Commit 058244c6 authored by Sebastian Andrzej Siewior's avatar Sebastian Andrzej Siewior Committed by Peter Zijlstra
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perf: Move irq_work_queue() where the event is prepared. 



Only if perf_event::pending_sigtrap is zero, the irq_work accounted by
increminging perf_event::nr_pending. The member perf_event::pending_addr
might be overwritten by a subsequent event if the signal was not yet
delivered and is expected. The irq_work will not be enqeueued again
because it has a check to be only enqueued once.

Move irq_work_queue() to where the counter is incremented and
perf_event::pending_sigtrap is set to make it more obvious that the
irq_work is scheduled once.

Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: default avatarMarco Elver <elver@google.com>
Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Link: https://lore.kernel.org/r/20240704170424.1466941-2-bigeasy@linutronix.de
parent 3a546541

kernel/events/core.c

+5 −5
Original line number Diff line number Diff line
@@ -9727,6 +9727,11 @@ static int __perf_event_overflow(struct perf_event *event, 
		if (!event->pending_sigtrap) {

			event->pending_sigtrap = pending_id;

			local_inc(&event->ctx->nr_pending);



			event->pending_addr = 0;

			if (valid_sample && (data->sample_flags & PERF_SAMPLE_ADDR))

				event->pending_addr = data->addr;

			irq_work_queue(&event->pending_irq);

		} else if (event->attr.exclude_kernel && valid_sample) {

			/*

			 * Should not be able to return to user space without
@@ -9742,11 +9747,6 @@ static int __perf_event_overflow(struct perf_event *event, 
			 */

			WARN_ON_ONCE(event->pending_sigtrap != pending_id);

		}



		event->pending_addr = 0;

		if (valid_sample && (data->sample_flags & PERF_SAMPLE_ADDR))

			event->pending_addr = data->addr;

		irq_work_queue(&event->pending_irq);

	}



	READ_ONCE(event->overflow_handler)(event, data, regs);