[tip: perf/urgent] perf/core: Consistently fail fork on allocation failures

[tip-bot2 for Alexander Shishkin]

The following commit has been merged into the perf/urgent branch of tip:

Commit-ID:     697d877849d4b34ab58d7078d6930bad0ef6fc66
Gitweb:        https://git.kernel.org/tip/697d877849d4b34ab58d7078d6930bad0ef6fc66
Author:        Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
AuthorDate:    Tue, 05 Nov 2019 09:57:02 +02:00
Committer:     Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Wed, 13 Nov 2019 08:16:43 +01:00

perf/core: Consistently fail fork on allocation failures

Commit:

  313ccb9615948 ("perf: Allocate context task_ctx_data for child event")

makes the inherit path skip over the current event in case of task_ctx_data
allocation failure. This, however, is inconsistent with allocation failures
in perf_event_alloc(), which would abort the fork.

Correct this by returning an error code on task_ctx_data allocation
failure and failing the fork in that case.

Signed-off-by: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Vince Weaver <vincent.weaver@xxxxxxxxx>
Link: https://lkml.kernel.org/r/20191105075702.60319-1-alexander.shishkin@xxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 kernel/events/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 7655441..466e333 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -11802,7 +11802,7 @@ inherit_event(struct perf_event *parent_event,
 						   GFP_KERNEL);
 		if (!child_ctx->task_ctx_data) {
 			free_event(child_event);
-			return NULL;
+			return ERR_PTR(-ENOMEM);
 		}
 	}