perf/core: Check return value of the perf_event_read() IPI

The call to smp_call_function_single in perf_event_read() may fail if
an invalid or not online CPU index is passed. Warn user if such bug is
present and return error.

Signed-off-by: David Carrillo-Cisneros <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Paul Turner <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vegard Nossum <[email protected]>
Cc: Vince Weaver <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
This commit is contained in:
David Carrillo-Cisneros authored and Ingo Molnar committed 2016-08-18 10:35:52 +02:00
1 parent 99f5bc9bfa
commit 71e7bc2bab
1 file changed
+4 -3
+4 -3
View File
@@ -3549,9 +3549,10 @@ static int perf_event_read(struct perf_event *event, bool group)
.group = group,
.ret = 0,
};
smp_call_function_single(event->oncpu,
__perf_event_read, &data, 1);
ret = data.ret;
ret = smp_call_function_single(event->oncpu, __perf_event_read, &data, 1);
/* The event must have been read from an online CPU: */
WARN_ON_ONCE(ret);
ret = ret ? : data.ret;
} else if (event->state == PERF_EVENT_STATE_INACTIVE) {
struct perf_event_context *ctx = event->ctx;
unsigned long flags;