* Re: BUG: soft lockup in smp_call_function [not found] <BL0PR11MB310606A8674B391DEA659089E1EEA@BL0PR11MB3106.namprd11.prod.outlook.com> @ 2023-09-13 11:07 ` Hillf Danton 2023-09-13 14:21 ` drm/vkms: deadlock between dev->event_lock and timer Tetsuo Handa [not found] ` <15f8fbd8-2dbc-3df7-c748-c76e3479e227@I-love.SAKURA.ne.jp> 0 siblings, 2 replies; 4+ messages in thread From: Hillf Danton @ 2023-09-13 11:07 UTC (permalink / raw) To: Sanan Hasanov Cc: peterz, Linus Torvalds, Tetsuo Handa, Thomas Gleixner, syzkaller, linux-mm, LKML On Tue, 12 Sep 2023 23:02:56 +0000 Sanan Hasanov <Sanan.Hasanov@ucf.edu> > Good day, dear maintainers, > > We found a bug using a modified kernel configuration file used by syzbot. > Thanks for your report. > 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 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. Hillf > 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 ^ permalink raw reply [flat|nested] 4+ messages in thread
* drm/vkms: deadlock between dev->event_lock and timer 2023-09-13 11:07 ` BUG: soft lockup in smp_call_function Hillf Danton @ 2023-09-13 14:21 ` Tetsuo Handa [not found] ` <15f8fbd8-2dbc-3df7-c748-c76e3479e227@I-love.SAKURA.ne.jp> 1 sibling, 0 replies; 4+ messages in thread From: Tetsuo Handa @ 2023-09-13 14:21 UTC (permalink / raw) To: Rodrigo Siqueira, Melissa Wen, Maira Canal, Haneen Mohammed, Daniel Vetter, David Airlie, DRI Cc: syzkaller, LKML, Hillf Danton, Sanan Hasanov Hello. A deadlock was reported in drivers/gpu/drm/vkms/ . It looks like this locking pattern remains as of 6.6-rc1. Please fix. void drm_crtc_vblank_off(struct drm_crtc *crtc) { spin_lock_irq(&dev->event_lock); drm_vblank_disable_and_save(dev, pipe) { __disable_vblank(dev, pipe) { crtc->funcs->disable_vblank(crtc) == vkms_disable_vblank { hrtimer_cancel(&out->vblank_hrtimer) { // Retries with dev->event_lock held until lock_hrtimer_base() succeeds. ret = hrtimer_try_to_cancel(timer) { base = lock_hrtimer_base(timer, &flags); // Fails forever because vkms_vblank_simulate() is in progress. } } } } } spin_unlock_irq(&dev->event_lock); } static void __run_hrtimer(...) { restart = fn(timer) == vkms_vblank_simulate { drm_crtc_handle_vblank(crtc) { drm_handle_vblank(struct drm_device *dev, unsigned int pipe) { spin_lock_irqsave(&dev->event_lock, irqflags); // Trying to hold dev->event_lock inside timer interrupt handler. => Deadlock was reported as a soft lockup. spin_unlock_irqrestore(&dev->event_lock, irqflags); } } } } On 2023/09/13 20:07, Hillf Danton wrote: > On Tue, 12 Sep 2023 23:02:56 +0000 Sanan Hasanov <Sanan.Hasanov@ucf.edu> >> Good day, dear maintainers, >> >> We found a bug using a modified kernel configuration file used by syzbot. >> > Thanks for your report. > >> 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 > > 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. > > Hillf > >> 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 ^ permalink raw reply [flat|nested] 4+ messages in thread
[parent not found: <15f8fbd8-2dbc-3df7-c748-c76e3479e227@I-love.SAKURA.ne.jp>]
* Re: BUG: soft lockup in smp_call_function [not found] ` <15f8fbd8-2dbc-3df7-c748-c76e3479e227@I-love.SAKURA.ne.jp> @ 2023-09-14 12:21 ` Hillf Danton 2023-09-14 13:13 ` Tetsuo Handa 0 siblings, 1 reply; 4+ messages in thread From: Hillf Danton @ 2023-09-14 12:21 UTC (permalink / raw) To: Tetsuo Handa Cc: Sanan Hasanov, Thomas Gleixner, Linus Torvalds, syzkaller, linux-mm, LKML 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? Yes, you are right. The diff below is my two cents (only for thoughts). --- x/include/linux/timer.h +++ y/include/linux/timer.h @@ -124,6 +124,9 @@ struct hrtimer { u8 is_rel; u8 is_soft; u8 is_hard; +#ifdef CONFIG_LOCKDEP + struct lockdep_map lockdep_map; +#endif }; /** @@ -369,33 +372,65 @@ static inline void hrtimer_cancel_wait_r /* Exported timer functions: */ /* Initialize timers: */ -extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock, - enum hrtimer_mode mode); -extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, clockid_t clock_id, - enum hrtimer_mode mode); +extern void hrtimer_init_key(struct hrtimer *timer, clockid_t which_clock, + enum hrtimer_mode mode, + const char *name, struct lock_class_key *key); +extern void hrtimer_init_sleeper_key(struct hrtimer_sleeper *sl, clockid_t clock_id, + enum hrtimer_mode mode, + const char *name, struct lock_class_key *key); +#ifdef CONFIG_LOCKDEP +#define hrtimer_init(t, c, m) \ + do { \ + static struct lock_class_key __key; \ + hrtimer_init_key(t, c, m, #t, &__key); \ + } while (0) + +#define hrtimer_init_sleeper(s, c, m) \ + do { \ + static struct lock_class_key __key; \ + hrtimer_init_sleeper_key(s, c, m, #s, &__key); \ + } while (0) +#else +#define hrtimer_init(t, c, m) \ + hrtimer_init_key(t, c, m, NULL, NULL) + +#define hrtimer_init_sleeper(s, c, m) \ + hrtimer_init_sleeper_key(s, c, m, NULL, NULL) +#endif #ifdef CONFIG_DEBUG_OBJECTS_TIMERS -extern void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t which_clock, - enum hrtimer_mode mode); -extern void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl, +extern void hrtimer_init_on_stack_key(struct hrtimer *timer, clockid_t which_clock, + enum hrtimer_mode mode, + const char *name, struct lock_class_key *key); +extern void hrtimer_init_sleeper_on_stack_key(struct hrtimer_sleeper *sl, clockid_t clock_id, - enum hrtimer_mode mode); + enum hrtimer_mode mode, + const char *name, struct lock_class_key *key); +#ifdef CONFIG_LOCKDEP + #define hrtimer_init_on_stack(t, c, m) \ + do { \ + static struct lock_class_key __key; \ + hrtimer_init_on_stack_key(t, c, m, #t, &__key); \ + } while (0) + #define hrtimer_init_sleeper_on_stack(s, c, m) \ + do { \ + static struct lock_class_key __key; \ + hrtimer_init_sleeper_on_stack_key(s, c, m, #s, &__key); \ + } while (0) +#else + #define hrtimer_init_on_stack(t, c, m) \ + hrtimer_init_on_stack_key(t, c, m, NULL, NULL) + #define hrtimer_init_sleeper_on_stack(s, c, m) \ + hrtimer_init_sleeper_on_stack_key(s, c, m, NULL, NULL) +#endif extern void destroy_hrtimer_on_stack(struct hrtimer *timer); #else -static inline void hrtimer_init_on_stack(struct hrtimer *timer, - clockid_t which_clock, - enum hrtimer_mode mode) -{ - hrtimer_init(timer, which_clock, mode); -} +#define hrtimer_init_on_stack(t, c, m) \ + hrtimer_init(t, c, m) -static inline void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl, - clockid_t clock_id, - enum hrtimer_mode mode) -{ - hrtimer_init_sleeper(sl, clock_id, mode); -} +#define hrtimer_init_sleeper_on_stack(s, c, m) \ + hrtimer_init_sleeper(s, c, m) static inline void destroy_hrtimer_on_stack(struct hrtimer *timer) { } #endif --- x/kernel/time/hrtimer.c +++ y/kernel/time/hrtimer.c @@ -428,22 +428,26 @@ static inline void debug_hrtimer_deactiv static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id, enum hrtimer_mode mode); -void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t clock_id, - enum hrtimer_mode mode) +void hrtimer_init_on_stack_key(struct hrtimer *timer, clockid_t clock_id, + enum hrtimer_mode mode, + const char *name, struct lock_class_key *key) { debug_object_init_on_stack(timer, &hrtimer_debug_descr); __hrtimer_init(timer, clock_id, mode); + lockdep_init_map(&timer->lockdep_map, name, key, 0); } EXPORT_SYMBOL_GPL(hrtimer_init_on_stack); static void __hrtimer_init_sleeper(struct hrtimer_sleeper *sl, clockid_t clock_id, enum hrtimer_mode mode); -void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl, - clockid_t clock_id, enum hrtimer_mode mode) +void hrtimer_init_sleeper_on_stack_key(struct hrtimer_sleeper *sl, + clockid_t clock_id, enum hrtimer_mode mode, + const char *name, struct lock_class_key *key) { debug_object_init_on_stack(&sl->timer, &hrtimer_debug_descr); __hrtimer_init_sleeper(sl, clock_id, mode); + lockdep_init_map(&sl->timer.lockdep_map, name, key, 0); } EXPORT_SYMBOL_GPL(hrtimer_init_sleeper_on_stack); @@ -1439,6 +1443,8 @@ int hrtimer_cancel(struct hrtimer *timer { int ret; + lock_map_acquire(&timer->lockdep_map); + lock_map_release(&timer->lockdep_map); do { ret = hrtimer_try_to_cancel(timer); @@ -1586,11 +1592,12 @@ static void __hrtimer_init(struct hrtime * but the PINNED bit is ignored as pinning happens * when the hrtimer is started */ -void hrtimer_init(struct hrtimer *timer, clockid_t clock_id, - enum hrtimer_mode mode) +void hrtimer_init_key(struct hrtimer *timer, clockid_t clock_id, enum hrtimer_mode mode, + const char *name, struct lock_class_key *key) { debug_init(timer, clock_id, mode); __hrtimer_init(timer, clock_id, mode); + lockdep_init_map(&timer->lockdep_map, name, key, 0); } EXPORT_SYMBOL_GPL(hrtimer_init); @@ -1647,6 +1654,11 @@ static void __run_hrtimer(struct hrtimer enum hrtimer_restart (*fn)(struct hrtimer *); bool expires_in_hardirq; int restart; +#ifdef CONFIG_LOCKDEP + struct lockdep_map lockdep_map; + + lockdep_copy_map(&lockdep_map, &timer->lockdep_map); +#endif lockdep_assert_held(&cpu_base->lock); @@ -1682,7 +1694,9 @@ static void __run_hrtimer(struct hrtimer trace_hrtimer_expire_entry(timer, now); expires_in_hardirq = lockdep_hrtimer_enter(timer); + lock_map_acquire(&lockdep_map); restart = fn(timer); + lock_map_release(&lockdep_map); lockdep_hrtimer_exit(expires_in_hardirq); trace_hrtimer_expire_exit(timer); @@ -2004,12 +2018,13 @@ static void __hrtimer_init_sleeper(struc * @clock_id: the clock to be used * @mode: timer mode abs/rel */ -void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, clockid_t clock_id, - enum hrtimer_mode mode) +void hrtimer_init_sleeper_key(struct hrtimer_sleeper *sl, clockid_t clock_id, + enum hrtimer_mode mode, + const char *name, struct lock_class_key *key) { debug_init(&sl->timer, clock_id, mode); __hrtimer_init_sleeper(sl, clock_id, mode); - + lockdep_init_map(&sl->timer.lockdep_map, name, key, 0); } EXPORT_SYMBOL_GPL(hrtimer_init_sleeper); -- ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: BUG: soft lockup in smp_call_function 2023-09-14 12:21 ` BUG: soft lockup in smp_call_function Hillf Danton @ 2023-09-14 13:13 ` Tetsuo Handa 0 siblings, 0 replies; 4+ messages in thread From: Tetsuo Handa @ 2023-09-14 13:13 UTC (permalink / raw) To: Thomas Gleixner Cc: Sanan Hasanov, Linus Torvalds, syzkaller, LKML, Hillf Danton 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); ---------------------------------------- ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2023-09-14 13:14 UTC | newest]
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[not found] <BL0PR11MB310606A8674B391DEA659089E1EEA@BL0PR11MB3106.namprd11.prod.outlook.com>
2023-09-13 11:07 ` BUG: soft lockup in smp_call_function Hillf Danton
2023-09-13 14:21 ` drm/vkms: deadlock between dev->event_lock and timer Tetsuo Handa
[not found] ` <15f8fbd8-2dbc-3df7-c748-c76e3479e227@I-love.SAKURA.ne.jp>
2023-09-14 12:21 ` BUG: soft lockup in smp_call_function Hillf Danton
2023-09-14 13:13 ` Tetsuo Handa
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