Good day, dear maintainers,
We found a bug using a modified kernel configuration file used by syzbot.
We enhanced the coverage of the configuration file using our tool, klocalizer.
Kernel Branch: 6.3.0-next-20230426
Kernel Config: https://drive.google.com/file/d/1WSUEWrith9-539qo6xRqmwy4LfDtmKpp/view?usp=sharing
Reproducer: https://drive.google.com/file/d/1pN6FfcjuUs6Wx94g1gufuYGjRbMMgiZ4/view?usp=sharing
Thank you!
Best regards,
Sanan Hasanov
watchdog: BUG: soft lockup - CPU#5 stuck for 26s! [kworker/u16:1:12]
Modules linked in:
irq event stamp: 192794
hardirqs last enabled at (192793): [<ffffffff89a0140a>] asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
hardirqs last disabled at (192794): [<ffffffff89975d4f>] sysvec_apic_timer_interrupt+0xf/0xc0 arch/x86/kernel/apic/apic.c:1106
softirqs last enabled at (187764): [<ffffffff814b94bd>] invoke_softirq kernel/softirq.c:445 [inline]
softirqs last enabled at (187764): [<ffffffff814b94bd>] __irq_exit_rcu+0x11d/0x190 kernel/softirq.c:650
softirqs last disabled at (187671): [<ffffffff814b94bd>] invoke_softirq kernel/softirq.c:445 [inline]
softirqs last disabled at (187671): [<ffffffff814b94bd>] __irq_exit_rcu+0x11d/0x190 kernel/softirq.c:650
CPU: 5 PID: 12 Comm: kworker/u16:1 Not tainted 6.3.0-next-20230426 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:294 [inline]
RIP: 0010:smp_call_function_many_cond+0x5bd/0x1020 kernel/smp.c:828
Code: 0b 00 85 ed 74 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 f4 4c 89 f5 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 b5 07 0b 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 46 08 00 00 8b 43 08 31
RSP: 0018:ffffc900000cf9e8 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff888119cc4d80 RCX: 0000000000000000
RDX: ffff888100325940 RSI: ffffffff8176807b RDI: 0000000000000005
RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffffed10233989b1
R13: 0000000000000001 R14: ffff888119cc4d88 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888119e80000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555556a6cc88 CR3: 000000000bb73000 CR4: 0000000000350ee0
Call Trace:
<TASK>
on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:996
on_each_cpu include/linux/smp.h:71 [inline]
text_poke_sync arch/x86/kernel/alternative.c:1770 [inline]
text_poke_bp_batch+0x237/0x770 arch/x86/kernel/alternative.c:1970
text_poke_flush arch/x86/kernel/alternative.c:2161 [inline]
text_poke_flush arch/x86/kernel/alternative.c:2158 [inline]
text_poke_finish+0x1a/0x30 arch/x86/kernel/alternative.c:2168
arch_jump_label_transform_apply+0x17/0x30 arch/x86/kernel/jump_label.c:146
jump_label_update+0x321/0x400 kernel/jump_label.c:829
static_key_enable_cpuslocked+0x1b5/0x270 kernel/jump_label.c:205
static_key_enable+0x1a/0x20 kernel/jump_label.c:218
toggle_allocation_gate mm/kfence/core.c:831 [inline]
toggle_allocation_gate+0xf4/0x220 mm/kfence/core.c:823
process_one_work+0x993/0x15e0 kernel/workqueue.c:2405
worker_thread+0x67d/0x10c0 kernel/workqueue.c:2552
kthread+0x33e/0x440 kernel/kthread.c:379
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
</TASK>
Sending NMI from CPU 5 to CPUs 0-4,6-7:
NMI backtrace for cpu 1
CPU: 1 PID: 20602 Comm: syz-executor.3 Not tainted 6.3.0-next-20230426 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4747 [inline]
RIP: 0010:__lock_acquire+0x489/0x5d00 kernel/locking/lockdep.c:5024
Code: 41 81 e5 ff 1f 45 0f b7 ed be 08 00 00 00 4c 89 e8 48 c1 e8 06 48 8d 3c c5 00 6b 2c 90 e8 5f 90 6e 00 4c 0f a3 2d d7 35 c9 0e <0f> 83 5c 0c 00 00 4f 8d 6c 6d 00 49 c1 e5 06 49 81 c5 20 6f 2c 90
RSP: 0018:ffffc90002aa7350 EFLAGS: 00000047
RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff81633521
RDX: fffffbfff2058d62 RSI: 0000000000000008 RDI: ffffffff902c6b08
RBP: ffff888042995940 R08: 0000000000000000 R09: ffffffff902c6b0f
R10: fffffbfff2058d61 R11: 0000000000000001 R12: ffff888119e2b818
R13: 0000000000000063 R14: 0000000000000002 R15: ffff888042996598
FS: 00007fdaad065700(0000) GS:ffff888119c80000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30623000 CR3: 0000000101969000 CR4: 0000000000350ee0
Call Trace:
<TASK>
lock_acquire kernel/locking/lockdep.c:5691 [inline]
lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5656
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x3d/0x60 kernel/locking/spinlock.c:162
lock_hrtimer_base kernel/time/hrtimer.c:173 [inline]
hrtimer_try_to_cancel kernel/time/hrtimer.c:1331 [inline]
hrtimer_try_to_cancel+0xa9/0x2e0 kernel/time/hrtimer.c:1316
hrtimer_cancel+0x17/0x40 kernel/time/hrtimer.c:1443
__disable_vblank drivers/gpu/drm/drm_vblank.c:434 [inline]
drm_vblank_disable_and_save+0x282/0x3d0 drivers/gpu/drm/drm_vblank.c:478
drm_crtc_vblank_off+0x312/0x970 drivers/gpu/drm/drm_vblank.c:1366
disable_outputs+0x7c7/0xbb0 drivers/gpu/drm/drm_atomic_helper.c:1202
drm_atomic_helper_commit_modeset_disables+0x1d/0x40 drivers/gpu/drm/drm_atomic_helper.c:1397
vkms_atomic_commit_tail+0x51/0x240 drivers/gpu/drm/vkms/vkms_drv.c:71
commit_tail+0x288/0x420 drivers/gpu/drm/drm_atomic_helper.c:1812
drm_atomic_helper_commit drivers/gpu/drm/drm_atomic_helper.c:2052 [inline]
drm_atomic_helper_commit+0x306/0x390 drivers/gpu/drm/drm_atomic_helper.c:1985
drm_atomic_commit+0x20a/0x2d0 drivers/gpu/drm/drm_atomic.c:1503
drm_client_modeset_commit_atomic+0x698/0x7e0 drivers/gpu/drm/drm_client_modeset.c:1045
drm_client_modeset_dpms+0x174/0x200 drivers/gpu/drm/drm_client_modeset.c:1226
drm_fb_helper_dpms drivers/gpu/drm/drm_fb_helper.c:323 [inline]
drm_fb_helper_blank+0xd1/0x260 drivers/gpu/drm/drm_fb_helper.c:356
fb_blank+0x105/0x190 drivers/video/fbdev/core/fbmem.c:1088
do_fb_ioctl+0x390/0x760 drivers/video/fbdev/core/fbmem.c:1180
fb_ioctl+0xeb/0x150 drivers/video/fbdev/core/fbmem.c:1204
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl fs/ioctl.c:856 [inline]
__x64_sys_ioctl+0x197/0x210 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0x80 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fdaabe8edcd
Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fdaad064bf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fdaabfbbf80 RCX: 00007fdaabe8edcd
RDX: 0000000000000004 RSI: 0000000000004611 RDI: 0000000000000003
RBP: 00007fdaabefc59c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffdadeffe9f R14: 00007ffdadf00040 R15: 00007fdaad064d80
</TASK>
NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline]
NMI backtrace for cpu 0 skipped: idling at default_idle+0xf/0x20 arch/x86/kernel/process.c:729
NMI backtrace for cpu 3 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
NMI backtrace for cpu 3 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline]
NMI backtrace for cpu 3 skipped: idling at default_idle+0xf/0x20 arch/x86/kernel/process.c:729
NMI backtrace for cpu 6 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
NMI backtrace for cpu 6 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline]
NMI backtrace for cpu 6 skipped: idling at default_idle+0xf/0x20 arch/x86/kernel/process.c:729
NMI backtrace for cpu 7 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
NMI backtrace for cpu 7 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline]
NMI backtrace for cpu 7 skipped: idling at default_idle+0xf/0x20 arch/x86/kernel/process.c:729
NMI backtrace for cpu 4
CPU: 4 PID: 20623 Comm: syz-executor.6 Not tainted 6.3.0-next-20230426 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
RIP: 0010:kvm_wait+0xb7/0x110 arch/x86/kernel/kvm.c:1064
Code: 40 38 c6 74 1b 48 83 c4 10 c3 c3 e8 93 d3 50 00 eb 07 0f 00 2d 4a 04 92 08 fb f4 48 83 c4 10 c3 eb 07 0f 00 2d 3a 04 92 08 f4 <48> 83 c4 10 c3 89 74 24 0c 48 89 3c 24 e8 d7 d4 50 00 8b 74 24 0c
RSP: 0018:ffffc90000300b50 EFLAGS: 00000046
RAX: 0000000000000003 RBX: 0000000000000000 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000003 RDI: ffff88810b0803d8
RBP: ffff88810b0803d8 R08: 0000000000000001 R09: ffff88810b0803d8
R10: ffffed102161007b R11: ffffc90000300ff8 R12: 0000000000000000
R13: ffffed102161007b R14: 0000000000000001 R15: ffff888119e3d3c0
FS: 0000000000000000(0000) GS:ffff888119e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f28183bd0b0 CR3: 000000000bb73000 CR4: 0000000000350ee0
Call Trace:
<IRQ>
pv_wait arch/x86/include/asm/paravirt.h:598 [inline]
pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline]
__pv_queued_spin_lock_slowpath+0x8e4/0xb80 kernel/locking/qspinlock.c:511
pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:586 [inline]
queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
do_raw_spin_lock+0x20d/0x2b0 kernel/locking/spinlock_debug.c:115
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
_raw_spin_lock_irqsave+0x45/0x60 kernel/locking/spinlock.c:162
drm_handle_vblank+0x11e/0xb80 drivers/gpu/drm/drm_vblank.c:1986
vkms_vblank_simulate+0xe8/0x3e0 drivers/gpu/drm/vkms/vkms_crtc.c:29
__run_hrtimer kernel/time/hrtimer.c:1685 [inline]
__hrtimer_run_queues+0x599/0xa30 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x320/0x7b0 kernel/time/hrtimer.c:1811
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline]
__sysvec_apic_timer_interrupt+0x14a/0x430 arch/x86/kernel/apic/apic.c:1112
sysvec_apic_timer_interrupt+0x92/0xc0 arch/x86/kernel/apic/apic.c:1106
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x11/0x70 kernel/kcov.c:207
Code: a8 01 00 00 e8 b0 ff ff ff 31 c0 c3 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 f3 0f 1e fa 65 8b 05 0d 33 82 7e 89 c1 48 8b 34 24 <81> e1 00 01 00 00 65 48 8b 14 25 40 bb 03 00 a9 00 01 ff 00 74 0e
RSP: 0018:ffffc90002be76d8 EFLAGS: 00000286
RAX: 0000000080000001 RBX: 0000000000000001 RCX: 0000000080000001
RDX: 00007f2817c77000 RSI: ffffffff81bcd756 RDI: ffffc90002be7ad8
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffffea00014fc480
R13: 0000000000000000 R14: dffffc0000000000 R15: 8000000053f12007
zap_drop_file_uffd_wp mm/memory.c:1352 [inline]
zap_install_uffd_wp_if_needed mm/memory.c:1371 [inline]
zap_pte_range mm/memory.c:1417 [inline]
zap_pmd_range mm/memory.c:1564 [inline]
zap_pud_range mm/memory.c:1593 [inline]
zap_p4d_range mm/memory.c:1614 [inline]
unmap_page_range+0x1046/0x4470 mm/memory.c:1635
unmap_single_vma+0x19a/0x2b0 mm/memory.c:1681
unmap_vmas+0x234/0x380 mm/memory.c:1720
exit_mmap+0x190/0x930 mm/mmap.c:3111
__mmput+0x128/0x4c0 kernel/fork.c:1351
mmput+0x60/0x70 kernel/fork.c:1373
exit_mm kernel/exit.c:564 [inline]
do_exit+0x9d1/0x29f0 kernel/exit.c:858
do_group_exit+0xd4/0x2a0 kernel/exit.c:1021
get_signal+0x2311/0x25c0 kernel/signal.c:2874
arch_do_signal_or_restart+0x79/0x5a0 arch/x86/kernel/signal.c:307
exit_to_user_mode_loop kernel/entry/common.c:168 [inline]
exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204
__syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297
do_syscall_64+0x46/0x80 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f281828edcd
Code: Unable to access opcode bytes at 0x7f281828eda3.
RSP: 002b:00007f28194c0c98 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f28183bbf80 RCX: 00007f281828edcd
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f28183bbf88
RBP: 00007f28183bbf88 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f28183bbf8c
R13: 00007ffd5038e1ef R14: 00007ffd5038e390 R15: 00007f28194c0d80
</TASK>
NMI backtrace for cpu 2 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
NMI backtrace for cpu 2 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline]
NMI backtrace for cpu 2 skipped: idling at default_idle+0xf/0x20 arch/x86/kernel/process.c:729
On 2023/09/13 20:07, Hillf Danton wrote:
>
> cpu1 cpu4 (see below)
> ==== ====
> drm_crtc_vblank_off __run_hrtimer
> spin_lock_irq(&dev->event_lock);
> ...
> drm_handle_vblank
> hrtimer_cancel spin_lock_irqsave(&dev->event_lock, irqflags);
>
>
> Deadlock should have been reported instead provided the lockdep_map in
> struct timer_list were added also to hrtimer, so it is highly appreciated
> if Tetsuo or Thomas adds it before 6.8 or 6.10.
Not me. ;-)
Since hrtimer_cancel() retries forever until lock_hrtimer_base() succeeds,
we want to add a lockdep annotation into hrtimer_cancel() so that we can
detect this type of deadlock?
On Tue, Sep 12, 2023 at 11:02:56PM +0000, Sanan Hasanov wrote:
> Good day, dear maintainers,
>
> We found a bug using a modified kernel configuration file used by syzbot.
>
> We enhanced the coverage of the configuration file using our tool, klocalizer.
>
> Kernel Branch: 6.3.0-next-20230426
> Kernel Config: https://drive.google.com/file/d/1WSUEWrith9-539qo6xRqmwy4LfDtmKpp/view?usp=sharing
> Reproducer: https://drive.google.com/file/d/1pN6FfcjuUs6Wx94g1gufuYGjRbMMgiZ4/view?usp=sharing
> Thank you!
AFAICT the thing is stuck in DRM somewhere...
> watchdog: BUG: soft lockup - CPU#5 stuck for 26s! [kworker/u16:1:12]
> Modules linked in:
> irq event stamp: 192794
> hardirqs last enabled at (192793): [<ffffffff89a0140a>] asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
> hardirqs last disabled at (192794): [<ffffffff89975d4f>] sysvec_apic_timer_interrupt+0xf/0xc0 arch/x86/kernel/apic/apic.c:1106
> softirqs last enabled at (187764): [<ffffffff814b94bd>] invoke_softirq kernel/softirq.c:445 [inline]
> softirqs last enabled at (187764): [<ffffffff814b94bd>] __irq_exit_rcu+0x11d/0x190 kernel/softirq.c:650
> softirqs last disabled at (187671): [<ffffffff814b94bd>] invoke_softirq kernel/softirq.c:445 [inline]
> softirqs last disabled at (187671): [<ffffffff814b94bd>] __irq_exit_rcu+0x11d/0x190 kernel/softirq.c:650
> CPU: 5 PID: 12 Comm: kworker/u16:1 Not tainted 6.3.0-next-20230426 #1
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
> Workqueue: events_unbound toggle_allocation_gate
> RIP: 0010:csd_lock_wait kernel/smp.c:294 [inline]
> RIP: 0010:smp_call_function_many_cond+0x5bd/0x1020 kernel/smp.c:828
> Code: 0b 00 85 ed 74 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 f4 4c 89 f5 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 b5 07 0b 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 46 08 00 00 8b 43 08 31
> RSP: 0018:ffffc900000cf9e8 EFLAGS: 00000293
> RAX: 0000000000000000 RBX: ffff888119cc4d80 RCX: 0000000000000000
> RDX: ffff888100325940 RSI: ffffffff8176807b RDI: 0000000000000005
> RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000
> R10: 0000000000000001 R11: 0000000000000001 R12: ffffed10233989b1
> R13: 0000000000000001 R14: ffff888119cc4d88 R15: 0000000000000001
> FS: 0000000000000000(0000) GS:ffff888119e80000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000555556a6cc88 CR3: 000000000bb73000 CR4: 0000000000350ee0
> Call Trace:
> <TASK>
> on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:996
> on_each_cpu include/linux/smp.h:71 [inline]
> text_poke_sync arch/x86/kernel/alternative.c:1770 [inline]
> text_poke_bp_batch+0x237/0x770 arch/x86/kernel/alternative.c:1970
> text_poke_flush arch/x86/kernel/alternative.c:2161 [inline]
> text_poke_flush arch/x86/kernel/alternative.c:2158 [inline]
> text_poke_finish+0x1a/0x30 arch/x86/kernel/alternative.c:2168
> arch_jump_label_transform_apply+0x17/0x30 arch/x86/kernel/jump_label.c:146
> jump_label_update+0x321/0x400 kernel/jump_label.c:829
> static_key_enable_cpuslocked+0x1b5/0x270 kernel/jump_label.c:205
> static_key_enable+0x1a/0x20 kernel/jump_label.c:218
> toggle_allocation_gate mm/kfence/core.c:831 [inline]
> toggle_allocation_gate+0xf4/0x220 mm/kfence/core.c:823
> process_one_work+0x993/0x15e0 kernel/workqueue.c:2405
> worker_thread+0x67d/0x10c0 kernel/workqueue.c:2552
> kthread+0x33e/0x440 kernel/kthread.c:379
> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
> </TASK>
Right, so this is waiting for an IPI to be processed.. while #1 has IRQs
disabled
> Sending NMI from CPU 5 to CPUs 0-4,6-7:
> NMI backtrace for cpu 1
> CPU: 1 PID: 20602 Comm: syz-executor.3 Not tainted 6.3.0-next-20230426 #1
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
> RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline]
> RIP: 0010:check_wait_context kernel/locking/lockdep.c:4747 [inline]
> RIP: 0010:__lock_acquire+0x489/0x5d00 kernel/locking/lockdep.c:5024
> Code: 41 81 e5 ff 1f 45 0f b7 ed be 08 00 00 00 4c 89 e8 48 c1 e8 06 48 8d 3c c5 00 6b 2c 90 e8 5f 90 6e 00 4c 0f a3 2d d7 35 c9 0e <0f> 83 5c 0c 00 00 4f 8d 6c 6d 00 49 c1 e5 06 49 81 c5 20 6f 2c 90
> RSP: 0018:ffffc90002aa7350 EFLAGS: 00000047
> RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff81633521
> RDX: fffffbfff2058d62 RSI: 0000000000000008 RDI: ffffffff902c6b08
> RBP: ffff888042995940 R08: 0000000000000000 R09: ffffffff902c6b0f
> R10: fffffbfff2058d61 R11: 0000000000000001 R12: ffff888119e2b818
> R13: 0000000000000063 R14: 0000000000000002 R15: ffff888042996598
> FS: 00007fdaad065700(0000) GS:ffff888119c80000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000001b30623000 CR3: 0000000101969000 CR4: 0000000000350ee0
> Call Trace:
> <TASK>
> lock_acquire kernel/locking/lockdep.c:5691 [inline]
> lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5656
> __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
> _raw_spin_lock_irqsave+0x3d/0x60 kernel/locking/spinlock.c:162
> lock_hrtimer_base kernel/time/hrtimer.c:173 [inline]
> hrtimer_try_to_cancel kernel/time/hrtimer.c:1331 [inline]
> hrtimer_try_to_cancel+0xa9/0x2e0 kernel/time/hrtimer.c:1316
> hrtimer_cancel+0x17/0x40 kernel/time/hrtimer.c:1443
And this is trying to cancel a hrtimer which is ran on CPU4 and won't be
making much progress.
> __disable_vblank drivers/gpu/drm/drm_vblank.c:434 [inline]
So we're here, holding vbl_lock, vblank_time_lock one of which is what
#4 is waiting on.
This also has IRQs disabled, which is what #1 is waiting on.
> drm_vblank_disable_and_save+0x282/0x3d0 drivers/gpu/drm/drm_vblank.c:478
> drm_crtc_vblank_off+0x312/0x970 drivers/gpu/drm/drm_vblank.c:1366
> disable_outputs+0x7c7/0xbb0 drivers/gpu/drm/drm_atomic_helper.c:1202
> drm_atomic_helper_commit_modeset_disables+0x1d/0x40 drivers/gpu/drm/drm_atomic_helper.c:1397
> vkms_atomic_commit_tail+0x51/0x240 drivers/gpu/drm/vkms/vkms_drv.c:71
> commit_tail+0x288/0x420 drivers/gpu/drm/drm_atomic_helper.c:1812
> drm_atomic_helper_commit drivers/gpu/drm/drm_atomic_helper.c:2052 [inline]
> drm_atomic_helper_commit+0x306/0x390 drivers/gpu/drm/drm_atomic_helper.c:1985
> drm_atomic_commit+0x20a/0x2d0 drivers/gpu/drm/drm_atomic.c:1503
> drm_client_modeset_commit_atomic+0x698/0x7e0 drivers/gpu/drm/drm_client_modeset.c:1045
> drm_client_modeset_dpms+0x174/0x200 drivers/gpu/drm/drm_client_modeset.c:1226
> drm_fb_helper_dpms drivers/gpu/drm/drm_fb_helper.c:323 [inline]
> drm_fb_helper_blank+0xd1/0x260 drivers/gpu/drm/drm_fb_helper.c:356
> fb_blank+0x105/0x190 drivers/video/fbdev/core/fbmem.c:1088
> do_fb_ioctl+0x390/0x760 drivers/video/fbdev/core/fbmem.c:1180
> fb_ioctl+0xeb/0x150 drivers/video/fbdev/core/fbmem.c:1204
> vfs_ioctl fs/ioctl.c:51 [inline]
> __do_sys_ioctl fs/ioctl.c:870 [inline]
> __se_sys_ioctl fs/ioctl.c:856 [inline]
> __x64_sys_ioctl+0x197/0x210 fs/ioctl.c:856
> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
> do_syscall_64+0x39/0x80 arch/x86/entry/common.c:80
> entry_SYSCALL_64_after_hwframe+0x63/0xcd
> RIP: 0033:0x7fdaabe8edcd
> Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007fdaad064bf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
> RAX: ffffffffffffffda RBX: 00007fdaabfbbf80 RCX: 00007fdaabe8edcd
> RDX: 0000000000000004 RSI: 0000000000004611 RDI: 0000000000000003
> RBP: 00007fdaabefc59c R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
> R13: 00007ffdadeffe9f R14: 00007ffdadf00040 R15: 00007fdaad064d80
> </TASK>
> CPU: 4 PID: 20623 Comm: syz-executor.6 Not tainted 6.3.0-next-20230426 #1
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
> RIP: 0010:kvm_wait+0xb7/0x110 arch/x86/kernel/kvm.c:1064
> Code: 40 38 c6 74 1b 48 83 c4 10 c3 c3 e8 93 d3 50 00 eb 07 0f 00 2d 4a 04 92 08 fb f4 48 83 c4 10 c3 eb 07 0f 00 2d 3a 04 92 08 f4 <48> 83 c4 10 c3 89 74 24 0c 48 89 3c 24 e8 d7 d4 50 00 8b 74 24 0c
> RSP: 0018:ffffc90000300b50 EFLAGS: 00000046
> RAX: 0000000000000003 RBX: 0000000000000000 RCX: dffffc0000000000
> RDX: 0000000000000000 RSI: 0000000000000003 RDI: ffff88810b0803d8
> RBP: ffff88810b0803d8 R08: 0000000000000001 R09: ffff88810b0803d8
> R10: ffffed102161007b R11: ffffc90000300ff8 R12: 0000000000000000
> R13: ffffed102161007b R14: 0000000000000001 R15: ffff888119e3d3c0
> FS: 0000000000000000(0000) GS:ffff888119e00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007f28183bd0b0 CR3: 000000000bb73000 CR4: 0000000000350ee0
> Call Trace:
> <IRQ>
> pv_wait arch/x86/include/asm/paravirt.h:598 [inline]
> pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline]
> __pv_queued_spin_lock_slowpath+0x8e4/0xb80 kernel/locking/qspinlock.c:511
> pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:586 [inline]
> queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
> queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
> do_raw_spin_lock+0x20d/0x2b0 kernel/locking/spinlock_debug.c:115
> __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
> _raw_spin_lock_irqsave+0x45/0x60 kernel/locking/spinlock.c:162
> drm_handle_vblank+0x11e/0xb80 drivers/gpu/drm/drm_vblank.c:1986
stuck on a spinlock held by #5
> vkms_vblank_simulate+0xe8/0x3e0 drivers/gpu/drm/vkms/vkms_crtc.c:29
> __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
> __hrtimer_run_queues+0x599/0xa30 kernel/time/hrtimer.c:1749
> hrtimer_interrupt+0x320/0x7b0 kernel/time/hrtimer.c:1811
> local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline]
> __sysvec_apic_timer_interrupt+0x14a/0x430 arch/x86/kernel/apic/apic.c:1112
> sysvec_apic_timer_interrupt+0x92/0xc0 arch/x86/kernel/apic/apic.c:1106
> </IRQ>
> <TASK>
> asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
> RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline]
> RIP: 0010:__sanitizer_cov_trace_pc+0x11/0x70 kernel/kcov.c:207
> Code: a8 01 00 00 e8 b0 ff ff ff 31 c0 c3 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 f3 0f 1e fa 65 8b 05 0d 33 82 7e 89 c1 48 8b 34 24 <81> e1 00 01 00 00 65 48 8b 14 25 40 bb 03 00 a9 00 01 ff 00 74 0e
> RSP: 0018:ffffc90002be76d8 EFLAGS: 00000286
> RAX: 0000000080000001 RBX: 0000000000000001 RCX: 0000000080000001
> RDX: 00007f2817c77000 RSI: ffffffff81bcd756 RDI: ffffc90002be7ad8
> RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
> R10: 0000000000000001 R11: 0000000000000001 R12: ffffea00014fc480
> R13: 0000000000000000 R14: dffffc0000000000 R15: 8000000053f12007
> zap_drop_file_uffd_wp mm/memory.c:1352 [inline]
> zap_install_uffd_wp_if_needed mm/memory.c:1371 [inline]
> zap_pte_range mm/memory.c:1417 [inline]
> zap_pmd_range mm/memory.c:1564 [inline]
> zap_pud_range mm/memory.c:1593 [inline]
> zap_p4d_range mm/memory.c:1614 [inline]
> unmap_page_range+0x1046/0x4470 mm/memory.c:1635
> unmap_single_vma+0x19a/0x2b0 mm/memory.c:1681
> unmap_vmas+0x234/0x380 mm/memory.c:1720
> exit_mmap+0x190/0x930 mm/mmap.c:3111
> __mmput+0x128/0x4c0 kernel/fork.c:1351
> mmput+0x60/0x70 kernel/fork.c:1373
> exit_mm kernel/exit.c:564 [inline]
> do_exit+0x9d1/0x29f0 kernel/exit.c:858
> do_group_exit+0xd4/0x2a0 kernel/exit.c:1021
> get_signal+0x2311/0x25c0 kernel/signal.c:2874
> arch_do_signal_or_restart+0x79/0x5a0 arch/x86/kernel/signal.c:307
> exit_to_user_mode_loop kernel/entry/common.c:168 [inline]
> exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204
> __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
> syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297
> do_syscall_64+0x46/0x80 arch/x86/entry/common.c:86
> entry_SYSCALL_64_after_hwframe+0x63/0xcd
> RIP: 0033:0x7f281828edcd
> Code: Unable to access opcode bytes at 0x7f281828eda3.
> RSP: 002b:00007f28194c0c98 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
> RAX: fffffffffffffe00 RBX: 00007f28183bbf80 RCX: 00007f281828edcd
> RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f28183bbf88
> RBP: 00007f28183bbf88 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 00007f28183bbf8c
> R13: 00007ffd5038e1ef R14: 00007ffd5038e390 R15: 00007f28194c0d80
> </TASK>
On 2023/09/14 21:21, Hillf Danton wrote:
> On Wed, 13 Sep 2023 23:30:23 +0900 Tetsuo Handa wrote:
>> On 2023/09/13 20:07, Hillf Danton wrote:
>>>
>>> cpu1 cpu4 (see below)
>>> ==== ====
>>> drm_crtc_vblank_off __run_hrtimer
>>> spin_lock_irq(&dev->event_lock);
>>> ...
>>> drm_handle_vblank
>>> hrtimer_cancel spin_lock_irqsave(&dev->event_lock, irqflags);
>>>
>>>
>>> Deadlock should have been reported instead provided the lockdep_map in
>>> struct timer_list were added also to hrtimer, so it is highly appreciated
>>> if Tetsuo or Thomas adds it before 6.8 or 6.10.
>>
>> Not me. ;-)
>>
>> Since hrtimer_cancel() retries forever until lock_hrtimer_base() succeeds,
>> we want to add a lockdep annotation into hrtimer_cancel() so that we can
>> detect this type of deadlock?
Here is a reproducer.
----------------------------------------
#include <linux/module.h>
#include <linux/delay.h>
static DEFINE_SPINLOCK(lock1);
static struct hrtimer timer1;
static enum hrtimer_restart timer_func(struct hrtimer *timer)
{
unsigned long flags;
mdelay(100); // Wait for test_init() to hold lock1.
spin_lock_irqsave(&lock1, flags);
spin_unlock_irqrestore(&lock1, flags);
return HRTIMER_RESTART;
}
static int __init test_init(void)
{
unsigned long flags;
hrtimer_init(&timer1, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
timer1.function = &timer_func;
hrtimer_start(&timer1, 1, HRTIMER_MODE_REL);
mdelay(10); // Wait for timer_func() to start.
spin_lock_irqsave(&lock1, flags);
hrtimer_cancel(&timer1); // Wait for timer_func() to finish.
spin_unlock_irqrestore(&lock1, flags);
return -EINVAL;
}
module_init(test_init);
MODULE_LICENSE("GPL");
----------------------------------------
----------------------------------------
[ 996.507681] test: loading out-of-tree module taints kernel.
[ 996.514019] test: module verification failed: signature and/or required key missing - tainting kernel
[ 1061.893054] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
[ 1061.900411] rcu: 4-...0: (1 GPs behind) idle=ed6c/1/0x4000000000000000 softirq=3304/3305 fqs=15784
[ 1061.909128] rcu: (detected by 0, t=65018 jiffies, g=12625, q=4422 ncpus=12)
[ 1061.915003] Sending NMI from CPU 0 to CPUs 4:
[ 1061.918972] NMI backtrace for cpu 4
[ 1061.919036] CPU: 4 PID: 3826 Comm: insmod Tainted: G OE 6.6.0-rc1+ #20
[ 1061.919093] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020
[ 1061.919095] RIP: 0010:delay_tsc+0x34/0xa0
[ 1061.919560] Code: ff 05 e8 b1 26 70 65 44 8b 0d e4 b1 26 70 0f 01 f9 66 90 48 c1 e2 20 48 09 c2 49 89 d0 eb 21 65 ff 0d c8 b1 26 70 74 54 f3 90 <65> ff 05 bd b1 26 70 65 8b 35 ba b1 26 70 41 39 f1 75 28 41 89 f1
[ 1061.919563] RSP: 0018:ffffb471c059cf00 EFLAGS: 00000083
[ 1061.919567] RAX: 0000028efe104ef6 RBX: 0000000000000041 RCX: 0000000000000004
[ 1061.919569] RDX: 00000000002192f8 RSI: 0000000000000004 RDI: 000000000027d81e
[ 1061.919571] RBP: ffff8970dafe5040 R08: 0000028efdeebbfe R09: 0000000000000004
[ 1061.919572] R10: 0000000000000001 R11: ffffffffc0a8d600 R12: ffffffff90e030e0
[ 1061.919574] R13: ffff8970dafe5040 R14: ffffffffc0a8b010 R15: ffff8970dafe5100
[ 1061.919630] FS: 00007fdd998eb740(0000) GS:ffff8970dae00000(0000) knlGS:0000000000000000
[ 1061.919633] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1061.919635] CR2: 0000000001edf678 CR3: 00000001a1060000 CR4: 0000000000350ee0
[ 1061.919639] Call Trace:
[ 1061.919641] <NMI>
[ 1061.919646] ? nmi_cpu_backtrace+0xb1/0x130
[ 1061.919711] ? nmi_cpu_backtrace_handler+0x11/0x20
[ 1061.922096] ? nmi_handle+0xe4/0x290
[ 1061.922163] ? default_do_nmi+0x49/0x100
[ 1061.922196] ? exc_nmi+0x152/0x1e0
[ 1061.922198] ? end_repeat_nmi+0x16/0x67
[ 1061.922340] ? __pfx_timer_func+0x10/0x10 [test]
[ 1061.922347] ? delay_tsc+0x34/0xa0
[ 1061.922349] ? delay_tsc+0x34/0xa0
[ 1061.922350] ? delay_tsc+0x34/0xa0
[ 1061.922352] </NMI>
[ 1061.922353] <IRQ>
[ 1061.922353] timer_func+0x19/0xff0 [test]
[ 1061.922358] __hrtimer_run_queues+0x177/0x3a0
[ 1061.922362] hrtimer_interrupt+0x104/0x240
[ 1061.922364] ? __do_softirq+0x2db/0x392
[ 1061.922827] __sysvec_apic_timer_interrupt+0x64/0x180
[ 1061.922833] sysvec_apic_timer_interrupt+0x65/0x80
[ 1061.922894] </IRQ>
[ 1061.922896] <TASK>
[ 1061.922898] asm_sysvec_apic_timer_interrupt+0x1a/0x20
[ 1061.922902] RIP: 0010:delay_tsc+0x4d/0xa0
[ 1061.922907] Code: c2 49 89 d0 eb 21 65 ff 0d c8 b1 26 70 74 54 f3 90 65 ff 05 bd b1 26 70 65 8b 35 ba b1 26 70 41 39 f1 75 28 41 89 f1 0f 01 f9 <66> 90 48 c1 e2 20 48 09 d0 48 89 c2 4c 29 c2 48 39 fa 72 c8 65 ff
[ 1061.922909] RSP: 0018:ffffb471c1e63bd0 EFLAGS: 00000246
[ 1061.922912] RAX: 00000000751ed8ab RBX: 000000000000000a RCX: 0000000000000004
[ 1061.922914] RDX: 0000000000000267 RSI: 0000000000000004 RDI: 000000000027d81e
[ 1061.922915] RBP: ffffffffc0a91010 R08: 00000267751adc59 R09: 0000000000000004
[ 1061.922917] R10: 0000000000000001 R11: ffffffff90cd85c8 R12: 0000000000000000
[ 1061.922918] R13: ffffb471c1e63d20 R14: 0000000000000000 R15: ffffffffc0a8d080
[ 1061.922923] ? __pfx_test_init+0x10/0x10 [test]
[ 1061.922934] test_init+0x52/0xff0 [test]
[ 1061.922941] do_one_initcall+0x5c/0x280
[ 1061.923004] ? kmalloc_trace+0xa9/0xc0
[ 1061.923105] do_init_module+0x60/0x240
[ 1061.923111] load_module+0x1f6e/0x20d0
[ 1061.923119] ? ima_post_read_file+0xe3/0xf0
[ 1061.923225] ? init_module_from_file+0x88/0xc0
[ 1061.923229] init_module_from_file+0x88/0xc0
[ 1061.923238] idempotent_init_module+0x19c/0x250
[ 1061.923244] ? security_capable+0x39/0x60
[ 1061.923304] __x64_sys_finit_module+0x5b/0xb0
[ 1061.923310] do_syscall_64+0x3b/0x90
[ 1061.923366] entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[ 1061.923421] RIP: 0033:0x7fdd986f8e29
[ 1061.923427] Code: 01 00 48 81 c4 80 00 00 00 e9 f1 fe ff ff 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 17 e0 2c 00 f7 d8 64 89 01 48
[ 1061.923429] RSP: 002b:00007ffe2f34dd18 EFLAGS: 00000206 ORIG_RAX: 0000000000000139
[ 1061.923432] RAX: ffffffffffffffda RBX: 0000000001ede240 RCX: 00007fdd986f8e29
[ 1061.923434] RDX: 0000000000000000 RSI: 000000000041a96e RDI: 0000000000000003
[ 1061.923435] RBP: 000000000041a96e R08: 0000000000000000 R09: 00007ffe2f34deb8
[ 1061.923436] R10: 0000000000000003 R11: 0000000000000206 R12: 0000000000000000
[ 1061.923437] R13: 0000000001ede210 R14: 0000000000000000 R15: 0000000000000000
[ 1061.923444] </TASK>
[ 1061.923446] INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 4.474 msecs
----------------------------------------
>
> Yes, you are right.
>
> The diff below is my two cents (only for thoughts).
>
I'm thinking something like below. (Completely untested.)
I haven't checked IRQ state handling. But in the last diff chunk, why raw_spin_unlock_irqrestore()
(which does not re-enable IRQs if the caller already disabled IRQs) is used before calling the callback
function and raw_spin_lock_irq() (which always disables IRQs) is used after calling the callback
function? Is it legal to disable IRQs again when the caller already disabled IRQs?
----------------------------------------
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index 0ee140176f10..5640730ec31c 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -123,8 +123,11 @@ struct hrtimer {
u8 state;
u8 is_rel;
u8 is_soft;
u8 is_hard;
+#ifdef CONFIG_LOCKDEP
+ struct lockdep_map lockdep_map;
+#endif
};
/**
* struct hrtimer_sleeper - simple sleeper structure
@@ -440,15 +443,15 @@ static inline void hrtimer_restart(struct hrtimer *timer)
hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
}
/* Query timers: */
-extern ktime_t __hrtimer_get_remaining(const struct hrtimer *timer, bool adjust);
+extern ktime_t __hrtimer_get_remaining(struct hrtimer *timer, bool adjust);
/**
* hrtimer_get_remaining - get remaining time for the timer
* @timer: the timer to read
*/
-static inline ktime_t hrtimer_get_remaining(const struct hrtimer *timer)
+static inline ktime_t hrtimer_get_remaining(struct hrtimer *timer)
{
return __hrtimer_get_remaining(timer, false);
}
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index 238262e4aba7..fe0681d34b56 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -161,14 +161,23 @@ static inline bool is_migration_base(struct hrtimer_clock_base *base)
* possible to set timer->base = &migration_base and drop the lock: the timer
* remains locked.
*/
static
-struct hrtimer_clock_base *lock_hrtimer_base(const struct hrtimer *timer,
+struct hrtimer_clock_base *lock_hrtimer_base(struct hrtimer *timer,
unsigned long *flags)
__acquires(&timer->base->lock)
{
struct hrtimer_clock_base *base;
+#ifdef CONFIG_LOCKDEP
+ unsigned long flags2;
+
+ local_irq_save(flags2);
+ lock_map_acquire(&timer->lockdep_map);
+ lock_map_release(&timer->lockdep_map);
+ local_irq_restore(flags2);
+#endif
+
for (;;) {
base = READ_ONCE(timer->base);
if (likely(base != &migration_base)) {
raw_spin_lock_irqsave(&base->cpu_base->lock, *flags);
@@ -1456,9 +1465,9 @@ EXPORT_SYMBOL_GPL(hrtimer_cancel);
* __hrtimer_get_remaining - get remaining time for the timer
* @timer: the timer to read
* @adjust: adjust relative timers when CONFIG_TIME_LOW_RES=y
*/
-ktime_t __hrtimer_get_remaining(const struct hrtimer *timer, bool adjust)
+ktime_t __hrtimer_get_remaining(struct hrtimer *timer, bool adjust)
{
unsigned long flags;
ktime_t rem;
@@ -1574,8 +1583,14 @@ static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
timer->is_soft = softtimer;
timer->is_hard = !!(mode & HRTIMER_MODE_HARD);
timer->base = &cpu_base->clock_base[base];
timerqueue_init(&timer->node);
+#ifdef CONFIG_LOCKDEP
+ {
+ static struct lock_class_key __key;
+ lockdep_init_map(&timer->lockdep_map, "hrtimer", &__key, 0);
+ }
+#endif
}
/**
* hrtimer_init - initialize a timer to the given clock
@@ -1684,9 +1699,19 @@ static void __run_hrtimer(struct hrtimer_cpu_base *cpu_base,
raw_spin_unlock_irqrestore(&cpu_base->lock, flags);
trace_hrtimer_expire_entry(timer, now);
expires_in_hardirq = lockdep_hrtimer_enter(timer);
+#ifdef CONFIG_LOCKDEP
+ local_irq_save(flags);
+ lock_map_acquire(&timer->lockdep_map);
+ local_irq_restore(flags);
+#endif
restart = fn(timer);
+#ifdef CONFIG_LOCKDEP
+ local_irq_save(flags);
+ lock_map_release(&timer->lockdep_map);
+ local_irq_restore(flags);
+#endif
lockdep_hrtimer_exit(expires_in_hardirq);
trace_hrtimer_expire_exit(timer);
raw_spin_lock_irq(&cpu_base->lock);
----------------------------------------