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SubmittingPatches ヘッダ部の JF 時代の翻訳者リストの扱い #2

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akiyks opened this issue Apr 29, 2022 · 2 comments
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@akiyks
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akiyks commented Apr 29, 2022

@tgkz

HOWTO では、コミット f012733 の RST 化の際に JF に関する情報が削除され、
翻訳者として柴田さんお一人が残る形になっています。
SubmittingPatches でも同様にしてよいのでしょうか?
記載されている Keiichi KII さんの e-mail アドレスは跳ね返される状態です。
JF が機能していないため問い合わせもできませんが、GPL の精神に準じると元の著作権
表記をそのまま残すことが配布の条件になるとも考えられます。
とすると、削除ではなくメインライン化時点のリストをそのまま残し、その旨を説明する
注釈を追加するのが良いのではないかと考えました。このリストは著作権表記に該当
しませんが。

その主旨の変更を先程プッシュした submitting-patches-1st-batch-rc1 ブランチの
最初のコミット 07e477c でやってみました。コメントいただけませんでしょうか?

2つ目のコミット e37a6e5 は、更新されるべきでなかったパスを戻すものです。
部分的なリバートなので、コミットを分けました。

その後のコミットは、追随リストの6番目 0af5270 ("Documentation/SubmittingPatches:
Request summaries for commit references") までに対応する更新です。
WIP-docs-ja-jp-cacheup-submittingpatches ブランチのものより、少し真面目に訳してみました。
翻訳へのレビューは linux-doc への投稿の後でも構いません。

akiyks pushed a commit that referenced this issue May 1, 2022
…/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 5.18, take #2

- Take care of faults occuring between the PARange and
  IPA range by injecting an exception

- Fix S2 faults taken from a host EL0 in protected mode

- Work around Oops caused by a PMU access from a 32bit
  guest when PMU has been created. This is a temporary
  bodge until we fix it for good.
@akiyks
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akiyks commented May 2, 2022

この件は柴田さんには判断できかねるのだと想像します。RSTまでには方針を決めたいです。
RST であれば、この古い翻訳者情報を RST 内のコメントに埋め込んで HTML や PDF から
隠すことも可能です。

submitting-patches-1st-batch-rc1 から先頭の2つのコミットを省いた5個のパッチをシリーズにして
linux-doc に投稿してみます。

akiyks pushed a commit that referenced this issue May 7, 2022
Current DP driver implementation has adding safe mode done at
dp_hpd_plug_handle() which is expected to be executed under event
thread context.

However there is possible circular locking happen (see blow stack trace)
after edp driver call dp_hpd_plug_handle() from dp_bridge_enable() which
is executed under drm_thread context.

After review all possibilities methods and as discussed on
https://patchwork.freedesktop.org/patch/483155/, supporting EDID
compliance tests in the driver is quite hacky. As seen with other
vendor drivers, supporting these will be much easier with IGT. Hence
removing all the related fail safe code for it so that no possibility
of circular lock will happen.
Reviewed-by: Stephen Boyd <[email protected]>
Reviewed-by: Douglas Anderson <[email protected]>
Reviewed-by: Dmitry Baryshkov <[email protected]>

======================================================
 WARNING: possible circular locking dependency detected
 5.15.35-lockdep torvalds#6 Tainted: G        W
 ------------------------------------------------------
 frecon/429 is trying to acquire lock:
 ffffff808dc3c4e8 (&dev->mode_config.mutex){+.+.}-{3:3}, at:
dp_panel_add_fail_safe_mode+0x4c/0xa0

 but task is already holding lock:
 ffffff808dc441e0 (&kms->commit_lock[i]){+.+.}-{3:3}, at: lock_crtcs+0xb4/0x124

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #3 (&kms->commit_lock[i]){+.+.}-{3:3}:
        __mutex_lock_common+0x174/0x1a64
        mutex_lock_nested+0x98/0xac
        lock_crtcs+0xb4/0x124
        msm_atomic_commit_tail+0x330/0x748
        commit_tail+0x19c/0x278
        drm_atomic_helper_commit+0x1dc/0x1f0
        drm_atomic_commit+0xc0/0xd8
        drm_atomic_helper_set_config+0xb4/0x134
        drm_mode_setcrtc+0x688/0x1248
        drm_ioctl_kernel+0x1e4/0x338
        drm_ioctl+0x3a4/0x684
        __arm64_sys_ioctl+0x118/0x154
        invoke_syscall+0x78/0x224
        el0_svc_common+0x178/0x200
        do_el0_svc+0x94/0x13c
        el0_svc+0x5c/0xec
        el0t_64_sync_handler+0x78/0x108
        el0t_64_sync+0x1a4/0x1a8

 -> #2 (crtc_ww_class_mutex){+.+.}-{3:3}:
        __mutex_lock_common+0x174/0x1a64
        ww_mutex_lock+0xb8/0x278
        modeset_lock+0x304/0x4ac
        drm_modeset_lock+0x4c/0x7c
        drmm_mode_config_init+0x4a8/0xc50
        msm_drm_init+0x274/0xac0
        msm_drm_bind+0x20/0x2c
        try_to_bring_up_master+0x3dc/0x470
        __component_add+0x18c/0x3c0
        component_add+0x1c/0x28
        dp_display_probe+0x954/0xa98
        platform_probe+0x124/0x15c
        really_probe+0x1b0/0x5f8
        __driver_probe_device+0x174/0x20c
        driver_probe_device+0x70/0x134
        __device_attach_driver+0x130/0x1d0
        bus_for_each_drv+0xfc/0x14c
        __device_attach+0x1bc/0x2bc
        device_initial_probe+0x1c/0x28
        bus_probe_device+0x94/0x178
        deferred_probe_work_func+0x1a4/0x1f0
        process_one_work+0x5d4/0x9dc
        worker_thread+0x898/0xccc
        kthread+0x2d4/0x3d4
        ret_from_fork+0x10/0x20

 -> #1 (crtc_ww_class_acquire){+.+.}-{0:0}:
        ww_acquire_init+0x1c4/0x2c8
        drm_modeset_acquire_init+0x44/0xc8
        drm_helper_probe_single_connector_modes+0xb0/0x12dc
        drm_mode_getconnector+0x5dc/0xfe8
        drm_ioctl_kernel+0x1e4/0x338
        drm_ioctl+0x3a4/0x684
        __arm64_sys_ioctl+0x118/0x154
        invoke_syscall+0x78/0x224
        el0_svc_common+0x178/0x200
        do_el0_svc+0x94/0x13c
        el0_svc+0x5c/0xec
        el0t_64_sync_handler+0x78/0x108
        el0t_64_sync+0x1a4/0x1a8

 -> #0 (&dev->mode_config.mutex){+.+.}-{3:3}:
        __lock_acquire+0x2650/0x672c
        lock_acquire+0x1b4/0x4ac
        __mutex_lock_common+0x174/0x1a64
        mutex_lock_nested+0x98/0xac
        dp_panel_add_fail_safe_mode+0x4c/0xa0
        dp_hpd_plug_handle+0x1f0/0x280
        dp_bridge_enable+0x94/0x2b8
        drm_atomic_bridge_chain_enable+0x11c/0x168
        drm_atomic_helper_commit_modeset_enables+0x500/0x740
        msm_atomic_commit_tail+0x3e4/0x748
        commit_tail+0x19c/0x278
        drm_atomic_helper_commit+0x1dc/0x1f0
        drm_atomic_commit+0xc0/0xd8
        drm_atomic_helper_set_config+0xb4/0x134
        drm_mode_setcrtc+0x688/0x1248
        drm_ioctl_kernel+0x1e4/0x338
        drm_ioctl+0x3a4/0x684
        __arm64_sys_ioctl+0x118/0x154
        invoke_syscall+0x78/0x224
        el0_svc_common+0x178/0x200
        do_el0_svc+0x94/0x13c
        el0_svc+0x5c/0xec
        el0t_64_sync_handler+0x78/0x108
        el0t_64_sync+0x1a4/0x1a8

Changes in v2:
-- re text commit title
-- remove all fail safe mode

Changes in v3:
-- remove dp_panel_add_fail_safe_mode() from dp_panel.h
-- add Fixes

Changes in v5:
--  [email protected]

Changes in v6:
--  fix Fixes commit ID

Fixes: 8b2c181 ("drm/msm/dp: add fail safe mode outside of event_mutex context")
Reported-by: Douglas Anderson <[email protected]>
Signed-off-by: Kuogee Hsieh <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Rob Clark <[email protected]>
akiyks pushed a commit that referenced this issue May 8, 2022
As reported by Alan, the CFI (Call Frame Information) in the VDSO time
routines is incorrect since commit ce7d805 ("powerpc/vdso: Prepare
for switching VDSO to generic C implementation.").

DWARF has a concept called the CFA (Canonical Frame Address), which on
powerpc is calculated as an offset from the stack pointer (r1). That
means when the stack pointer is changed there must be a corresponding
CFI directive to update the calculation of the CFA.

The current code is missing those directives for the changes to r1,
which prevents gdb from being able to generate a backtrace from inside
VDSO functions, eg:

  Breakpoint 1, 0x00007ffff7f804dc in __kernel_clock_gettime ()
  (gdb) bt
  #0  0x00007ffff7f804dc in __kernel_clock_gettime ()
  #1  0x00007ffff7d8872c in clock_gettime@@GLIBC_2.17 () from /lib64/libc.so.6
  #2  0x00007fffffffd960 in ?? ()
  #3  0x00007ffff7d8872c in clock_gettime@@GLIBC_2.17 () from /lib64/libc.so.6
  Backtrace stopped: frame did not save the PC

Alan helpfully describes some rules for correctly maintaining the CFI information:

  1) Every adjustment to the current frame address reg (ie. r1) must be
     described, and exactly at the instruction where r1 changes. Why?
     Because stack unwinding might want to access previous frames.

  2) If a function changes LR or any non-volatile register, the save
     location for those regs must be given. The CFI can be at any
     instruction after the saves up to the point that the reg is
     changed.
     (Exception: LR save should be described before a bl. not after)

  3) If asychronous unwind info is needed then restores of LR and
     non-volatile regs must also be described. The CFI can be at any
     instruction after the reg is restored up to the point where the
     save location is (potentially) trashed.

Fix the inability to backtrace by adding CFI directives describing the
changes to r1, ie. satisfying rule 1.

Also change the information for LR to point to the copy saved on the
stack, not the value in r0 that will be overwritten by the function
call.

Finally, add CFI directives describing the save/restore of r2.

With the fix gdb can correctly back trace and navigate up and down the stack:

  Breakpoint 1, 0x00007ffff7f804dc in __kernel_clock_gettime ()
  (gdb) bt
  #0  0x00007ffff7f804dc in __kernel_clock_gettime ()
  #1  0x00007ffff7d8872c in clock_gettime@@GLIBC_2.17 () from /lib64/libc.so.6
  #2  0x0000000100015b60 in gettime ()
  #3  0x000000010000c8bc in print_long_format ()
  #4  0x000000010000d180 in print_current_files ()
  #5  0x00000001000054ac in main ()
  (gdb) up
  #1  0x00007ffff7d8872c in clock_gettime@@GLIBC_2.17 () from /lib64/libc.so.6
  (gdb)
  #2  0x0000000100015b60 in gettime ()
  (gdb)
  #3  0x000000010000c8bc in print_long_format ()
  (gdb)
  #4  0x000000010000d180 in print_current_files ()
  (gdb)
  #5  0x00000001000054ac in main ()
  (gdb)
  Initial frame selected; you cannot go up.
  (gdb) down
  #4  0x000000010000d180 in print_current_files ()
  (gdb)
  #3  0x000000010000c8bc in print_long_format ()
  (gdb)
  #2  0x0000000100015b60 in gettime ()
  (gdb)
  #1  0x00007ffff7d8872c in clock_gettime@@GLIBC_2.17 () from /lib64/libc.so.6
  (gdb)
  #0  0x00007ffff7f804dc in __kernel_clock_gettime ()
  (gdb)

Fixes: ce7d805 ("powerpc/vdso: Prepare for switching VDSO to generic C implementation.")
Cc: [email protected] # v5.11+
Reported-by: Alan Modra <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Reviewed-by: Segher Boessenkool <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
@tgkz
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tgkz commented May 10, 2022

連休でストップしてしまいました

著作権上は翻訳後のテキストには翻訳者に二次著作者としての権利が発生するのだと理解しています。この例ではKiiさんがその権利を持っているので、その名前だけはコメント欄に残しておくのが適切だと思います。残りのレビューアなどは不要と思います。
HOWTOを RSTにした際にはJFのヘッダを削除することで他のファイルのRST化のリファレンスにしたいと思っていたので現在の方向性は良いと思います。

akiyks pushed a commit that referenced this issue May 19, 2022
Now when Intel Elkhart Lake uses again common bit timing and there are
no other users for custom bit timing, we can bring back the changes
done by the commit 0ddd83f ("can: m_can: remove support for
custom bit timing").

This effectively reverts commit ea768b2 ("Revert "can: m_can:
remove support for custom bit timing"") while taking into account
commit ea22ba4 ("can: m_can: make custom bittiming fields const")
and commit 7d4a101 ("can: dev: add sanity check in
can_set_static_ctrlmode()").

Link: https://lore.kernel.org/all/[email protected]
Signed-off-by: Jarkko Nikula <[email protected]>
Signed-off-by: Marc Kleine-Budde <[email protected]>
akiyks pushed a commit that referenced this issue May 19, 2022
Do not allow to write timestamps on RX rings if PF is being configured.
When PF is being configured RX rings can be freed or rebuilt. If at the
same time timestamps are updated, the kernel will crash by dereferencing
null RX ring pointer.

PID: 1449   TASK: ff187d28ed658040  CPU: 34  COMMAND: "ice-ptp-0000:51"
 #0 [ff1966a94a713bb0] machine_kexec at ffffffff9d05a0be
 #1 [ff1966a94a713c08] __crash_kexec at ffffffff9d192e9d
 #2 [ff1966a94a713cd0] crash_kexec at ffffffff9d1941bd
 #3 [ff1966a94a713ce8] oops_end at ffffffff9d01bd54
 #4 [ff1966a94a713d08] no_context at ffffffff9d06bda4
 #5 [ff1966a94a713d60] __bad_area_nosemaphore at ffffffff9d06c10c
 torvalds#6 [ff1966a94a713da8] do_page_fault at ffffffff9d06cae4
 torvalds#7 [ff1966a94a713de0] page_fault at ffffffff9da0107e
    [exception RIP: ice_ptp_update_cached_phctime+91]
    RIP: ffffffffc076db8b  RSP: ff1966a94a713e98  RFLAGS: 00010246
    RAX: 16e3db9c6b7ccae4  RBX: ff187d269dd3c180  RCX: ff187d269cd4d018
    RDX: 0000000000000000  RSI: 0000000000000000  RDI: 0000000000000000
    RBP: ff187d269cfcc644   R8: ff187d339b9641b0   R9: 0000000000000000
    R10: 0000000000000002  R11: 0000000000000000  R12: ff187d269cfcc648
    R13: ffffffff9f128784  R14: ffffffff9d101b70  R15: ff187d269cfcc640
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 torvalds#8 [ff1966a94a713ea0] ice_ptp_periodic_work at ffffffffc076dbef [ice]
 torvalds#9 [ff1966a94a713ee0] kthread_worker_fn at ffffffff9d101c1b
 torvalds#10 [ff1966a94a713f10] kthread at ffffffff9d101b4d
 torvalds#11 [ff1966a94a713f50] ret_from_fork at ffffffff9da0023f

Fixes: 77a7811 ("ice: enable receive hardware timestamping")
Signed-off-by: Arkadiusz Kubalewski <[email protected]>
Reviewed-by: Michal Schmidt <[email protected]>
Tested-by: Dave Cain <[email protected]>
Tested-by: Gurucharan <[email protected]> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <[email protected]>
akiyks pushed a commit that referenced this issue May 19, 2022
Currently, software objects of flow steering are created and destroyed
during reload flow. In case a device is unloaded, the following error
is printed during grace period:

 mlx5_core 0000:00:0b.0: mlx5_fw_fatal_reporter_err_work:690:(pid 95):
    Driver is in error state. Unloading

As a solution to fix use-after-free bugs, where we try to access
these objects, when reading the value of flow_steering_mode devlink
param[1], let's split flow steering creation and destruction into two
routines:
    * init and cleanup: memory, cache, and pools allocation/free.
    * create and destroy: namespaces initialization and cleanup.

While at it, re-order the cleanup function to mirror the init function.

[1]
Kasan trace:

[  385.119849 ] BUG: KASAN: use-after-free in mlx5_devlink_fs_mode_get+0x3b/0xa0
[  385.119849 ] Read of size 4 at addr ffff888104b79308 by task bash/291
[  385.119849 ]
[  385.119849 ] CPU: 1 PID: 291 Comm: bash Not tainted 5.17.0-rc1+ #2
[  385.119849 ] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-2.fc32 04/01/2014
[  385.119849 ] Call Trace:
[  385.119849 ]  <TASK>
[  385.119849 ]  dump_stack_lvl+0x6e/0x91
[  385.119849 ]  print_address_description.constprop.0+0x1f/0x160
[  385.119849 ]  ? mlx5_devlink_fs_mode_get+0x3b/0xa0
[  385.119849 ]  ? mlx5_devlink_fs_mode_get+0x3b/0xa0
[  385.119849 ]  kasan_report.cold+0x83/0xdf
[  385.119849 ]  ? devlink_param_notify+0x20/0x190
[  385.119849 ]  ? mlx5_devlink_fs_mode_get+0x3b/0xa0
[  385.119849 ]  mlx5_devlink_fs_mode_get+0x3b/0xa0
[  385.119849 ]  devlink_nl_param_fill+0x18a/0xa50
[  385.119849 ]  ? _raw_spin_lock_irqsave+0x8d/0xe0
[  385.119849 ]  ? devlink_flash_update_timeout_notify+0xf0/0xf0
[  385.119849 ]  ? __wake_up_common+0x4b/0x1e0
[  385.119849 ]  ? preempt_count_sub+0x14/0xc0
[  385.119849 ]  ? _raw_spin_unlock_irqrestore+0x28/0x40
[  385.119849 ]  ? __wake_up_common_lock+0xe3/0x140
[  385.119849 ]  ? __wake_up_common+0x1e0/0x1e0
[  385.119849 ]  ? __sanitizer_cov_trace_const_cmp8+0x27/0x80
[  385.119849 ]  ? __rcu_read_unlock+0x48/0x70
[  385.119849 ]  ? kasan_unpoison+0x23/0x50
[  385.119849 ]  ? __kasan_slab_alloc+0x2c/0x80
[  385.119849 ]  ? memset+0x20/0x40
[  385.119849 ]  ? __sanitizer_cov_trace_const_cmp4+0x25/0x80
[  385.119849 ]  devlink_param_notify+0xce/0x190
[  385.119849 ]  devlink_unregister+0x92/0x2b0
[  385.119849 ]  remove_one+0x41/0x140
[  385.119849 ]  pci_device_remove+0x68/0x140
[  385.119849 ]  ? pcibios_free_irq+0x10/0x10
[  385.119849 ]  __device_release_driver+0x294/0x3f0
[  385.119849 ]  device_driver_detach+0x82/0x130
[  385.119849 ]  unbind_store+0x193/0x1b0
[  385.119849 ]  ? subsys_interface_unregister+0x270/0x270
[  385.119849 ]  drv_attr_store+0x4e/0x70
[  385.119849 ]  ? drv_attr_show+0x60/0x60
[  385.119849 ]  sysfs_kf_write+0xa7/0xc0
[  385.119849 ]  kernfs_fop_write_iter+0x23a/0x2f0
[  385.119849 ]  ? sysfs_kf_bin_read+0x160/0x160
[  385.119849 ]  new_sync_write+0x311/0x430
[  385.119849 ]  ? new_sync_read+0x480/0x480
[  385.119849 ]  ? _raw_spin_lock+0x87/0xe0
[  385.119849 ]  ? __sanitizer_cov_trace_cmp4+0x25/0x80
[  385.119849 ]  ? security_file_permission+0x94/0xa0
[  385.119849 ]  vfs_write+0x4c7/0x590
[  385.119849 ]  ksys_write+0xf6/0x1e0
[  385.119849 ]  ? __x64_sys_read+0x50/0x50
[  385.119849 ]  ? fpregs_assert_state_consistent+0x99/0xa0
[  385.119849 ]  do_syscall_64+0x3d/0x90
[  385.119849 ]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[  385.119849 ] RIP: 0033:0x7fc36ef38504
[  385.119849 ] Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b3 0f 1f
80 00 00 00 00 48 8d 05 f9 61 0d 00 8b 00 85 c0 75 13 b8 01 00 00 00 0f
05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 41 54 49 89 d4 55 48 89 f5 53
[  385.119849 ] RSP: 002b:00007ffde0ff3d08 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[  385.119849 ] RAX: ffffffffffffffda RBX: 000000000000000c RCX: 00007fc36ef38504
[  385.119849 ] RDX: 000000000000000c RSI: 00007fc370521040 RDI: 0000000000000001
[  385.119849 ] RBP: 00007fc370521040 R08: 00007fc36f00b8c0 R09: 00007fc36ee4b740
[  385.119849 ] R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc36f00a760
[  385.119849 ] R13: 000000000000000c R14: 00007fc36f005760 R15: 000000000000000c
[  385.119849 ]  </TASK>
[  385.119849 ]
[  385.119849 ] Allocated by task 65:
[  385.119849 ]  kasan_save_stack+0x1e/0x40
[  385.119849 ]  __kasan_kmalloc+0x81/0xa0
[  385.119849 ]  mlx5_init_fs+0x11b/0x1160
[  385.119849 ]  mlx5_load+0x13c/0x220
[  385.119849 ]  mlx5_load_one+0xda/0x160
[  385.119849 ]  mlx5_recover_device+0xb8/0x100
[  385.119849 ]  mlx5_health_try_recover+0x2f9/0x3a1
[  385.119849 ]  devlink_health_reporter_recover+0x75/0x100
[  385.119849 ]  devlink_health_report+0x26c/0x4b0
[  385.275909 ]  mlx5_fw_fatal_reporter_err_work+0x11e/0x1b0
[  385.275909 ]  process_one_work+0x520/0x970
[  385.275909 ]  worker_thread+0x378/0x950
[  385.275909 ]  kthread+0x1bb/0x200
[  385.275909 ]  ret_from_fork+0x1f/0x30
[  385.275909 ]
[  385.275909 ] Freed by task 65:
[  385.275909 ]  kasan_save_stack+0x1e/0x40
[  385.275909 ]  kasan_set_track+0x21/0x30
[  385.275909 ]  kasan_set_free_info+0x20/0x30
[  385.275909 ]  __kasan_slab_free+0xfc/0x140
[  385.275909 ]  kfree+0xa5/0x3b0
[  385.275909 ]  mlx5_unload+0x2e/0xb0
[  385.275909 ]  mlx5_unload_one+0x86/0xb0
[  385.275909 ]  mlx5_fw_fatal_reporter_err_work.cold+0xca/0xcf
[  385.275909 ]  process_one_work+0x520/0x970
[  385.275909 ]  worker_thread+0x378/0x950
[  385.275909 ]  kthread+0x1bb/0x200
[  385.275909 ]  ret_from_fork+0x1f/0x30
[  385.275909 ]
[  385.275909 ] The buggy address belongs to the object at ffff888104b79300
[  385.275909 ]  which belongs to the cache kmalloc-128 of size 128
[  385.275909 ] The buggy address is located 8 bytes inside of
[  385.275909 ]  128-byte region [ffff888104b79300, ffff888104b79380)
[  385.275909 ] The buggy address belongs to the page:
[  385.275909 ] page:00000000de44dd39 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x104b78
[  385.275909 ] head:00000000de44dd39 order:1 compound_mapcount:0
[  385.275909 ] flags: 0x8000000000010200(slab|head|zone=2)
[  385.275909 ] raw: 8000000000010200 0000000000000000 dead000000000122 ffff8881000428c0
[  385.275909 ] raw: 0000000000000000 0000000080200020 00000001ffffffff 0000000000000000
[  385.275909 ] page dumped because: kasan: bad access detected
[  385.275909 ]
[  385.275909 ] Memory state around the buggy address:
[  385.275909 ]  ffff888104b79200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc
[  385.275909 ]  ffff888104b79280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  385.275909 ] >ffff888104b79300: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  385.275909 ]                       ^
[  385.275909 ]  ffff888104b79380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  385.275909 ]  ffff888104b79400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  385.275909 ]]

Fixes: e890acd ("net/mlx5: Add devlink flow_steering_mode parameter")
Signed-off-by: Shay Drory <[email protected]>
Reviewed-by: Mark Bloch <[email protected]>
Signed-off-by: Saeed Mahameed <[email protected]>
akiyks pushed a commit that referenced this issue May 21, 2022
The splat below can be seen when running kvm-unit-test:

     =============================
     WARNING: suspicious RCU usage
     5.18.0-rc7 #5 Tainted: G          IOE
     -----------------------------
     /home/kernel/linux/arch/x86/kvm/../../../virt/kvm/eventfd.c:80 RCU-list traversed in non-reader section!!

     other info that might help us debug this:

     rcu_scheduler_active = 2, debug_locks = 1
     4 locks held by qemu-system-x86/35124:
      #0: ffff9725391d80b8 (&vcpu->mutex){+.+.}-{4:4}, at: kvm_vcpu_ioctl+0x77/0x710 [kvm]
      #1: ffffbd25cfb2a0b8 (&kvm->srcu){....}-{0:0}, at: vcpu_enter_guest+0xdeb/0x1900 [kvm]
      #2: ffffbd25cfb2b920 (&kvm->irq_srcu){....}-{0:0}, at: kvm_hv_notify_acked_sint+0x79/0x1e0 [kvm]
      #3: ffffbd25cfb2b920 (&kvm->irq_srcu){....}-{0:0}, at: irqfd_resampler_ack+0x5/0x110 [kvm]

     stack backtrace:
     CPU: 2 PID: 35124 Comm: qemu-system-x86 Tainted: G          IOE     5.18.0-rc7 #5
     Call Trace:
      <TASK>
      dump_stack_lvl+0x6c/0x9b
      irqfd_resampler_ack+0xfd/0x110 [kvm]
      kvm_notify_acked_gsi+0x32/0x90 [kvm]
      kvm_hv_notify_acked_sint+0xc5/0x1e0 [kvm]
      kvm_hv_set_msr_common+0xec1/0x1160 [kvm]
      kvm_set_msr_common+0x7c3/0xf60 [kvm]
      vmx_set_msr+0x394/0x1240 [kvm_intel]
      kvm_set_msr_ignored_check+0x86/0x200 [kvm]
      kvm_emulate_wrmsr+0x4f/0x1f0 [kvm]
      vmx_handle_exit+0x6fb/0x7e0 [kvm_intel]
      vcpu_enter_guest+0xe5a/0x1900 [kvm]
      kvm_arch_vcpu_ioctl_run+0x16e/0xac0 [kvm]
      kvm_vcpu_ioctl+0x279/0x710 [kvm]
      __x64_sys_ioctl+0x83/0xb0
      do_syscall_64+0x3b/0x90
      entry_SYSCALL_64_after_hwframe+0x44/0xae

resampler-list is protected by irq_srcu (see kvm_irqfd_assign), so fix
the false positive by using list_for_each_entry_srcu().

Signed-off-by: Wanpeng Li <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>
akiyks pushed a commit that referenced this issue May 24, 2022
In idtentry_vc(), vc_switch_off_ist() determines a safe stack to
switch to, off of the IST stack. Annotate the new stack switch with
ENCODE_FRAME_POINTER in case UNWINDER_FRAME_POINTER is used.

A stack walk before looks like this:

  CPU: 0 PID: 0 Comm: swapper Not tainted 5.18.0-rc7+ #2
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
  Call Trace:
   <TASK>
   dump_stack_lvl
   dump_stack
   kernel_exc_vmm_communication
   asm_exc_vmm_communication
   ? native_read_msr
   ? __x2apic_disable.part.0
   ? x2apic_setup
   ? cpu_init
   ? trap_init
   ? start_kernel
   ? x86_64_start_reservations
   ? x86_64_start_kernel
   ? secondary_startup_64_no_verify
   </TASK>

and with the fix, the stack dump is exact:

  CPU: 0 PID: 0 Comm: swapper Not tainted 5.18.0-rc7+ #3
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
  Call Trace:
   <TASK>
   dump_stack_lvl
   dump_stack
   kernel_exc_vmm_communication
   asm_exc_vmm_communication
  RIP: 0010:native_read_msr
  Code: ...
  < snipped regs >
   ? __x2apic_disable.part.0
   x2apic_setup
   cpu_init
   trap_init
   start_kernel
   x86_64_start_reservations
   x86_64_start_kernel
   secondary_startup_64_no_verify
   </TASK>

  [ bp: Test in a SEV-ES guest and rewrite the commit message to
    explain what exactly this does. ]

Fixes: a13644f ("x86/entry/64: Add entry code for #VC handler")
Signed-off-by: Lai Jiangshan <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Acked-by: Josh Poimboeuf <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
akiyks pushed a commit that referenced this issue May 24, 2022
Problem statement:

Once the user has disabled turbo frequency by

# echo 1 > /sys/devices/system/cpu/intel_pstate/no_turbo

the cfs_rq's util_avg becomes quite small when compared with
CPU capacity.

Step to reproduce:

# echo 1 > /sys/devices/system/cpu/intel_pstate/no_turbo

# ./x86_cpuload --count 1 --start 3 --timeout 100 --busy 99

would launch 1 thread and bind it to CPU3, lasting for 100 seconds,
with a CPU utilization of 99%. [1]

top result:
%Cpu3  : 98.4 us,  0.0 sy,  0.0 ni,  1.6 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st

check util_avg:
cat /sys/kernel/debug/sched/debug | grep "cfs_rq\[3\]" -A 20 | grep util_avg
  .util_avg                      : 611

So the util_avg/cpu capacity is 611/1024, which is much smaller than
98.4% shown in the top result.

This might impact some logic in the scheduler. For example,
group_is_overloaded() would compare the group_capacity and group_util
in the sched group, to check if this sched group is overloaded or not.
With this gap, even when there is a nearly 100% workload, the sched
group will not be regarded as overloaded. Besides group_is_overloaded(),
there are also other victims. There is a ongoing work that aims to
optimize the task wakeup in a LLC domain. The main idea is to stop
searching idle CPUs if the sched domain is overloaded[2]. This proposal
also relies on the util_avg/CPU capacity to decide whether the LLC
domain is overloaded.

Analysis:

CPU frequency invariance has caused this difference. In summary,
the util_sum of cfs rq would decay quite fast when the CPU is in
idle, when the CPU frequency invariance is enabled.

The detail is as followed:

As depicted in update_rq_clock_pelt(), when the frequency invariance
is enabled, there would be two clock variables on each rq, clock_task
and clock_pelt:

   The clock_pelt scales the time to reflect the effective amount of
   computation done during the running delta time but then syncs back to
   clock_task when rq is idle.

   absolute time    | 1| 2| 3| 4| 5| 6| 7| 8| 9|10|11|12|13|14|15|16
   @ max frequency  ------******---------------******---------------
   @ half frequency ------************---------************---------
   clock pelt       | 1| 2|    3|    4| 7| 8| 9|   10|   11|14|15|16

The fast decay of util_sum during idle is due to:

 1. rq->clock_pelt is always behind rq->clock_task
 2. rq->last_update is updated to rq->clock_pelt' after invoking
    ___update_load_sum()
 3. Then the CPU becomes idle, the rq->clock_pelt' would be suddenly
    increased a lot to rq->clock_task
 4. Enters ___update_load_sum() again, the idle period is calculated by
    rq->clock_task - rq->last_update, AKA, rq->clock_task - rq->clock_pelt'.
    The lower the CPU frequency is, the larger the delta =
    rq->clock_task - rq->clock_pelt' will be. Since the idle period will be
    used to decay the util_sum only, the util_sum drops significantly during
    idle period.

Proposal:

This symptom is not only caused by disabling turbo frequency, but it
would also appear if the user limits the max frequency at runtime.

Because, if the frequency is always lower than the max frequency,
CPU frequency invariance would decay the util_sum quite fast during
idle.

As some end users would disable turbo after boot up, this patch aims to
present this symptom and deals with turbo scenarios for now.

It might be ideal if CPU frequency invariance is aware of the max CPU
frequency (user specified) at runtime in the future.

Link: https://github.com/yu-chen-surf/x86_cpuload.git #1
Link: https://lore.kernel.org/lkml/[email protected]/ #2
Signed-off-by: Chen Yu <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Giovanni Gherdovich <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
akiyks pushed a commit that referenced this issue May 27, 2022
Add the description for the i.MX8MP media blk-ctrl.

Signed-off-by: Paul Elder <[email protected]>
Reviewed-by: Laurent Pinchart <[email protected]>
Signed-off-by: Laurent Pinchart <[email protected]>
Reviewed-by: Marek Vasut <[email protected]>
Tested-by: Marek Vasut <[email protected]> # MX8MP LCDIF #1 and #2
Signed-off-by: Lucas Stach <[email protected]>
Signed-off-by: Shawn Guo <[email protected]>
akiyks pushed a commit that referenced this issue May 27, 2022
When shmem_reconfigure() calls __percpu_counter_compare(), the second
parameter is unsigned long long.  But in the definition of
__percpu_counter_compare(), the second parameter is s64.  So when
__percpu_counter_compare() executes abs(count - rhs), UBSAN shows the
following warning:

================================================================================
UBSAN: Undefined behaviour in lib/percpu_counter.c:209:6
signed integer overflow:
0 - -9223372036854775808 cannot be represented in type 'long long int'
CPU: 1 PID: 9636 Comm: syz-executor.2 Tainted: G                 ---------r-  - 4.18.0 #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Call Trace:
 __dump_stack home/install/linux-rh-3-10/lib/dump_stack.c:77 [inline]
 dump_stack+0x125/0x1ae home/install/linux-rh-3-10/lib/dump_stack.c:117
 ubsan_epilogue+0xe/0x81 home/install/linux-rh-3-10/lib/ubsan.c:159
 handle_overflow+0x19d/0x1ec home/install/linux-rh-3-10/lib/ubsan.c:190
 __percpu_counter_compare+0x124/0x140 home/install/linux-rh-3-10/lib/percpu_counter.c:209
 percpu_counter_compare home/install/linux-rh-3-10/./include/linux/percpu_counter.h:50 [inline]
 shmem_remount_fs+0x1ce/0x6b0 home/install/linux-rh-3-10/mm/shmem.c:3530
 do_remount_sb+0x11b/0x530 home/install/linux-rh-3-10/fs/super.c:888
 do_remount home/install/linux-rh-3-10/fs/namespace.c:2344 [inline]
 do_mount+0xf8d/0x26b0 home/install/linux-rh-3-10/fs/namespace.c:2844
 ksys_mount+0xad/0x120 home/install/linux-rh-3-10/fs/namespace.c:3075
 __do_sys_mount home/install/linux-rh-3-10/fs/namespace.c:3089 [inline]
 __se_sys_mount home/install/linux-rh-3-10/fs/namespace.c:3086 [inline]
 __x64_sys_mount+0xbf/0x160 home/install/linux-rh-3-10/fs/namespace.c:3086
 do_syscall_64+0xca/0x5c0 home/install/linux-rh-3-10/arch/x86/entry/common.c:298
 entry_SYSCALL_64_after_hwframe+0x6a/0xdf
RIP: 0033:0x46b5e9
Code: 5d db fa ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 2b db fa ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f54d5f22c68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 000000000077bf60 RCX: 000000000046b5e9
RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000000
RBP: 000000000077bf60 R08: 0000000020000140 R09: 0000000000000000
R10: 00000000026740a4 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd1fb1592f R14: 00007f54d5f239c0 R15: 000000000077bf6c
================================================================================

[[email protected]: tweak error message text]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Luo Meng <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Yu Kuai <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
akiyks pushed a commit that referenced this issue May 27, 2022
pty_write() invokes kmalloc() which may invoke a normal printk() to print
failure message.  This can cause a deadlock in the scenario reported by
syz-bot below:

       CPU0              CPU1                    CPU2
       ----              ----                    ----
                         lock(console_owner);
                                                 lock(&port_lock_key);
  lock(&port->lock);
                         lock(&port_lock_key);
                                                 lock(&port->lock);
  lock(console_owner);

As commit dbdda84 ("printk: Add console owner and waiter logic to
load balance console writes") said, such deadlock can be prevented by
using printk_deferred() in kmalloc() (which is invoked in the section
guarded by the port->lock).  But there are too many printk() on the
kmalloc() path, and kmalloc() can be called from anywhere, so changing
printk() to printk_deferred() is too complicated and inelegant.

Therefore, this patch chooses to specify __GFP_NOWARN to kmalloc(), so
that printk() will not be called, and this deadlock problem can be
avoided.

Syzbot reported the following lockdep error:

======================================================
WARNING: possible circular locking dependency detected
5.4.143-00237-g08ccc19a-dirty torvalds#10 Not tainted
------------------------------------------------------
syz-executor.4/29420 is trying to acquire lock:
ffffffff8aedb2a0 (console_owner){....}-{0:0}, at: console_trylock_spinning kernel/printk/printk.c:1752 [inline]
ffffffff8aedb2a0 (console_owner){....}-{0:0}, at: vprintk_emit+0x2ca/0x470 kernel/printk/printk.c:2023

but task is already holding lock:
ffff8880119c9158 (&port->lock){-.-.}-{2:2}, at: pty_write+0xf4/0x1f0 drivers/tty/pty.c:120

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #2 (&port->lock){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x35/0x50 kernel/locking/spinlock.c:159
       tty_port_tty_get drivers/tty/tty_port.c:288 [inline]          		<-- lock(&port->lock);
       tty_port_default_wakeup+0x1d/0xb0 drivers/tty/tty_port.c:47
       serial8250_tx_chars+0x530/0xa80 drivers/tty/serial/8250/8250_port.c:1767
       serial8250_handle_irq.part.0+0x31f/0x3d0 drivers/tty/serial/8250/8250_port.c:1854
       serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1827 [inline] 	<-- lock(&port_lock_key);
       serial8250_default_handle_irq+0xb2/0x220 drivers/tty/serial/8250/8250_port.c:1870
       serial8250_interrupt+0xfd/0x200 drivers/tty/serial/8250/8250_core.c:126
       __handle_irq_event_percpu+0x109/0xa50 kernel/irq/handle.c:156
       [...]

-> #1 (&port_lock_key){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x35/0x50 kernel/locking/spinlock.c:159
       serial8250_console_write+0x184/0xa40 drivers/tty/serial/8250/8250_port.c:3198
										<-- lock(&port_lock_key);
       call_console_drivers kernel/printk/printk.c:1819 [inline]
       console_unlock+0x8cb/0xd00 kernel/printk/printk.c:2504
       vprintk_emit+0x1b5/0x470 kernel/printk/printk.c:2024			<-- lock(console_owner);
       vprintk_func+0x8d/0x250 kernel/printk/printk_safe.c:394
       printk+0xba/0xed kernel/printk/printk.c:2084
       register_console+0x8b3/0xc10 kernel/printk/printk.c:2829
       univ8250_console_init+0x3a/0x46 drivers/tty/serial/8250/8250_core.c:681
       console_init+0x49d/0x6d3 kernel/printk/printk.c:2915
       start_kernel+0x5e9/0x879 init/main.c:713
       secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241

-> #0 (console_owner){....}-{0:0}:
       [...]
       lock_acquire+0x127/0x340 kernel/locking/lockdep.c:4734
       console_trylock_spinning kernel/printk/printk.c:1773 [inline]		<-- lock(console_owner);
       vprintk_emit+0x307/0x470 kernel/printk/printk.c:2023
       vprintk_func+0x8d/0x250 kernel/printk/printk_safe.c:394
       printk+0xba/0xed kernel/printk/printk.c:2084
       fail_dump lib/fault-inject.c:45 [inline]
       should_fail+0x67b/0x7c0 lib/fault-inject.c:144
       __should_failslab+0x152/0x1c0 mm/failslab.c:33
       should_failslab+0x5/0x10 mm/slab_common.c:1224
       slab_pre_alloc_hook mm/slab.h:468 [inline]
       slab_alloc_node mm/slub.c:2723 [inline]
       slab_alloc mm/slub.c:2807 [inline]
       __kmalloc+0x72/0x300 mm/slub.c:3871
       kmalloc include/linux/slab.h:582 [inline]
       tty_buffer_alloc+0x23f/0x2a0 drivers/tty/tty_buffer.c:175
       __tty_buffer_request_room+0x156/0x2a0 drivers/tty/tty_buffer.c:273
       tty_insert_flip_string_fixed_flag+0x93/0x250 drivers/tty/tty_buffer.c:318
       tty_insert_flip_string include/linux/tty_flip.h:37 [inline]
       pty_write+0x126/0x1f0 drivers/tty/pty.c:122				<-- lock(&port->lock);
       n_tty_write+0xa7a/0xfc0 drivers/tty/n_tty.c:2356
       do_tty_write drivers/tty/tty_io.c:961 [inline]
       tty_write+0x512/0x930 drivers/tty/tty_io.c:1045
       __vfs_write+0x76/0x100 fs/read_write.c:494
       [...]

other info that might help us debug this:

Chain exists of:
  console_owner --> &port_lock_key --> &port->lock

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: b6da31b ("tty: Fix data race in tty_insert_flip_string_fixed_flag")
Signed-off-by: Qi Zheng <[email protected]>
Acked-by: Jiri Slaby <[email protected]>
Acked-by: Greg Kroah-Hartman <[email protected]>
Cc: Akinobu Mita <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Steven Rostedt (Google) <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
akiyks pushed a commit that referenced this issue May 27, 2022
When user_dlm_destroy_lock failed, it didn't clean up the flags it set
before exit.  For USER_LOCK_IN_TEARDOWN, if this function fails because of
lock is still in used, next time when unlink invokes this function, it
will return succeed, and then unlink will remove inode and dentry if lock
is not in used(file closed), but the dlm lock is still linked in dlm lock
resource, then when bast come in, it will trigger a panic due to
user-after-free.  See the following panic call trace.  To fix this,
USER_LOCK_IN_TEARDOWN should be reverted if fail.  And also error should
be returned if USER_LOCK_IN_TEARDOWN is set to let user know that unlink
fail.

For the case of ocfs2_dlm_unlock failure, besides USER_LOCK_IN_TEARDOWN,
USER_LOCK_BUSY is also required to be cleared.  Even though spin lock is
released in between, but USER_LOCK_IN_TEARDOWN is still set, for
USER_LOCK_BUSY, if before every place that waits on this flag,
USER_LOCK_IN_TEARDOWN is checked to bail out, that will make sure no flow
waits on the busy flag set by user_dlm_destroy_lock(), then we can
simplely revert USER_LOCK_BUSY when ocfs2_dlm_unlock fails.  Fix
user_dlm_cluster_lock() which is the only function not following this.

[  941.336392] (python,26174,16):dlmfs_unlink:562 ERROR: unlink
004fb0000060000b5a90b8c847b72e1, error -16 from destroy
[  989.757536] ------------[ cut here ]------------
[  989.757709] kernel BUG at fs/ocfs2/dlmfs/userdlm.c:173!
[  989.757876] invalid opcode: 0000 [#1] SMP
[  989.758027] Modules linked in: ksplice_2zhuk2jr_ib_ipoib_new(O)
ksplice_2zhuk2jr(O) mptctl mptbase xen_netback xen_blkback xen_gntalloc
xen_gntdev xen_evtchn cdc_ether usbnet mii ocfs2 jbd2 rpcsec_gss_krb5
auth_rpcgss nfsv4 nfsv3 nfs_acl nfs fscache lockd grace ocfs2_dlmfs
ocfs2_stack_o2cb ocfs2_dlm ocfs2_nodemanager ocfs2_stackglue configfs bnx2fc
fcoe libfcoe libfc scsi_transport_fc sunrpc ipmi_devintf bridge stp llc
rds_rdma rds bonding ib_sdp ib_ipoib rdma_ucm ib_ucm ib_uverbs ib_umad
rdma_cm ib_cm iw_cm falcon_lsm_serviceable(PE) falcon_nf_netcontain(PE)
mlx4_vnic falcon_kal(E) falcon_lsm_pinned_13402(E) mlx4_ib ib_sa ib_mad
ib_core ib_addr xenfs xen_privcmd dm_multipath iTCO_wdt iTCO_vendor_support
pcspkr sb_edac edac_core i2c_i801 lpc_ich mfd_core ipmi_ssif i2c_core ipmi_si
ipmi_msghandler
[  989.760686]  ioatdma sg ext3 jbd mbcache sd_mod ahci libahci ixgbe dca ptp
pps_core vxlan udp_tunnel ip6_udp_tunnel megaraid_sas mlx4_core crc32c_intel
be2iscsi bnx2i cnic uio cxgb4i cxgb4 cxgb3i libcxgbi ipv6 cxgb3 mdio
libiscsi_tcp qla4xxx iscsi_boot_sysfs libiscsi scsi_transport_iscsi wmi
dm_mirror dm_region_hash dm_log dm_mod [last unloaded:
ksplice_2zhuk2jr_ib_ipoib_old]
[  989.761987] CPU: 10 PID: 19102 Comm: dlm_thread Tainted: P           OE
4.1.12-124.57.1.el6uek.x86_64 #2
[  989.762290] Hardware name: Oracle Corporation ORACLE SERVER
X5-2/ASM,MOTHERBOARD,1U, BIOS 30350100 06/17/2021
[  989.762599] task: ffff880178af6200 ti: ffff88017f7c8000 task.ti:
ffff88017f7c8000
[  989.762848] RIP: e030:[<ffffffffc07d4316>]  [<ffffffffc07d4316>]
__user_dlm_queue_lockres.part.4+0x76/0x80 [ocfs2_dlmfs]
[  989.763185] RSP: e02b:ffff88017f7cbcb8  EFLAGS: 00010246
[  989.763353] RAX: 0000000000000000 RBX: ffff880174d48008 RCX:
0000000000000003
[  989.763565] RDX: 0000000000120012 RSI: 0000000000000003 RDI:
ffff880174d48170
[  989.763778] RBP: ffff88017f7cbcc8 R08: ffff88021f4293b0 R09:
0000000000000000
[  989.763991] R10: ffff880179c8c000 R11: 0000000000000003 R12:
ffff880174d48008
[  989.764204] R13: 0000000000000003 R14: ffff880179c8c000 R15:
ffff88021db7a000
[  989.764422] FS:  0000000000000000(0000) GS:ffff880247480000(0000)
knlGS:ffff880247480000
[  989.764685] CS:  e033 DS: 0000 ES: 0000 CR0: 0000000080050033
[  989.764865] CR2: ffff8000007f6800 CR3: 0000000001ae0000 CR4:
0000000000042660
[  989.765081] Stack:
[  989.765167]  0000000000000003 ffff880174d48040 ffff88017f7cbd18
ffffffffc07d455f
[  989.765442]  ffff88017f7cbd88 ffffffff816fb639 ffff88017f7cbd38
ffff8800361b5600
[  989.765717]  ffff88021db7a000 ffff88021f429380 0000000000000003
ffffffffc0453020
[  989.765991] Call Trace:
[  989.766093]  [<ffffffffc07d455f>] user_bast+0x5f/0xf0 [ocfs2_dlmfs]
[  989.766287]  [<ffffffff816fb639>] ? schedule_timeout+0x169/0x2d0
[  989.766475]  [<ffffffffc0453020>] ? o2dlm_lock_ast_wrapper+0x20/0x20
[ocfs2_stack_o2cb]
[  989.766738]  [<ffffffffc045303a>] o2dlm_blocking_ast_wrapper+0x1a/0x20
[ocfs2_stack_o2cb]
[  989.767010]  [<ffffffffc0864ec6>] dlm_do_local_bast+0x46/0xe0 [ocfs2_dlm]
[  989.767217]  [<ffffffffc084f5cc>] ? dlm_lockres_calc_usage+0x4c/0x60
[ocfs2_dlm]
[  989.767466]  [<ffffffffc08501f1>] dlm_thread+0xa31/0x1140 [ocfs2_dlm]
[  989.767662]  [<ffffffff816f78da>] ? __schedule+0x24a/0x810
[  989.767834]  [<ffffffff816f78ce>] ? __schedule+0x23e/0x810
[  989.768006]  [<ffffffff816f78da>] ? __schedule+0x24a/0x810
[  989.768178]  [<ffffffff816f78ce>] ? __schedule+0x23e/0x810
[  989.768349]  [<ffffffff816f78da>] ? __schedule+0x24a/0x810
[  989.768521]  [<ffffffff816f78ce>] ? __schedule+0x23e/0x810
[  989.768693]  [<ffffffff816f78da>] ? __schedule+0x24a/0x810
[  989.768893]  [<ffffffff816f78ce>] ? __schedule+0x23e/0x810
[  989.769067]  [<ffffffff816f78da>] ? __schedule+0x24a/0x810
[  989.769241]  [<ffffffff810ce4d0>] ? wait_woken+0x90/0x90
[  989.769411]  [<ffffffffc084f7c0>] ? dlm_kick_thread+0x80/0x80 [ocfs2_dlm]
[  989.769617]  [<ffffffff810a8bbb>] kthread+0xcb/0xf0
[  989.769774]  [<ffffffff816f78da>] ? __schedule+0x24a/0x810
[  989.769945]  [<ffffffff816f78da>] ? __schedule+0x24a/0x810
[  989.770117]  [<ffffffff810a8af0>] ? kthread_create_on_node+0x180/0x180
[  989.770321]  [<ffffffff816fdaa1>] ret_from_fork+0x61/0x90
[  989.770492]  [<ffffffff810a8af0>] ? kthread_create_on_node+0x180/0x180
[  989.770689] Code: d0 00 00 00 f0 45 7d c0 bf 00 20 00 00 48 89 83 c0 00 00
00 48 89 83 c8 00 00 00 e8 55 c1 8c c0 83 4b 04 10 48 83 c4 08 5b 5d c3 <0f>
0b 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 55 41 54 53 48 83
[  989.771892] RIP  [<ffffffffc07d4316>]
__user_dlm_queue_lockres.part.4+0x76/0x80 [ocfs2_dlmfs]
[  989.772174]  RSP <ffff88017f7cbcb8>
[  989.772704] ---[ end trace ebd1e38cebcc93a8 ]---
[  989.772907] Kernel panic - not syncing: Fatal exception
[  989.773173] Kernel Offset: disabled

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Junxiao Bi <[email protected]>
Reviewed-by: Joseph Qi <[email protected]>
Cc: Mark Fasheh <[email protected]>
Cc: Joel Becker <[email protected]>
Cc: Joseph Qi <[email protected]>
Cc: Changwei Ge <[email protected]>
Cc: Gang He <[email protected]>
Cc: Jun Piao <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
akiyks pushed a commit that referenced this issue May 28, 2022
The irqchip ops are called with a raw spinlock held, so the subsequent
regmap usage cannot use a plain spinlock.

spi-hid-apple-of spi0.0: spihid_apple_of_probe:74

=============================
[ BUG: Invalid wait context ]
5.18.0-asahi-00176-g0fa3ab03bdea #1337 Not tainted
-----------------------------
kworker/u20:3/86 is trying to lock:
ffff8000166b5018 (pinctrl_apple_gpio:462:(&regmap_config)->lock){....}-{3:3}, at: regmap_lock_spinlock+0x18/0x30
other info that might help us debug this:
context-{5:5}
7 locks held by kworker/u20:3/86:
 #0: ffff800017725d48 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1c8/0x670
 #1: ffff80001e33bdd0 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work+0x1c8/0x670
 #2: ffff800017d629a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x30/0x17c
 #3: ffff80002414e618 (&ctlr->add_lock){+.+.}-{4:4}, at: spi_add_device+0x40/0x80
 #4: ffff800024116990 (&dev->mutex){....}-{4:4}, at: __device_attach+0x30/0x17c
 #5: ffff800022d4be58 (request_class){+.+.}-{4:4}, at: __setup_irq+0xa8/0x720
 torvalds#6: ffff800022d4bcc8 (lock_class){....}-{2:2}, at: __setup_irq+0xcc/0x720

Fixes: a0f160f ("pinctrl: add pinctrl/GPIO driver for Apple SoCs")
Signed-off-by: Hector Martin <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Linus Walleij <[email protected]>
akiyks pushed a commit that referenced this issue May 30, 2022
We see the following GPF when register_ftrace_direct fails:

[ ] general protection fault, probably for non-canonical address \
  0x200000000000010: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI
[...]
[ ] RIP: 0010:ftrace_find_rec_direct+0x53/0x70
[ ] Code: 48 c1 e0 03 48 03 42 08 48 8b 10 31 c0 48 85 d2 74 [...]
[ ] RSP: 0018:ffffc9000138bc10 EFLAGS: 00010206
[ ] RAX: 0000000000000000 RBX: ffffffff813e0df0 RCX: 000000000000003b
[ ] RDX: 0200000000000000 RSI: 000000000000000c RDI: ffffffff813e0df0
[ ] RBP: ffffffffa00a3000 R08: ffffffff81180ce0 R09: 0000000000000001
[ ] R10: ffffc9000138bc18 R11: 0000000000000001 R12: ffffffff813e0df0
[ ] R13: ffffffff813e0df0 R14: ffff888171b56400 R15: 0000000000000000
[ ] FS:  00007fa9420c7780(0000) GS:ffff888ff6a00000(0000) knlGS:000000000
[ ] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ ] CR2: 000000000770d000 CR3: 0000000107d50003 CR4: 0000000000370ee0
[ ] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ ] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ ] Call Trace:
[ ]  <TASK>
[ ]  register_ftrace_direct+0x54/0x290
[ ]  ? render_sigset_t+0xa0/0xa0
[ ]  bpf_trampoline_update+0x3f5/0x4a0
[ ]  ? 0xffffffffa00a3000
[ ]  bpf_trampoline_link_prog+0xa9/0x140
[ ]  bpf_tracing_prog_attach+0x1dc/0x450
[ ]  bpf_raw_tracepoint_open+0x9a/0x1e0
[ ]  ? find_held_lock+0x2d/0x90
[ ]  ? lock_release+0x150/0x430
[ ]  __sys_bpf+0xbd6/0x2700
[ ]  ? lock_is_held_type+0xd8/0x130
[ ]  __x64_sys_bpf+0x1c/0x20
[ ]  do_syscall_64+0x3a/0x80
[ ]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[ ] RIP: 0033:0x7fa9421defa9
[ ] Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 9 f8 [...]
[ ] RSP: 002b:00007ffed743bd78 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
[ ] RAX: ffffffffffffffda RBX: 00000000069d2480 RCX: 00007fa9421defa9
[ ] RDX: 0000000000000078 RSI: 00007ffed743bd80 RDI: 0000000000000011
[ ] RBP: 00007ffed743be00 R08: 0000000000bb7270 R09: 0000000000000000
[ ] R10: 00000000069da210 R11: 0000000000000246 R12: 0000000000000001
[ ] R13: 00007ffed743c4b0 R14: 00000000069d2480 R15: 0000000000000001
[ ]  </TASK>
[ ] Modules linked in: klp_vm(OK)
[ ] ---[ end trace 0000000000000000 ]---

One way to trigger this is:
  1. load a livepatch that patches kernel function xxx;
  2. run bpftrace -e 'kfunc:xxx {}', this will fail (expected for now);
  3. repeat #2 => gpf.

This is because the entry is added to direct_functions, but not removed.
Fix this by remove the entry from direct_functions when
register_ftrace_direct fails.

Also remove the last trailing space from ftrace.c, so we don't have to
worry about it anymore.

Link: https://lkml.kernel.org/r/[email protected]

Cc: [email protected]
Fixes: 763e34e ("ftrace: Add register_ftrace_direct()")
Signed-off-by: Song Liu <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>
akiyks pushed a commit that referenced this issue Jun 1, 2022
Let's avoid false-alarmed lockdep warning.

[   58.914674] [T1501146] -> #2 (&sb->s_type->i_mutex_key#20){+.+.}-{3:3}:
[   58.915975] [T1501146] system_server:        down_write+0x7c/0xe0
[   58.916738] [T1501146] system_server:        f2fs_quota_sync+0x60/0x1a8
[   58.917563] [T1501146] system_server:        block_operations+0x16c/0x43c
[   58.918410] [T1501146] system_server:        f2fs_write_checkpoint+0x114/0x318
[   58.919312] [T1501146] system_server:        f2fs_issue_checkpoint+0x178/0x21c
[   58.920214] [T1501146] system_server:        f2fs_sync_fs+0x48/0x6c
[   58.920999] [T1501146] system_server:        f2fs_do_sync_file+0x334/0x738
[   58.921862] [T1501146] system_server:        f2fs_sync_file+0x30/0x48
[   58.922667] [T1501146] system_server:        __arm64_sys_fsync+0x84/0xf8
[   58.923506] [T1501146] system_server:        el0_svc_common.llvm.12821150825140585682+0xd8/0x20c
[   58.924604] [T1501146] system_server:        do_el0_svc+0x28/0xa0
[   58.925366] [T1501146] system_server:        el0_svc+0x24/0x38
[   58.926094] [T1501146] system_server:        el0_sync_handler+0x88/0xec
[   58.926920] [T1501146] system_server:        el0_sync+0x1b4/0x1c0

[   58.927681] [T1501146] -> #1 (&sbi->cp_global_sem){+.+.}-{3:3}:
[   58.928889] [T1501146] system_server:        down_write+0x7c/0xe0
[   58.929650] [T1501146] system_server:        f2fs_write_checkpoint+0xbc/0x318
[   58.930541] [T1501146] system_server:        f2fs_issue_checkpoint+0x178/0x21c
[   58.931443] [T1501146] system_server:        f2fs_sync_fs+0x48/0x6c
[   58.932226] [T1501146] system_server:        sync_filesystem+0xac/0x130
[   58.933053] [T1501146] system_server:        generic_shutdown_super+0x38/0x150
[   58.933958] [T1501146] system_server:        kill_block_super+0x24/0x58
[   58.934791] [T1501146] system_server:        kill_f2fs_super+0xcc/0x124
[   58.935618] [T1501146] system_server:        deactivate_locked_super+0x90/0x120
[   58.936529] [T1501146] system_server:        deactivate_super+0x74/0xac
[   58.937356] [T1501146] system_server:        cleanup_mnt+0x128/0x168
[   58.938150] [T1501146] system_server:        __cleanup_mnt+0x18/0x28
[   58.938944] [T1501146] system_server:        task_work_run+0xb8/0x14c
[   58.939749] [T1501146] system_server:        do_notify_resume+0x114/0x1e8
[   58.940595] [T1501146] system_server:        work_pending+0xc/0x5f0

[   58.941375] [T1501146] -> #0 (&sbi->gc_lock){+.+.}-{3:3}:
[   58.942519] [T1501146] system_server:        __lock_acquire+0x1270/0x2868
[   58.943366] [T1501146] system_server:        lock_acquire+0x114/0x294
[   58.944169] [T1501146] system_server:        down_write+0x7c/0xe0
[   58.944930] [T1501146] system_server:        f2fs_issue_checkpoint+0x13c/0x21c
[   58.945831] [T1501146] system_server:        f2fs_sync_fs+0x48/0x6c
[   58.946614] [T1501146] system_server:        f2fs_do_sync_file+0x334/0x738
[   58.947472] [T1501146] system_server:        f2fs_ioc_commit_atomic_write+0xc8/0x14c
[   58.948439] [T1501146] system_server:        __f2fs_ioctl+0x674/0x154c
[   58.949253] [T1501146] system_server:        f2fs_ioctl+0x54/0x88
[   58.950018] [T1501146] system_server:        __arm64_sys_ioctl+0xa8/0x110
[   58.950865] [T1501146] system_server:        el0_svc_common.llvm.12821150825140585682+0xd8/0x20c
[   58.951965] [T1501146] system_server:        do_el0_svc+0x28/0xa0
[   58.952727] [T1501146] system_server:        el0_svc+0x24/0x38
[   58.953454] [T1501146] system_server:        el0_sync_handler+0x88/0xec
[   58.954279] [T1501146] system_server:        el0_sync+0x1b4/0x1c0

Cc: [email protected]
Signed-off-by: Jaegeuk Kim <[email protected]>
akiyks pushed a commit that referenced this issue Jun 1, 2022
Send along the already-allocated fattr along with nfs4_fs_locations, and
drop the memcpy of fattr.  We end up growing two more allocations, but this
fixes up a crash as:

PID: 790    TASK: ffff88811b43c000  CPU: 0   COMMAND: "ls"
 #0 [ffffc90000857920] panic at ffffffff81b9bfde
 #1 [ffffc900008579c0] do_trap at ffffffff81023a9b
 #2 [ffffc90000857a10] do_error_trap at ffffffff81023b78
 #3 [ffffc90000857a58] exc_stack_segment at ffffffff81be1f45
 #4 [ffffc90000857a80] asm_exc_stack_segment at ffffffff81c009de
 #5 [ffffc90000857b08] nfs_lookup at ffffffffa0302322 [nfs]
 torvalds#6 [ffffc90000857b70] __lookup_slow at ffffffff813a4a5f
 torvalds#7 [ffffc90000857c60] walk_component at ffffffff813a86c4
 torvalds#8 [ffffc90000857cb8] path_lookupat at ffffffff813a9553
 torvalds#9 [ffffc90000857cf0] filename_lookup at ffffffff813ab86b

Suggested-by: Trond Myklebust <[email protected]>
Fixes: 9558a00 ("NFS: Remove the label from the nfs4_lookup_res struct")
Signed-off-by: Benjamin Coddington <[email protected]>
Signed-off-by: Anna Schumaker <[email protected]>
akiyks pushed a commit that referenced this issue Jun 2, 2022
A rare BUG_ON triggered in assoc_array_gc:

    [3430308.818153] kernel BUG at lib/assoc_array.c:1609!

Which corresponded to the statement currently at line 1593 upstream:

    BUG_ON(assoc_array_ptr_is_meta(p));

Using the data from the core dump, I was able to generate a userspace
reproducer[1] and determine the cause of the bug.

[1]: https://github.com/brenns10/kernel_stuff/tree/master/assoc_array_gc

After running the iterator on the entire branch, an internal tree node
looked like the following:

    NODE (nr_leaves_on_branch: 3)
      SLOT [0] NODE (2 leaves)
      SLOT [1] NODE (1 leaf)
      SLOT [2..f] NODE (empty)

In the userspace reproducer, the pr_devel output when compressing this
node was:

    -- compress node 0x5607cc089380 --
    free=0, leaves=0
    [0] retain node 2/1 [nx 0]
    [1] fold node 1/1 [nx 0]
    [2] fold node 0/1 [nx 2]
    [3] fold node 0/2 [nx 2]
    [4] fold node 0/3 [nx 2]
    [5] fold node 0/4 [nx 2]
    [6] fold node 0/5 [nx 2]
    [7] fold node 0/6 [nx 2]
    [8] fold node 0/7 [nx 2]
    [9] fold node 0/8 [nx 2]
    [10] fold node 0/9 [nx 2]
    [11] fold node 0/10 [nx 2]
    [12] fold node 0/11 [nx 2]
    [13] fold node 0/12 [nx 2]
    [14] fold node 0/13 [nx 2]
    [15] fold node 0/14 [nx 2]
    after: 3

At slot 0, an internal node with 2 leaves could not be folded into the
node, because there was only one available slot (slot 0). Thus, the
internal node was retained. At slot 1, the node had one leaf, and was
able to be folded in successfully. The remaining nodes had no leaves,
and so were removed. By the end of the compression stage, there were 14
free slots, and only 3 leaf nodes. The tree was ascended and then its
parent node was compressed. When this node was seen, it could not be
folded, due to the internal node it contained.

The invariant for compression in this function is: whenever
nr_leaves_on_branch < ASSOC_ARRAY_FAN_OUT, the node should contain all
leaf nodes. The compression step currently cannot guarantee this, given
the corner case shown above.

To fix this issue, retry compression whenever we have retained a node,
and yet nr_leaves_on_branch < ASSOC_ARRAY_FAN_OUT. This second
compression will then allow the node in slot 1 to be folded in,
satisfying the invariant. Below is the output of the reproducer once the
fix is applied:

    -- compress node 0x560e9c562380 --
    free=0, leaves=0
    [0] retain node 2/1 [nx 0]
    [1] fold node 1/1 [nx 0]
    [2] fold node 0/1 [nx 2]
    [3] fold node 0/2 [nx 2]
    [4] fold node 0/3 [nx 2]
    [5] fold node 0/4 [nx 2]
    [6] fold node 0/5 [nx 2]
    [7] fold node 0/6 [nx 2]
    [8] fold node 0/7 [nx 2]
    [9] fold node 0/8 [nx 2]
    [10] fold node 0/9 [nx 2]
    [11] fold node 0/10 [nx 2]
    [12] fold node 0/11 [nx 2]
    [13] fold node 0/12 [nx 2]
    [14] fold node 0/13 [nx 2]
    [15] fold node 0/14 [nx 2]
    internal nodes remain despite enough space, retrying
    -- compress node 0x560e9c562380 --
    free=14, leaves=1
    [0] fold node 2/15 [nx 0]
    after: 3

Changes
=======
DH:
 - Use false instead of 0.
 - Reorder the inserted lines in a couple of places to put retained before
   next_slot.

ver #2)
 - Fix typo in pr_devel, correct comparison to "<="

Fixes: 3cb9895 ("Add a generic associative array implementation.")
Cc: <[email protected]>
Signed-off-by: Stephen Brennan <[email protected]>
Signed-off-by: David Howells <[email protected]>
cc: Andrew Morton <[email protected]>
cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]/ # v1
Link: https://lore.kernel.org/r/[email protected]/ # v2
Reviewed-by: Jarkko Sakkinen <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
akiyks pushed a commit that referenced this issue Jun 2, 2022
Since 3e135cd ("netfilter: nft_dynset: dynamic stateful expression
instantiation"), it is possible to attach stateful expressions to set
elements.

cd5125d ("netfilter: nf_tables: split set destruction in deactivate
and destroy phase") introduces conditional destruction on the object to
accomodate transaction semantics.

nft_expr_init() calls expr->ops->init() first, then check for
NFT_STATEFUL_EXPR, this stills allows to initialize a non-stateful
lookup expressions which points to a set, which might lead to UAF since
the set is not properly detached from the set->binding for this case.
Anyway, this combination is non-sense from nf_tables perspective.

This patch fixes this problem by checking for NFT_STATEFUL_EXPR before
expr->ops->init() is called.

The reporter provides a KASAN splat and a poc reproducer (similar to
those autogenerated by syzbot to report use-after-free errors). It is
unknown to me if they are using syzbot or if they use similar automated
tool to locate the bug that they are reporting.

For the record, this is the KASAN splat.

[   85.431824] ==================================================================
[   85.432901] BUG: KASAN: use-after-free in nf_tables_bind_set+0x81b/0xa20
[   85.433825] Write of size 8 at addr ffff8880286f0e98 by task poc/776
[   85.434756]
[   85.434999] CPU: 1 PID: 776 Comm: poc Tainted: G        W         5.18.0+ #2
[   85.436023] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014

Fixes: 0b2d8a7 ("netfilter: nf_tables: add helper functions for expression handling")
Reported-and-tested-by: Aaron Adams <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
akiyks pushed a commit that referenced this issue Jun 2, 2022
…nel/git/at91/linux into arm/late

AT91 SoC #2 for 5.19:

- One Kconfig fix for random build error

* tag 'at91-soc-5.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/at91/linux:
  ARM: at91: pm: Fix rand build error

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnd Bergmann <[email protected]>
akiyks pushed a commit that referenced this issue Jun 2, 2022
…el/git/at91/linux into arm/late

AT91 DT #2 for 5.19:

- at91: more DT compliance updates for RTC and RTT nodes
- at91: sama7g5: add microphone support

* tag 'at91-dt-5.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/at91/linux:
  ARM: dts: at91: sama7g5ek: add node for PDMC0
  ARM: dts: at91: sama7g5: add nodes for PDMC
  ARM: dts: at91: Use the generic "rtc" node name for the rtt IPs
  ARM: dts: at91: Add the required 'atmel, rtt-rtc-time-reg' property

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnd Bergmann <[email protected]>
akiyks pushed a commit that referenced this issue Jun 10, 2022
While randstruct was satisfied with using an open-coded "void *" offset
cast for the netfs_i_context <-> inode casting, __builtin_object_size() as
used by FORTIFY_SOURCE was not as easily fooled.  This was causing the
following complaint[1] from gcc v12:

  In file included from include/linux/string.h:253,
                   from include/linux/ceph/ceph_debug.h:7,
                   from fs/ceph/inode.c:2:
  In function 'fortify_memset_chk',
      inlined from 'netfs_i_context_init' at include/linux/netfs.h:326:2,
      inlined from 'ceph_alloc_inode' at fs/ceph/inode.c:463:2:
  include/linux/fortify-string.h:242:25: warning: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Wattribute-warning]
    242 |                         __write_overflow_field(p_size_field, size);
        |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Fix this by embedding a struct inode into struct netfs_i_context (which
should perhaps be renamed to struct netfs_inode).  The struct inode
vfs_inode fields are then removed from the 9p, afs, ceph and cifs inode
structs and vfs_inode is then simply changed to "netfs.inode" in those
filesystems.

Further, rename netfs_i_context to netfs_inode, get rid of the
netfs_inode() function that converted a netfs_i_context pointer to an
inode pointer (that can now be done with &ctx->inode) and rename the
netfs_i_context() function to netfs_inode() (which is now a wrapper
around container_of()).

Most of the changes were done with:

  perl -p -i -e 's/vfs_inode/netfs.inode/'g \
        `git grep -l 'vfs_inode' -- fs/{9p,afs,ceph,cifs}/*.[ch]`

Kees suggested doing it with a pair structure[2] and a special
declarator to insert that into the network filesystem's inode
wrapper[3], but I think it's cleaner to embed it - and then it doesn't
matter if struct randomisation reorders things.

Dave Chinner suggested using a filesystem-specific VFS_I() function in
each filesystem to convert that filesystem's own inode wrapper struct
into the VFS inode struct[4].

Version #2:
 - Fix a couple of missed name changes due to a disabled cifs option.
 - Rename nfs_i_context to nfs_inode
 - Use "netfs" instead of "nic" as the member name in per-fs inode wrapper
   structs.

[ This also undoes commit 507160f ("netfs: gcc-12: temporarily
  disable '-Wattribute-warning' for now") that is no longer needed ]

Fixes: bc899ee ("netfs: Add a netfs inode context")
Reported-by: Jeff Layton <[email protected]>
Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Xiubo Li <[email protected]>
cc: Jonathan Corbet <[email protected]>
cc: Eric Van Hensbergen <[email protected]>
cc: Latchesar Ionkov <[email protected]>
cc: Dominique Martinet <[email protected]>
cc: Christian Schoenebeck <[email protected]>
cc: Marc Dionne <[email protected]>
cc: Ilya Dryomov <[email protected]>
cc: Steve French <[email protected]>
cc: William Kucharski <[email protected]>
cc: "Matthew Wilcox (Oracle)" <[email protected]>
cc: Dave Chinner <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]/ [1]
Link: https://lore.kernel.org/r/[email protected]/ [2]
Link: https://lore.kernel.org/r/[email protected]/ [3]
Link: https://lore.kernel.org/r/[email protected]/ [4]
Link: https://lore.kernel.org/r/165296786831.3591209.12111293034669289733.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/165305805651.4094995.7763502506786714216.stgit@warthog.procyon.org.uk # v2
Signed-off-by: Linus Torvalds <[email protected]>
akiyks pushed a commit that referenced this issue Jun 23, 2022
Hulk Robot reports incorrect sp->rx_count_cooked value in decode_std_command().
This should be caused by the subtracting from sp->rx_count_cooked before.
It seems that sp->rx_count_cooked value is changed to 0, which bypassed the
previous judgment.

The situation is shown below:

         (Thread 1)			|  (Thread 2)
decode_std_command()		| resync_tnc()
...					|
if (rest == 2)			|
	sp->rx_count_cooked -= 2;	|
else if (rest == 3)			| ...
					| sp->rx_count_cooked = 0;
	sp->rx_count_cooked -= 1;	|
for (i = 0; i < sp->rx_count_cooked; i++) // report error
	checksum += sp->cooked_buf[i];

sp->rx_count_cooked is a shared variable but is not protected by a lock.
The same applies to sp->rx_count. This patch adds a lock to fix the bug.

The fail log is shown below:
=======================================================================
UBSAN: array-index-out-of-bounds in drivers/net/hamradio/6pack.c:925:31
index 400 is out of range for type 'unsigned char [400]'
CPU: 3 PID: 7433 Comm: kworker/u10:1 Not tainted 5.18.0-rc5-00163-g4b97bac0756a #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Workqueue: events_unbound flush_to_ldisc
Call Trace:
 <TASK>
 dump_stack_lvl+0xcd/0x134
 ubsan_epilogue+0xb/0x50
 __ubsan_handle_out_of_bounds.cold+0x62/0x6c
 sixpack_receive_buf+0xfda/0x1330
 tty_ldisc_receive_buf+0x13e/0x180
 tty_port_default_receive_buf+0x6d/0xa0
 flush_to_ldisc+0x213/0x3f0
 process_one_work+0x98f/0x1620
 worker_thread+0x665/0x1080
 kthread+0x2e9/0x3a0
 ret_from_fork+0x1f/0x30
 ...

Reported-by: Hulk Robot <[email protected]>
Signed-off-by: Xu Jia <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
akiyks pushed a commit that referenced this issue Jun 24, 2022
…/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 5.19, take #2

- Fix a regression with pKVM when kmemleak is enabled

- Add Oliver Upton as an official KVM/arm64 reviewer
akiyks pushed a commit that referenced this issue Jul 1, 2022
This was missed in c3ed222 ("NFSv4: Fix free of uninitialized
nfs4_label on referral lookup.") and causes a panic when mounting
with '-o trunkdiscovery':

PID: 1604   TASK: ffff93dac3520000  CPU: 3   COMMAND: "mount.nfs"
 #0 [ffffb79140f738f8] machine_kexec at ffffffffaec64bee
 #1 [ffffb79140f73950] __crash_kexec at ffffffffaeda67fd
 #2 [ffffb79140f73a18] crash_kexec at ffffffffaeda76ed
 #3 [ffffb79140f73a30] oops_end at ffffffffaec2658d
 #4 [ffffb79140f73a50] general_protection at ffffffffaf60111e
    [exception RIP: nfs_fattr_init+0x5]
    RIP: ffffffffc0c18265  RSP: ffffb79140f73b08  RFLAGS: 00010246
    RAX: 0000000000000000  RBX: ffff93dac304a800  RCX: 0000000000000000
    RDX: ffffb79140f73bb0  RSI: ffff93dadc8cbb40  RDI: d03ee11cfaf6bd50
    RBP: ffffb79140f73be8   R8: ffffffffc0691560   R9: 0000000000000006
    R10: ffff93db3ffd3df8  R11: 0000000000000000  R12: ffff93dac4040000
    R13: ffff93dac2848e00  R14: ffffb79140f73b60  R15: ffffb79140f73b30
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #5 [ffffb79140f73b08] _nfs41_proc_get_locations at ffffffffc0c73d53 [nfsv4]
 torvalds#6 [ffffb79140f73bf0] nfs4_proc_get_locations at ffffffffc0c83e90 [nfsv4]
 torvalds#7 [ffffb79140f73c60] nfs4_discover_trunking at ffffffffc0c83fb7 [nfsv4]
 torvalds#8 [ffffb79140f73cd8] nfs_probe_fsinfo at ffffffffc0c0f95f [nfs]
 torvalds#9 [ffffb79140f73da0] nfs_probe_server at ffffffffc0c1026a [nfs]
    RIP: 00007f6254fce26e  RSP: 00007ffc69496ac8  RFLAGS: 00000246
    RAX: ffffffffffffffda  RBX: 0000000000000000  RCX: 00007f6254fce26e
    RDX: 00005600220a82a0  RSI: 00005600220a64d0  RDI: 00005600220a6520
    RBP: 00007ffc69496c50   R8: 00005600220a8710   R9: 003035322e323231
    R10: 0000000000000000  R11: 0000000000000246  R12: 00007ffc69496c50
    R13: 00005600220a8440  R14: 0000000000000010  R15: 0000560020650ef9
    ORIG_RAX: 00000000000000a5  CS: 0033  SS: 002b

Fixes: c3ed222 ("NFSv4: Fix free of uninitialized nfs4_label on referral lookup.")
Signed-off-by: Scott Mayhew <[email protected]>
Signed-off-by: Anna Schumaker <[email protected]>
akiyks pushed a commit that referenced this issue Jul 12, 2022
…nline extents

When doing a direct IO read or write, we always return -ENOTBLK when we
find a compressed extent (or an inline extent) so that we fallback to
buffered IO. This however is not ideal in case we are in a NOWAIT context
(io_uring for example), because buffered IO can block and we currently
have no support for NOWAIT semantics for buffered IO, so if we need to
fallback to buffered IO we should first signal the caller that we may
need to block by returning -EAGAIN instead.

This behaviour can also result in short reads being returned to user
space, which although it's not incorrect and user space should be able
to deal with partial reads, it's somewhat surprising and even some popular
applications like QEMU (Link tag #1) and MariaDB (Link tag #2) don't
deal with short reads properly (or at all).

The short read case happens when we try to read from a range that has a
non-compressed and non-inline extent followed by a compressed extent.
After having read the first extent, when we find the compressed extent we
return -ENOTBLK from btrfs_dio_iomap_begin(), which results in iomap to
treat the request as a short read, returning 0 (success) and waiting for
previously submitted bios to complete (this happens at
fs/iomap/direct-io.c:__iomap_dio_rw()). After that, and while at
btrfs_file_read_iter(), we call filemap_read() to use buffered IO to
read the remaining data, and pass it the number of bytes we were able to
read with direct IO. Than at filemap_read() if we get a page fault error
when accessing the read buffer, we return a partial read instead of an
-EFAULT error, because the number of bytes previously read is greater
than zero.

So fix this by returning -EAGAIN for NOWAIT direct IO when we find a
compressed or an inline extent.

Reported-by: Dominique MARTINET <[email protected]>
Link: https://lore.kernel.org/linux-btrfs/[email protected]/
Link: https://jira.mariadb.org/browse/MDEV-27900?focusedCommentId=216582&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-216582
Tested-by: Dominique MARTINET <[email protected]>
CC: [email protected] # 5.10+
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Filipe Manana <[email protected]>
Signed-off-by: David Sterba <[email protected]>
akiyks pushed a commit that referenced this issue Jul 14, 2022
…tion

Each cset (css_set) is pinned by its tasks. When we're moving tasks around
across csets for a migration, we need to hold the source and destination
csets to ensure that they don't go away while we're moving tasks about. This
is done by linking cset->mg_preload_node on either the
mgctx->preloaded_src_csets or mgctx->preloaded_dst_csets list. Using the
same cset->mg_preload_node for both the src and dst lists was deemed okay as
a cset can't be both the source and destination at the same time.

Unfortunately, this overloading becomes problematic when multiple tasks are
involved in a migration and some of them are identity noop migrations while
others are actually moving across cgroups. For example, this can happen with
the following sequence on cgroup1:

 #1> mkdir -p /sys/fs/cgroup/misc/a/b
 #2> echo $$ > /sys/fs/cgroup/misc/a/cgroup.procs
 #3> RUN_A_COMMAND_WHICH_CREATES_MULTIPLE_THREADS &
 #4> PID=$!
 #5> echo $PID > /sys/fs/cgroup/misc/a/b/tasks
 torvalds#6> echo $PID > /sys/fs/cgroup/misc/a/cgroup.procs

the process including the group leader back into a. In this final migration,
non-leader threads would be doing identity migration while the group leader
is doing an actual one.

After #3, let's say the whole process was in cset A, and that after #4, the
leader moves to cset B. Then, during torvalds#6, the following happens:

 1. cgroup_migrate_add_src() is called on B for the leader.

 2. cgroup_migrate_add_src() is called on A for the other threads.

 3. cgroup_migrate_prepare_dst() is called. It scans the src list.

 4. It notices that B wants to migrate to A, so it tries to A to the dst
    list but realizes that its ->mg_preload_node is already busy.

 5. and then it notices A wants to migrate to A as it's an identity
    migration, it culls it by list_del_init()'ing its ->mg_preload_node and
    putting references accordingly.

 6. The rest of migration takes place with B on the src list but nothing on
    the dst list.

This means that A isn't held while migration is in progress. If all tasks
leave A before the migration finishes and the incoming task pins it, the
cset will be destroyed leading to use-after-free.

This is caused by overloading cset->mg_preload_node for both src and dst
preload lists. We wanted to exclude the cset from the src list but ended up
inadvertently excluding it from the dst list too.

This patch fixes the issue by separating out cset->mg_preload_node into
->mg_src_preload_node and ->mg_dst_preload_node, so that the src and dst
preloadings don't interfere with each other.

Signed-off-by: Tejun Heo <[email protected]>
Reported-by: Mukesh Ojha <[email protected]>
Reported-by: shisiyuan <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Link: https://www.spinics.net/lists/cgroups/msg33313.html
Fixes: f817de9 ("cgroup: prepare migration path for unified hierarchy")
Cc: [email protected] # v3.16+
akiyks pushed a commit that referenced this issue Jul 15, 2022
…ernel/git/at91/linux into arm/fixes

AT91 fixes for 5.19 #2

It contains 2 DT fixes:
- one for SAMA5D2 to fix the i2s1 assigned-clock-parents property
- one for kswitch-d10 (LAN966 based) enforcing proper settings
  on GPIO pins

* tag 'at91-fixes-5.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/at91/linux:
  ARM: dts: at91: sama5d2: Fix typo in i2s1 node
  ARM: dts: kswitch-d10: use open drain mode for coma-mode pins

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnd Bergmann <[email protected]>
akiyks pushed a commit that referenced this issue Oct 25, 2024
Hou Tao says:

====================
Add the missing BPF_LINK_TYPE invocation for sockmap

From: Hou Tao <[email protected]>

Hi,

The tiny patch set fixes the out-of-bound read problem when reading the
fdinfo of sock map link fd. And in order to spot such omission early for
the newly-added link type in the future, it also checks the validity of
the link->type and adds a WARN_ONCE() for missed invocation.

Please see individual patches for more details. And comments are always
welcome.

v3:
  * patch #2: check and warn the validity of link->type instead of
    adding a static assertion for bpf_link_type_strs array.

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

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Andrii Nakryiko <[email protected]>
akiyks pushed a commit that referenced this issue Nov 1, 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]>
akiyks pushed a commit that referenced this issue Nov 1, 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]>
akiyks pushed a commit that referenced this issue Nov 2, 2024
generic/077 on x86_32 CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP=y with highmem,
on huge=always tmpfs, issues a warning and then hangs (interruptibly):

WARNING: CPU: 5 PID: 3517 at mm/highmem.c:622 kunmap_local_indexed+0x62/0xc9
CPU: 5 UID: 0 PID: 3517 Comm: cp Not tainted 6.12.0-rc4 #2
...
copy_page_from_iter_atomic+0xa6/0x5ec
generic_perform_write+0xf6/0x1b4
shmem_file_write_iter+0x54/0x67

Fix copy_page_from_iter_atomic() by limiting it in that case
(include/linux/skbuff.h skb_frag_must_loop() does similar).

But going forward, perhaps CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP is too
surprising, has outlived its usefulness, and should just be removed?

Fixes: 908a1ad ("iov_iter: Handle compound highmem pages in copy_page_from_iter_atomic()")
Signed-off-by: Hugh Dickins <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Christoph Hellwig <[email protected]>
Cc: [email protected]
Signed-off-by: Christian Brauner <[email protected]>
akiyks pushed a commit that referenced this issue Nov 6, 2024
Currently, when configuring TMU (Time Management Unit) mode of a given
router, we take into account only its own TMU requirements ignoring
other routers in the domain. This is problematic if the router we are
configuring has lower TMU requirements than what is already configured
in the domain.

In the scenario below, we have a host router with two USB4 ports: A and
B. Port A connected to device router #1 (which supports CL states) and
existing DisplayPort tunnel, thus, the TMU mode is HiFi uni-directional.

1. Initial topology

          [Host]
         A/
         /
 [Device #1]
   /
Monitor

2. Plug in device #2 (that supports CL states) to downstream port B of
   the host router

         [Host]
        A/    B\
        /       \
 [Device #1]    [Device #2]
   /
Monitor

The TMU mode on port B and port A will be configured to LowRes which is
not what we want and will cause monitor to start flickering.

To address this we first scan the domain and search for any router
configured to HiFi uni-directional mode, and if found, configure TMU
mode of the given router to HiFi uni-directional as well.

Cc: [email protected]
Signed-off-by: Gil Fine <[email protected]>
Signed-off-by: Mika Westerberg <[email protected]>
akiyks pushed a commit that referenced this issue Nov 6, 2024
Running rcutorture scenario TREE05, the below warning is triggered.

[   32.604594] WARNING: suspicious RCU usage
[   32.605928] 6.11.0-rc5-00040-g4ba4f1afb6a9 #55238 Not tainted
[   32.607812] -----------------------------
[   32.609140] kernel/events/core.c:13946 RCU-list traversed in non-reader section!!
[   32.611595] other info that might help us debug this:
[   32.614247] rcu_scheduler_active = 2, debug_locks = 1
[   32.616392] 3 locks held by cpuhp/4/35:
[   32.617687]  #0: ffffffffb666a650 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread_fun+0x4e/0x200
[   32.620563]  #1: ffffffffb666cd20 (cpuhp_state-down){+.+.}-{0:0}, at: cpuhp_thread_fun+0x4e/0x200
[   32.623412]  #2: ffffffffb677c288 (pmus_lock){+.+.}-{3:3}, at: perf_event_exit_cpu_context+0x32/0x2f0

In perf_event_clear_cpumask(), uses list_for_each_entry_rcu() without an
obvious RCU read-side critical section.

Either pmus_srcu or pmus_lock is good enough to protect the pmus list.
In the current context, pmus_lock is already held. The
list_for_each_entry_rcu() is not required.

Fixes: 4ba4f1a ("perf: Generic hotplug support for a PMU with a scope")
Closes: https://lore.kernel.org/lkml/2b66dff8-b827-494b-b151-1ad8d56f13e6@paulmck-laptop/
Closes: https://lore.kernel.org/oe-lkp/[email protected]
Reported-by: "Paul E. McKenney" <[email protected]>
Reported-by: kernel test robot <[email protected]>
Suggested-by: Peter Zijlstra <[email protected]>
Signed-off-by: Kan Liang <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Tested-by: "Paul E. McKenney" <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
akiyks pushed a commit that referenced this issue Nov 6, 2024
When we compile and load lib/slub_kunit.c,it will cause a panic.

The root cause is that __kmalloc_cache_noprof was directly called instead
of kmem_cache_alloc,which resulted in no alloc_tag being allocated.This
caused current->alloc_tag to be null,leading to a null pointer dereference
in alloc_tag_ref_set.

Despite the fact that my colleague Pei Xiao will later fix the code in
slub_kunit.c,we still need fix null pointer check logic for ref and tag to
avoid panic caused by a null pointer dereference.

Here is the log for the panic:

[   74.779373][ T2158] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020
[   74.780130][ T2158] Mem abort info:
[   74.780406][ T2158]   ESR = 0x0000000096000004
[   74.780756][ T2158]   EC = 0x25: DABT (current EL), IL = 32 bits
[   74.781225][ T2158]   SET = 0, FnV = 0
[   74.781529][ T2158]   EA = 0, S1PTW = 0
[   74.781836][ T2158]   FSC = 0x04: level 0 translation fault
[   74.782288][ T2158] Data abort info:
[   74.782577][ T2158]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
[   74.783068][ T2158]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[   74.783533][ T2158]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[   74.784010][ T2158] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000105f34000
[   74.784586][ T2158] [0000000000000020] pgd=0000000000000000, p4d=0000000000000000
[   74.785293][ T2158] Internal error: Oops: 0000000096000004 [#1] SMP
[   74.785805][ T2158] Modules linked in: slub_kunit kunit ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 ipt_REJECT nf_reject_ipv4 xt_conntrack ebtable_nat ebtable_broute ip6table_nat ip6table_mangle 4
[   74.790661][ T2158] CPU: 0 UID: 0 PID: 2158 Comm: kunit_try_catch Kdump: loaded Tainted: G        W        N 6.12.0-rc3+ #2
[   74.791535][ T2158] Tainted: [W]=WARN, [N]=TEST
[   74.791889][ T2158] Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
[   74.792479][ T2158] pstate: 40400005 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[   74.793101][ T2158] pc : alloc_tagging_slab_alloc_hook+0x120/0x270
[   74.793607][ T2158] lr : alloc_tagging_slab_alloc_hook+0x120/0x270
[   74.794095][ T2158] sp : ffff800084d33cd0
[   74.794418][ T2158] x29: ffff800084d33cd0 x28: 0000000000000000 x27: 0000000000000000
[   74.795095][ T2158] x26: 0000000000000000 x25: 0000000000000012 x24: ffff80007b30e314
[   74.795822][ T2158] x23: ffff000390ff6f10 x22: 0000000000000000 x21: 0000000000000088
[   74.796555][ T2158] x20: ffff000390285840 x19: fffffd7fc3ef7830 x18: ffffffffffffffff
[   74.797283][ T2158] x17: ffff8000800e63b4 x16: ffff80007b33afc4 x15: ffff800081654c00
[   74.798011][ T2158] x14: 0000000000000000 x13: 205d383531325420 x12: 5b5d383734363537
[   74.798744][ T2158] x11: ffff800084d337e0 x10: 000000000000005d x9 : 00000000ffffffd0
[   74.799476][ T2158] x8 : 7f7f7f7f7f7f7f7f x7 : ffff80008219d188 x6 : c0000000ffff7fff
[   74.800206][ T2158] x5 : ffff0003fdbc9208 x4 : ffff800081edd188 x3 : 0000000000000001
[   74.800932][ T2158] x2 : 0beaa6dee1ac5a00 x1 : 0beaa6dee1ac5a00 x0 : ffff80037c2cb000
[   74.801656][ T2158] Call trace:
[   74.801954][ T2158]  alloc_tagging_slab_alloc_hook+0x120/0x270
[   74.802494][ T2158]  __kmalloc_cache_noprof+0x148/0x33c
[   74.802976][ T2158]  test_kmalloc_redzone_access+0x4c/0x104 [slub_kunit]
[   74.803607][ T2158]  kunit_try_run_case+0x70/0x17c [kunit]
[   74.804124][ T2158]  kunit_generic_run_threadfn_adapter+0x2c/0x4c [kunit]
[   74.804768][ T2158]  kthread+0x10c/0x118
[   74.805141][ T2158]  ret_from_fork+0x10/0x20
[   74.805540][ T2158] Code: b9400a80 11000400 b9000a80 97ffd858 (f94012d3)
[   74.806176][ T2158] SMP: stopping secondary CPUs
[   74.808130][ T2158] Starting crashdump kernel...

Link: https://lkml.kernel.org/r/[email protected]
Fixes: e0a955b ("mm/codetag: add pgalloc_tag_copy()")
Signed-off-by: Hao Ge <[email protected]>
Acked-by: Suren Baghdasaryan <[email protected]>
Suggested-by: Suren Baghdasaryan <[email protected]>
Acked-by: Yu Zhao <[email protected]>
Cc: Kent Overstreet <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
akiyks pushed a commit that referenced this issue Nov 8, 2024
The scope of the TX skb is wider than just mse102x_tx_frame_spi(),
so in case the TX skb room needs to be expanded, we should free the
the temporary skb instead of the original skb. Otherwise the original
TX skb pointer would be freed again in mse102x_tx_work(), which leads
to crashes:

  Internal error: Oops: 0000000096000004 [#2] PREEMPT SMP
  CPU: 0 PID: 712 Comm: kworker/0:1 Tainted: G      D            6.6.23
  Hardware name: chargebyte Charge SOM DC-ONE (DT)
  Workqueue: events mse102x_tx_work [mse102x]
  pstate: 20400009 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
  pc : skb_release_data+0xb8/0x1d8
  lr : skb_release_data+0x1ac/0x1d8
  sp : ffff8000819a3cc0
  x29: ffff8000819a3cc0 x28: ffff0000046daa60 x27: ffff0000057f2dc0
  x26: ffff000005386c00 x25: 0000000000000002 x24: 00000000ffffffff
  x23: 0000000000000000 x22: 0000000000000001 x21: ffff0000057f2e50
  x20: 0000000000000006 x19: 0000000000000000 x18: ffff00003fdacfcc
  x17: e69ad452d0c49def x16: 84a005feff870102 x15: 0000000000000000
  x14: 000000000000024a x13: 0000000000000002 x12: 0000000000000000
  x11: 0000000000000400 x10: 0000000000000930 x9 : ffff00003fd913e8
  x8 : fffffc00001bc008
  x7 : 0000000000000000 x6 : 0000000000000008
  x5 : ffff00003fd91340 x4 : 0000000000000000 x3 : 0000000000000009
  x2 : 00000000fffffffe x1 : 0000000000000000 x0 : 0000000000000000
  Call trace:
   skb_release_data+0xb8/0x1d8
   kfree_skb_reason+0x48/0xb0
   mse102x_tx_work+0x164/0x35c [mse102x]
   process_one_work+0x138/0x260
   worker_thread+0x32c/0x438
   kthread+0x118/0x11c
   ret_from_fork+0x10/0x20
  Code: aa1303e0 97fffab6 72001c1f 54000141 (f9400660)

Cc: [email protected]
Fixes: 2f207cb ("net: vertexcom: Add MSE102x SPI support")
Signed-off-by: Stefan Wahren <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
akiyks pushed a commit that referenced this issue Nov 20, 2024
A sig_alg backend has just been introduced with the intent of moving all
asymmetric sign/verify algorithms to it one by one.

Migrate the sign/verify operations from rsa-pkcs1pad.c to a separate
rsassa-pkcs1.c which uses the new backend.

Consequently there are now two templates which build on the "rsa"
akcipher_alg:

* The existing "pkcs1pad" template, which is instantiated as an
  akcipher_instance and retains the encrypt/decrypt operations of
  RSAES-PKCS1-v1_5 (RFC 8017 sec 7.2).

* The new "pkcs1" template, which is instantiated as a sig_instance
  and contains the sign/verify operations of RSASSA-PKCS1-v1_5
  (RFC 8017 sec 8.2).

In a separate step, rsa-pkcs1pad.c could optionally be renamed to
rsaes-pkcs1.c for clarity.  Additional "oaep" and "pss" templates
could be added for RSAES-OAEP and RSASSA-PSS.

Note that it's currently allowed to allocate a "pkcs1pad(rsa)" transform
without specifying a hash algorithm.  That makes sense if the transform
is only used for encrypt/decrypt and continues to be supported.  But for
sign/verify, such transforms previously did not insert the Full Hash
Prefix into the padding.  The resulting message encoding was incompliant
with EMSA-PKCS1-v1_5 (RFC 8017 sec 9.2) and therefore nonsensical.

From here on in, it is no longer allowed to allocate a transform without
specifying a hash algorithm if the transform is used for sign/verify
operations.  This simplifies the code because the insertion of the Full
Hash Prefix is no longer optional, so various "if (digest_info)" clauses
can be removed.

There has been a previous attempt to forbid transform allocation without
specifying a hash algorithm, namely by commit c0d20d2 ("crypto:
rsa-pkcs1pad - Require hash to be present").  It had to be rolled back
with commit b3a8c8a ("crypto: rsa-pkcs1pad: Allow hash to be
optional [ver #2]"), presumably because it broke allocation of a
transform which was solely used for encrypt/decrypt, not sign/verify.
Avoid such breakage by allowing transform allocation for encrypt/decrypt
with and without specifying a hash algorithm (and simply ignoring the
hash algorithm in the former case).

So again, specifying a hash algorithm is now mandatory for sign/verify,
but optional and ignored for encrypt/decrypt.

The new sig_alg API uses kernel buffers instead of sglists, which
avoids the overhead of copying signature and digest from sglists back
into kernel buffers.  rsassa-pkcs1.c is thus simplified quite a bit.

sig_alg is always synchronous, whereas the underlying "rsa" akcipher_alg
may be asynchronous.  So await the result of the akcipher_alg, similar
to crypto_akcipher_sync_{en,de}crypt().

As part of the migration, rename "rsa_digest_info" to "hash_prefix" to
adhere to the spec language in RFC 9580.  Otherwise keep the code
unmodified wherever possible to ease reviewing and bisecting.  Leave
several simplification and hardening opportunities to separate commits.

rsassa-pkcs1.c uses modern __free() syntax for allocation of buffers
which need to be freed by kfree_sensitive(), hence a DEFINE_FREE()
clause for kfree_sensitive() is introduced herein as a byproduct.

Signed-off-by: Lukas Wunner <[email protected]>
Signed-off-by: Herbert Xu <[email protected]>
akiyks pushed a commit that referenced this issue Nov 20, 2024
nx842_remove() call of_reconfig_notifier_unregister while holding the
devdata_spinlock. This could lead to an invalid wait context error during
kexec reboot, as of_reconfig_notifier_unregister tries to acquire a read-write
semaphore (check logs) while holding a spinlock.

Move the of_reconfig_notifier_unregister() call before acquiring the
spinlock to prevent this race condition invalid wait contexts during system
shutdown or kexec operations.

Log:

[ BUG: Invalid wait context ]
6.11.0-test2-10547-g684a64bf32b6-dirty torvalds#79 Not tainted
-----------------------------
kexec/61926 is trying to lock:
c000000002d8b590 ((of_reconfig_chain).rwsem){++++}-{4:4}, at: blocking_notifier_chain_unregister+0x44/0xa0
other info that might help us debug this:
context-{5:5}
4 locks held by kexec/61926:
 #0: c000000002926c70 (system_transition_mutex){+.+.}-{4:4}, at: __do_sys_reboot+0xf8/0x2e0
 #1: c00000000291af30 (&dev->mutex){....}-{4:4}, at: device_shutdown+0x160/0x310
 #2: c000000051011938 (&dev->mutex){....}-{4:4}, at: device_shutdown+0x174/0x310
 #3: c000000002d88070 (devdata_mutex){....}-{3:3}, at: nx842_remove+0xac/0x1bc
stack backtrace:
CPU: 2 UID: 0 PID: 61926 Comm: kexec Not tainted 6.11.0-test2-10547-g684a64bf32b6-dirty torvalds#79
Hardware name: IBM,9080-HEX POWER10 (architected) 0x800200 0xf000006 of:IBM,FW1060.00 (NH1060_012) hv:phyp pSeries
Call Trace:
[c0000000bb577400] [c000000001239704] dump_stack_lvl+0xc8/0x130 (unreliable)
[c0000000bb577440] [c000000000248398] __lock_acquire+0xb68/0xf00
[c0000000bb577550] [c000000000248820] lock_acquire.part.0+0xf0/0x2a0
[c0000000bb577670] [c00000000127faa0] down_write+0x70/0x1e0
[c0000000bb5776b0] [c0000000001acea4] blocking_notifier_chain_unregister+0x44/0xa0
[c0000000bb5776e0] [c000000000e2312c] of_reconfig_notifier_unregister+0x2c/0x40
[c0000000bb577700] [c000000000ded24c] nx842_remove+0x148/0x1bc
[c0000000bb577790] [c00000000011a114] vio_bus_remove+0x54/0xc0
[c0000000bb5777c0] [c000000000c1a44c] device_shutdown+0x20c/0x310
[c0000000bb577850] [c0000000001b0ab4] kernel_restart_prepare+0x54/0x70
[c0000000bb577870] [c000000000308718] kernel_kexec+0xa8/0x110
[c0000000bb5778e0] [c0000000001b1144] __do_sys_reboot+0x214/0x2e0
[c0000000bb577a40] [c000000000032f98] system_call_exception+0x148/0x310
[c0000000bb577e50] [c00000000000cedc] system_call_vectored_common+0x15c/0x2ec
--- interrupt: 3000 at 0x7fffa07e7df8
NIP:  00007fffa07e7df8 LR: 00007fffa07e7df8 CTR: 0000000000000000
REGS: c0000000bb577e80 TRAP: 3000   Not tainted  (6.11.0-test2-10547-g684a64bf32b6-dirty)
MSR:  800000000280f033   CR: 48022484  XER: 00000000
IRQMASK: 0
GPR00: 0000000000000058 00007ffff961f1e0 00007fffa08f7100 fffffffffee1dead
GPR04: 0000000028121969 0000000045584543 0000000000000000 0000000000000003
GPR08: 0000000000000003 0000000000000000 0000000000000000 0000000000000000
GPR12: 0000000000000000 00007fffa0a9b360 ffffffffffffffff 0000000000000000
GPR16: 0000000000000001 0000000000000002 0000000000000001 0000000000000001
GPR20: 000000011710f520 0000000000000000 0000000000000000 0000000000000001
GPR24: 0000000129be0480 0000000000000003 0000000000000003 00007ffff961f2b0
GPR28: 00000001170f2d30 00000001170f2d28 00007fffa08f18d0 0000000129be04a0
NIP [00007fffa07e7df8] 0x7fffa07e7df8
LR [00007fffa07e7df8] 0x7fffa07e7df8
--- interrupt: 3000

Suggested-by: Michael Ellerman <[email protected]>
Signed-off-by: Vishal Chourasia <[email protected]>
Signed-off-by: Herbert Xu <[email protected]>
akiyks pushed a commit that referenced this issue Nov 20, 2024
encrypt_blob(), decrypt_blob() and create_signature() were some of the
functions added in 2018 by
commit 5a30771 ("KEYS: Provide missing asymmetric key subops for new
key type ops [ver #2]")
however, they've not been used.

Remove them.

Signed-off-by: Dr. David Alan Gilbert <[email protected]>
Reviewed-by: Jarkko Sakkinen <[email protected]>
Signed-off-by: Herbert Xu <[email protected]>
akiyks pushed a commit that referenced this issue Nov 20, 2024
Lockdep gives a false positive splat as it can't distinguish the lock
which is taken by different IRQ descriptors from different IRQ chips
that are organized in a way of a hierarchy:

   ======================================================
   WARNING: possible circular locking dependency detected
   6.12.0-rc5-next-20241101-00148-g9fabf8160b53 torvalds#562 Tainted: G        W
   ------------------------------------------------------
   modprobe/141 is trying to acquire lock:
   ffff899446947868 (intel_soc_pmic_bxtwc:502:(&bxtwc_regmap_config)->lock){+.+.}-{4:4}, at: regmap_update_bits_base+0x33/0x90

   but task is already holding lock:
   ffff899446947c68 (&d->lock){+.+.}-{4:4}, at: __setup_irq+0x682/0x790

   which lock already depends on the new lock.

   -> #3 (&d->lock){+.+.}-{4:4}:
   -> #2 (&desc->request_mutex){+.+.}-{4:4}:
   -> #1 (ipclock){+.+.}-{4:4}:
   -> #0 (intel_soc_pmic_bxtwc:502:(&bxtwc_regmap_config)->lock){+.+.}-{4:4}:

   Chain exists of:
     intel_soc_pmic_bxtwc:502:(&bxtwc_regmap_config)->lock --> &desc->request_mutex --> &d->lock

    Possible unsafe locking scenario:

          CPU0                    CPU1
          ----                    ----
     lock(&d->lock);
                                  lock(&desc->request_mutex);
                                  lock(&d->lock);
     lock(intel_soc_pmic_bxtwc:502:(&bxtwc_regmap_config)->lock);

    *** DEADLOCK ***

   3 locks held by modprobe/141:
    #0: ffff8994419368f8 (&dev->mutex){....}-{4:4}, at: __driver_attach+0xf6/0x250
    #1: ffff89944690b250 (&desc->request_mutex){+.+.}-{4:4}, at: __setup_irq+0x1a2/0x790
    #2: ffff899446947c68 (&d->lock){+.+.}-{4:4}, at: __setup_irq+0x682/0x790

Set a lockdep class when we map the IRQ so that it doesn't warn about
a lockdep bug that doesn't exist.

Fixes: 4af8be6 ("regmap: Convert regmap_irq to use irq_domain")
Signed-off-by: Andy Shevchenko <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Mark Brown <[email protected]>
akiyks pushed a commit that referenced this issue Nov 20, 2024
…dfl()

When getting an LLC CPU mask in the default CPU selection policy,
scx_select_cpu_dfl(), a pointer to the sched_domain is dereferenced
using rcu_read_lock() without holding rcu_read_lock(). Such an unprotected
dereference often causes the following warning and can cause an invalid
memory access in the worst case.

Therefore, protect dereference of a sched_domain pointer using a pair
of rcu_read_lock() and unlock().

[   20.996135] =============================
[   20.996345] WARNING: suspicious RCU usage
[   20.996563] 6.11.0-virtme torvalds#17 Tainted: G        W
[   20.996576] -----------------------------
[   20.996576] kernel/sched/ext.c:3323 suspicious rcu_dereference_check() usage!
[   20.996576]
[   20.996576] other info that might help us debug this:
[   20.996576]
[   20.996576]
[   20.996576] rcu_scheduler_active = 2, debug_locks = 1
[   20.996576] 4 locks held by kworker/8:1/140:
[   20.996576]  #0: ffff8b18c00dd348 ((wq_completion)pm){+.+.}-{0:0}, at: process_one_work+0x4a0/0x590
[   20.996576]  #1: ffffb3da01f67e58 ((work_completion)(&dev->power.work)){+.+.}-{0:0}, at: process_one_work+0x1ba/0x590
[   20.996576]  #2: ffffffffa316f9f0 (&rcu_state.gp_wq){..-.}-{2:2}, at: swake_up_one+0x15/0x60
[   20.996576]  #3: ffff8b1880398a60 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0x59/0x7d0
[   20.996576]
[   20.996576] stack backtrace:
[   20.996576] CPU: 8 UID: 0 PID: 140 Comm: kworker/8:1 Tainted: G        W          6.11.0-virtme torvalds#17
[   20.996576] Tainted: [W]=WARN
[   20.996576] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014
[   20.996576] Workqueue: pm pm_runtime_work
[   20.996576] Sched_ext: simple (disabling+all), task: runnable_at=-6ms
[   20.996576] Call Trace:
[   20.996576]  <IRQ>
[   20.996576]  dump_stack_lvl+0x6f/0xb0
[   20.996576]  lockdep_rcu_suspicious.cold+0x4e/0x96
[   20.996576]  scx_select_cpu_dfl+0x234/0x260
[   20.996576]  select_task_rq_scx+0xfb/0x190
[   20.996576]  select_task_rq+0x47/0x110
[   20.996576]  try_to_wake_up+0x110/0x7d0
[   20.996576]  swake_up_one+0x39/0x60
[   20.996576]  rcu_core+0xb08/0xe50
[   20.996576]  ? srso_alias_return_thunk+0x5/0xfbef5
[   20.996576]  ? mark_held_locks+0x40/0x70
[   20.996576]  handle_softirqs+0xd3/0x410
[   20.996576]  irq_exit_rcu+0x78/0xa0
[   20.996576]  sysvec_apic_timer_interrupt+0x73/0x80
[   20.996576]  </IRQ>
[   20.996576]  <TASK>
[   20.996576]  asm_sysvec_apic_timer_interrupt+0x1a/0x20
[   20.996576] RIP: 0010:_raw_spin_unlock_irqrestore+0x36/0x70
[   20.996576] Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 11 b4 36 ff 48 89 df e8 99 0d 37 ff f7 c5 00 02 00 00 75 17 9c 58 f6 c4 02 75 2b <65> ff 0d 5b 55 3c 5e 74 16 5b 5d e9 95 8e 28 00 e8 a5 ee 44 ff 9c
[   20.996576] RSP: 0018:ffffb3da01f67d20 EFLAGS: 00000246
[   20.996576] RAX: 0000000000000002 RBX: ffffffffa4640220 RCX: 0000000000000040
[   20.996576] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffffa1c7b27b
[   20.996576] RBP: 0000000000000246 R08: 0000000000000001 R09: 0000000000000000
[   20.996576] R10: 0000000000000001 R11: 000000000000021c R12: 0000000000000246
[   20.996576] R13: ffff8b1881363958 R14: 0000000000000000 R15: ffff8b1881363800
[   20.996576]  ? _raw_spin_unlock_irqrestore+0x4b/0x70
[   20.996576]  serial_port_runtime_resume+0xd4/0x1a0
[   20.996576]  ? __pfx_serial_port_runtime_resume+0x10/0x10
[   20.996576]  __rpm_callback+0x44/0x170
[   20.996576]  ? __pfx_serial_port_runtime_resume+0x10/0x10
[   20.996576]  rpm_callback+0x55/0x60
[   20.996576]  ? __pfx_serial_port_runtime_resume+0x10/0x10
[   20.996576]  rpm_resume+0x582/0x7b0
[   20.996576]  pm_runtime_work+0x7c/0xb0
[   20.996576]  process_one_work+0x1fb/0x590
[   20.996576]  worker_thread+0x18e/0x350
[   20.996576]  ? __pfx_worker_thread+0x10/0x10
[   20.996576]  kthread+0xe2/0x110
[   20.996576]  ? __pfx_kthread+0x10/0x10
[   20.996576]  ret_from_fork+0x34/0x50
[   20.996576]  ? __pfx_kthread+0x10/0x10
[   20.996576]  ret_from_fork_asm+0x1a/0x30
[   20.996576]  </TASK>
[   21.056592] sched_ext: BPF scheduler "simple" disabled (unregistered from user space)

Signed-off-by: Changwoo Min <[email protected]>
Acked-by: Andrea Righi <[email protected]>
Signed-off-by: Tejun Heo <[email protected]>
akiyks pushed a commit that referenced this issue Nov 24, 2024
copy_from_kernel_nofault() can be called when doing read of /proc/kcore.
/proc/kcore can have some unmapped kfence objects which when read via
copy_from_kernel_nofault() can cause page faults. Since *_nofault()
functions define their own fixup table for handling fault, use that
instead of asking kfence to handle such faults.

Hence we search the exception tables for the nip which generated the
fault. If there is an entry then we let the fixup table handler handle the
page fault by returning an error from within ___do_page_fault().

This can be easily triggered if someone tries to do dd from /proc/kcore.
eg. dd if=/proc/kcore of=/dev/null bs=1M

Some example false negatives:

  ===============================
  BUG: KFENCE: invalid read in copy_from_kernel_nofault+0x9c/0x1a0
  Invalid read at 0xc0000000fdff0000:
   copy_from_kernel_nofault+0x9c/0x1a0
   0xc00000000665f950
   read_kcore_iter+0x57c/0xa04
   proc_reg_read_iter+0xe4/0x16c
   vfs_read+0x320/0x3ec
   ksys_read+0x90/0x154
   system_call_exception+0x120/0x310
   system_call_vectored_common+0x15c/0x2ec

  BUG: KFENCE: use-after-free read in copy_from_kernel_nofault+0x9c/0x1a0
  Use-after-free read at 0xc0000000fe050000 (in kfence-#2):
   copy_from_kernel_nofault+0x9c/0x1a0
   0xc00000000665f950
   read_kcore_iter+0x57c/0xa04
   proc_reg_read_iter+0xe4/0x16c
   vfs_read+0x320/0x3ec
   ksys_read+0x90/0x154
   system_call_exception+0x120/0x310
   system_call_vectored_common+0x15c/0x2ec

Fixes: 90cbac0 ("powerpc: Enable KFENCE for PPC32")
Suggested-by: Christophe Leroy <[email protected]>
Reported-by: Disha Goel <[email protected]>
Signed-off-by: Ritesh Harjani (IBM) <[email protected]>
Reviewed-by: Christophe Leroy <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://patch.msgid.link/a411788081d50e3b136c6270471e35aba3dfafa3.1729271995.git.ritesh.list@gmail.com
akiyks pushed a commit that referenced this issue Nov 24, 2024
The dtl_access_lock needs to be a rw_sempahore, a sleeping lock, because
the code calls kmalloc() while holding it, which can sleep:

  # echo 1 > /proc/powerpc/vcpudispatch_stats
  BUG: sleeping function called from invalid context at include/linux/sched/mm.h:337
  in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 199, name: sh
  preempt_count: 1, expected: 0
  3 locks held by sh/199:
   #0: c00000000a0743f8 (sb_writers#3){.+.+}-{0:0}, at: vfs_write+0x324/0x438
   #1: c0000000028c7058 (dtl_enable_mutex){+.+.}-{3:3}, at: vcpudispatch_stats_write+0xd4/0x5f4
   #2: c0000000028c70b8 (dtl_access_lock){+.+.}-{2:2}, at: vcpudispatch_stats_write+0x220/0x5f4
  CPU: 0 PID: 199 Comm: sh Not tainted 6.10.0-rc4 torvalds#152
  Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1202 0xf000005 of:SLOF,HEAD hv:linux,kvm pSeries
  Call Trace:
    dump_stack_lvl+0x130/0x148 (unreliable)
    __might_resched+0x174/0x410
    kmem_cache_alloc_noprof+0x340/0x3d0
    alloc_dtl_buffers+0x124/0x1ac
    vcpudispatch_stats_write+0x2a8/0x5f4
    proc_reg_write+0xf4/0x150
    vfs_write+0xfc/0x438
    ksys_write+0x88/0x148
    system_call_exception+0x1c4/0x5a0
    system_call_common+0xf4/0x258

Fixes: 06220d7 ("powerpc/pseries: Introduce rwlock to gatekeep DTLB usage")
Tested-by: Kajol Jain <[email protected]>
Reviewed-by: Nysal Jan K.A <[email protected]>
Reviewed-by: Kajol Jain <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://patch.msgid.link/[email protected]
akiyks pushed a commit that referenced this issue Nov 24, 2024
…bled

Use the Accessed bit in SPTEs even when A/D bits are disabled in hardware,
i.e. propagate accessed information to SPTE.Accessed even when KVM is
doing manual tracking by making SPTEs not-present.  In addition to
eliminating a small amount of code in is_accessed_spte(), this also paves
the way for preserving Accessed information when a SPTE is zapped in
response to a mmu_notifier PROTECTION event, e.g. if a SPTE is zapped
because NUMA balancing kicks in.

Note, EPT is the only flavor of paging in which A/D bits are conditionally
enabled, and the Accessed (and Dirty) bit is software-available when A/D
bits are disabled.

Note #2, there are currently no concrete plans to preserve Accessed
information.  Explorations on that front were the initial catalyst, but
the cleanup is the motivation for the actual commit.

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>
akiyks pushed a commit that referenced this issue Nov 24, 2024
Target slot selection for recompression is just a simple iteration over
zram->table entries (stored pages) from slot 0 to max slot.  Given that
zram->table slots are written in random order and are not sorted by size,
a simple iteration over slots selects suboptimal targets for
recompression.  This is not a problem if we recompress every single
zram->table slot, but we never do that in reality.  In reality we limit
the number of slots we can recompress (via max_pages parameter) and hence
proper slot selection becomes very important.  The strategy is quite
simple, suppose we have two candidate slots for recompression, one of size
48 bytes and one of size 2800 bytes, and we can recompress only one, then
it certainly makes more sense to pick 2800 entry for recompression. 
Because even if we manage to compress 48 bytes objects even further the
savings are going to be very small.  Potential savings after good
re-compression of 2800 bytes objects are much higher.

This patch reworks slot selection and introduces the strategy described
above: among candidate slots always select the biggest ones first.

For that the patch introduces zram_pp_ctl (post-processing) structure
which holds NUM_PP_BUCKETS pp buckets of slots.  Slots are assigned to a
particular group based on their sizes - the larger the size of the slot
the higher the group index.  This, basically, sorts slots by size in liner
time (we still perform just one iteration over zram->table slots).  When
we select slot for recompression we always first lookup in higher pp
buckets (those that hold the largest slots).  Which achieves the desired
behavior.

TEST
====

A very simple demonstration: zram is configured with zstd, and zstd with
dict as a recompression stream.  A limited (max 4096 pages) recompression
is performed then, with a log of sizes of slots that were recompressed. 
You can see that patched zram selects slots for recompression in
significantly different manner, which leads to higher memory savings (see
column #2 of mm_stat output).

BASE
----

*** initial state of zram device
/sys/block/zram0/mm_stat
1750994944 504491413 514203648        0 514203648        1        0    34204    34204

*** recompress idle max_pages=4096
/sys/block/zram0/mm_stat
1750994944 504262229 514953216        0 514203648        1        0    34204    34204

Sizes of selected objects for recompression:
... 45 58 24 226 91 40 24 24 24 424 2104 93 2078 2078 2078 959 154 ...

PATCHED
-------

*** initial state of zram device
/sys/block/zram0/mm_stat
1750982656 504492801 514170880        0 514170880        1        0    34204    34204

*** recompress idle max_pages=4096
/sys/block/zram0/mm_stat
1750982656 503716710 517586944        0 514170880        1        0    34204    34204

Sizes of selected objects for recompression:
... 3680 3694 3667 3590 3614 3553 3537 3548 3550 3542 3543 3537 ...

Note, pp-slots are not strictly sorted, there is a PP_BUCKET_SIZE_RANGE
variation of sizes within particular bucket.

[[email protected]: do not skip the first bucket]
  Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Sergey Senozhatsky <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Dan Carpenter <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
akiyks pushed a commit that referenced this issue Nov 24, 2024
Writeback suffers from the same problem as recompression did before -
target slot selection for writeback is just a simple iteration over
zram->table entries (stored pages) which selects suboptimal targets for
writeback.  This is especially problematic for writeback, because we
uncompress objects before writeback so each of them takes 4K out of
limited writeback storage.  For example, when we take a 48 bytes slot and
store it as a 4K object to writeback device we only save 48 bytes of
memory (release from zsmalloc pool).  We naturally want to pick the
largest objects for writeback, because then each writeback will release
the largest amount of memory.

This patch applies the same solution and strategy as for recompression
target selection: pp control (post-process) with 16 buckets of candidate
pp slots.  Slots are assigned to pp buckets based on sizes - the larger
the slot the higher the group index.  This gives us sorted by size lists
of candidate slots (in linear time), so that among post-processing
candidate slots we always select the largest ones first and maximize the
memory saving.

TEST
====

A very simple demonstration: zram is configured with a writeback device. 
A limited writeback (wb_limit 2500 pages) is performed then, with a log of
sizes of slots that were written back.  You can see that patched zram
selects slots for recompression in significantly different manner, which
leads to higher memory savings (see column #2 of mm_stat output).

BASE
----

*** initial state of zram device
/sys/block/zram0/mm_stat
1750327296 619765836 631902208        0 631902208        1        0    34278    34278

*** writeback idle wb_limit 2500
/sys/block/zram0/mm_stat
1750327296 617622333 631578624        0 631902208        1        0    34278    34278

Sizes of selected objects for writeback:
... 193 349 46 46 46 46 852 1002 543 162 107 49 34 34 34 ...

PATCHED
-------

*** initial state of zram device
/sys/block/zram0/mm_stat
1750319104 619760957 631992320        0 631992320        1        0    34278    34278

*** writeback idle wb_limit 2500
/sys/block/zram0/mm_stat
1750319104 612672056 626135040        0 631992320        1        0    34278    34278

Sizes of selected objects for writeback:
... 3667 3580 3581 3580 3581 3581 3581 3231 3211 3203 3231 3246 ...

Note, pp-slots are not strictly sorted, there is a PP_BUCKET_SIZE_RANGE
variation of sizes within particular bucket.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Sergey Senozhatsky <[email protected]>
Cc: Minchan Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
akiyks pushed a commit that referenced this issue Nov 24, 2024
Patch series "page allocation tag compression", v4.

This patchset implements several improvements:

1. Gracefully handles module unloading while there are used
   allocations allocated from that module;

2. Provides an option to store page allocation tag references in the
   page flags, removing dependency on page extensions and eliminating the
   memory overhead from storing page allocation references (~0.2% of total
   system memory).  This also improves page allocation performance when
   CONFIG_MEM_ALLOC_PROFILING is enabled by eliminating page extension
   lookup.  Page allocation performance overhead is reduced from 41% to
   5.5%.

Patch #1 introduces mas_for_each_rev() helper function.

Patch #2 introduces shutdown_mem_profiling() helper function to be used
when disabling memory allocation profiling.

Patch #3 copies module tags into virtually contiguous memory which
serves two purposes:

- Lets us deal with the situation when module is unloaded while there
  are still live allocations from that module.  Since we are using a copy
  version of the tags we can safely unload the module.  Space and gaps in
  this contiguous memory are managed using a maple tree.

- Enables simple indexing of the tags in the later patches.

Patch #4 changes the way we allocate virtually contiguous memory for
module tags to reserve only vitrual area and populate physical pages only
as needed at module load time.

Patch #5 abstracts page allocation tag reference to simplify later
changes.

Patch torvalds#6 adds compression option to the sysctl.vm.mem_profiling boot
parameter for storing page allocation tag references inside page flags if
they fit.  If the number of available page flag bits is insufficient to
address all kernel allocations, memory allocation profiling gets disabled
with an appropriate warning.


This patch (of 6):

Add mas_for_each_rev() function to iterate maple tree nodes in reverse
order.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Suren Baghdasaryan <[email protected]>
Suggested-by: Liam R. Howlett <[email protected]>
Reviewed-by: Liam R. Howlett <[email protected]>
Reviewed-by: Pasha Tatashin <[email protected]>
Cc: Ard Biesheuvel <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Borislav Petkov (AMD) <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Daniel Gomez <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Davidlohr Bueso <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Dennis Zhou <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: John Hubbard <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Kalesh Singh <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Kent Overstreet <[email protected]>
Cc: Luis Chamberlain <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Rapoport (Microsoft) <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Paul E. McKenney <[email protected]>
Cc: Petr Pavlu <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Sami Tolvanen <[email protected]>
Cc: Sourav Panda <[email protected]>
Cc: Steven Rostedt (Google) <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Thomas Huth <[email protected]>
Cc: Uladzislau Rezki (Sony) <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Xiongwei Song <[email protected]>
Cc: Yu Zhao <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
akiyks pushed a commit that referenced this issue Nov 26, 2024
Patch series "Improve the copy of task comm", v8.

Using {memcpy,strncpy,strcpy,kstrdup} to copy the task comm relies on the
length of task comm.  Changes in the task comm could result in a
destination string that is overflow.  Therefore, we should explicitly
ensure the destination string is always NUL-terminated, regardless of the
task comm.  This approach will facilitate future extensions to the task
comm.

As suggested by Linus [0], we can identify all relevant code with the
following git grep command:

  git grep 'memcpy.*->comm\>'
  git grep 'kstrdup.*->comm\>'
  git grep 'strncpy.*->comm\>'
  git grep 'strcpy.*->comm\>'

PATCH #2~#4:   memcpy
PATCH #5~torvalds#6:   kstrdup
PATCH torvalds#7:      strcpy

Please note that strncpy() is not included in this series as it is being
tracked by another effort. [1]


This patch (of 7):

We want to eliminate the use of __get_task_comm() for the following
reasons:

- The task_lock() is unnecessary
  Quoted from Linus [0]:
  : Since user space can randomly change their names anyway, using locking
  : was always wrong for readers (for writers it probably does make sense
  : to have some lock - although practically speaking nobody cares there
  : either, but at least for a writer some kind of race could have
  : long-term mixed results

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lore.kernel.org/all/CAHk-=wivfrF0_zvf+oj6==Sh=-npJooP8chLPEfaFV0oNYTTBA@mail.gmail.com [0]
Link: https://lore.kernel.org/all/CAHk-=whWtUC-AjmGJveAETKOMeMFSTwKwu99v7+b6AyHMmaDFA@mail.gmail.com/
Link: https://lore.kernel.org/all/CAHk-=wjAmmHUg6vho1KjzQi2=psR30+CogFd4aXrThr2gsiS4g@mail.gmail.com/ [0]
Link: KSPP#90 [1]
Signed-off-by: Yafang Shao <[email protected]>
Suggested-by: Linus Torvalds <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Eric Biederman <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Matus Jokay <[email protected]>
Cc: Alejandro Colomar <[email protected]>
Cc: "Serge E. Hallyn" <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Justin Stitt <[email protected]>
Cc: Steven Rostedt (Google) <[email protected]>
Cc: Tetsuo Handa <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: David Airlie <[email protected]>
Cc: Eric Paris <[email protected]>
Cc: James Morris <[email protected]>
Cc: Maarten Lankhorst <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Maxime Ripard <[email protected]>
Cc: Ondrej Mosnacek <[email protected]>
Cc: Paul Moore <[email protected]>
Cc: Quentin Monnet <[email protected]>
Cc: Simon Horman <[email protected]>
Cc: Stephen Smalley <[email protected]>
Cc: Thomas Zimmermann <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
akiyks pushed a commit that referenced this issue Nov 27, 2024
Perf test case 84 'perf pipe recording and injection test'
sometime fails on s390, especially on z/VM virtual machines.

This is caused by a very short run time of workload

  # perf test -w noploop

which runs for 1 second. Occasionally this is not long
enough and the perf report has no samples for symbol noploop.

Fix this and enlarge the runtime for the perf work load
to 3 seconds. This ensures the symbol noploop is always
present. Since only s390 is affected, make this loop
architecture dependend.

Output before:
 Inject -b build-ids test
 [ perf record: Woken up 1 times to write data ]
 [ perf record: Captured and wrote 0.195 MB - ]
 [ perf record: Woken up 1 times to write data ]
 [ perf record: Captured and wrote 0.277 MB - ]
 [ perf record: Woken up 1 times to write data ]
 [ perf record: Captured and wrote 0.195 MB - ]
 [ perf record: Woken up 1 times to write data ]
 [ perf record: Captured and wrote 0.160 MB
			 /tmp/perf.data.ELzRdq (4031 samples) ]
 [ perf record: Woken up 1 times to write data ]
 [ perf record: Captured and wrote 0.195 MB - ]
 [ perf record: Woken up 1 times to write data ]
 [ perf record: Captured and wrote 0.195 MB - ]
 Inject -b build-ids test [Success]

 Inject --buildid-all build-ids test
 [ perf record: Woken up 1 times to write data ]
 [ perf record: Captured and wrote 0.195 MB - ]
 [ perf record: Woken up 1 times to write data ]
 [ perf record: Captured and wrote 0.014 MB - ]
 Inject --buildid-all build-ids test [Failed - cannot find
				noploop function in pipe #2]

Output after:
Successful execution for over 10 times in a loop.

Signed-off-by: Thomas Richter <[email protected]>
Reviewed-by: Sumanth Korikkar <[email protected]>
Reviewed-by: Ian Rogers <[email protected]>
Suggested-by: Namhyung Kim <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Namhyung Kim <[email protected]>
akiyks pushed a commit that referenced this issue Nov 27, 2024
syzbot reports deadlock issue of f2fs as below:

======================================================
WARNING: possible circular locking dependency detected
6.12.0-rc3-syzkaller-00087-gc964ced77262 #0 Not tainted
------------------------------------------------------
kswapd0/79 is trying to acquire lock:
ffff888011824088 (&sbi->sb_lock){++++}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2199 [inline]
ffff888011824088 (&sbi->sb_lock){++++}-{3:3}, at: f2fs_record_stop_reason+0x52/0x1d0 fs/f2fs/super.c:4068

but task is already holding lock:
ffff88804bd92610 (sb_internal#2){.+.+}-{0:0}, at: f2fs_evict_inode+0x662/0x15c0 fs/f2fs/inode.c:842

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #2 (sb_internal#2){.+.+}-{0:0}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1716 [inline]
       sb_start_intwrite+0x4d/0x1c0 include/linux/fs.h:1899
       f2fs_evict_inode+0x662/0x15c0 fs/f2fs/inode.c:842
       evict+0x4e8/0x9b0 fs/inode.c:725
       f2fs_evict_inode+0x1a4/0x15c0 fs/f2fs/inode.c:807
       evict+0x4e8/0x9b0 fs/inode.c:725
       dispose_list fs/inode.c:774 [inline]
       prune_icache_sb+0x239/0x2f0 fs/inode.c:963
       super_cache_scan+0x38c/0x4b0 fs/super.c:223
       do_shrink_slab+0x701/0x1160 mm/shrinker.c:435
       shrink_slab+0x1093/0x14d0 mm/shrinker.c:662
       shrink_one+0x43b/0x850 mm/vmscan.c:4818
       shrink_many mm/vmscan.c:4879 [inline]
       lru_gen_shrink_node mm/vmscan.c:4957 [inline]
       shrink_node+0x3799/0x3de0 mm/vmscan.c:5937
       kswapd_shrink_node mm/vmscan.c:6765 [inline]
       balance_pgdat mm/vmscan.c:6957 [inline]
       kswapd+0x1ca3/0x3700 mm/vmscan.c:7226
       kthread+0x2f0/0x390 kernel/kthread.c:389
       ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #1 (fs_reclaim){+.+.}-{0:0}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
       __fs_reclaim_acquire mm/page_alloc.c:3834 [inline]
       fs_reclaim_acquire+0x88/0x130 mm/page_alloc.c:3848
       might_alloc include/linux/sched/mm.h:318 [inline]
       prepare_alloc_pages+0x147/0x5b0 mm/page_alloc.c:4493
       __alloc_pages_noprof+0x16f/0x710 mm/page_alloc.c:4722
       alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
       alloc_pages_noprof mm/mempolicy.c:2345 [inline]
       folio_alloc_noprof+0x128/0x180 mm/mempolicy.c:2352
       filemap_alloc_folio_noprof+0xdf/0x500 mm/filemap.c:1010
       do_read_cache_folio+0x2eb/0x850 mm/filemap.c:3787
       read_mapping_folio include/linux/pagemap.h:1011 [inline]
       f2fs_commit_super+0x3c0/0x7d0 fs/f2fs/super.c:4032
       f2fs_record_stop_reason+0x13b/0x1d0 fs/f2fs/super.c:4079
       f2fs_handle_critical_error+0x2ac/0x5c0 fs/f2fs/super.c:4174
       f2fs_write_inode+0x35f/0x4d0 fs/f2fs/inode.c:785
       write_inode fs/fs-writeback.c:1503 [inline]
       __writeback_single_inode+0x711/0x10d0 fs/fs-writeback.c:1723
       writeback_single_inode+0x1f3/0x660 fs/fs-writeback.c:1779
       sync_inode_metadata+0xc4/0x120 fs/fs-writeback.c:2849
       f2fs_release_file+0xa8/0x100 fs/f2fs/file.c:1941
       __fput+0x23f/0x880 fs/file_table.c:431
       task_work_run+0x24f/0x310 kernel/task_work.c:228
       resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
       exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
       exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
       __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
       syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218
       do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&sbi->sb_lock){++++}-{3:3}:
       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+0x1384/0x2050 kernel/locking/lockdep.c:5202
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
       down_write+0x99/0x220 kernel/locking/rwsem.c:1577
       f2fs_down_write fs/f2fs/f2fs.h:2199 [inline]
       f2fs_record_stop_reason+0x52/0x1d0 fs/f2fs/super.c:4068
       f2fs_handle_critical_error+0x2ac/0x5c0 fs/f2fs/super.c:4174
       f2fs_evict_inode+0xa61/0x15c0 fs/f2fs/inode.c:883
       evict+0x4e8/0x9b0 fs/inode.c:725
       f2fs_evict_inode+0x1a4/0x15c0 fs/f2fs/inode.c:807
       evict+0x4e8/0x9b0 fs/inode.c:725
       dispose_list fs/inode.c:774 [inline]
       prune_icache_sb+0x239/0x2f0 fs/inode.c:963
       super_cache_scan+0x38c/0x4b0 fs/super.c:223
       do_shrink_slab+0x701/0x1160 mm/shrinker.c:435
       shrink_slab+0x1093/0x14d0 mm/shrinker.c:662
       shrink_one+0x43b/0x850 mm/vmscan.c:4818
       shrink_many mm/vmscan.c:4879 [inline]
       lru_gen_shrink_node mm/vmscan.c:4957 [inline]
       shrink_node+0x3799/0x3de0 mm/vmscan.c:5937
       kswapd_shrink_node mm/vmscan.c:6765 [inline]
       balance_pgdat mm/vmscan.c:6957 [inline]
       kswapd+0x1ca3/0x3700 mm/vmscan.c:7226
       kthread+0x2f0/0x390 kernel/kthread.c:389
       ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

other info that might help us debug this:

Chain exists of:
  &sbi->sb_lock --> fs_reclaim --> sb_internal#2

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rlock(sb_internal#2);
                               lock(fs_reclaim);
                               lock(sb_internal#2);
  lock(&sbi->sb_lock);

Root cause is there will be potential deadlock in between
below tasks:

Thread A				Kswapd
- f2fs_ioc_commit_atomic_write
 - mnt_want_write_file -- down_read lock A
					- balance_pgdat
					 - __fs_reclaim_acquire  -- lock B
					  - shrink_node
					   - prune_icache_sb
					    - dispose_list
					     - f2fs_evict_inode
					      - sb_start_intwrite  -- down_read lock A
 - f2fs_do_sync_file
  - f2fs_write_inode
   - f2fs_handle_critical_error
    - f2fs_record_stop_reason
     - f2fs_commit_super
      - read_mapping_folio
       - filemap_alloc_folio_noprof
        - fs_reclaim_acquire  -- lock B

Both threads try to acquire read lock of lock A, then its upcoming write
lock grabber will trigger deadlock.

Let's always create an asynchronous task in f2fs_handle_critical_error()
rather than calling f2fs_record_stop_reason() synchronously to avoid
this potential deadlock issue.

Fixes: b62e71b ("f2fs: support errors=remount-ro|continue|panic mountoption")
Reported-by: [email protected]
Closes: https://lore.kernel.org/all/[email protected]
Signed-off-by: Chao Yu <[email protected]>
Reviewed-by: Daejun Park <[email protected]>
Signed-off-by: Jaegeuk Kim <[email protected]>
akiyks pushed a commit that referenced this issue Nov 28, 2024
Commit bab1c29 ("LoongArch: Fix sleeping in atomic context in
setup_tlb_handler()") changes the gfp flag from GFP_KERNEL to GFP_ATOMIC
for alloc_pages_node(). However, for PREEMPT_RT kernels we can still get
a "sleeping in atomic context" error:

[    0.372259] BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
[    0.372266] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 0, name: swapper/1
[    0.372268] preempt_count: 1, expected: 0
[    0.372270] RCU nest depth: 1, expected: 1
[    0.372272] 3 locks held by swapper/1/0:
[    0.372274]  #0: 900000000c9f5e60 (&pcp->lock){+.+.}-{3:3}, at: get_page_from_freelist+0x524/0x1c60
[    0.372294]  #1: 90000000087013b8 (rcu_read_lock){....}-{1:3}, at: rt_spin_trylock+0x50/0x140
[    0.372305]  #2: 900000047fffd388 (&zone->lock){+.+.}-{3:3}, at: __rmqueue_pcplist+0x30c/0xea0
[    0.372314] irq event stamp: 0
[    0.372316] hardirqs last  enabled at (0): [<0000000000000000>] 0x0
[    0.372322] hardirqs last disabled at (0): [<9000000005947320>] copy_process+0x9c0/0x26e0
[    0.372329] softirqs last  enabled at (0): [<9000000005947320>] copy_process+0x9c0/0x26e0
[    0.372335] softirqs last disabled at (0): [<0000000000000000>] 0x0
[    0.372341] CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.12.0-rc7+ #1891
[    0.372346] Hardware name: Loongson Loongson-3A5000-7A1000-1w-CRB/Loongson-LS3A5000-7A1000-1w-CRB, BIOS vUDK2018-LoongArch-V2.0.0-prebeta9 10/21/2022
[    0.372349] Stack : 0000000000000089 9000000005a0db9c 90000000071519c8 9000000100388000
[    0.372486]         900000010038b890 0000000000000000 900000010038b898 9000000007e53788
[    0.372492]         900000000815bcc8 900000000815bcc0 900000010038b700 0000000000000001
[    0.372498]         0000000000000001 4b031894b9d6b725 00000000055ec000 9000000100338fc0
[    0.372503]         00000000000000c4 0000000000000001 000000000000002d 0000000000000003
[    0.372509]         0000000000000030 0000000000000003 00000000055ec000 0000000000000003
[    0.372515]         900000000806d000 9000000007e53788 00000000000000b0 0000000000000004
[    0.372521]         0000000000000000 0000000000000000 900000000c9f5f10 0000000000000000
[    0.372526]         90000000076f12d8 9000000007e53788 9000000005924778 0000000000000000
[    0.372532]         00000000000000b0 0000000000000004 0000000000000000 0000000000070000
[    0.372537]         ...
[    0.372540] Call Trace:
[    0.372542] [<9000000005924778>] show_stack+0x38/0x180
[    0.372548] [<90000000071519c4>] dump_stack_lvl+0x94/0xe4
[    0.372555] [<900000000599b880>] __might_resched+0x1a0/0x260
[    0.372561] [<90000000071675cc>] rt_spin_lock+0x4c/0x140
[    0.372565] [<9000000005cbb768>] __rmqueue_pcplist+0x308/0xea0
[    0.372570] [<9000000005cbed84>] get_page_from_freelist+0x564/0x1c60
[    0.372575] [<9000000005cc0d98>] __alloc_pages_noprof+0x218/0x1820
[    0.372580] [<900000000593b36c>] tlb_init+0x1ac/0x298
[    0.372585] [<9000000005924b74>] per_cpu_trap_init+0x114/0x140
[    0.372589] [<9000000005921964>] cpu_probe+0x4e4/0xa60
[    0.372592] [<9000000005934874>] start_secondary+0x34/0xc0
[    0.372599] [<900000000715615c>] smpboot_entry+0x64/0x6c

This is because in PREEMPT_RT kernels normal spinlocks are replaced by
rt spinlocks and rt_spin_lock() will cause sleeping. Fix it by disabling
NUMA optimization completely for PREEMPT_RT kernels.

Signed-off-by: Huacai Chen <[email protected]>
akiyks pushed a commit that referenced this issue Nov 30, 2024
…ndex

Intel SoundWire machine driver always uses Pin number 2 and above.
Currently, the pin number is used as the FW DAI index directly. As a
result, FW DAI 0 and 1 are never used. That worked fine because we use
up to 2 DAIs in a SDW link. Convert the topology pin index to ALH dai
index, the mapping is using 2-off indexing, iow, pin #2 is ALH dai #0.

The issue exists since beginning. And the Fixes tag is the first commit
that this commit can be applied.

Fixes: b66bfc3 ("ASoC: SOF: sof-audio: Fix broken early bclk feature for SSP")
Signed-off-by: Bard Liao <[email protected]>
Reviewed-by: Péter Ujfalusi <[email protected]>
Reviewed-by: Liam Girdwood <[email protected]>
Reviewed-by: Kai Vehmanen <[email protected]>
Reviewed-by: Ranjani Sridharan <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Mark Brown <[email protected]>
akiyks pushed a commit that referenced this issue Dec 2, 2024
…ux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 changes for 6.13, part #2

 - Constrain invalidations from GICR_INVLPIR to only affect the LPI
   INTID space

 - Set of robustness improvements to the management of vgic irqs and GIC
   ITS table entries

 - Fix compilation issue w/ CONFIG_CC_OPTIMIZE_FOR_SIZE=y where
   set_sysreg_masks() wasn't getting inlined, breaking check for a
   constant sysreg index

 - Correct KVM's vPMU overflow condition to match the architecture for
   hyp and non-hyp counters
akiyks pushed a commit that referenced this issue Dec 2, 2024
…to HEAD

KVM/riscv changes for 6.13 part #2

- Svade and Svadu extension support for Host and Guest/VM
akiyks pushed a commit that referenced this issue Dec 7, 2024
Konstantin Shkolnyy says:

====================
vsock/test: fix wrong setsockopt() parameters

Parameters were created using wrong C types, which caused them to be of
wrong size on some architectures, causing problems.

The problem with SO_RCVLOWAT was found on s390 (big endian), while x86-64
didn't show it. After the fix, all tests pass on s390.
Then Stefano Garzarella pointed out that SO_VM_SOCKETS_* calls might have
a similar problem, which turned out to be true, hence, the second patch.

Changes for v8:
- Fix whitespace warnings from "checkpatch.pl --strict"
- Add maintainers to Cc:
Changes for v7:
- Rebase on top of https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git
- Add the "net" tags to the subjects
Changes for v6:
- rework the patch #3 to avoid creating a new file for new functions,
and exclude vsock_perf from calling the new functions.
- add "Reviewed-by:" to the patch #2.
Changes for v5:
- in the patch #2 replace the introduced uint64_t with unsigned long long
to match documentation
- add a patch #3 that verifies every setsockopt() call.
Changes for v4:
- add "Reviewed-by:" to the first patch, and add a second patch fixing
SO_VM_SOCKETS_* calls, which depends on the first one (hence, it's now
a patch series.)
Changes for v3:
- fix the same problem in vsock_perf and update commit message
Changes for v2:
- add "Fixes:" lines to the commit message
====================

Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
akiyks pushed a commit that referenced this issue Dec 7, 2024
Add more test cases for LPM trie in test_maps:

1) test_lpm_trie_update_flags
It constructs various use cases for BPF_EXIST and BPF_NOEXIST and check
whether the return value of update operation is expected.

2) test_lpm_trie_update_full_maps
It tests the update operations on a full LPM trie map. Adding new node
will fail and overwriting the value of existed node will succeed.

3) test_lpm_trie_iterate_strs and test_lpm_trie_iterate_ints
There two test cases test whether the iteration through get_next_key is
sorted and expected. These two test cases delete the minimal key after
each iteration and check whether next iteration returns the second
minimal key. The only difference between these two test cases is the
former one saves strings in the LPM trie and the latter saves integers.
Without the fix of get_next_key, these two cases will fail as shown
below:
  test_lpm_trie_iterate_strs(1091):FAIL:iterate #2 got abc exp abS
  test_lpm_trie_iterate_ints(1142):FAIL:iterate #1 got 0x2 exp 0x1

Signed-off-by: Hou Tao <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
akiyks pushed a commit that referenced this issue Dec 7, 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 torvalds#6~torvalds#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 torvalds#8: move test_lpm_map to map_tests to make it run regularly.
Patch torvalds#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 torvalds#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 torvalds#6: use one bpf mem allocator and update commit message to
    clarify that using bpf mem allocator is more appropriate.
  * patch torvalds#7: update commit message to add the possible max running time
    for update operation.
  * patch torvalds#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]>
akiyks pushed a commit that referenced this issue 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
 torvalds#6 [ff61d23de260fcc8] nvme_rdma_setup_ctrl at ffffffffc1268ced
 torvalds#7 [ff61d23de260fd28] nvme_rdma_create_ctrl at ffffffffc126919b
 torvalds#8 [ff61d23de260fd68] nvmf_dev_write at ffffffffc024f362
 torvalds#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]>
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