diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/irq-entry-common.h | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/include/linux/irq-entry-common.h b/include/linux/irq-entry-common.h index 0bb6c03481fa..c74b5c87e10f 100644 --- a/include/linux/irq-entry-common.h +++ b/include/linux/irq-entry-common.h @@ -468,6 +468,25 @@ static inline void irqentry_exit_to_kernel_mode_preempt(struct pt_regs *regs, irqentry_exit_cond_resched(); } +/* + * The deferred hrtimer rearm is the tail of the timer interrupt, moved to the + * interrupt return path so that it runs after a possible reschedule. By now + * irq_exit_rcu() has left lockdep's hardirq context. Re-enter it for the + * rearm, so that the hrtimer base lock and the timekeeping sequence count are + * not chained onto the locks held by the interrupted context, which would add + * new lock chains for every lock stack an interrupt hits. + * + * The rearm on return to user mode needs no such annotation: no locks are + * held there, so it uses the same lock chains as the rearm in hardirq + * context. + */ +static __always_inline void irqentry_hrtimer_rearm_deferred(void) +{ + lockdep_hardirq_enter(); + hrtimer_rearm_deferred(); + lockdep_hardirq_exit(); +} + /** * irqentry_exit_to_kernel_mode_after_preempt - Establish trace, lockdep and RCU state * @regs: Pointer to current's pt_regs @@ -491,7 +510,7 @@ irqentry_exit_to_kernel_mode_after_preempt(struct pt_regs *regs, irqentry_state_ */ if (state.exit_rcu) { instrumentation_begin(); - hrtimer_rearm_deferred(); + irqentry_hrtimer_rearm_deferred(); /* Tell the tracer that IRET will enable interrupts */ trace_hardirqs_on_prepare(); lockdep_hardirqs_on_prepare(); @@ -502,7 +521,7 @@ irqentry_exit_to_kernel_mode_after_preempt(struct pt_regs *regs, irqentry_state_ } instrumentation_begin(); - hrtimer_rearm_deferred(); + irqentry_hrtimer_rearm_deferred(); /* Covers both tracing and lockdep */ trace_hardirqs_on(); instrumentation_end(); |