From: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Date: Tue, 5 Nov 2019 07:57:02 +0000 (+0200)
Subject: perf/core: Consistently fail fork on allocation failures
X-Git-Tag: v5.3.16~85
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b9366c7cb7d0e5b302d337921c87ddc870bb6c3a;p=thirdparty%2Fkernel%2Fstable.git

perf/core: Consistently fail fork on allocation failures

[ Upstream commit 697d877849d4b34ab58d7078d6930bad0ef6fc66 ]

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@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: https://lkml.kernel.org/r/20191105075702.60319-1-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 53173883513c1..25942e43b8d48 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -11719,7 +11719,7 @@ 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);
 		}
 	}