fe0ef64.qcow2, error = -116
[232066.588183] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000058
[232066.588586] Mem abort info:
[232066.588701]   ESR = 0x0000000096000007
[232066.588862]   EC = 0x25: DABT (current EL), IL = 32 bits
[232066.589084]   SET = 0, FnV = 0
[232066.589216]   EA = 0, S1PTW = 0
[232066.589340]   FSC = 0x07: level 3 translation fault
[232066.589559] Data abort info:
[232066.589683]   ISV = 0, ISS = 0x00000007
[232066.589842]   CM = 0, WnR = 0
[232066.589967] user pgtable: 64k pages, 48-bit VAs, pgdp=00002000956ff400
[232066.590231] [0000000000000058] pgd=08001100ae100003, p4d=08001100ae100003, pud=08001100ae100003, pmd=08001100b3c00003, pte=0000000000000000
[232066.590757] Internal error: Oops: 96000007 [#1] SMP
[232066.590958] Modules linked in: rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache netfs ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm vhost_net vhost vhost_iotlb tap tun ipt_rpfilter xt_multiport ip_set_hash_ip ip_set_hash_net xfrm_interface xfrm6_tunnel tunnel4 tunnel6 esp4 ah4 wireguard libcurve25519_generic veth xt_addrtype xt_set nf_conntrack_netlink ip_set_hash_ipportnet ip_set_hash_ipportip ip_set_bitmap_port ip_set_hash_ipport dummy ip_set ip_vs_sh ip_vs_wrr ip_vs_rr ip_vs iptable_filter sch_ingress nfnetlink_cttimeout vport_gre ip_gre ip_tunnel gre vport_geneve geneve vport_vxlan vxlan ip6_udp_tunnel udp_tunnel openvswitch nf_conncount dm_round_robin dm_service_time dm_multipath xt_nat xt_MASQUERADE nft_chain_nat nf_nat xt_mark xt_conntrack xt_comment nft_compat nft_counter nf_tables nfnetlink ocfs2 ocfs2_nodemanager ocfs2_stackglue iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ipmi_ssif nbd overlay 8021q garp mrp bonding tls rfkill sunrpc ext4 mbcache jbd2
[232066.591052]  vfat fat cas_cache cas_disk ses enclosure scsi_transport_sas sg acpi_ipmi ipmi_si ipmi_devintf ipmi_msghandler ip_tables vfio_pci vfio_pci_core vfio_virqfd vfio_iommu_type1 vfio dm_mirror dm_region_hash dm_log dm_mod nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 br_netfilter bridge stp llc fuse xfs libcrc32c ast drm_vram_helper qla2xxx drm_kms_helper syscopyarea crct10dif_ce sysfillrect ghash_ce sysimgblt sha2_ce fb_sys_fops cec sha256_arm64 sha1_ce drm_ttm_helper ttm nvme_fc igb sbsa_gwdt nvme_fabrics drm nvme_core i2c_algo_bit i40e scsi_transport_fc megaraid_sas aes_neon_bs
[232066.596953] CPU: 6 PID: 4124696 Comm: 10.253.166.125- Kdump: loaded Not tainted 5.15.131-9.cl9_ocfs2.aarch64 #1
[232066.597356] Hardware name: Great Wall .\x93\x8e...RF6260 V5/GWMSSE2GL1T, BIOS T656FBE_V3.0.18 2024-01-06
[232066.597721] pstate: 20400009 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[232066.598034] pc : nfs4_reclaim_open_state+0x220/0x800 [nfsv4]
[232066.598327] lr : nfs4_reclaim_open_state+0x12c/0x800 [nfsv4]
[232066.598595] sp : ffff8000f568fc70
[232066.598731] x29: ffff8000f568fc70 x28: 0000000000001000 x27: ffff21003db33000
[232066.599030] x26: ffff800005521ae0 x25: ffff0100f98fa3f0 x24: 0000000000000001
[232066.599319] x23: ffff800009920008 x22: ffff21003db33040 x21: ffff21003db33050
[232066.599628] x20: ffff410172fe9e40 x19: ffff410172fe9e00 x18: 0000000000000000
[232066.599914] x17: 0000000000000000 x16: 0000000000000004 x15: 0000000000000000
[232066.600195] x14: 0000000000000000 x13: ffff800008e685a8 x12: 00000000eac0c6e6
[232066.600498] x11: 0000000000000000 x10: 0000000000000008 x9 : ffff8000054e5828
[232066.600784] x8 : 00000000ffffffbf x7 : 0000000000000001 x6 : 000000000a9eb14a
[232066.601062] x5 : 0000000000000000 x4 : ffff70ff8a14a800 x3 : 0000000000000058
[232066.601348] x2 : 0000000000000001 x1 : 54dce46366daa6c6 x0 : 0000000000000000
[232066.601636] Call trace:
[232066.601749]  nfs4_reclaim_open_state+0x220/0x800 [nfsv4]
[232066.601998]  nfs4_do_reclaim+0x1b8/0x28c [nfsv4]
[232066.602218]  nfs4_state_manager+0x928/0x10f0 [nfsv4]
[232066.602455]  nfs4_run_state_manager+0x78/0x1b0 [nfsv4]
[232066.602690]  kthread+0x110/0x114
[232066.602830]  ret_from_fork+0x10/0x20
[232066.602985] Code: 1400000d f9403f20 f9402e61 91016003 (f9402c00)
[232066.603284] SMP: stopping secondary CPUs
[232066.606936] Starting crashdump kernel...
[232066.607146] Bye!

Analysing the vmcore, we know that nfs4_copy_state listed by destination
nfs_server->ss_copies was added by the field copies in handle_async_copy(),
and we found a waiting copy process with the stack as:
PID: 3511963  TASK: ffff710028b47e00  CPU: 0   COMMAND: "cp"
 #0 [ffff8001116ef740] __switch_to at ffff8000081b92f4
 #1 [ffff8001116ef760] __schedule at ffff800008dd0650
 #2 [ffff8001116ef7c0] schedule at ffff800008dd0a00
 #3 [ffff8001116ef7e0] schedule_timeout at ffff800008dd6aa0
 #4 [ffff8001116ef860] __wait_for_common at ffff800008dd166c
 #5 [ffff8001116ef8e0] wait_for_completion_interruptible at ffff800008dd1898
 #6 [ffff8001116ef8f0] handle_async_copy at ffff8000055142f4 [nfsv4]
 #7 [ffff8001116ef970] _nfs42_proc_copy at ffff8000055147c8 [nfsv4]
 #8 [ffff8001116efa80] nfs42_proc_copy at ffff800005514cf0 [nfsv4]
 #9 [ffff8001116efc50] __nfs4_copy_file_range.constprop.0 at ffff8000054ed694 [nfsv4]

The NULL-pointer dereference was due to nfs42_complete_copies() listed
the nfs_server->ss_copies by the field ss_copies of nfs4_copy_state.
So the nfs4_copy_state address ffff0100f98fa3f0 was offset by 0x10 and
the data accessed through this pointer was also incorrect. Generally,
the ordered list nfs4_state_owner->so_states indicate open(O_RDWR) or
open(O_WRITE) states are reclaimed firstly by nfs4_reclaim_open_state().
When destination state reclaim is failed with NFS_STATE_RECOVERY_FAILED
and copies are not deleted in nfs_server->ss_copies, the source state
may be passed to the nfs42_complete_copies() process earlier, resulting
in this crash scene finally. To solve this issue, we add a list_head
nfs_server->ss_src_copies for a server-to-server copy specially.

Fixes: 0e65a32 ("NFS: handle source server reboot")
Signed-off-by: Yanjun Zhang <[email protected]>
Reviewed-by: Trond Myklebust <[email protected]>
Signed-off-by: Anna Schumaker <[email protected]>
gsomlo pushed a commit that referenced this pull request Oct 20, 2024
Syzkaller reported a lockdep splat:

  ============================================
  WARNING: possible recursive locking detected
  6.11.0-rc6-syzkaller-00019-g67784a74e258 #0 Not tainted
  --------------------------------------------
  syz-executor364/5113 is trying to acquire lock:
  ffff8880449f1958 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
  ffff8880449f1958 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328

  but task is already holding lock:
  ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
  ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328

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

         CPU0
         ----
    lock(k-slock-AF_INET);
    lock(k-slock-AF_INET);

   *** DEADLOCK ***

   May be due to missing lock nesting notation

  7 locks held by syz-executor364/5113:
   #0: ffff8880449f0e18 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline]
   #0: ffff8880449f0e18 (sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg+0x153/0x1b10 net/mptcp/protocol.c:1806
   #1: ffff88803fe39ad8 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline]
   #1: ffff88803fe39ad8 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg_fastopen+0x11f/0x530 net/mptcp/protocol.c:1727
   #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
   #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
   #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x5f/0x1b80 net/ipv4/ip_output.c:470
   #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
   #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
   #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x45f/0x1390 net/ipv4/ip_output.c:228
   #4: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline]
   #4: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x33b/0x15b0 net/core/dev.c:6104
   #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
   #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
   #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0x230/0x5f0 net/ipv4/ip_input.c:232
   #6: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
   #6: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328

  stack backtrace:
  CPU: 0 UID: 0 PID: 5113 Comm: syz-executor364 Not tainted 6.11.0-rc6-syzkaller-00019-g67784a74e258 #0
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
  Call Trace:
   <IRQ>
   __dump_stack lib/dump_stack.c:93 [inline]
   dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
   check_deadlock kernel/locking/lockdep.c:3061 [inline]
   validate_chain+0x15d3/0x5900 kernel/locking/lockdep.c:3855
   __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142
   lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
   __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
   _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
   spin_lock include/linux/spinlock.h:351 [inline]
   sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328
   mptcp_sk_clone_init+0x32/0x13c0 net/mptcp/protocol.c:3279
   subflow_syn_recv_sock+0x931/0x1920 net/mptcp/subflow.c:874
   tcp_check_req+0xfe4/0x1a20 net/ipv4/tcp_minisocks.c:853
   tcp_v4_rcv+0x1c3e/0x37f0 net/ipv4/tcp_ipv4.c:2267
   ip_protocol_deliver_rcu+0x22e/0x440 net/ipv4/ip_input.c:205
   ip_local_deliver_finish+0x341/0x5f0 net/ipv4/ip_input.c:233
   NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314
   NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314
   __netif_receive_skb_one_core net/core/dev.c:5661 [inline]
   __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5775
   process_backlog+0x662/0x15b0 net/core/dev.c:6108
   __napi_poll+0xcb/0x490 net/core/dev.c:6772
   napi_poll net/core/dev.c:6841 [inline]
   net_rx_action+0x89b/0x1240 net/core/dev.c:6963
   handle_softirqs+0x2c4/0x970 kernel/softirq.c:554
   do_softirq+0x11b/0x1e0 kernel/softirq.c:455
   </IRQ>
   <TASK>
   __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382
   local_bh_enable include/linux/bottom_half.h:33 [inline]
   rcu_read_unlock_bh include/linux/rcupdate.h:908 [inline]
   __dev_queue_xmit+0x1763/0x3e90 net/core/dev.c:4450
   dev_queue_xmit include/linux/netdevice.h:3105 [inline]
   neigh_hh_output include/net/neighbour.h:526 [inline]
   neigh_output include/net/neighbour.h:540 [inline]
   ip_finish_output2+0xd41/0x1390 net/ipv4/ip_output.c:235
   ip_local_out net/ipv4/ip_output.c:129 [inline]
   __ip_queue_xmit+0x118c/0x1b80 net/ipv4/ip_output.c:535
   __tcp_transmit_skb+0x2544/0x3b30 net/ipv4/tcp_output.c:1466
   tcp_rcv_synsent_state_process net/ipv4/tcp_input.c:6542 [inline]
   tcp_rcv_state_process+0x2c32/0x4570 net/ipv4/tcp_input.c:6729
   tcp_v4_do_rcv+0x77d/0xc70 net/ipv4/tcp_ipv4.c:1934
   sk_backlog_rcv include/net/sock.h:1111 [inline]
   __release_sock+0x214/0x350 net/core/sock.c:3004
   release_sock+0x61/0x1f0 net/core/sock.c:3558
   mptcp_sendmsg_fastopen+0x1ad/0x530 net/mptcp/protocol.c:1733
   mptcp_sendmsg+0x1884/0x1b10 net/mptcp/protocol.c:1812
   sock_sendmsg_nosec net/socket.c:730 [inline]
   __sock_sendmsg+0x1a6/0x270 net/socket.c:745
   ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597
   ___sys_sendmsg net/socket.c:2651 [inline]
   __sys_sendmmsg+0x3b2/0x740 net/socket.c:2737
   __do_sys_sendmmsg net/socket.c:2766 [inline]
   __se_sys_sendmmsg net/socket.c:2763 [inline]
   __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2763
   do_syscall_x64 arch/x86/entry/common.c:52 [inline]
   do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
  RIP: 0033:0x7f04fb13a6b9
  Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 01 1a 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
  RSP: 002b:00007ffd651f42d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
  RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f04fb13a6b9
  RDX: 0000000000000001 RSI: 0000000020000d00 RDI: 0000000000000004
  RBP: 00007ffd651f4310 R08: 0000000000000001 R09: 0000000000000001
  R10: 0000000020000080 R11: 0000000000000246 R12: 00000000000f4240
  R13: 00007f04fb187449 R14: 00007ffd651f42f4 R15: 00007ffd651f4300
   </TASK>

As noted by Cong Wang, the splat is false positive, but the code
path leading to the report is an unexpected one: a client is
attempting an MPC handshake towards the in-kernel listener created
by the in-kernel PM for a port based signal endpoint.

Such connection will be never accepted; many of them can make the
listener queue full and preventing the creation of MPJ subflow via
such listener - its intended role.

Explicitly detect this scenario at initial-syn time and drop the
incoming MPC request.

Fixes: 1729cf1 ("mptcp: create the listening socket for new port")
Cc: [email protected]
Reported-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=f4aacdfef2c6a6529c3e
Cc: Cong Wang <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>
Reviewed-by: Matthieu Baerts (NGI0) <[email protected]>
Reviewed-by: Mat Martineau <[email protected]>
Signed-off-by: Matthieu Baerts (NGI0) <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
gsomlo pushed a commit that referenced this pull request Nov 4, 2024
Hou Tao says:

====================
The patch set fixes several issues in bits iterator. Patch #1 fixes the
kmemleak problem of bits iterator. Patch #2~#3 fix the overflow problem
of nr_bits. Patch #4 fixes the potential stack corruption when bits
iterator is used on 32-bit host. Patch #5 adds more test cases for bits
iterator.

Please see the individual patches for more details. And comments are
always welcome.
---
v4:
 * patch #1: add ack from Yafang
 * patch #3: revert code-churn like changes:
   (1) compute nr_bytes and nr_bits before the check of nr_words.
   (2) use nr_bits == 64 to check for single u64, preventing build
       warning on 32-bit hosts.
 * patch #4: use "BITS_PER_LONG == 32" instead of "!defined(CONFIG_64BIT)"

v3: https://lore.kernel.org/bpf/[email protected]/T/#t
  * split the bits-iterator related patches from "Misc fixes for bpf"
    patch set
  * patch #1: use "!nr_bits || bits >= nr_bits" to stop the iteration
  * patch #2: add a new helper for the overflow problem
  * patch #3: decrease the limitation from 512 to 511 and check whether
    nr_bytes is too large for bpf memory allocator explicitly
  * patch #5: add two more test cases for bit iterator

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

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
gsomlo pushed a commit that referenced this pull request Nov 4, 2024
Petr Machata says:

====================
mlxsw: Fixes

In this patchset:

- Tx header should be pushed for each packet which is transmitted via
  Spectrum ASICs. Patch #1 adds a missing call to skb_cow_head() to make
  sure that there is both enough room to push the Tx header and that the
  SKB header is not cloned and can be modified.

- Commit b5b60bb ("mlxsw: pci: Use page pool for Rx buffers
  allocation") converted mlxsw to use page pool for Rx buffers allocation.
  Sync for CPU and for device should be done for Rx pages. In patches #2
  and #3, add the missing calls to sync pages for, respectively, CPU and
  the device.

- Patch #4 then fixes a bug to IPv6 GRE forwarding offload. Patch #5 adds
  a generic forwarding test that fails with mlxsw ports prior to the fix.
====================

Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
gsomlo pushed a commit that referenced this pull request Nov 18, 2024
When CONFIG_KASAN_SW_TAGS and CONFIG_KASAN_STACK are enabled, the
object_is_on_stack() function may produce incorrect results due to the
presence of tags in the obj pointer, while the stack pointer does not have
tags.  This discrepancy can lead to incorrect stack object detection and
subsequently trigger warnings if CONFIG_DEBUG_OBJECTS is also enabled.

Example of the warning:

ODEBUG: object 3eff800082ea7bb0 is NOT on stack ffff800082ea0000, but annotated.
------------[ cut here ]------------
WARNING: CPU: 0 PID: 1 at lib/debugobjects.c:557 __debug_object_init+0x330/0x364
Modules linked in:
CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.0-rc5 #4
Hardware name: linux,dummy-virt (DT)
pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __debug_object_init+0x330/0x364
lr : __debug_object_init+0x330/0x364
sp : ffff800082ea7b40
x29: ffff800082ea7b40 x28: 98ff0000c0164518 x27: 98ff0000c0164534
x26: ffff800082d93ec8 x25: 0000000000000001 x24: 1cff0000c00172a0
x23: 0000000000000000 x22: ffff800082d93ed0 x21: ffff800081a24418
x20: 3eff800082ea7bb0 x19: efff800000000000 x18: 0000000000000000
x17: 00000000000000ff x16: 0000000000000047 x15: 206b63617473206e
x14: 0000000000000018 x13: ffff800082ea7780 x12: 0ffff800082ea78e
x11: 0ffff800082ea790 x10: 0ffff800082ea79d x9 : 34d77febe173e800
x8 : 34d77febe173e800 x7 : 0000000000000001 x6 : 0000000000000001
x5 : feff800082ea74b8 x4 : ffff800082870a90 x3 : ffff80008018d3c4
x2 : 0000000000000001 x1 : ffff800082858810 x0 : 0000000000000050
Call trace:
 __debug_object_init+0x330/0x364
 debug_object_init_on_stack+0x30/0x3c
 schedule_hrtimeout_range_clock+0xac/0x26c
 schedule_hrtimeout+0x1c/0x30
 wait_task_inactive+0x1d4/0x25c
 kthread_bind_mask+0x28/0x98
 init_rescuer+0x1e8/0x280
 workqueue_init+0x1a0/0x3cc
 kernel_init_freeable+0x118/0x200
 kernel_init+0x28/0x1f0
 ret_from_fork+0x10/0x20
---[ end trace 0000000000000000 ]---
ODEBUG: object 3eff800082ea7bb0 is NOT on stack ffff800082ea0000, but annotated.
------------[ cut here ]------------

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Qun-Wei Lin <[email protected]>
Cc: Andrew Yang <[email protected]>
Cc: AngeloGioacchino Del Regno <[email protected]>
Cc: Casper Li <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Chinwen Chang <[email protected]>
Cc: Kent Overstreet <[email protected]>
Cc: Matthias Brugger <[email protected]>
Cc: Pasha Tatashin <[email protected]>
Cc: Shakeel Butt <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
gsomlo pushed a commit that referenced this pull request Dec 8, 2024
Kernel will hang on destroy admin_q while we create ctrl failed, such
as following calltrace:

PID: 23644    TASK: ff2d52b40f439fc0  CPU: 2    COMMAND: "nvme"
 #0 [ff61d23de260fb78] __schedule at ffffffff8323bc15
 #1 [ff61d23de260fc08] schedule at ffffffff8323c014
 #2 [ff61d23de260fc28] blk_mq_freeze_queue_wait at ffffffff82a3dba1
 #3 [ff61d23de260fc78] blk_freeze_queue at ffffffff82a4113a
 #4 [ff61d23de260fc90] blk_cleanup_queue at ffffffff82a33006
 #5 [ff61d23de260fcb0] nvme_rdma_destroy_admin_queue at ffffffffc12686ce
 #6 [ff61d23de260fcc8] nvme_rdma_setup_ctrl at ffffffffc1268ced
 #7 [ff61d23de260fd28] nvme_rdma_create_ctrl at ffffffffc126919b
 #8 [ff61d23de260fd68] nvmf_dev_write at ffffffffc024f362
 #9 [ff61d23de260fe38] vfs_write at ffffffff827d5f25
    RIP: 00007fda7891d574  RSP: 00007ffe2ef06958  RFLAGS: 00000202
    RAX: ffffffffffffffda  RBX: 000055e8122a4d90  RCX: 00007fda7891d574
    RDX: 000000000000012b  RSI: 000055e8122a4d90  RDI: 0000000000000004
    RBP: 00007ffe2ef079c0   R8: 000000000000012b   R9: 000055e8122a4d90
    R10: 0000000000000000  R11: 0000000000000202  R12: 0000000000000004
    R13: 000055e8122923c0  R14: 000000000000012b  R15: 00007fda78a54500
    ORIG_RAX: 0000000000000001  CS: 0033  SS: 002b

This due to we have quiesced admi_q before cancel requests, but forgot
to unquiesce before destroy it, as a result we fail to drain the
pending requests, and hang on blk_mq_freeze_queue_wait() forever. Here
try to reuse nvme_rdma_teardown_admin_queue() to fix this issue and
simplify the code.

Fixes: 958dc1d ("nvme-rdma: add clean action for failed reconnection")
Reported-by: Yingfu.zhou <[email protected]>
Signed-off-by: Chunguang.xu <[email protected]>
Signed-off-by: Yue.zhao <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Hannes Reinecke <[email protected]>
Signed-off-by: Keith Busch <[email protected]>
gsomlo pushed a commit that referenced this pull request Dec 8, 2024
Hou Tao says:

====================
This patch set fixes several issues for LPM trie. These issues were
found during adding new test cases or were reported by syzbot.

The patch set is structured as follows:

Patch #1~#2 are clean-ups for lpm_trie_update_elem().
Patch #3 handles BPF_EXIST and BPF_NOEXIST correctly for LPM trie.
Patch #4 fixes the accounting of n_entries when doing in-place update.
Patch #5 fixes the exact match condition in trie_get_next_key() and it
may skip keys when the passed key is not found in the map.
Patch #6~#7 switch from kmalloc() to bpf memory allocator for LPM trie
to fix several lock order warnings reported by syzbot. It also enables
raw_spinlock_t for LPM trie again. After these changes, the LPM trie will
be closer to being usable in any context (though the reentrance check of
trie->lock is still missing, but it is on my todo list).
Patch #8: move test_lpm_map to map_tests to make it run regularly.
Patch #9: add test cases for the issues fixed by patch #3~#5.

Please see individual patches for more details. Comments are always
welcome.

Change Log:
v3:
  * patch #2: remove the unnecessary NULL-init for im_node
  * patch #6: alloc the leaf node before disabling IRQ to low
    the possibility of -ENOMEM when leaf_size is large; Free
    these nodes outside the trie lock (Suggested by Alexei)
  * collect review and ack tags (Thanks for Toke & Daniel)

v2: https://lore.kernel.org/bpf/[email protected]/
  * collect review tags (Thanks for Toke)
  * drop "Add bpf_mem_cache_is_mergeable() helper" patch
  * patch #3~#4: add fix tag
  * patch #4: rename the helper to trie_check_add_elem() and increase
    n_entries in it.
  * patch #6: use one bpf mem allocator and update commit message to
    clarify that using bpf mem allocator is more appropriate.
  * patch #7: update commit message to add the possible max running time
    for update operation.
  * patch #9: update commit message to specify the purpose of these test
    cases.

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

Link: https://lore.kernel.org/all/[email protected]/
Signed-off-by: Alexei Starovoitov <[email protected]>
gsomlo pushed a commit that referenced this pull request Dec 14, 2024
Its used from trace__run(), for the 'perf trace' live mode, i.e. its
strace-like, non-perf.data file processing mode, the most common one.

The trace__run() function will set trace->host using machine__new_host()
that is supposed to give a machine instance representing the running
machine, and since we'll use perf_env__arch_strerrno() to get the right
errno -> string table, we need to use machine->env, so initialize it in
machine__new_host().

Before the patch:

  (gdb) run trace --errno-summary -a sleep 1
  <SNIP>
   Summary of events:

   gvfs-afc-volume (3187), 2 events, 0.0%

     syscall            calls  errors  total       min       avg       max       stddev
                                       (msec)    (msec)    (msec)    (msec)        (%)
     --------------- --------  ------ -------- --------- --------- ---------     ------
     pselect6               1      0     0.000     0.000     0.000     0.000      0.00%

   GUsbEventThread (3519), 2 events, 0.0%

     syscall            calls  errors  total       min       avg       max       stddev
                                       (msec)    (msec)    (msec)    (msec)        (%)
     --------------- --------  ------ -------- --------- --------- ---------     ------
     poll                   1      0     0.000     0.000     0.000     0.000      0.00%
  <SNIP>
  Program received signal SIGSEGV, Segmentation fault.
  0x00000000005caba0 in perf_env__arch_strerrno (env=0x0, err=110) at util/env.c:478
  478		if (env->arch_strerrno == NULL)
  (gdb) bt
  #0  0x00000000005caba0 in perf_env__arch_strerrno (env=0x0, err=110) at util/env.c:478
  #1  0x00000000004b75d2 in thread__dump_stats (ttrace=0x14f58f0, trace=0x7fffffffa5b0, fp=0x7ffff6ff74e0 <_IO_2_1_stderr_>) at builtin-trace.c:4673
  #2  0x00000000004b78bf in trace__fprintf_thread (fp=0x7ffff6ff74e0 <_IO_2_1_stderr_>, thread=0x10fa0b0, trace=0x7fffffffa5b0) at builtin-trace.c:4708
  #3  0x00000000004b7ad9 in trace__fprintf_thread_summary (trace=0x7fffffffa5b0, fp=0x7ffff6ff74e0 <_IO_2_1_stderr_>) at builtin-trace.c:4747
  #4  0x00000000004b656e in trace__run (trace=0x7fffffffa5b0, argc=2, argv=0x7fffffffde60) at builtin-trace.c:4456
  #5  0x00000000004ba43e in cmd_trace (argc=2, argv=0x7fffffffde60) at builtin-trace.c:5487
  #6  0x00000000004c0414 in run_builtin (p=0xec3068 <commands+648>, argc=5, argv=0x7fffffffde60) at perf.c:351
  #7  0x00000000004c06bb in handle_internal_command (argc=5, argv=0x7fffffffde60) at perf.c:404
  #8  0x00000000004c0814 in run_argv (argcp=0x7fffffffdc4c, argv=0x7fffffffdc40) at perf.c:448
  #9  0x00000000004c0b5d in main (argc=5, argv=0x7fffffffde60) at perf.c:560
  (gdb)

After:

  root@number:~# perf trace -a --errno-summary sleep 1
  <SNIP>
     pw-data-loop (2685), 1410 events, 16.0%

     syscall            calls  errors  total       min       avg       max       stddev
                                       (msec)    (msec)    (msec)    (msec)        (%)
     --------------- --------  ------ -------- --------- --------- ---------     ------
     epoll_wait           188      0   983.428     0.000     5.231    15.595      8.68%
     ioctl                 94      0     0.811     0.004     0.009     0.016      2.82%
     read                 188      0     0.322     0.001     0.002     0.006      5.15%
     write                141      0     0.280     0.001     0.002     0.018      8.39%
     timerfd_settime       94      0     0.138     0.001     0.001     0.007      6.47%

   gnome-control-c (179406), 1848 events, 20.9%

     syscall            calls  errors  total       min       avg       max       stddev
                                       (msec)    (msec)    (msec)    (msec)        (%)
     --------------- --------  ------ -------- --------- --------- ---------     ------
     poll                 222      0   959.577     0.000     4.322    21.414     11.40%
     recvmsg              150      0     0.539     0.001     0.004     0.013      5.12%
     write                300      0     0.442     0.001     0.001     0.007      3.29%
     read                 150      0     0.183     0.001     0.001     0.009      5.53%
     getpid               102      0     0.101     0.000     0.001     0.008      7.82%

  root@number:~#

Fixes: 54373b5 ("perf env: Introduce perf_env__arch_strerrno()")
Reported-by: Veronika Molnarova <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Acked-by: Veronika Molnarova <[email protected]>
Acked-by: Michael Petlan <[email protected]>
Tested-by: Michael Petlan <[email protected]>
Link: https://lore.kernel.org/r/Z0XffUgNSv_9OjOi@x1
Signed-off-by: Namhyung Kim <[email protected]>
gsomlo pushed a commit that referenced this pull request Dec 14, 2024
…s_lock

For storing a value to a queue attribute, the queue_attr_store function
first freezes the queue (->q_usage_counter(io)) and then acquire
->sysfs_lock. This seems not correct as the usual ordering should be to
acquire ->sysfs_lock before freezing the queue. This incorrect ordering
causes the following lockdep splat which we are able to reproduce always
simply by accessing /sys/kernel/debug file using ls command:

[   57.597146] WARNING: possible circular locking dependency detected
[   57.597154] 6.12.0-10553-gb86545e02e8c torvalds#20 Tainted: G        W
[   57.597162] ------------------------------------------------------
[   57.597168] ls/4605 is trying to acquire lock:
[   57.597176] c00000003eb56710 (&mm->mmap_lock){++++}-{4:4}, at: __might_fault+0x58/0xc0
[   57.597200]
               but task is already holding lock:
[   57.597207] c0000018e27c6810 (&sb->s_type->i_mutex_key#3){++++}-{4:4}, at: iterate_dir+0x94/0x1d4
[   57.597226]
               which lock already depends on the new lock.

[   57.597233]
               the existing dependency chain (in reverse order) is:
[   57.597241]
               -> #5 (&sb->s_type->i_mutex_key#3){++++}-{4:4}:
[   57.597255]        down_write+0x6c/0x18c
[   57.597264]        start_creating+0xb4/0x24c
[   57.597274]        debugfs_create_dir+0x2c/0x1e8
[   57.597283]        blk_register_queue+0xec/0x294
[   57.597292]        add_disk_fwnode+0x2e4/0x548
[   57.597302]        brd_alloc+0x2c8/0x338
[   57.597309]        brd_init+0x100/0x178
[   57.597317]        do_one_initcall+0x88/0x3e4
[   57.597326]        kernel_init_freeable+0x3cc/0x6e0
[   57.597334]        kernel_init+0x34/0x1cc
[   57.597342]        ret_from_kernel_user_thread+0x14/0x1c
[   57.597350]
               -> #4 (&q->debugfs_mutex){+.+.}-{4:4}:
[   57.597362]        __mutex_lock+0xfc/0x12a0
[   57.597370]        blk_register_queue+0xd4/0x294
[   57.597379]        add_disk_fwnode+0x2e4/0x548
[   57.597388]        brd_alloc+0x2c8/0x338
[   57.597395]        brd_init+0x100/0x178
[   57.597402]        do_one_initcall+0x88/0x3e4
[   57.597410]        kernel_init_freeable+0x3cc/0x6e0
[   57.597418]        kernel_init+0x34/0x1cc
[   57.597426]        ret_from_kernel_user_thread+0x14/0x1c
[   57.597434]
               -> #3 (&q->sysfs_lock){+.+.}-{4:4}:
[   57.597446]        __mutex_lock+0xfc/0x12a0
[   57.597454]        queue_attr_store+0x9c/0x110
[   57.597462]        sysfs_kf_write+0x70/0xb0
[   57.597471]        kernfs_fop_write_iter+0x1b0/0x2ac
[   57.597480]        vfs_write+0x3dc/0x6e8
[   57.597488]        ksys_write+0x84/0x140
[   57.597495]        system_call_exception+0x130/0x360
[   57.597504]        system_call_common+0x160/0x2c4
[   57.597516]
               -> #2 (&q->q_usage_counter(io)torvalds#21){++++}-{0:0}:
[   57.597530]        __submit_bio+0x5ec/0x828
[   57.597538]        submit_bio_noacct_nocheck+0x1e4/0x4f0
[   57.597547]        iomap_readahead+0x2a0/0x448
[   57.597556]        xfs_vm_readahead+0x28/0x3c
[   57.597564]        read_pages+0x88/0x41c
[   57.597571]        page_cache_ra_unbounded+0x1ac/0x2d8
[   57.597580]        filemap_get_pages+0x188/0x984
[   57.597588]        filemap_read+0x13c/0x4bc
[   57.597596]        xfs_file_buffered_read+0x88/0x17c
[   57.597605]        xfs_file_read_iter+0xac/0x158
[   57.597614]        vfs_read+0x2d4/0x3b4
[   57.597622]        ksys_read+0x84/0x144
[   57.597629]        system_call_exception+0x130/0x360
[   57.597637]        system_call_common+0x160/0x2c4
[   57.597647]
               -> #1 (mapping.invalidate_lock#2){++++}-{4:4}:
[   57.597661]        down_read+0x6c/0x220
[   57.597669]        filemap_fault+0x870/0x100c
[   57.597677]        xfs_filemap_fault+0xc4/0x18c
[   57.597684]        __do_fault+0x64/0x164
[   57.597693]        __handle_mm_fault+0x1274/0x1dac
[   57.597702]        handle_mm_fault+0x248/0x484
[   57.597711]        ___do_page_fault+0x428/0xc0c
[   57.597719]        hash__do_page_fault+0x30/0x68
[   57.597727]        do_hash_fault+0x90/0x35c
[   57.597736]        data_access_common_virt+0x210/0x220
[   57.597745]        _copy_from_user+0xf8/0x19c
[   57.597754]        sel_write_load+0x178/0xd54
[   57.597762]        vfs_write+0x108/0x6e8
[   57.597769]        ksys_write+0x84/0x140
[   57.597777]        system_call_exception+0x130/0x360
[   57.597785]        system_call_common+0x160/0x2c4
[   57.597794]
               -> #0 (&mm->mmap_lock){++++}-{4:4}:
[   57.597806]        __lock_acquire+0x17cc/0x2330
[   57.597814]        lock_acquire+0x138/0x400
[   57.597822]        __might_fault+0x7c/0xc0
[   57.597830]        filldir64+0xe8/0x390
[   57.597839]        dcache_readdir+0x80/0x2d4
[   57.597846]        iterate_dir+0xd8/0x1d4
[   57.597855]        sys_getdents64+0x88/0x2d4
[   57.597864]        system_call_exception+0x130/0x360
[   57.597872]        system_call_common+0x160/0x2c4
[   57.597881]
               other info that might help us debug this:

[   57.597888] Chain exists of:
                 &mm->mmap_lock --> &q->debugfs_mutex --> &sb->s_type->i_mutex_key#3

[   57.597905]  Possible unsafe locking scenario:

[   57.597911]        CPU0                    CPU1
[   57.597917]        ----                    ----
[   57.597922]   rlock(&sb->s_type->i_mutex_key#3);
[   57.597932]                                lock(&q->debugfs_mutex);
[   57.597940]                                lock(&sb->s_type->i_mutex_key#3);
[   57.597950]   rlock(&mm->mmap_lock);
[   57.597958]
                *** DEADLOCK ***

[   57.597965] 2 locks held by ls/4605:
[   57.597971]  #0: c0000000137c12f8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0xcc/0x154
[   57.597989]  #1: c0000018e27c6810 (&sb->s_type->i_mutex_key#3){++++}-{4:4}, at: iterate_dir+0x94/0x1d4

Prevent the above lockdep warning by acquiring ->sysfs_lock before
freezing the queue while storing a queue attribute in queue_attr_store
function. Later, we also found[1] another function __blk_mq_update_nr_
hw_queues where we first freeze queue and then acquire the ->sysfs_lock.
So we've also updated lock ordering in __blk_mq_update_nr_hw_queues
function and ensured that in all code paths we follow the correct lock
ordering i.e. acquire ->sysfs_lock before freezing the queue.

[1] https://lore.kernel.org/all/CAFj5m9Ke8+EHKQBs_Nk6hqd=LGXtk4mUxZUN5==ZcCjnZSBwHw@mail.gmail.com/

Reported-by: [email protected]
Fixes: af28141 ("block: freeze the queue in queue_attr_store")
Tested-by: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Nilay Shroff <[email protected]>
Reviewed-by: Ming Lei <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>
gsomlo pushed a commit that referenced this pull request Jan 7, 2025
syzbot reports that a recent fix causes nesting issues between the (now)
raw timeoutlock and the eventfd locking:

=============================
[ BUG: Invalid wait context ]
6.13.0-rc4-00080-g9828a4c0901f torvalds#29 Not tainted
-----------------------------
kworker/u32:0/68094 is trying to lock:
ffff000014d7a520 (&ctx->wqh#2){..-.}-{3:3}, at: eventfd_signal_mask+0x64/0x180
other info that might help us debug this:
context-{5:5}
6 locks held by kworker/u32:0/68094:
 #0: ffff0000c1d98148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x4e8/0xfc0
 #1: ffff80008d927c78 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x53c/0xfc0
 #2: ffff0000c59bc3d8 (&ctx->completion_lock){+.+.}-{3:3}, at: io_kill_timeouts+0x40/0x180
 #3: ffff0000c59bc358 (&ctx->timeout_lock){-.-.}-{2:2}, at: io_kill_timeouts+0x48/0x180
 #4: ffff800085127aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x8/0x38
 #5: ffff800085127aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x8/0x38
stack backtrace:
CPU: 7 UID: 0 PID: 68094 Comm: kworker/u32:0 Not tainted 6.13.0-rc4-00080-g9828a4c0901f torvalds#29
Hardware name: linux,dummy-virt (DT)
Workqueue: iou_exit io_ring_exit_work
Call trace:
 show_stack+0x1c/0x30 (C)
 __dump_stack+0x24/0x30
 dump_stack_lvl+0x60/0x80
 dump_stack+0x14/0x20
 __lock_acquire+0x19f8/0x60c8
 lock_acquire+0x1a4/0x540
 _raw_spin_lock_irqsave+0x90/0xd0
 eventfd_signal_mask+0x64/0x180
 io_eventfd_signal+0x64/0x108
 io_req_local_work_add+0x294/0x430
 __io_req_task_work_add+0x1c0/0x270
 io_kill_timeout+0x1f0/0x288
 io_kill_timeouts+0xd4/0x180
 io_uring_try_cancel_requests+0x2e8/0x388
 io_ring_exit_work+0x150/0x550
 process_one_work+0x5e8/0xfc0
 worker_thread+0x7ec/0xc80
 kthread+0x24c/0x300
 ret_from_fork+0x10/0x20

because after the preempt-rt fix for the timeout lock nesting inside
the io-wq lock, we now have the eventfd spinlock nesting inside the
raw timeout spinlock.

Rather than play whack-a-mole with other nesting on the timeout lock,
split the deletion and killing of timeouts so queueing the task_work
for the timeout cancelations can get done outside of the timeout lock.

Reported-by: [email protected]
Fixes: 020b40f ("io_uring: make ctx->timeout_lock a raw spinlock")
Signed-off-by: Jens Axboe <[email protected]>
gsomlo pushed a commit that referenced this pull request Jan 7, 2025
…le_direct_reclaim()

The task sometimes continues looping in throttle_direct_reclaim() because
allow_direct_reclaim(pgdat) keeps returning false.  

 #0 [ffff80002cb6f8d0] __switch_to at ffff8000080095ac
 #1 [ffff80002cb6f900] __schedule at ffff800008abbd1c
 #2 [ffff80002cb6f990] schedule at ffff800008abc50c
 #3 [ffff80002cb6f9b0] throttle_direct_reclaim at ffff800008273550
 #4 [ffff80002cb6fa20] try_to_free_pages at ffff800008277b68
 #5 [ffff80002cb6fae0] __alloc_pages_nodemask at ffff8000082c4660
 #6 [ffff80002cb6fc50] alloc_pages_vma at ffff8000082e4a98
 #7 [ffff80002cb6fca0] do_anonymous_page at ffff80000829f5a8
 #8 [ffff80002cb6fce0] __handle_mm_fault at ffff8000082a5974
 #9 [ffff80002cb6fd90] handle_mm_fault at ffff8000082a5bd4

At this point, the pgdat contains the following two zones:

        NODE: 4  ZONE: 0  ADDR: ffff00817fffe540  NAME: "DMA32"
          SIZE: 20480  MIN/LOW/HIGH: 11/28/45
          VM_STAT:
                NR_FREE_PAGES: 359
        NR_ZONE_INACTIVE_ANON: 18813
          NR_ZONE_ACTIVE_ANON: 0
        NR_ZONE_INACTIVE_FILE: 50
          NR_ZONE_ACTIVE_FILE: 0
          NR_ZONE_UNEVICTABLE: 0
        NR_ZONE_WRITE_PENDING: 0
                     NR_MLOCK: 0
                    NR_BOUNCE: 0
                   NR_ZSPAGES: 0
            NR_FREE_CMA_PAGES: 0

        NODE: 4  ZONE: 1  ADDR: ffff00817fffec00  NAME: "Normal"
          SIZE: 8454144  PRESENT: 98304  MIN/LOW/HIGH: 68/166/264
          VM_STAT:
                NR_FREE_PAGES: 146
        NR_ZONE_INACTIVE_ANON: 94668
          NR_ZONE_ACTIVE_ANON: 3
        NR_ZONE_INACTIVE_FILE: 735
          NR_ZONE_ACTIVE_FILE: 78
          NR_ZONE_UNEVICTABLE: 0
        NR_ZONE_WRITE_PENDING: 0
                     NR_MLOCK: 0
                    NR_BOUNCE: 0
                   NR_ZSPAGES: 0
            NR_FREE_CMA_PAGES: 0

In allow_direct_reclaim(), while processing ZONE_DMA32, the sum of
inactive/active file-backed pages calculated in zone_reclaimable_pages()
based on the result of zone_page_state_snapshot() is zero.  

Additionally, since this system lacks swap, the calculation of inactive/
active anonymous pages is skipped.

        crash> p nr_swap_pages
        nr_swap_pages = $1937 = {
          counter = 0
        }

As a result, ZONE_DMA32 is deemed unreclaimable and skipped, moving on to
the processing of the next zone, ZONE_NORMAL, despite ZONE_DMA32 having
free pages significantly exceeding the high watermark.

The problem is that the pgdat->kswapd_failures hasn't been incremented.

        crash> px ((struct pglist_data *) 0xffff00817fffe540)->kswapd_failures
        $1935 = 0x0

This is because the node deemed balanced.  The node balancing logic in
balance_pgdat() evaluates all zones collectively.  If one or more zones
(e.g., ZONE_DMA32) have enough free pages to meet their watermarks, the
entire node is deemed balanced.  This causes balance_pgdat() to exit early
before incrementing the kswapd_failures, as it considers the overall
memory state acceptable, even though some zones (like ZONE_NORMAL) remain
under significant pressure.


The patch ensures that zone_reclaimable_pages() includes free pages
(NR_FREE_PAGES) in its calculation when no other reclaimable pages are
available (e.g., file-backed or anonymous pages).  This change prevents
zones like ZONE_DMA32, which have sufficient free pages, from being
mistakenly deemed unreclaimable.  By doing so, the patch ensures proper
node balancing, avoids masking pressure on other zones like ZONE_NORMAL,
and prevents infinite loops in throttle_direct_reclaim() caused by
allow_direct_reclaim(pgdat) repeatedly returning false.


The kernel hangs due to a task stuck in throttle_direct_reclaim(), caused
by a node being incorrectly deemed balanced despite pressure in certain
zones, such as ZONE_NORMAL.  This issue arises from
zone_reclaimable_pages() returning 0 for zones without reclaimable file-
backed or anonymous pages, causing zones like ZONE_DMA32 with sufficient
free pages to be skipped.

The lack of swap or reclaimable pages results in ZONE_DMA32 being ignored
during reclaim, masking pressure in other zones.  Consequently,
pgdat->kswapd_failures remains 0 in balance_pgdat(), preventing fallback
mechanisms in allow_direct_reclaim() from being triggered, leading to an
infinite loop in throttle_direct_reclaim().

This patch modifies zone_reclaimable_pages() to account for free pages
(NR_FREE_PAGES) when no other reclaimable pages exist.  This ensures zones
with sufficient free pages are not skipped, enabling proper balancing and
reclaim behavior.

[[email protected]: coding-style cleanups]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 5a1c84b ("mm: remove reclaim and compaction retry approximations")
Signed-off-by: Seiji Nishikawa <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
gsomlo pushed a commit that referenced this pull request Jan 7, 2025
…nt message

Address a bug in the kernel that triggers a "sleeping function called from
invalid context" warning when /sys/kernel/debug/kmemleak is printed under
specific conditions:
- CONFIG_PREEMPT_RT=y
- Set SELinux as the LSM for the system
- Set kptr_restrict to 1
- kmemleak buffer contains at least one item

BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 136, name: cat
preempt_count: 1, expected: 0
RCU nest depth: 2, expected: 2
6 locks held by cat/136:
 #0: ffff32e64bcbf950 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xb8/0xe30
 #1: ffffafe6aaa9dea0 (scan_mutex){+.+.}-{3:3}, at: kmemleak_seq_start+0x34/0x128
 #3: ffff32e6546b1cd0 (&object->lock){....}-{2:2}, at: kmemleak_seq_show+0x3c/0x1e0
 #4: ffffafe6aa8d8560 (rcu_read_lock){....}-{1:2}, at: has_ns_capability_noaudit+0x8/0x1b0
 #5: ffffafe6aabbc0f8 (notif_lock){+.+.}-{2:2}, at: avc_compute_av+0xc4/0x3d0
irq event stamp: 136660
hardirqs last  enabled at (136659): [<ffffafe6a80fd7a0>] _raw_spin_unlock_irqrestore+0xa8/0xd8
hardirqs last disabled at (136660): [<ffffafe6a80fd85c>] _raw_spin_lock_irqsave+0x8c/0xb0
softirqs last  enabled at (0): [<ffffafe6a5d50b28>] copy_process+0x11d8/0x3df8
softirqs last disabled at (0): [<0000000000000000>] 0x0
Preemption disabled at:
[<ffffafe6a6598a4c>] kmemleak_seq_show+0x3c/0x1e0
CPU: 1 UID: 0 PID: 136 Comm: cat Tainted: G            E      6.11.0-rt7+ torvalds#34
Tainted: [E]=UNSIGNED_MODULE
Hardware name: linux,dummy-virt (DT)
Call trace:
 dump_backtrace+0xa0/0x128
 show_stack+0x1c/0x30
 dump_stack_lvl+0xe8/0x198
 dump_stack+0x18/0x20
 rt_spin_lock+0x8c/0x1a8
 avc_perm_nonode+0xa0/0x150
 cred_has_capability.isra.0+0x118/0x218
 selinux_capable+0x50/0x80
 security_capable+0x7c/0xd0
 has_ns_capability_noaudit+0x94/0x1b0
 has_capability_noaudit+0x20/0x30
 restricted_pointer+0x21c/0x4b0
 pointer+0x298/0x760
 vsnprintf+0x330/0xf70
 seq_printf+0x178/0x218
 print_unreferenced+0x1a4/0x2d0
 kmemleak_seq_show+0xd0/0x1e0
 seq_read_iter+0x354/0xe30
 seq_read+0x250/0x378
 full_proxy_read+0xd8/0x148
 vfs_read+0x190/0x918
 ksys_read+0xf0/0x1e0
 __arm64_sys_read+0x70/0xa8
 invoke_syscall.constprop.0+0xd4/0x1d8
 el0_svc+0x50/0x158
 el0t_64_sync+0x17c/0x180

%pS and %pK, in the same back trace line, are redundant, and %pS can void
%pK service in certain contexts.

%pS alone already provides the necessary information, and if it cannot
resolve the symbol, it falls back to printing the raw address voiding
the original intent behind the %pK.

Additionally, %pK requires a privilege check CAP_SYSLOG enforced through
the LSM, which can trigger a "sleeping function called from invalid
context" warning under RT_PREEMPT kernels when the check occurs in an
atomic context. This issue may also affect other LSMs.

This change avoids the unnecessary privilege check and resolves the
sleeping function warning without any loss of information.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 3a6f33d ("mm/kmemleak: use %pK to display kernel pointers in backtrace")
Signed-off-by: Alessandro Carminati <[email protected]>
Acked-by: Sebastian Andrzej Siewior <[email protected]>
Acked-by: Catalin Marinas <[email protected]>
Cc: Clément Léger <[email protected]>
Cc: Alessandro Carminati <[email protected]>
Cc: Eric Chanudet <[email protected]>
Cc: Gabriele Paoloni <[email protected]>
Cc: Juri Lelli <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Thomas Weißschuh <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
gsomlo pushed a commit that referenced this pull request Jan 15, 2025
The tcpci_irq() may meet below NULL pointer dereference issue:

[    2.641851] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010
[    2.641951] status 0x1, 0x37f
[    2.650659] Mem abort info:
[    2.656490]   ESR = 0x0000000096000004
[    2.660230]   EC = 0x25: DABT (current EL), IL = 32 bits
[    2.665532]   SET = 0, FnV = 0
[    2.668579]   EA = 0, S1PTW = 0
[    2.671715]   FSC = 0x04: level 0 translation fault
[    2.676584] Data abort info:
[    2.679459]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
[    2.684936]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[    2.689980]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[    2.695284] [0000000000000010] user address but active_mm is swapper
[    2.701632] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
[    2.707883] Modules linked in:
[    2.710936] CPU: 1 UID: 0 PID: 87 Comm: irq/111-2-0051 Not tainted 6.12.0-rc6-06316-g7f63786ad3d1-dirty #4
[    2.720570] Hardware name: NXP i.MX93 11X11 EVK board (DT)
[    2.726040] pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[    2.732989] pc : tcpci_irq+0x38/0x318
[    2.736647] lr : _tcpci_irq+0x14/0x20
[    2.740295] sp : ffff80008324bd30
[    2.743597] x29: ffff80008324bd70 x28: ffff800080107894 x27: ffff800082198f70
[    2.750721] x26: ffff0000050e6680 x25: ffff000004d172ac x24: ffff0000050f0000
[    2.757845] x23: ffff000004d17200 x22: 0000000000000001 x21: ffff0000050f0000
[    2.764969] x20: ffff000004d17200 x19: 0000000000000000 x18: 0000000000000001
[    2.772093] x17: 0000000000000000 x16: ffff80008183d8a0 x15: ffff00007fbab040
[    2.779217] x14: ffff00007fb918c0 x13: 0000000000000000 x12: 000000000000017a
[    2.786341] x11: 0000000000000001 x10: 0000000000000a90 x9 : ffff80008324bd00
[    2.793465] x8 : ffff0000050f0af0 x7 : ffff00007fbaa840 x6 : 0000000000000031
[    2.800589] x5 : 000000000000017a x4 : 0000000000000002 x3 : 0000000000000002
[    2.807713] x2 : ffff80008324bd3a x1 : 0000000000000010 x0 : 0000000000000000
[    2.814838] Call trace:
[    2.817273]  tcpci_irq+0x38/0x318
[    2.820583]  _tcpci_irq+0x14/0x20
[    2.823885]  irq_thread_fn+0x2c/0xa8
[    2.827456]  irq_thread+0x16c/0x2f4
[    2.830940]  kthread+0x110/0x114
[    2.834164]  ret_from_fork+0x10/0x20
[    2.837738] Code: f9426420 f9001fe0 d2800000 52800201 (f9400a60)

This may happen on shared irq case. Such as two Type-C ports share one
irq. After the first port finished tcpci_register_port(), it may trigger
interrupt. However, if the interrupt comes by chance the 2nd port finishes
devm_request_threaded_irq(), the 2nd port interrupt handler will run at
first. Then the above issue happens due to tcpci is still a NULL pointer
in tcpci_irq() when dereference to regmap.

  devm_request_threaded_irq()
				<-- port1 irq comes
  disable_irq(client->irq);
  tcpci_register_port()

This will restore the logic to the state before commit (77e8510 "usb:
typec: tcpci: support edge irq").

However, moving tcpci_register_port() earlier creates a problem when use
edge irq because tcpci_init() will be called before
devm_request_threaded_irq(). The tcpci_init() writes the ALERT_MASK to
the hardware to tell it to start generating interrupts but we're not ready
to deal with them yet, then the ALERT events may be missed and ALERT line
will not recover to high level forever. To avoid the issue, this will also
set ALERT_MASK register after devm_request_threaded_irq() return.

Fixes: 77e8510 ("usb: typec: tcpci: support edge irq")
Cc: stable <[email protected]>
Tested-by: Emanuele Ghidoli <[email protected]>
Signed-off-by: Xu Yang <[email protected]>
Reviewed-by: Francesco Dolcini <[email protected]>
Reviewed-by: Heikki Krogerus <[email protected]>
Reviewed-by: Dan Carpenter <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
gsomlo pushed a commit that referenced this pull request Jan 19, 2025
irq_chip functions may be called in raw spinlock context. Therefore, we
must also use a raw spinlock for our own internal locking.

This fixes the following lockdep splat:

[    5.349336] =============================
[    5.353349] [ BUG: Invalid wait context ]
[    5.357361] 6.13.0-rc5+ torvalds#69 Tainted: G        W
[    5.363031] -----------------------------
[    5.367045] kworker/u17:1/44 is trying to lock:
[    5.371587] ffffff88018b02c0 (&chip->gpio_lock){....}-{3:3}, at: xgpio_irq_unmask (drivers/gpio/gpio-xilinx.c:433 (discriminator 8))
[    5.380079] other info that might help us debug this:
[    5.385138] context-{5:5}
[    5.387762] 5 locks held by kworker/u17:1/44:
[    5.392123] #0: ffffff8800014958 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work (kernel/workqueue.c:3204)
[    5.402260] #1: ffffffc082fcbdd8 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work (kernel/workqueue.c:3205)
[    5.411528] #2: ffffff880172c900 (&dev->mutex){....}-{4:4}, at: __device_attach (drivers/base/dd.c:1006)
[    5.419929] #3: ffffff88039c8268 (request_class#2){+.+.}-{4:4}, at: __setup_irq (kernel/irq/internals.h:156 kernel/irq/manage.c:1596)
[    5.428331] #4: ffffff88039c80c8 (lock_class#2){....}-{2:2}, at: __setup_irq (kernel/irq/manage.c:1614)
[    5.436472] stack backtrace:
[    5.439359] CPU: 2 UID: 0 PID: 44 Comm: kworker/u17:1 Tainted: G        W          6.13.0-rc5+ torvalds#69
[    5.448690] Tainted: [W]=WARN
[    5.451656] Hardware name: xlnx,zynqmp (DT)
[    5.455845] Workqueue: events_unbound deferred_probe_work_func
[    5.461699] Call trace:
[    5.464147] show_stack+0x18/0x24 C
[    5.467821] dump_stack_lvl (lib/dump_stack.c:123)
[    5.471501] dump_stack (lib/dump_stack.c:130)
[    5.474824] __lock_acquire (kernel/locking/lockdep.c:4828 kernel/locking/lockdep.c:4898 kernel/locking/lockdep.c:5176)
[    5.478758] lock_acquire (arch/arm64/include/asm/percpu.h:40 kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851 kernel/locking/lockdep.c:5814)
[    5.482429] _raw_spin_lock_irqsave (include/linux/spinlock_api_smp.h:111 kernel/locking/spinlock.c:162)
[    5.486797] xgpio_irq_unmask (drivers/gpio/gpio-xilinx.c:433 (discriminator 8))
[    5.490737] irq_enable (kernel/irq/internals.h:236 kernel/irq/chip.c:170 kernel/irq/chip.c:439 kernel/irq/chip.c:432 kernel/irq/chip.c:345)
[    5.494060] __irq_startup (kernel/irq/internals.h:241 kernel/irq/chip.c:180 kernel/irq/chip.c:250)
[    5.497645] irq_startup (kernel/irq/chip.c:270)
[    5.501143] __setup_irq (kernel/irq/manage.c:1807)
[    5.504728] request_threaded_irq (kernel/irq/manage.c:2208)

Fixes: a32c7ca ("gpio: gpio-xilinx: Add interrupt support")
Signed-off-by: Sean Anderson <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Bartosz Golaszewski <[email protected]>
gsomlo pushed a commit that referenced this pull request Jan 19, 2025
This commit addresses a circular locking dependency issue within the GFX
isolation mechanism. The problem was identified by a warning indicating
a potential deadlock due to inconsistent lock acquisition order.

- The `amdgpu_gfx_enforce_isolation_ring_begin_use` and
  `amdgpu_gfx_enforce_isolation_ring_end_use` functions previously
  acquired `enforce_isolation_mutex` and called `amdgpu_gfx_kfd_sch_ctrl`,
  leading to potential deadlocks. ie., If `amdgpu_gfx_kfd_sch_ctrl` is
  called while `enforce_isolation_mutex` is held, and
  `amdgpu_gfx_enforce_isolation_handler` is called while `kfd_sch_mutex` is
  held, it can create a circular dependency.

By ensuring consistent lock usage, this fix resolves the issue:

[  606.297333] ======================================================
[  606.297343] WARNING: possible circular locking dependency detected
[  606.297353] 6.10.0-amd-mlkd-610-311224-lof torvalds#19 Tainted: G           OE
[  606.297365] ------------------------------------------------------
[  606.297375] kworker/u96:3/3825 is trying to acquire lock:
[  606.297385] ffff9aa64e431cb8 ((work_completion)(&(&adev->gfx.enforce_isolation[i].work)->work)){+.+.}-{0:0}, at: __flush_work+0x232/0x610
[  606.297413]
               but task is already holding lock:
[  606.297423] ffff9aa64e432338 (&adev->gfx.kfd_sch_mutex){+.+.}-{3:3}, at: amdgpu_gfx_kfd_sch_ctrl+0x51/0x4d0 [amdgpu]
[  606.297725]
               which lock already depends on the new lock.

[  606.297738]
               the existing dependency chain (in reverse order) is:
[  606.297749]
               -> #2 (&adev->gfx.kfd_sch_mutex){+.+.}-{3:3}:
[  606.297765]        __mutex_lock+0x85/0x930
[  606.297776]        mutex_lock_nested+0x1b/0x30
[  606.297786]        amdgpu_gfx_kfd_sch_ctrl+0x51/0x4d0 [amdgpu]
[  606.298007]        amdgpu_gfx_enforce_isolation_ring_begin_use+0x2a4/0x5d0 [amdgpu]
[  606.298225]        amdgpu_ring_alloc+0x48/0x70 [amdgpu]
[  606.298412]        amdgpu_ib_schedule+0x176/0x8a0 [amdgpu]
[  606.298603]        amdgpu_job_run+0xac/0x1e0 [amdgpu]
[  606.298866]        drm_sched_run_job_work+0x24f/0x430 [gpu_sched]
[  606.298880]        process_one_work+0x21e/0x680
[  606.298890]        worker_thread+0x190/0x350
[  606.298899]        kthread+0xe7/0x120
[  606.298908]        ret_from_fork+0x3c/0x60
[  606.298919]        ret_from_fork_asm+0x1a/0x30
[  606.298929]
               -> #1 (&adev->enforce_isolation_mutex){+.+.}-{3:3}:
[  606.298947]        __mutex_lock+0x85/0x930
[  606.298956]        mutex_lock_nested+0x1b/0x30
[  606.298966]        amdgpu_gfx_enforce_isolation_handler+0x87/0x370 [amdgpu]
[  606.299190]        process_one_work+0x21e/0x680
[  606.299199]        worker_thread+0x190/0x350
[  606.299208]        kthread+0xe7/0x120
[  606.299217]        ret_from_fork+0x3c/0x60
[  606.299227]        ret_from_fork_asm+0x1a/0x30
[  606.299236]
               -> #0 ((work_completion)(&(&adev->gfx.enforce_isolation[i].work)->work)){+.+.}-{0:0}:
[  606.299257]        __lock_acquire+0x16f9/0x2810
[  606.299267]        lock_acquire+0xd1/0x300
[  606.299276]        __flush_work+0x250/0x610
[  606.299286]        cancel_delayed_work_sync+0x71/0x80
[  606.299296]        amdgpu_gfx_kfd_sch_ctrl+0x287/0x4d0 [amdgpu]
[  606.299509]        amdgpu_gfx_enforce_isolation_ring_begin_use+0x2a4/0x5d0 [amdgpu]
[  606.299723]        amdgpu_ring_alloc+0x48/0x70 [amdgpu]
[  606.299909]        amdgpu_ib_schedule+0x176/0x8a0 [amdgpu]
[  606.300101]        amdgpu_job_run+0xac/0x1e0 [amdgpu]
[  606.300355]        drm_sched_run_job_work+0x24f/0x430 [gpu_sched]
[  606.300369]        process_one_work+0x21e/0x680
[  606.300378]        worker_thread+0x190/0x350
[  606.300387]        kthread+0xe7/0x120
[  606.300396]        ret_from_fork+0x3c/0x60
[  606.300406]        ret_from_fork_asm+0x1a/0x30
[  606.300416]
               other info that might help us debug this:

[  606.300428] Chain exists of:
                 (work_completion)(&(&adev->gfx.enforce_isolation[i].work)->work) --> &adev->enforce_isolation_mutex --> &adev->gfx.kfd_sch_mutex

[  606.300458]  Possible unsafe locking scenario:

[  606.300468]        CPU0                    CPU1
[  606.300476]        ----                    ----
[  606.300484]   lock(&adev->gfx.kfd_sch_mutex);
[  606.300494]                                lock(&adev->enforce_isolation_mutex);
[  606.300508]                                lock(&adev->gfx.kfd_sch_mutex);
[  606.300521]   lock((work_completion)(&(&adev->gfx.enforce_isolation[i].work)->work));
[  606.300536]
                *** DEADLOCK ***

[  606.300546] 5 locks held by kworker/u96:3/3825:
[  606.300555]  #0: ffff9aa5aa1f5d58 ((wq_completion)comp_1.1.0){+.+.}-{0:0}, at: process_one_work+0x3f5/0x680
[  606.300577]  #1: ffffaa53c3c97e40 ((work_completion)(&sched->work_run_job)){+.+.}-{0:0}, at: process_one_work+0x1d6/0x680
[  606.300600]  #2: ffff9aa64e463c98 (&adev->enforce_isolation_mutex){+.+.}-{3:3}, at: amdgpu_gfx_enforce_isolation_ring_begin_use+0x1c3/0x5d0 [amdgpu]
[  606.300837]  #3: ffff9aa64e432338 (&adev->gfx.kfd_sch_mutex){+.+.}-{3:3}, at: amdgpu_gfx_kfd_sch_ctrl+0x51/0x4d0 [amdgpu]
[  606.301062]  #4: ffffffff8c1a5660 (rcu_read_lock){....}-{1:2}, at: __flush_work+0x70/0x610
[  606.301083]
               stack backtrace:
[  606.301092] CPU: 14 PID: 3825 Comm: kworker/u96:3 Tainted: G           OE      6.10.0-amd-mlkd-610-311224-lof torvalds#19
[  606.301109] Hardware name: Gigabyte Technology Co., Ltd. X570S GAMING X/X570S GAMING X, BIOS F7 03/22/2024
[  606.301124] Workqueue: comp_1.1.0 drm_sched_run_job_work [gpu_sched]
[  606.301140] Call Trace:
[  606.301146]  <TASK>
[  606.301154]  dump_stack_lvl+0x9b/0xf0
[  606.301166]  dump_stack+0x10/0x20
[  606.301175]  print_circular_bug+0x26c/0x340
[  606.301187]  check_noncircular+0x157/0x170
[  606.301197]  ? register_lock_class+0x48/0x490
[  606.301213]  __lock_acquire+0x16f9/0x2810
[  606.301230]  lock_acquire+0xd1/0x300
[  606.301239]  ? __flush_work+0x232/0x610
[  606.301250]  ? srso_alias_return_thunk+0x5/0xfbef5
[  606.301261]  ? mark_held_locks+0x54/0x90
[  606.301274]  ? __flush_work+0x232/0x610
[  606.301284]  __flush_work+0x250/0x610
[  606.301293]  ? __flush_work+0x232/0x610
[  606.301305]  ? __pfx_wq_barrier_func+0x10/0x10
[  606.301318]  ? mark_held_locks+0x54/0x90
[  606.301331]  ? srso_alias_return_thunk+0x5/0xfbef5
[  606.301345]  cancel_delayed_work_sync+0x71/0x80
[  606.301356]  amdgpu_gfx_kfd_sch_ctrl+0x287/0x4d0 [amdgpu]
[  606.301661]  amdgpu_gfx_enforce_isolation_ring_begin_use+0x2a4/0x5d0 [amdgpu]
[  606.302050]  ? srso_alias_return_thunk+0x5/0xfbef5
[  606.302069]  amdgpu_ring_alloc+0x48/0x70 [amdgpu]
[  606.302452]  amdgpu_ib_schedule+0x176/0x8a0 [amdgpu]
[  606.302862]  ? drm_sched_entity_error+0x82/0x190 [gpu_sched]
[  606.302890]  amdgpu_job_run+0xac/0x1e0 [amdgpu]
[  606.303366]  drm_sched_run_job_work+0x24f/0x430 [gpu_sched]
[  606.303388]  process_one_work+0x21e/0x680
[  606.303409]  worker_thread+0x190/0x350
[  606.303424]  ? __pfx_worker_thread+0x10/0x10
[  606.303437]  kthread+0xe7/0x120
[  606.303449]  ? __pfx_kthread+0x10/0x10
[  606.303463]  ret_from_fork+0x3c/0x60
[  606.303476]  ? __pfx_kthread+0x10/0x10
[  606.303489]  ret_from_fork_asm+0x1a/0x30
[  606.303512]  </TASK>

v2: Refactor lock handling to resolve circular dependency (Alex)

- Introduced a `sched_work` flag to defer the call to
  `amdgpu_gfx_kfd_sch_ctrl` until after releasing
  `enforce_isolation_mutex`.
- This change ensures that `amdgpu_gfx_kfd_sch_ctrl` is called outside
  the critical section, preventing the circular dependency and deadlock.
- The `sched_work` flag is set within the mutex-protected section if
  conditions are met, and the actual function call is made afterward.
- This approach ensures consistent lock acquisition order.

Fixes: afefd6f ("drm/amdgpu: Implement Enforce Isolation Handler for KGD/KFD serialization")
Cc: Christian König <[email protected]>
Cc: Alex Deucher <[email protected]>
Signed-off-by: Srinivasan Shanmugam <[email protected]>
Suggested-by: Alex Deucher <[email protected]>
Reviewed-by: Alex Deucher <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>
(cherry picked from commit 0b6b2dd)
Cc: [email protected]
gsomlo pushed a commit that referenced this pull request Jan 19, 2025
Attempt to enable IPsec packet offload in tunnel mode in debug kernel
generates the following kernel panic, which is happening due to two
issues:
1. In SA add section, the should be _bh() variant when marking SA mode.
2. There is not needed flush_workqueue in SA delete routine. It is not
needed as at this stage as it is removed from SADB and the running work
will be canceled later in SA free.

 =====================================================
 WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
 6.12.0+ #4 Not tainted
 -----------------------------------------------------
 charon/1337 [HC0[0]:SC0[4]:HE1:SE0] is trying to acquire:
 ffff88810f365020 (&xa->xa_lock#24){+.+.}-{3:3}, at: mlx5e_xfrm_del_state+0xca/0x1e0 [mlx5_core]

 and this task is already holding:
 ffff88813e0f0d48 (&x->lock){+.-.}-{3:3}, at: xfrm_state_delete+0x16/0x30
 which would create a new lock dependency:
  (&x->lock){+.-.}-{3:3} -> (&xa->xa_lock#24){+.+.}-{3:3}

 but this new dependency connects a SOFTIRQ-irq-safe lock:
  (&x->lock){+.-.}-{3:3}

 ... which became SOFTIRQ-irq-safe at:
   lock_acquire+0x1be/0x520
   _raw_spin_lock_bh+0x34/0x40
   xfrm_timer_handler+0x91/0xd70
   __hrtimer_run_queues+0x1dd/0xa60
   hrtimer_run_softirq+0x146/0x2e0
   handle_softirqs+0x266/0x860
   irq_exit_rcu+0x115/0x1a0
   sysvec_apic_timer_interrupt+0x6e/0x90
   asm_sysvec_apic_timer_interrupt+0x16/0x20
   default_idle+0x13/0x20
   default_idle_call+0x67/0xa0
   do_idle+0x2da/0x320
   cpu_startup_entry+0x50/0x60
   start_secondary+0x213/0x2a0
   common_startup_64+0x129/0x138

 to a SOFTIRQ-irq-unsafe lock:
  (&xa->xa_lock#24){+.+.}-{3:3}

 ... which became SOFTIRQ-irq-unsafe at:
 ...
   lock_acquire+0x1be/0x520
   _raw_spin_lock+0x2c/0x40
   xa_set_mark+0x70/0x110
   mlx5e_xfrm_add_state+0xe48/0x2290 [mlx5_core]
   xfrm_dev_state_add+0x3bb/0xd70
   xfrm_add_sa+0x2451/0x4a90
   xfrm_user_rcv_msg+0x493/0x880
   netlink_rcv_skb+0x12e/0x380
   xfrm_netlink_rcv+0x6d/0x90
   netlink_unicast+0x42f/0x740
   netlink_sendmsg+0x745/0xbe0
   __sock_sendmsg+0xc5/0x190
   __sys_sendto+0x1fe/0x2c0
   __x64_sys_sendto+0xdc/0x1b0
   do_syscall_64+0x6d/0x140
   entry_SYSCALL_64_after_hwframe+0x4b/0x53

 other info that might help us debug this:

  Possible interrupt unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(&xa->xa_lock#24);
                                local_irq_disable();
                                lock(&x->lock);
                                lock(&xa->xa_lock#24);
   <Interrupt>
     lock(&x->lock);

  *** DEADLOCK ***

 2 locks held by charon/1337:
  #0: ffffffff87f8f858 (&net->xfrm.xfrm_cfg_mutex){+.+.}-{4:4}, at: xfrm_netlink_rcv+0x5e/0x90
  #1: ffff88813e0f0d48 (&x->lock){+.-.}-{3:3}, at: xfrm_state_delete+0x16/0x30

 the dependencies between SOFTIRQ-irq-safe lock and the holding lock:
 -> (&x->lock){+.-.}-{3:3} ops: 29 {
    HARDIRQ-ON-W at:
                     lock_acquire+0x1be/0x520
                     _raw_spin_lock_bh+0x34/0x40
                     xfrm_alloc_spi+0xc0/0xe60
                     xfrm_alloc_userspi+0x5f6/0xbc0
                     xfrm_user_rcv_msg+0x493/0x880
                     netlink_rcv_skb+0x12e/0x380
                     xfrm_netlink_rcv+0x6d/0x90
                     netlink_unicast+0x42f/0x740
                     netlink_sendmsg+0x745/0xbe0
                     __sock_sendmsg+0xc5/0x190
                     __sys_sendto+0x1fe/0x2c0
                     __x64_sys_sendto+0xdc/0x1b0
                     do_syscall_64+0x6d/0x140
                     entry_SYSCALL_64_after_hwframe+0x4b/0x53
    IN-SOFTIRQ-W at:
                     lock_acquire+0x1be/0x520
                     _raw_spin_lock_bh+0x34/0x40
                     xfrm_timer_handler+0x91/0xd70
                     __hrtimer_run_queues+0x1dd/0xa60
                     hrtimer_run_softirq+0x146/0x2e0
                     handle_softirqs+0x266/0x860
                     irq_exit_rcu+0x115/0x1a0
                     sysvec_apic_timer_interrupt+0x6e/0x90
                     asm_sysvec_apic_timer_interrupt+0x16/0x20
                     default_idle+0x13/0x20
                     default_idle_call+0x67/0xa0
                     do_idle+0x2da/0x320
                     cpu_startup_entry+0x50/0x60
                     start_secondary+0x213/0x2a0
                     common_startup_64+0x129/0x138
    INITIAL USE at:
                    lock_acquire+0x1be/0x520
                    _raw_spin_lock_bh+0x34/0x40
                    xfrm_alloc_spi+0xc0/0xe60
                    xfrm_alloc_userspi+0x5f6/0xbc0
                    xfrm_user_rcv_msg+0x493/0x880
                    netlink_rcv_skb+0x12e/0x380
                    xfrm_netlink_rcv+0x6d/0x90
                    netlink_unicast+0x42f/0x740
                    netlink_sendmsg+0x745/0xbe0
                    __sock_sendmsg+0xc5/0x190
                    __sys_sendto+0x1fe/0x2c0
                    __x64_sys_sendto+0xdc/0x1b0
                    do_syscall_64+0x6d/0x140
                    entry_SYSCALL_64_after_hwframe+0x4b/0x53
  }
  ... key      at: [<ffffffff87f9cd20>] __key.18+0x0/0x40

 the dependencies between the lock to be acquired
  and SOFTIRQ-irq-unsafe lock:
 -> (&xa->xa_lock#24){+.+.}-{3:3} ops: 9 {
    HARDIRQ-ON-W at:
                     lock_acquire+0x1be/0x520
                     _raw_spin_lock_bh+0x34/0x40
                     mlx5e_xfrm_add_state+0xc5b/0x2290 [mlx5_core]
                     xfrm_dev_state_add+0x3bb/0xd70
                     xfrm_add_sa+0x2451/0x4a90
                     xfrm_user_rcv_msg+0x493/0x880
                     netlink_rcv_skb+0x12e/0x380
                     xfrm_netlink_rcv+0x6d/0x90
                     netlink_unicast+0x42f/0x740
                     netlink_sendmsg+0x745/0xbe0
                     __sock_sendmsg+0xc5/0x190
                     __sys_sendto+0x1fe/0x2c0
                     __x64_sys_sendto+0xdc/0x1b0
                     do_syscall_64+0x6d/0x140
                     entry_SYSCALL_64_after_hwframe+0x4b/0x53
    SOFTIRQ-ON-W at:
                     lock_acquire+0x1be/0x520
                     _raw_spin_lock+0x2c/0x40
                     xa_set_mark+0x70/0x110
                     mlx5e_xfrm_add_state+0xe48/0x2290 [mlx5_core]
                     xfrm_dev_state_add+0x3bb/0xd70
                     xfrm_add_sa+0x2451/0x4a90
                     xfrm_user_rcv_msg+0x493/0x880
                     netlink_rcv_skb+0x12e/0x380
                     xfrm_netlink_rcv+0x6d/0x90
                     netlink_unicast+0x42f/0x740
                     netlink_sendmsg+0x745/0xbe0
                     __sock_sendmsg+0xc5/0x190
                     __sys_sendto+0x1fe/0x2c0
                     __x64_sys_sendto+0xdc/0x1b0
                     do_syscall_64+0x6d/0x140
                     entry_SYSCALL_64_after_hwframe+0x4b/0x53
    INITIAL USE at:
                    lock_acquire+0x1be/0x520
                    _raw_spin_lock_bh+0x34/0x40
                    mlx5e_xfrm_add_state+0xc5b/0x2290 [mlx5_core]
                    xfrm_dev_state_add+0x3bb/0xd70
                    xfrm_add_sa+0x2451/0x4a90
                    xfrm_user_rcv_msg+0x493/0x880
                    netlink_rcv_skb+0x12e/0x380
                    xfrm_netlink_rcv+0x6d/0x90
                    netlink_unicast+0x42f/0x740
                    netlink_sendmsg+0x745/0xbe0
                    __sock_sendmsg+0xc5/0x190
                    __sys_sendto+0x1fe/0x2c0
                    __x64_sys_sendto+0xdc/0x1b0
                    do_syscall_64+0x6d/0x140
                    entry_SYSCALL_64_after_hwframe+0x4b/0x53
  }
  ... key      at: [<ffffffffa078ff60>] __key.48+0x0/0xfffffffffff210a0 [mlx5_core]
  ... acquired at:
    __lock_acquire+0x30a0/0x5040
    lock_acquire+0x1be/0x520
    _raw_spin_lock_bh+0x34/0x40
    mlx5e_xfrm_del_state+0xca/0x1e0 [mlx5_core]
    xfrm_dev_state_delete+0x90/0x160
    __xfrm_state_delete+0x662/0xae0
    xfrm_state_delete+0x1e/0x30
    xfrm_del_sa+0x1c2/0x340
    xfrm_user_rcv_msg+0x493/0x880
    netlink_rcv_skb+0x12e/0x380
    xfrm_netlink_rcv+0x6d/0x90
    netlink_unicast+0x42f/0x740
    netlink_sendmsg+0x745/0xbe0
    __sock_sendmsg+0xc5/0x190
    __sys_sendto+0x1fe/0x2c0
    __x64_sys_sendto+0xdc/0x1b0
    do_syscall_64+0x6d/0x140
    entry_SYSCALL_64_after_hwframe+0x4b/0x53

 stack backtrace:
 CPU: 7 UID: 0 PID: 1337 Comm: charon Not tainted 6.12.0+ #4
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
 Call Trace:
  <TASK>
  dump_stack_lvl+0x74/0xd0
  check_irq_usage+0x12e8/0x1d90
  ? print_shortest_lock_dependencies_backwards+0x1b0/0x1b0
  ? check_chain_key+0x1bb/0x4c0
  ? __lockdep_reset_lock+0x180/0x180
  ? check_path.constprop.0+0x24/0x50
  ? mark_lock+0x108/0x2fb0
  ? print_circular_bug+0x9b0/0x9b0
  ? mark_lock+0x108/0x2fb0
  ? print_usage_bug.part.0+0x670/0x670
  ? check_prev_add+0x1c4/0x2310
  check_prev_add+0x1c4/0x2310
  __lock_acquire+0x30a0/0x5040
  ? lockdep_set_lock_cmp_fn+0x190/0x190
  ? lockdep_set_lock_cmp_fn+0x190/0x190
  lock_acquire+0x1be/0x520
  ? mlx5e_xfrm_del_state+0xca/0x1e0 [mlx5_core]
  ? lockdep_hardirqs_on_prepare+0x400/0x400
  ? __xfrm_state_delete+0x5f0/0xae0
  ? lock_downgrade+0x6b0/0x6b0
  _raw_spin_lock_bh+0x34/0x40
  ? mlx5e_xfrm_del_state+0xca/0x1e0 [mlx5_core]
  mlx5e_xfrm_del_state+0xca/0x1e0 [mlx5_core]
  xfrm_dev_state_delete+0x90/0x160
  __xfrm_state_delete+0x662/0xae0
  xfrm_state_delete+0x1e/0x30
  xfrm_del_sa+0x1c2/0x340
  ? xfrm_get_sa+0x250/0x250
  ? check_chain_key+0x1bb/0x4c0
  xfrm_user_rcv_msg+0x493/0x880
  ? copy_sec_ctx+0x270/0x270
  ? check_chain_key+0x1bb/0x4c0
  ? lockdep_set_lock_cmp_fn+0x190/0x190
  ? lockdep_set_lock_cmp_fn+0x190/0x190
  netlink_rcv_skb+0x12e/0x380
  ? copy_sec_ctx+0x270/0x270
  ? netlink_ack+0xd90/0xd90
  ? netlink_deliver_tap+0xcd/0xb60
  xfrm_netlink_rcv+0x6d/0x90
  netlink_unicast+0x42f/0x740
  ? netlink_attachskb+0x730/0x730
  ? lock_acquire+0x1be/0x520
  netlink_sendmsg+0x745/0xbe0
  ? netlink_unicast+0x740/0x740
  ? __might_fault+0xbb/0x170
  ? netlink_unicast+0x740/0x740
  __sock_sendmsg+0xc5/0x190
  ? fdget+0x163/0x1d0
  __sys_sendto+0x1fe/0x2c0
  ? __x64_sys_getpeername+0xb0/0xb0
  ? do_user_addr_fault+0x856/0xe30
  ? lock_acquire+0x1be/0x520
  ? __task_pid_nr_ns+0x117/0x410
  ? lock_downgrade+0x6b0/0x6b0
  __x64_sys_sendto+0xdc/0x1b0
  ? lockdep_hardirqs_on_prepare+0x284/0x400
  do_syscall_64+0x6d/0x140
  entry_SYSCALL_64_after_hwframe+0x4b/0x53
 RIP: 0033:0x7f7d31291ba4
 Code: 7d e8 89 4d d4 e8 4c 42 f7 ff 44 8b 4d d0 4c 8b 45 c8 89 c3 44 8b 55 d4 8b 7d e8 b8 2c 00 00 00 48 8b 55 d8 48 8b 75 e0 0f 05 <48> 3d 00 f0 ff ff 77 34 89 df 48 89 45 e8 e8 99 42 f7 ff 48 8b 45
 RSP: 002b:00007f7d2ccd94f0 EFLAGS: 00000297 ORIG_RAX: 000000000000002c
 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f7d31291ba4
 RDX: 0000000000000028 RSI: 00007f7d2ccd96a0 RDI: 000000000000000a
 RBP: 00007f7d2ccd9530 R08: 00007f7d2ccd9598 R09: 000000000000000c
 R10: 0000000000000000 R11: 0000000000000297 R12: 0000000000000028
 R13: 00007f7d2ccd9598 R14: 00007f7d2ccd96a0 R15: 00000000000000e1
  </TASK>

Fixes: 4c24272 ("net/mlx5e: Listen to ARP events to update IPsec L2 headers in tunnel mode")
Signed-off-by: Leon Romanovsky <[email protected]>
Signed-off-by: Tariq Toukan <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>
gsomlo pushed a commit that referenced this pull request Feb 7, 2025
When COWing a relocation tree path, at relocation.c:replace_path(), we
can trigger a lockdep splat while we are in the btrfs_search_slot() call
against the relocation root. This happens in that callchain at
ctree.c:read_block_for_search() when we happen to find a child extent
buffer already loaded through the fs tree with a lockdep class set to
the fs tree. So when we attempt to lock that extent buffer through a
relocation tree we have to reset the lockdep class to the class for a
relocation tree, since a relocation tree has extent buffers that used
to belong to a fs tree and may currently be already loaded (we swap
extent buffers between the two trees at the end of replace_path()).

However we are missing calls to btrfs_maybe_reset_lockdep_class() to reset
the lockdep class at ctree.c:read_block_for_search() before we read lock
an extent buffer, just like we did for btrfs_search_slot() in commit
b40130b ("btrfs: fix lockdep splat with reloc root extent buffers").

So add the missing btrfs_maybe_reset_lockdep_class() calls before the
attempts to read lock an extent buffer at ctree.c:read_block_for_search().

The lockdep splat was reported by syzbot and it looks like this:

   ======================================================
   WARNING: possible circular locking dependency detected
   6.13.0-rc5-syzkaller-00163-gab75170520d4 #0 Not tainted
   ------------------------------------------------------
   syz.0.0/5335 is trying to acquire lock:
   ffff8880545dbc38 (btrfs-tree-01){++++}-{4:4}, at: btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146

   but task is already holding lock:
   ffff8880545dba58 (btrfs-treloc-02/1){+.+.}-{4:4}, at: btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189

   which lock already depends on the new lock.

   the existing dependency chain (in reverse order) is:

   -> #2 (btrfs-treloc-02/1){+.+.}-{4:4}:
          reacquire_held_locks+0x3eb/0x690 kernel/locking/lockdep.c:5374
          __lock_release kernel/locking/lockdep.c:5563 [inline]
          lock_release+0x396/0xa30 kernel/locking/lockdep.c:5870
          up_write+0x79/0x590 kernel/locking/rwsem.c:1629
          btrfs_force_cow_block+0x14b3/0x1fd0 fs/btrfs/ctree.c:660
          btrfs_cow_block+0x371/0x830 fs/btrfs/ctree.c:755
          btrfs_search_slot+0xc01/0x3180 fs/btrfs/ctree.c:2153
          replace_path+0x1243/0x2740 fs/btrfs/relocation.c:1224
          merge_reloc_root+0xc46/0x1ad0 fs/btrfs/relocation.c:1692
          merge_reloc_roots+0x3b3/0x980 fs/btrfs/relocation.c:1942
          relocate_block_group+0xb0a/0xd40 fs/btrfs/relocation.c:3754
          btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4087
          btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3494
          __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4278
          btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4655
          btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3670
          vfs_ioctl fs/ioctl.c:51 [inline]
          __do_sys_ioctl fs/ioctl.c:906 [inline]
          __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
          do_syscall_x64 arch/x86/entry/common.c:52 [inline]
          do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
          entry_SYSCALL_64_after_hwframe+0x77/0x7f

   -> #1 (btrfs-tree-01/1){+.+.}-{4:4}:
          lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
          down_write_nested+0xa2/0x220 kernel/locking/rwsem.c:1693
          btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189
          btrfs_init_new_buffer fs/btrfs/extent-tree.c:5052 [inline]
          btrfs_alloc_tree_block+0x41c/0x1440 fs/btrfs/extent-tree.c:5132
          btrfs_force_cow_block+0x526/0x1fd0 fs/btrfs/ctree.c:573
          btrfs_cow_block+0x371/0x830 fs/btrfs/ctree.c:755
          btrfs_search_slot+0xc01/0x3180 fs/btrfs/ctree.c:2153
          btrfs_insert_empty_items+0x9c/0x1a0 fs/btrfs/ctree.c:4351
          btrfs_insert_empty_item fs/btrfs/ctree.h:688 [inline]
          btrfs_insert_inode_ref+0x2bb/0xf80 fs/btrfs/inode-item.c:330
          btrfs_rename_exchange fs/btrfs/inode.c:7990 [inline]
          btrfs_rename2+0xcb7/0x2b90 fs/btrfs/inode.c:8374
          vfs_rename+0xbdb/0xf00 fs/namei.c:5067
          do_renameat2+0xd94/0x13f0 fs/namei.c:5224
          __do_sys_renameat2 fs/namei.c:5258 [inline]
          __se_sys_renameat2 fs/namei.c:5255 [inline]
          __x64_sys_renameat2+0xce/0xe0 fs/namei.c:5255
          do_syscall_x64 arch/x86/entry/common.c:52 [inline]
          do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
          entry_SYSCALL_64_after_hwframe+0x77/0x7f

   -> #0 (btrfs-tree-01){++++}-{4:4}:
          check_prev_add kernel/locking/lockdep.c:3161 [inline]
          check_prevs_add kernel/locking/lockdep.c:3280 [inline]
          validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
          __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
          lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
          down_read_nested+0xb5/0xa50 kernel/locking/rwsem.c:1649
          btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146
          btrfs_tree_read_lock fs/btrfs/locking.h:188 [inline]
          read_block_for_search+0x718/0xbb0 fs/btrfs/ctree.c:1610
          btrfs_search_slot+0x1274/0x3180 fs/btrfs/ctree.c:2237
          replace_path+0x1243/0x2740 fs/btrfs/relocation.c:1224
          merge_reloc_root+0xc46/0x1ad0 fs/btrfs/relocation.c:1692
          merge_reloc_roots+0x3b3/0x980 fs/btrfs/relocation.c:1942
          relocate_block_group+0xb0a/0xd40 fs/btrfs/relocation.c:3754
          btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4087
          btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3494
          __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4278
          btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4655
          btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3670
          vfs_ioctl fs/ioctl.c:51 [inline]
          __do_sys_ioctl fs/ioctl.c:906 [inline]
          __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
          do_syscall_x64 arch/x86/entry/common.c:52 [inline]
          do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
          entry_SYSCALL_64_after_hwframe+0x77/0x7f

   other info that might help us debug this:

   Chain exists of:
     btrfs-tree-01 --> btrfs-tree-01/1 --> btrfs-treloc-02/1

    Possible unsafe locking scenario:

          CPU0                    CPU1
          ----                    ----
     lock(btrfs-treloc-02/1);
                                  lock(btrfs-tree-01/1);
                                  lock(btrfs-treloc-02/1);
     rlock(btrfs-tree-01);

    *** DEADLOCK ***

   8 locks held by syz.0.0/5335:
    #0: ffff88801e3ae420 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write_file+0x5e/0x200 fs/namespace.c:559
    #1: ffff888052c760d0 (&fs_info->reclaim_bgs_lock){+.+.}-{4:4}, at: __btrfs_balance+0x4c2/0x26b0 fs/btrfs/volumes.c:4183
    #2: ffff888052c74850 (&fs_info->cleaner_mutex){+.+.}-{4:4}, at: btrfs_relocate_block_group+0x775/0xd90 fs/btrfs/relocation.c:4086
    #3: ffff88801e3ae610 (sb_internal#2){.+.+}-{0:0}, at: merge_reloc_root+0xf11/0x1ad0 fs/btrfs/relocation.c:1659
    #4: ffff888052c76470 (btrfs_trans_num_writers){++++}-{0:0}, at: join_transaction+0x405/0xda0 fs/btrfs/transaction.c:288
    #5: ffff888052c76498 (btrfs_trans_num_extwriters){++++}-{0:0}, at: join_transaction+0x405/0xda0 fs/btrfs/transaction.c:288
    #6: ffff8880545db878 (btrfs-tree-01/1){+.+.}-{4:4}, at: btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189
    #7: ffff8880545dba58 (btrfs-treloc-02/1){+.+.}-{4:4}, at: btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189

   stack backtrace:
   CPU: 0 UID: 0 PID: 5335 Comm: syz.0.0 Not tainted 6.13.0-rc5-syzkaller-00163-gab75170520d4 #0
   Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
   Call Trace:
    <TASK>
    __dump_stack lib/dump_stack.c:94 [inline]
    dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
    print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074
    check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206
    check_prev_add kernel/locking/lockdep.c:3161 [inline]
    check_prevs_add kernel/locking/lockdep.c:3280 [inline]
    validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
    __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
    lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
    down_read_nested+0xb5/0xa50 kernel/locking/rwsem.c:1649
    btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146
    btrfs_tree_read_lock fs/btrfs/locking.h:188 [inline]
    read_block_for_search+0x718/0xbb0 fs/btrfs/ctree.c:1610
    btrfs_search_slot+0x1274/0x3180 fs/btrfs/ctree.c:2237
    replace_path+0x1243/0x2740 fs/btrfs/relocation.c:1224
    merge_reloc_root+0xc46/0x1ad0 fs/btrfs/relocation.c:1692
    merge_reloc_roots+0x3b3/0x980 fs/btrfs/relocation.c:1942
    relocate_block_group+0xb0a/0xd40 fs/btrfs/relocation.c:3754
    btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4087
    btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3494
    __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4278
    btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4655
    btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3670
    vfs_ioctl fs/ioctl.c:51 [inline]
    __do_sys_ioctl fs/ioctl.c:906 [inline]
    __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
    do_syscall_x64 arch/x86/entry/common.c:52 [inline]
    do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
    entry_SYSCALL_64_after_hwframe+0x77/0x7f
   RIP: 0033:0x7f1ac6985d29
   Code: ff ff c3 (...)
   RSP: 002b:00007f1ac63fe038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
   RAX: ffffffffffffffda RBX: 00007f1ac6b76160 RCX: 00007f1ac6985d29
   RDX: 0000000020000180 RSI: 00000000c4009420 RDI: 0000000000000007
   RBP: 00007f1ac6a01b08 R08: 0000000000000000 R09: 0000000000000000
   R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
   R13: 0000000000000001 R14: 00007f1ac6b76160 R15: 00007fffda145a88
    </TASK>

Reported-by: [email protected]
Link: https://lore.kernel.org/linux-btrfs/[email protected]/
Fixes: 9978599 ("btrfs: reduce lock contention when eb cache miss for btree search")
Signed-off-by: Filipe Manana <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
gsomlo pushed a commit that referenced this pull request Feb 18, 2025
We have several places across the kernel where we want to access another
task's syscall arguments, such as ptrace(2), seccomp(2), etc., by making
a call to syscall_get_arguments().

This works for register arguments right away by accessing the task's
`regs' member of `struct pt_regs', however for stack arguments seen with
32-bit/o32 kernels things are more complicated.  Technically they ought
to be obtained from the user stack with calls to an access_remote_vm(),
but we have an easier way available already.

So as to be able to access syscall stack arguments as regular function
arguments following the MIPS calling convention we copy them over from
the user stack to the kernel stack in arch/mips/kernel/scall32-o32.S, in
handle_sys(), to the current stack frame's outgoing argument space at
the top of the stack, which is where the handler called expects to see
its incoming arguments.  This area is also pointed at by the `pt_regs'
pointer obtained by task_pt_regs().

Make the o32 stack argument space a proper member of `struct pt_regs'
then, by renaming the existing member from `pad0' to `args' and using
generated offsets to access the space.  No functional change though.

With the change in place the o32 kernel stack frame layout at the entry
to a syscall handler invoked by handle_sys() is therefore as follows:

$sp + 68 -> |         ...         | <- pt_regs.regs[9]
            +---------------------+
$sp + 64 -> |         $t0         | <- pt_regs.regs[8]
            +---------------------+
$sp + 60 -> |   $a3/argument #4   | <- pt_regs.regs[7]
            +---------------------+
$sp + 56 -> |   $a2/argument #3   | <- pt_regs.regs[6]
            +---------------------+
$sp + 52 -> |   $a1/argument #2   | <- pt_regs.regs[5]
            +---------------------+
$sp + 48 -> |   $a0/argument #1   | <- pt_regs.regs[4]
            +---------------------+
$sp + 44 -> |         $v1         | <- pt_regs.regs[3]
            +---------------------+
$sp + 40 -> |         $v0         | <- pt_regs.regs[2]
            +---------------------+
$sp + 36 -> |         $at         | <- pt_regs.regs[1]
            +---------------------+
$sp + 32 -> |        $zero        | <- pt_regs.regs[0]
            +---------------------+
$sp + 28 -> |  stack argument #8  | <- pt_regs.args[7]
            +---------------------+
$sp + 24 -> |  stack argument #7  | <- pt_regs.args[6]
            +---------------------+
$sp + 20 -> |  stack argument #6  | <- pt_regs.args[5]
            +---------------------+
$sp + 16 -> |  stack argument #5  | <- pt_regs.args[4]
            +---------------------+
$sp + 12 -> | psABI space for $a3 | <- pt_regs.args[3]
            +---------------------+
$sp +  8 -> | psABI space for $a2 | <- pt_regs.args[2]
            +---------------------+
$sp +  4 -> | psABI space for $a1 | <- pt_regs.args[1]
            +---------------------+
$sp +  0 -> | psABI space for $a0 | <- pt_regs.args[0]
            +---------------------+

holding user data received and with the first 4 frame slots reserved by
the psABI for the compiler to spill the incoming arguments from $a0-$a3
registers (which it sometimes does according to its needs) and the next
4 frame slots designated by the psABI for any stack function arguments
that follow.  This data is also available for other tasks to peek/poke
at as reqired and where permitted.

Signed-off-by: Maciej W. Rozycki <[email protected]>
Signed-off-by: Thomas Bogendoerfer <[email protected]>
gsomlo pushed a commit that referenced this pull request Mar 18, 2025
Use raw_spinlock in order to fix spurious messages about invalid context
when spinlock debugging is enabled. The lock is only used to serialize
register access.

    [    4.239592] =============================
    [    4.239595] [ BUG: Invalid wait context ]
    [    4.239599] 6.13.0-rc7-arm64-renesas-05496-gd088502a519f torvalds#35 Not tainted
    [    4.239603] -----------------------------
    [    4.239606] kworker/u8:5/76 is trying to lock:
    [    4.239609] ffff0000091898a0 (&p->lock){....}-{3:3}, at: gpio_rcar_config_interrupt_input_mode+0x34/0x164
    [    4.239641] other info that might help us debug this:
    [    4.239643] context-{5:5}
    [    4.239646] 5 locks held by kworker/u8:5/76:
    [    4.239651]  #0: ffff0000080fb148 ((wq_completion)async){+.+.}-{0:0}, at: process_one_work+0x190/0x62c
    [    4.250180] OF: /soc/sound@ec500000/ports/port@0/endpoint: Read of boolean property 'frame-master' with a value.
    [    4.254094]  #1: ffff80008299bd80 ((work_completion)(&entry->work)){+.+.}-{0:0}, at: process_one_work+0x1b8/0x62c
    [    4.254109]  #2: ffff00000920c8f8
    [    4.258345] OF: /soc/sound@ec500000/ports/port@1/endpoint: Read of boolean property 'bitclock-master' with a value.
    [    4.264803]  (&dev->mutex){....}-{4:4}, at: __device_attach_async_helper+0x3c/0xdc
    [    4.264820]  #3: ffff00000a50ca40 (request_class#2){+.+.}-{4:4}, at: __setup_irq+0xa0/0x690
    [    4.264840]  #4:
    [    4.268872] OF: /soc/sound@ec500000/ports/port@1/endpoint: Read of boolean property 'frame-master' with a value.
    [    4.273275] ffff00000a50c8c8 (lock_class){....}-{2:2}, at: __setup_irq+0xc4/0x690
    [    4.296130] renesas_sdhi_internal_dmac ee100000.mmc: mmc1 base at 0x00000000ee100000, max clock rate 200 MHz
    [    4.304082] stack backtrace:
    [    4.304086] CPU: 1 UID: 0 PID: 76 Comm: kworker/u8:5 Not tainted 6.13.0-rc7-arm64-renesas-05496-gd088502a519f torvalds#35
    [    4.304092] Hardware name: Renesas Salvator-X 2nd version board based on r8a77965 (DT)
    [    4.304097] Workqueue: async async_run_entry_fn
    [    4.304106] Call trace:
    [    4.304110]  show_stack+0x14/0x20 (C)
    [    4.304122]  dump_stack_lvl+0x6c/0x90
    [    4.304131]  dump_stack+0x14/0x1c
    [    4.304138]  __lock_acquire+0xdfc/0x1584
    [    4.426274]  lock_acquire+0x1c4/0x33c
    [    4.429942]  _raw_spin_lock_irqsave+0x5c/0x80
    [    4.434307]  gpio_rcar_config_interrupt_input_mode+0x34/0x164
    [    4.440061]  gpio_rcar_irq_set_type+0xd4/0xd8
    [    4.444422]  __irq_set_trigger+0x5c/0x178
    [    4.448435]  __setup_irq+0x2e4/0x690
    [    4.452012]  request_threaded_irq+0xc4/0x190
    [    4.456285]  devm_request_threaded_irq+0x7c/0xf4
    [    4.459398] ata1: link resume succeeded after 1 retries
    [    4.460902]  mmc_gpiod_request_cd_irq+0x68/0xe0
    [    4.470660]  mmc_start_host+0x50/0xac
    [    4.474327]  mmc_add_host+0x80/0xe4
    [    4.477817]  tmio_mmc_host_probe+0x2b0/0x440
    [    4.482094]  renesas_sdhi_probe+0x488/0x6f4
    [    4.486281]  renesas_sdhi_internal_dmac_probe+0x60/0x78
    [    4.491509]  platform_probe+0x64/0xd8
    [    4.495178]  really_probe+0xb8/0x2a8
    [    4.498756]  __driver_probe_device+0x74/0x118
    [    4.503116]  driver_probe_device+0x3c/0x154
    [    4.507303]  __device_attach_driver+0xd4/0x160
    [    4.511750]  bus_for_each_drv+0x84/0xe0
    [    4.515588]  __device_attach_async_helper+0xb0/0xdc
    [    4.520470]  async_run_entry_fn+0x30/0xd8
    [    4.524481]  process_one_work+0x210/0x62c
    [    4.528494]  worker_thread+0x1ac/0x340
    [    4.532245]  kthread+0x10c/0x110
    [    4.535476]  ret_from_fork+0x10/0x20

Signed-off-by: Niklas Söderlund <[email protected]>
Reviewed-by: Geert Uytterhoeven <[email protected]>
Tested-by: Geert Uytterhoeven <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Bartosz Golaszewski <[email protected]>
gsomlo pushed a commit that referenced this pull request Mar 18, 2025
…cal section

A circular lock dependency splat has been seen involving down_trylock():

  ======================================================
  WARNING: possible circular locking dependency detected
  6.12.0-41.el10.s390x+debug
  ------------------------------------------------------
  dd/32479 is trying to acquire lock:
  0015a20accd0d4f8 ((console_sem).lock){-.-.}-{2:2}, at: down_trylock+0x26/0x90

  but task is already holding lock:
  000000017e461698 (&zone->lock){-.-.}-{2:2}, at: rmqueue_bulk+0xac/0x8f0

  the existing dependency chain (in reverse order) is:
  -> #4 (&zone->lock){-.-.}-{2:2}:
  -> #3 (hrtimer_bases.lock){-.-.}-{2:2}:
  -> #2 (&rq->__lock){-.-.}-{2:2}:
  -> #1 (&p->pi_lock){-.-.}-{2:2}:
  -> #0 ((console_sem).lock){-.-.}-{2:2}:

The console_sem -> pi_lock dependency is due to calling try_to_wake_up()
while holding the console_sem raw_spinlock. This dependency can be broken
by using wake_q to do the wakeup instead of calling try_to_wake_up()
under the console_sem lock. This will also make the semaphore's
raw_spinlock become a terminal lock without taking any further locks
underneath it.

The hrtimer_bases.lock is a raw_spinlock while zone->lock is a
spinlock. The hrtimer_bases.lock -> zone->lock dependency happens via
the debug_objects_fill_pool() helper function in the debugobjects code.

  -> #4 (&zone->lock){-.-.}-{2:2}:
         __lock_acquire+0xe86/0x1cc0
         lock_acquire.part.0+0x258/0x630
         lock_acquire+0xb8/0xe0
         _raw_spin_lock_irqsave+0xb4/0x120
         rmqueue_bulk+0xac/0x8f0
         __rmqueue_pcplist+0x580/0x830
         rmqueue_pcplist+0xfc/0x470
         rmqueue.isra.0+0xdec/0x11b0
         get_page_from_freelist+0x2ee/0xeb0
         __alloc_pages_noprof+0x2c2/0x520
         alloc_pages_mpol_noprof+0x1fc/0x4d0
         alloc_pages_noprof+0x8c/0xe0
         allocate_slab+0x320/0x460
         ___slab_alloc+0xa58/0x12b0
         __slab_alloc.isra.0+0x42/0x60
         kmem_cache_alloc_noprof+0x304/0x350
         fill_pool+0xf6/0x450
         debug_object_activate+0xfe/0x360
         enqueue_hrtimer+0x34/0x190
         __run_hrtimer+0x3c8/0x4c0
         __hrtimer_run_queues+0x1b2/0x260
         hrtimer_interrupt+0x316/0x760
         do_IRQ+0x9a/0xe0
         do_irq_async+0xf6/0x160

Normally a raw_spinlock to spinlock dependency is not legitimate
and will be warned if CONFIG_PROVE_RAW_LOCK_NESTING is enabled,
but debug_objects_fill_pool() is an exception as it explicitly
allows this dependency for non-PREEMPT_RT kernel without causing
PROVE_RAW_LOCK_NESTING lockdep splat. As a result, this dependency is
legitimate and not a bug.

Anyway, semaphore is the only locking primitive left that is still
using try_to_wake_up() to do wakeup inside critical section, all the
other locking primitives had been migrated to use wake_q to do wakeup
outside of the critical section. It is also possible that there are
other circular locking dependencies involving printk/console_sem or
other existing/new semaphores lurking somewhere which may show up in
the future. Let just do the migration now to wake_q to avoid headache
like this.

Reported-by: [email protected]
Signed-off-by: Waiman Long <[email protected]>
Signed-off-by: Boqun Feng <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
gsomlo pushed a commit that referenced this pull request Mar 18, 2025
…/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.14, take #4

- Fix a couple of bugs affecting pKVM's PSCI relay implementation
  when running in the hVHE mode, resulting in the host being entered
  with the MMU in an unknown state, and EL2 being in the wrong mode.
gsomlo pushed a commit that referenced this pull request Apr 1, 2025
perf test 11 hwmon fails on s390 with this error

 # ./perf test -Fv 11
 --- start ---
 ---- end ----
 11.1: Basic parsing test             : Ok
 --- start ---
 Testing 'temp_test_hwmon_event1'
 Using CPUID IBM,3931,704,A01,3.7,002f
 temp_test_hwmon_event1 -> hwmon_a_test_hwmon_pmu/temp_test_hwmon_event1/
 FAILED tests/hwmon_pmu.c:189 Unexpected config for
    'temp_test_hwmon_event1', 292470092988416 != 655361
 ---- end ----
 11.2: Parsing without PMU name       : FAILED!
 --- start ---
 Testing 'hwmon_a_test_hwmon_pmu/temp_test_hwmon_event1/'
 FAILED tests/hwmon_pmu.c:189 Unexpected config for
    'hwmon_a_test_hwmon_pmu/temp_test_hwmon_event1/',
    292470092988416 != 655361
 ---- end ----
 11.3: Parsing with PMU name          : FAILED!
 #

The root cause is in member test_event::config which is initialized
to 0xA0001 or 655361. During event parsing a long list event parsing
functions are called and end up with this gdb call stack:

 #0  hwmon_pmu__config_term (hwm=0x168dfd0, attr=0x3ffffff5ee8,
	term=0x168db60, err=0x3ffffff81c8) at util/hwmon_pmu.c:623
 #1  hwmon_pmu__config_terms (pmu=0x168dfd0, attr=0x3ffffff5ee8,
	terms=0x3ffffff5ea8, err=0x3ffffff81c8) at util/hwmon_pmu.c:662
 #2  0x00000000012f870c in perf_pmu__config_terms (pmu=0x168dfd0,
	attr=0x3ffffff5ee8, terms=0x3ffffff5ea8, zero=false,
	apply_hardcoded=false, err=0x3ffffff81c8) at util/pmu.c:1519
 #3  0x00000000012f88a4 in perf_pmu__config (pmu=0x168dfd0, attr=0x3ffffff5ee8,
	head_terms=0x3ffffff5ea8, apply_hardcoded=false, err=0x3ffffff81c8)
	at util/pmu.c:1545
 #4  0x00000000012680c4 in parse_events_add_pmu (parse_state=0x3ffffff7fb8,
	list=0x168dc00, pmu=0x168dfd0, const_parsed_terms=0x3ffffff6090,
	auto_merge_stats=true, alternate_hw_config=10)
	at util/parse-events.c:1508
 #5  0x00000000012684c6 in parse_events_multi_pmu_add (parse_state=0x3ffffff7fb8,
	event_name=0x168ec10 "temp_test_hwmon_event1", hw_config=10,
	const_parsed_terms=0x0, listp=0x3ffffff6230, loc_=0x3ffffff70e0)
	at util/parse-events.c:1592
 #6  0x00000000012f0e4e in parse_events_parse (_parse_state=0x3ffffff7fb8,
	scanner=0x16878c0) at util/parse-events.y:293
 #7  0x00000000012695a0 in parse_events__scanner (str=0x3ffffff81d8
	"temp_test_hwmon_event1", input=0x0, parse_state=0x3ffffff7fb8)
	at util/parse-events.c:1867
 #8  0x000000000126a1e8 in __parse_events (evlist=0x168b580,
	str=0x3ffffff81d8 "temp_test_hwmon_event1", pmu_filter=0x0,
	err=0x3ffffff81c8, fake_pmu=false, warn_if_reordered=true,
	fake_tp=false) at util/parse-events.c:2136
 #9  0x00000000011e36aa in parse_events (evlist=0x168b580,
	str=0x3ffffff81d8 "temp_test_hwmon_event1", err=0x3ffffff81c8)
	at /root/linux/tools/perf/util/parse-events.h:41
 #10 0x00000000011e3e64 in do_test (i=0, with_pmu=false, with_alias=false)
	at tests/hwmon_pmu.c:164
 #11 0x00000000011e422c in test__hwmon_pmu (with_pmu=false)
	at tests/hwmon_pmu.c:219
 #12 0x00000000011e431c in test__hwmon_pmu_without_pmu (test=0x1610368
	<suite.hwmon_pmu>, subtest=1) at tests/hwmon_pmu.c:23

where the attr::config is set to value 292470092988416 or 0x10a0000000000
in line 625 of file ./util/hwmon_pmu.c:

   attr->config = key.type_and_num;

However member key::type_and_num is defined as union and bit field:

   union hwmon_pmu_event_key {
        long type_and_num;
        struct {
                int num :16;
                enum hwmon_type type :8;
        };
   };

s390 is big endian and Intel is little endian architecture.
The events for the hwmon dummy pmu have num = 1 or num = 2 and
type is set to HWMON_TYPE_TEMP (which is 10).
On s390 this assignes member key::type_and_num the value of
0x10a0000000000 (which is 292470092988416) as shown in above
trace output.

Fix this and export the structure/union hwmon_pmu_event_key
so the test shares the same implementation as the event parsing
functions for union and bit fields. This should avoid
endianess issues on all platforms.

Output after:
 # ./perf test -F 11
 11.1: Basic parsing test         : Ok
 11.2: Parsing without PMU name   : Ok
 11.3: Parsing with PMU name      : Ok
 #

Fixes: 531ee0f ("perf test: Add hwmon "PMU" test")
Signed-off-by: Thomas Richter <[email protected]>
Reviewed-by: Ian Rogers <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Namhyung Kim <[email protected]>
gsomlo pushed a commit that referenced this pull request Apr 1, 2025
Ian told me that there are many memory leaks in the hierarchy mode.  I
can easily reproduce it with the follwing command.

  $ make DEBUG=1 EXTRA_CFLAGS=-fsanitize=leak

  $ perf record --latency -g -- ./perf test -w thloop

  $ perf report -H --stdio
  ...
  Indirect leak of 168 byte(s) in 21 object(s) allocated from:
      #0 0x7f3414c16c65 in malloc ../../../../src/libsanitizer/lsan/lsan_interceptors.cpp:75
      #1 0x55ed3602346e in map__get util/map.h:189
      #2 0x55ed36024cc4 in hist_entry__init util/hist.c:476
      #3 0x55ed36025208 in hist_entry__new util/hist.c:588
      #4 0x55ed36027c05 in hierarchy_insert_entry util/hist.c:1587
      #5 0x55ed36027e2e in hists__hierarchy_insert_entry util/hist.c:1638
      #6 0x55ed36027fa4 in hists__collapse_insert_entry util/hist.c:1685
      #7 0x55ed360283e8 in hists__collapse_resort util/hist.c:1776
      #8 0x55ed35de0323 in report__collapse_hists /home/namhyung/project/linux/tools/perf/builtin-report.c:735
      #9 0x55ed35de15b4 in __cmd_report /home/namhyung/project/linux/tools/perf/builtin-report.c:1119
      #10 0x55ed35de43dc in cmd_report /home/namhyung/project/linux/tools/perf/builtin-report.c:1867
      #11 0x55ed35e66767 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:351
      #12 0x55ed35e66a0e in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:404
      #13 0x55ed35e66b67 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:448
      torvalds#14 0x55ed35e66eb0 in main /home/namhyung/project/linux/tools/perf/perf.c:556
      #15 0x7f340ac33d67 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
  ...

  $ perf report -H --stdio 2>&1 | grep -c '^Indirect leak'
  93

I found that hist_entry__delete() missed to release child entries in the
hierarchy tree (hroot_{in,out}).  It needs to iterate the child entries
and call hist_entry__delete() recursively.

After this change:

  $ perf report -H --stdio 2>&1 | grep -c '^Indirect leak'
  0

Reported-by: Ian Rogers <[email protected]>
Tested-by Thomas Falcon <[email protected]>
Reviewed-by: Ian Rogers <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Namhyung Kim <[email protected]>
gsomlo pushed a commit that referenced this pull request Apr 1, 2025
…uctions

Add several ./test_progs tests:

  - arena_atomics/load_acquire
  - arena_atomics/store_release
  - verifier_load_acquire/*
  - verifier_store_release/*
  - verifier_precision/bpf_load_acquire
  - verifier_precision/bpf_store_release

The last two tests are added to check if backtrack_insn() handles the
new instructions correctly.

Additionally, the last test also makes sure that the verifier
"remembers" the value (in src_reg) we store-release into e.g. a stack
slot.  For example, if we take a look at the test program:

    #0:  r1 = 8;
      /* store_release((u64 *)(r10 - 8), r1); */
    #1:  .8byte %[store_release];
    #2:  r1 = *(u64 *)(r10 - 8);
    #3:  r2 = r10;
    #4:  r2 += r1;
    #5:  r0 = 0;
    #6:  exit;

At #1, if the verifier doesn't remember that we wrote 8 to the stack,
then later at #4 we would be adding an unbounded scalar value to the
stack pointer, which would cause the program to be rejected:

  VERIFIER LOG:
  =============
...
  math between fp pointer and register with unbounded min value is not allowed

For easier CI integration, instead of using built-ins like
__atomic_{load,store}_n() which depend on the new
__BPF_FEATURE_LOAD_ACQ_STORE_REL pre-defined macro, manually craft
load-acquire/store-release instructions using __imm_insn(), as suggested
by Eduard.

All new tests depend on:

  (1) Clang major version >= 18, and
  (2) ENABLE_ATOMICS_TESTS is defined (currently implies -mcpu=v3 or
      v4), and
  (3) JIT supports load-acquire/store-release (currently arm64 and
      x86-64)

In .../progs/arena_atomics.c:

  /* 8-byte-aligned */
  __u8 __arena_global load_acquire8_value = 0x12;
  /* 1-byte hole */
  __u16 __arena_global load_acquire16_value = 0x1234;

That 1-byte hole in the .addr_space.1 ELF section caused clang-17 to
crash:

  fatal error: error in backend: unable to write nop sequence of 1 bytes

To work around such llvm-17 CI job failures, conditionally define
__arena_global variables as 64-bit if __clang_major__ < 18, to make sure
.addr_space.1 has no holes.  Ideally we should avoid compiling this file
using clang-17 at all (arena tests depend on
__BPF_FEATURE_ADDR_SPACE_CAST, and are skipped for llvm-17 anyway), but
that is a separate topic.

Acked-by: Eduard Zingerman <[email protected]>
Signed-off-by: Peilin Ye <[email protected]>
Link: https://lore.kernel.org/r/1b46c6feaf0f1b6984d9ec80e500cc7383e9da1a.1741049567.git.yepeilin@google.com
Signed-off-by: Alexei Starovoitov <[email protected]>
gsomlo pushed a commit that referenced this pull request Apr 1, 2025
The env.pmu_mapping can be leaked when it reads data from a pipe on AMD.
For a pipe data, it reads the header data including pmu_mapping from
PERF_RECORD_HEADER_FEATURE runtime.  But it's already set in:

  perf_session__new()
    __perf_session__new()
      evlist__init_trace_event_sample_raw()
        evlist__has_amd_ibs()
          perf_env__nr_pmu_mappings()

Then it'll overwrite that when it processes the HEADER_FEATURE record.
Here's a report from address sanitizer.

  Direct leak of 2689 byte(s) in 1 object(s) allocated from:
    #0 0x7fed8f814596 in realloc ../../../../src/libsanitizer/lsan/lsan_interceptors.cpp:98
    #1 0x5595a7d416b1 in strbuf_grow util/strbuf.c:64
    #2 0x5595a7d414ef in strbuf_init util/strbuf.c:25
    #3 0x5595a7d0f4b7 in perf_env__read_pmu_mappings util/env.c:362
    #4 0x5595a7d12ab7 in perf_env__nr_pmu_mappings util/env.c:517
    #5 0x5595a7d89d2f in evlist__has_amd_ibs util/amd-sample-raw.c:315
    #6 0x5595a7d87fb2 in evlist__init_trace_event_sample_raw util/sample-raw.c:23
    #7 0x5595a7d7f893 in __perf_session__new util/session.c:179
    #8 0x5595a7b79572 in perf_session__new util/session.h:115
    #9 0x5595a7b7e9dc in cmd_report builtin-report.c:1603
    #10 0x5595a7c019eb in run_builtin perf.c:351
    #11 0x5595a7c01c92 in handle_internal_command perf.c:404
    #12 0x5595a7c01deb in run_argv perf.c:448
    #13 0x5595a7c02134 in main perf.c:556
    torvalds#14 0x7fed85833d67 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58

Let's free the existing pmu_mapping data if any.

Cc: Ravi Bangoria <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Namhyung Kim <[email protected]>
gsomlo pushed a commit that referenced this pull request Apr 7, 2025
v2:
- Created a single error handling unlock and exit in veth_pool_store
- Greatly expanded commit message with previous explanatory-only text

Summary: Use rtnl_mutex to synchronize veth_pool_store with itself,
ibmveth_close and ibmveth_open, preventing multiple calls in a row to
napi_disable.

Background: Two (or more) threads could call veth_pool_store through
writing to /sys/devices/vio/30000002/pool*/*. You can do this easily
with a little shell script. This causes a hang.

I configured LOCKDEP, compiled ibmveth.c with DEBUG, and built a new
kernel. I ran this test again and saw:

    Setting pool0/active to 0
    Setting pool1/active to 1
    [   73.911067][ T4365] ibmveth 30000002 eth0: close starting
    Setting pool1/active to 1
    Setting pool1/active to 0
    [   73.911367][ T4366] ibmveth 30000002 eth0: close starting
    [   73.916056][ T4365] ibmveth 30000002 eth0: close complete
    [   73.916064][ T4365] ibmveth 30000002 eth0: open starting
    [  110.808564][  T712] systemd-journald[712]: Sent WATCHDOG=1 notification.
    [  230.808495][  T712] systemd-journald[712]: Sent WATCHDOG=1 notification.
    [  243.683786][  T123] INFO: task stress.sh:4365 blocked for more than 122 seconds.
    [  243.683827][  T123]       Not tainted 6.14.0-01103-g2df0c02dab82-dirty #8
    [  243.683833][  T123] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
    [  243.683838][  T123] task:stress.sh       state:D stack:28096 pid:4365  tgid:4365  ppid:4364   task_flags:0x400040 flags:0x00042000
    [  243.683852][  T123] Call Trace:
    [  243.683857][  T123] [c00000000c38f690] [0000000000000001] 0x1 (unreliable)
    [  243.683868][  T123] [c00000000c38f840] [c00000000001f908] __switch_to+0x318/0x4e0
    [  243.683878][  T123] [c00000000c38f8a0] [c000000001549a70] __schedule+0x500/0x12a0
    [  243.683888][  T123] [c00000000c38f9a0] [c00000000154a878] schedule+0x68/0x210
    [  243.683896][  T123] [c00000000c38f9d0] [c00000000154ac80] schedule_preempt_disabled+0x30/0x50
    [  243.683904][  T123] [c00000000c38fa00] [c00000000154dbb0] __mutex_lock+0x730/0x10f0
    [  243.683913][  T123] [c00000000c38fb10] [c000000001154d40] napi_enable+0x30/0x60
    [  243.683921][  T123] [c00000000c38fb40] [c000000000f4ae94] ibmveth_open+0x68/0x5dc
    [  243.683928][  T123] [c00000000c38fbe0] [c000000000f4aa20] veth_pool_store+0x220/0x270
    [  243.683936][  T123] [c00000000c38fc70] [c000000000826278] sysfs_kf_write+0x68/0xb0
    [  243.683944][  T123] [c00000000c38fcb0] [c0000000008240b8] kernfs_fop_write_iter+0x198/0x2d0
    [  243.683951][  T123] [c00000000c38fd00] [c00000000071b9ac] vfs_write+0x34c/0x650
    [  243.683958][  T123] [c00000000c38fdc0] [c00000000071bea8] ksys_write+0x88/0x150
    [  243.683966][  T123] [c00000000c38fe10] [c0000000000317f4] system_call_exception+0x124/0x340
    [  243.683973][  T123] [c00000000c38fe50] [c00000000000d05c] system_call_vectored_common+0x15c/0x2ec
    ...
    [  243.684087][  T123] Showing all locks held in the system:
    [  243.684095][  T123] 1 lock held by khungtaskd/123:
    [  243.684099][  T123]  #0: c00000000278e370 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x50/0x248
    [  243.684114][  T123] 4 locks held by stress.sh/4365:
    [  243.684119][  T123]  #0: c00000003a4cd3f8 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x88/0x150
    [  243.684132][  T123]  #1: c000000041aea888 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x154/0x2d0
    [  243.684143][  T123]  #2: c0000000366fb9a8 (kn->active#64){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x160/0x2d0
    [  243.684155][  T123]  #3: c000000035ff4cb8 (&dev->lock){+.+.}-{3:3}, at: napi_enable+0x30/0x60
    [  243.684166][  T123] 5 locks held by stress.sh/4366:
    [  243.684170][  T123]  #0: c00000003a4cd3f8 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x88/0x150
    [  243.684183][  T123]  #1: c00000000aee2288 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x154/0x2d0
    [  243.684194][  T123]  #2: c0000000366f4ba8 (kn->active#64){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x160/0x2d0
    [  243.684205][  T123]  #3: c000000035ff4cb8 (&dev->lock){+.+.}-{3:3}, at: napi_disable+0x30/0x60
    [  243.684216][  T123]  #4: c0000003ff9bbf18 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0x138/0x12a0

From the ibmveth debug, two threads are calling veth_pool_store, which
calls ibmveth_close and ibmveth_open. Here's the sequence:

  T4365             T4366
  ----------------- ----------------- ---------
  veth_pool_store   veth_pool_store
                    ibmveth_close
  ibmveth_close
  napi_disable
                    napi_disable
  ibmveth_open
  napi_enable                         <- HANG

ibmveth_close calls napi_disable at the top and ibmveth_open calls
napi_enable at the top.

https://docs.kernel.org/networking/napi.html]] says

  The control APIs are not idempotent. Control API calls are safe
  against concurrent use of datapath APIs but an incorrect sequence of
  control API calls may result in crashes, deadlocks, or race
  conditions. For example, calling napi_disable() multiple times in a
  row will deadlock.

In the normal open and close paths, rtnl_mutex is acquired to prevent
other callers. This is missing from veth_pool_store. Use rtnl_mutex in
veth_pool_store fixes these hangs.

Signed-off-by: Dave Marquardt <[email protected]>
Fixes: 860f242 ("[PATCH] ibmveth change buffer pools dynamically")
Reviewed-by: Nick Child <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
gsomlo pushed a commit that referenced this pull request Apr 13, 2025
Commit 7da55c2 ("drm/amd/display: Remove incorrect FP context
start") removes the FP context protection of dml2_create(), and it said
"All the DC_FP_START/END should be used before call anything from DML2".

However, dml2_validate()/dml21_validate() are not protected from their
callers, causing such errors:

 do_fpu invoked from kernel context![#1]:
 CPU: 10 UID: 0 PID: 331 Comm: kworker/10:1H Not tainted 6.14.0-rc6+ #4
 Workqueue: events_highpri dm_irq_work_func [amdgpu]
 pc ffff800003191eb0 ra ffff800003191e60 tp 9000000107a94000 sp 9000000107a975b0
 a0 9000000140ce4910 a1 0000000000000000 a2 9000000140ce49b0 a3 9000000140ce49a8
 a4 9000000140ce49a8 a5 0000000100000000 a6 0000000000000001 a7 9000000107a97660
 t0 ffff800003790000 t1 9000000140ce5000 t2 0000000000000001 t3 0000000000000000
 t4 0000000000000004 t5 0000000000000000 t6 0000000000000000 t7 0000000000000000
 t8 0000000100000000 u0 ffff8000031a3b9c s9 9000000130bc0000 s0 9000000132400000
 s1 9000000140ec0000 s2 9000000132400000 s3 9000000140ce0000 s4 90000000057f8b88
 s5 9000000140ec0000 s6 9000000140ce4910 s7 0000000000000001 s8 9000000130d45010
 ra: ffff800003191e60 dml21_map_dc_state_into_dml_display_cfg+0x40/0x1140 [amdgpu]
   ERA: ffff800003191eb0 dml21_map_dc_state_into_dml_display_cfg+0x90/0x1140 [amdgpu]
  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
  PRMD: 00000004 (PPLV0 +PIE -PWE)
  EUEN: 00000000 (-FPE -SXE -ASXE -BTE)
  ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
 ESTAT: 000f0000 [FPD] (IS= ECode=15 EsubCode=0)
  PRID: 0014d010 (Loongson-64bit, Loongson-3C6000/S)
 Process kworker/10:1H (pid: 331, threadinfo=000000007bf9ddb0, task=00000000cc4ab9f3)
 Stack : 0000000100000000 0000043800000780 0000000100000001 0000000100000001
         0000000000000000 0000078000000000 0000000000000438 0000078000000000
         0000000000000438 0000078000000000 0000000000000438 0000000100000000
         0000000100000000 0000000100000000 0000000100000000 0000000100000000
         0000000000000001 9000000140ec0000 9000000132400000 9000000132400000
         ffff800003408000 ffff800003408000 9000000132400000 9000000140ce0000
         9000000140ce0000 ffff800003193850 0000000000000001 9000000140ec0000
         9000000132400000 9000000140ec0860 9000000140ec0738 0000000000000001
         90000001405e8000 9000000130bc0000 9000000140ec02a8 ffff8000031b5db8
         0000000000000000 0000043800000780 0000000000000003 ffff8000031b79cc
         ...
 Call Trace:
 [<ffff800003191eb0>] dml21_map_dc_state_into_dml_display_cfg+0x90/0x1140 [amdgpu]
 [<ffff80000319384c>] dml21_validate+0xcc/0x520 [amdgpu]
 [<ffff8000031b8948>] dc_validate_global_state+0x2e8/0x460 [amdgpu]
 [<ffff800002e94034>] create_validate_stream_for_sink+0x3d4/0x420 [amdgpu]
 [<ffff800002e940e4>] amdgpu_dm_connector_mode_valid+0x64/0x240 [amdgpu]
 [<900000000441d6b8>] drm_connector_mode_valid+0x38/0x80
 [<900000000441d824>] __drm_helper_update_and_validate+0x124/0x3e0
 [<900000000441ddc0>] drm_helper_probe_single_connector_modes+0x2e0/0x620
 [<90000000044050dc>] drm_client_modeset_probe+0x23c/0x1780
 [<9000000004420384>] __drm_fb_helper_initial_config_and_unlock+0x44/0x5a0
 [<9000000004403acc>] drm_client_dev_hotplug+0xcc/0x140
 [<ffff800002e9ab50>] handle_hpd_irq_helper+0x1b0/0x1e0 [amdgpu]
 [<90000000038f5da0>] process_one_work+0x160/0x300
 [<90000000038f6718>] worker_thread+0x318/0x440
 [<9000000003901b8c>] kthread+0x12c/0x220
 [<90000000038b1484>] ret_from_kernel_thread+0x8/0xa4

Unfortunately, protecting dml2_validate()/dml21_validate() out of DML2
causes "sleeping function called from invalid context", so protect them
with DC_FP_START() and DC_FP_END() inside.

Fixes: 7da55c2 ("drm/amd/display: Remove incorrect FP context start")
Cc: [email protected]
Signed-off-by: Huacai Chen <[email protected]>
Tested-by: Dongyan Qian <[email protected]>
Reviewed-by: Aurabindo Pillai <[email protected]>
Tested-by: Daniel Wheeler <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>
gsomlo pushed a commit that referenced this pull request Apr 13, 2025
If we finds a vq without a name in our input array in
virtio_ccw_find_vqs(), we treat it as "non-existing" and set the vq pointer
to NULL; we will not call virtio_ccw_setup_vq() to allocate/setup a vq.

Consequently, we create only a queue if it actually exists (name != NULL)
and assign an incremental queue index to each such existing queue.

However, in virtio_ccw_register_adapter_ind()->get_airq_indicator() we
will not ignore these "non-existing queues", but instead assign an airq
indicator to them.

Besides never releasing them in virtio_ccw_drop_indicators() (because
there is no virtqueue), the bigger issue seems to be that there will be a
disagreement between the device and the Linux guest about the airq
indicator to be used for notifying a queue, because the indicator bit
for adapter I/O interrupt is derived from the queue index.

The virtio spec states under "Setting Up Two-Stage Queue Indicators":

	... indicator contains the guest address of an area wherein the
	indicators for the devices are contained, starting at bit_nr, one
	bit per virtqueue of the device.

And further in "Notification via Adapter I/O Interrupts":

	For notifying the driver of virtqueue buffers, the device sets the
	bit in the guest-provided indicator area at the corresponding
	offset.

For example, QEMU uses in virtio_ccw_notify() the queue index (passed as
"vector") to select the relevant indicator bit. If a queue does not exist,
it does not have a corresponding indicator bit assigned, because it
effectively doesn't have a queue index.

Using a virtio-balloon-ccw device under QEMU with free-page-hinting
disabled ("free-page-hint=off") but free-page-reporting enabled
("free-page-reporting=on") will result in free page reporting
not working as expected: in the virtio_balloon driver, we'll be stuck
forever in virtballoon_free_page_report()->wait_event(), because the
waitqueue will not be woken up as the notification from the device is
lost: it would use the wrong indicator bit.

Free page reporting stops working and we get splats (when configured to
detect hung wqs) like:

 INFO: task kworker/1:3:463 blocked for more than 61 seconds.
       Not tainted 6.14.0 #4
 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
 task:kworker/1:3 [...]
 Workqueue: events page_reporting_process
 Call Trace:
  [<000002f404e6dfb2>] __schedule+0x402/0x1640
  [<000002f404e6f22e>] schedule+0x3e/0xe0
  [<000002f3846a88fa>] virtballoon_free_page_report+0xaa/0x110 [virtio_balloon]
  [<000002f40435c8a4>] page_reporting_process+0x2e4/0x740
  [<000002f403fd3ee2>] process_one_work+0x1c2/0x400
  [<000002f403fd4b96>] worker_thread+0x296/0x420
  [<000002f403fe10b4>] kthread+0x124/0x290
  [<000002f403f4e0dc>] __ret_from_fork+0x3c/0x60
  [<000002f404e77272>] ret_from_fork+0xa/0x38

There was recently a discussion [1] whether the "holes" should be
treated differently again, effectively assigning also non-existing
queues a queue index: that should also fix the issue, but requires other
workarounds to not break existing setups.

Let's fix it without affecting existing setups for now by properly ignoring
the non-existing queues, so the indicator bits will match the queue
indexes.

[1] https://lore.kernel.org/all/[email protected]/

Fixes: a229989 ("virtio: don't allocate vqs when names[i] = NULL")
Reported-by: Chandra Merla <[email protected]>
Cc: [email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Tested-by: Thomas Huth <[email protected]>
Reviewed-by: Thomas Huth <[email protected]>
Reviewed-by: Cornelia Huck <[email protected]>
Acked-by: Michael S. Tsirkin <[email protected]>
Acked-by: Christian Borntraeger <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Heiko Carstens <[email protected]>
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