perf: Fixup SIGTRAP and sample_flags interaction

Peter Zijlstra · Peter Zijlstra · commit af169b7759a9 · 2022-11-24T10:12:23.000+01:00
The perf_event_attr::sigtrap functionality relies on data->addr being set. However commit 7b08463 ("perf: Use sample_flags for addr") changed this to only initialize data->addr when not 0. Fixes: 7b08463 ("perf: Use sample_flags for addr") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/Y3426b4OimE%2FI5po%40hirez.programming.kicks-ass.net
diff --git a/kernel/events/core.c b/kernel/events/core.c
@@ -9328,7 +9328,10 @@ static int __perf_event_overflow(struct perf_event *event,
 			 */
 			WARN_ON_ONCE(event->pending_sigtrap != pending_id);
 		}
-		event->pending_addr = data->addr;
+
+		event->pending_addr = 0;
+		if (data->sample_flags & PERF_SAMPLE_ADDR)
+			event->pending_addr = data->addr;
 		irq_work_queue(&event->pending_irq);
 	}
 

Original file line number	Diff line number	Diff line change
`@@ -9328,7 +9328,10 @@ static int __perf_event_overflow(struct perf_event *event,`
`9328`	`9328`	`*/`
`9329`	`9329`	`WARN_ON_ONCE(event->pending_sigtrap != pending_id);`
`9330`	`9330`	`}`
`9331`		`- event->pending_addr = data->addr;`
	`9331`	`+`
	`9332`	`+ event->pending_addr = 0;`
	`9333`	`+ if (data->sample_flags & PERF_SAMPLE_ADDR)`
	`9334`	`+ event->pending_addr = data->addr;`
`9332`	`9335`	`irq_work_queue(&event->pending_irq);`
`9333`	`9336`	`}`
`9334`	`9337`