diff options
Diffstat (limited to 'debian/patches-rt/0001-perf-Move-irq_work_queue-where-the-event-is-prepared.patch')
| -rw-r--r-- | debian/patches-rt/0001-perf-Move-irq_work_queue-where-the-event-is-prepared.patch | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/debian/patches-rt/0001-perf-Move-irq_work_queue-where-the-event-is-prepared.patch b/debian/patches-rt/0001-perf-Move-irq_work_queue-where-the-event-is-prepared.patch new file mode 100644 index 000000000..08a2950a4 --- /dev/null +++ b/debian/patches-rt/0001-perf-Move-irq_work_queue-where-the-event-is-prepared.patch @@ -0,0 +1,42 @@ +From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +Date: Tue, 12 Mar 2024 19:01:49 +0100 +Subject: [PATCH 1/4] perf: Move irq_work_queue() where the event is prepared. +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.8/older/patches-6.8.2-rt11.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 <elver@google.com> +Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> +Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com> +Link: https://lore.kernel.org/r/20240312180814.3373778-2-bigeasy@linutronix.de +Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +--- + kernel/events/core.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +--- a/kernel/events/core.c ++++ b/kernel/events/core.c +@@ -9595,6 +9595,7 @@ static int __perf_event_overflow(struct + if (!event->pending_sigtrap) { + event->pending_sigtrap = pending_id; + local_inc(&event->ctx->nr_pending); ++ irq_work_queue(&event->pending_irq); + } else if (event->attr.exclude_kernel && valid_sample) { + /* + * Should not be able to return to user space without +@@ -9614,7 +9615,6 @@ static int __perf_event_overflow(struct + 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); |