6.1-stable review patch. If anyone has any objections, please let me know.
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From: Thomas Gleixner tglx@linutronix.de
[ Upstream commit 82ed6f7ef58f9634fe4462dd721902c580f01569 ]
The timer code still has a few BUG_ON()s left which are crashing the kernel in situations where it still can recover or simply refuse to take an action.
Remove the one in the hotplug callback which checks for the CPU being offline. If that happens then the whole hotplug machinery will explode in colourful ways.
Replace the rest with WARN_ON_ONCE() and conditional returns where appropriate.
Signed-off-by: Thomas Gleixner tglx@linutronix.de Tested-by: Guenter Roeck linux@roeck-us.net Reviewed-by: Jacob Keller jacob.e.keller@intel.com Reviewed-by: Anna-Maria Behnsen anna-maria@linutronix.de Link: https://lore.kernel.org/r/20221123201624.769128888@linutronix.de Signed-off-by: Jeongjun Park aha310510@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- kernel/time/timer.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)
--- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -1208,7 +1208,8 @@ EXPORT_SYMBOL(timer_reduce); */ void add_timer(struct timer_list *timer) { - BUG_ON(timer_pending(timer)); + if (WARN_ON_ONCE(timer_pending(timer))) + return; __mod_timer(timer, timer->expires, MOD_TIMER_NOTPENDING); } EXPORT_SYMBOL(add_timer); @@ -1227,7 +1228,8 @@ void add_timer_on(struct timer_list *tim struct timer_base *new_base, *base; unsigned long flags;
- BUG_ON(timer_pending(timer) || !timer->function); + if (WARN_ON_ONCE(timer_pending(timer) || !timer->function)) + return;
new_base = get_timer_cpu_base(timer->flags, cpu);
@@ -2047,8 +2049,6 @@ int timers_dead_cpu(unsigned int cpu) struct timer_base *new_base; int b, i;
- BUG_ON(cpu_online(cpu)); - for (b = 0; b < NR_BASES; b++) { old_base = per_cpu_ptr(&timer_bases[b], cpu); new_base = get_cpu_ptr(&timer_bases[b]); @@ -2065,7 +2065,8 @@ int timers_dead_cpu(unsigned int cpu) */ forward_timer_base(new_base);
- BUG_ON(old_base->running_timer); + WARN_ON_ONCE(old_base->running_timer); + old_base->running_timer = NULL;
for (i = 0; i < WHEEL_SIZE; i++) migrate_timer_list(new_base, old_base->vectors + i);