From: Sebastian Andrzej Siewior Date: Thu, 4 Jul 2024 19:03:35 +0200 Subject: [PATCH 1/7] perf: Move irq_work_queue() where the event is prepared. Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.10/older/patches-6.10.2-rt14.tar.xz 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. Tested-by: Marco Elver Tested-by: Arnaldo Carvalho de Melo Link: https://lore.kernel.org/r/20240704170424.1466941-2-bigeasy@linutronix.de Signed-off-by: Sebastian Andrzej Siewior --- kernel/events/core.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -9738,6 +9738,11 @@ static int __perf_event_overflow(struct 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 @@ -9753,11 +9758,6 @@ static int __perf_event_overflow(struct */ 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);