Messages in this thread Patch in this message | | | Date | Fri, 13 Oct 2023 23:51:29 +0900 | From | Tetsuo Handa <> | Subject | [PATCH] clocksource: disable irq when holding watchdog_lock. |
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Lockdep found that spin_lock(&watchdog_lock) from call_timer_fn() is not safe. Use spin_lock_irqsave(&watchdog_lock, flags) instead.
[ 0.378387] TSC synchronization [CPU#0 -> CPU#1]: [ 0.378387] Measured 55060 cycles TSC warp between CPUs, turning off TSC clock. [ 0.378387] tsc: Marking TSC unstable due to check_tsc_sync_source failed [ 0.926101] [ 0.926387] ================================ [ 0.926387] WARNING: inconsistent lock state [ 0.926387] 6.6.0-rc5-00192-g10a6e5feccb8 #2 Not tainted [ 0.926387] -------------------------------- [ 0.926387] inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. [ 0.926387] swapper/0/0 [HC0[0]:SC1[1]:HE1:SE0] takes: [ 0.926387] ffffffff8cfa1c78 (watchdog_lock){?.-.}-{2:2}, at: clocksource_watchdog+0x23/0x5a0 [ 0.926387] {IN-HARDIRQ-W} state was registered at: [ 0.926387] lock_acquire+0xc1/0x2c0 [ 0.926387] _raw_spin_lock_irqsave+0x3f/0x60 [ 0.926387] clocksource_mark_unstable+0x1b/0x90 [ 0.926387] mark_tsc_unstable+0x41/0x50 [ 0.926387] check_tsc_sync_source+0x14f/0x180 [ 0.926387] __flush_smp_call_function_queue+0x16f/0x560 [ 0.926387] __sysvec_call_function_single+0x36/0x110 [ 0.926387] sysvec_call_function_single+0x69/0x90 [ 0.926387] asm_sysvec_call_function_single+0x1a/0x20 [ 0.926387] default_idle+0xf/0x20 [ 0.926387] default_idle_call+0x7f/0x180 [ 0.926387] do_idle+0x1e1/0x220 [ 0.926387] cpu_startup_entry+0x2a/0x30 [ 0.926387] rest_init+0xf4/0x190 [ 0.926387] arch_call_rest_init+0xe/0x30 [ 0.926387] start_kernel+0x763/0x910 [ 0.926387] x86_64_start_reservations+0x18/0x30 [ 0.926387] x86_64_start_kernel+0xca/0xe0 [ 0.926387] secondary_startup_64_no_verify+0x178/0x17b [ 0.926387] irq event stamp: 138774 [ 0.926387] hardirqs last enabled at (138774): [<ffffffff8bb99968>] _raw_spin_unlock_irq+0x28/0x50 [ 0.926387] hardirqs last disabled at (138773): [<ffffffff8bb99687>] _raw_spin_lock_irq+0x47/0x50 [ 0.926387] softirqs last enabled at (138216): [<ffffffff8b0904ff>] irq_exit_rcu+0x7f/0xa0 [ 0.926387] softirqs last disabled at (138267): [<ffffffff8b0904ff>] irq_exit_rcu+0x7f/0xa0 [ 0.926387] [ 0.926387] other info that might help us debug this: [ 0.926387] Possible unsafe locking scenario: [ 0.926387] [ 0.926387] CPU0 [ 0.926387] ---- [ 0.926387] lock(watchdog_lock); [ 0.926387] <Interrupt> [ 0.926387] lock(watchdog_lock); [ 0.926387] [ 0.926387] *** DEADLOCK *** [ 0.926387] [ 0.926387] 1 lock held by swapper/0/0: [ 0.926387] #0: ffffa2d680003ea0 ((&watchdog_timer)){+.-.}-{0:0}, at: call_timer_fn+0x77/0x220 [ 0.926387] [ 0.926387] stack backtrace: [ 0.926387] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.6.0-rc5-00192-g10a6e5feccb8 #2 [ 0.926387] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 0.926387] Call Trace: [ 0.926387] <IRQ> [ 0.926387] dump_stack_lvl+0x4b/0x80 [ 0.926387] mark_lock.part.0+0xa1c/0xf30 [ 0.926387] __lock_acquire+0x3a9/0x2550 [ 0.926387] lock_acquire+0xc1/0x2c0 [ 0.926387] ? clocksource_watchdog+0x23/0x5a0 [ 0.926387] ? __pfx_clocksource_watchdog+0x10/0x10 [ 0.926387] ? __pfx_clocksource_watchdog+0x10/0x10 [ 0.926387] _raw_spin_lock+0x30/0x40 [ 0.926387] ? clocksource_watchdog+0x23/0x5a0 [ 0.926387] clocksource_watchdog+0x23/0x5a0 [ 0.926387] ? __run_timers.part.0+0x30/0x2c0 [ 0.926387] ? __pfx_clocksource_watchdog+0x10/0x10 [ 0.926387] ? __pfx_clocksource_watchdog+0x10/0x10 [ 0.926387] call_timer_fn+0xa5/0x220 [ 0.926387] __run_timers.part.0+0x200/0x2c0 [ 0.926387] run_timer_softirq+0x2a/0x50 [ 0.926387] __do_softirq+0xc4/0x3c8 [ 0.926387] irq_exit_rcu+0x7f/0xa0 [ 0.926387] sysvec_apic_timer_interrupt+0x6e/0x90 [ 0.926387] </IRQ> [ 0.926387] <TASK> [ 0.926387] asm_sysvec_apic_timer_interrupt+0x1a/0x20 [ 0.926387] RIP: 0010:default_idle+0xf/0x20 [ 0.926387] Code: 4c 01 c7 4c 29 c2 e9 72 ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 03 a9 27 00 fb f4 <fa> c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 [ 0.926387] RSP: 0000:ffffffff8c803e70 EFLAGS: 00010206 [ 0.926387] RAX: 0000000000021bed RBX: ffffffff8c8369c0 RCX: 4000000000000000 [ 0.926387] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8b0f0091 [ 0.926387] RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001 [ 0.926387] R10: 0000000000000028 R11: 0000000000000000 R12: 0000000000000000 [ 0.926387] R13: 0000000000000000 R14: ffffffff8c836038 R15: 0000000000000095 [ 0.926387] ? do_idle+0x1e1/0x220 [ 0.926387] default_idle_call+0x7f/0x180 [ 0.926387] do_idle+0x1e1/0x220 [ 0.926387] cpu_startup_entry+0x2a/0x30 [ 0.926387] rest_init+0xf4/0x190 [ 0.926387] arch_call_rest_init+0xe/0x30 [ 0.926387] start_kernel+0x763/0x910 [ 0.926387] x86_64_start_reservations+0x18/0x30 [ 0.926387] x86_64_start_kernel+0xca/0xe0 [ 0.926387] secondary_startup_64_no_verify+0x178/0x17b [ 0.926387] </TASK>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> --- kernel/time/clocksource.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index c108ed8a9804..4e8fc0a5ca9d 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -405,8 +405,9 @@ static void clocksource_watchdog(struct timer_list *unused) enum wd_read_status read_ret; unsigned long extra_wait = 0; u32 md; + unsigned long flags; - spin_lock(&watchdog_lock); + spin_lock_irqsave(&watchdog_lock, flags); if (!watchdog_running) goto out; @@ -554,7 +555,7 @@ static void clocksource_watchdog(struct timer_list *unused) add_timer_on(&watchdog_timer, next_cpu); } out: - spin_unlock(&watchdog_lock); + spin_unlock_irqrestore(&watchdog_lock, flags); } static inline void clocksource_start_watchdog(void) -- 2.34.1
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