diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c index 7ef0e98d31e28e3f451744d503fec9ca5f5a5a5b..c3797701339cbd575ca3c58ed9f0313e16e74cc8 100644 --- a/kernel/events/hw_breakpoint.c +++ b/kernel/events/hw_breakpoint.c @@ -117,7 +117,17 @@ static struct mutex *bp_constraints_lock(struct perf_event *bp) struct mutex *tsk_mtx = get_task_bps_mutex(bp); if (tsk_mtx) { - mutex_lock(tsk_mtx); + /* + * Fully analogous to the perf_try_init_event() nesting + * argument in the comment near perf_event_ctx_lock_nested(); + * this child->perf_event_mutex cannot ever deadlock against + * the parent->perf_event_mutex usage from + * perf_event_task_{en,dis}able(). + * + * Specifically, inherited events will never occur on + * ->perf_event_list. + */ + mutex_lock_nested(tsk_mtx, SINGLE_DEPTH_NESTING); percpu_down_read(&bp_cpuinfo_sem); } else { percpu_down_write(&bp_cpuinfo_sem);