From: Jiri Olsa <jolsa@kernel.org>
Date: Sun, 15 Apr 2018 09:23:50 +0000 (+0200)
Subject: perf: Return proper values for user stack errors
X-Git-Tag: v5.15~8969^2^2~11
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=78b562fbfa2cf0a9fcb23c3154756b690f4905c1;p=platform%2Fkernel%2Flinux-starfive.git

perf: Return proper values for user stack errors

Return immediately when we find issue in the user stack checks. The
error value could get overwritten by following check for
PERF_SAMPLE_REGS_INTR.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: syzkaller-bugs@googlegroups.com
Cc: x86@kernel.org
Fixes: 60e2364e60e8 ("perf: Add ability to sample machine state on interrupt")
Link: http://lkml.kernel.org/r/20180415092352.12403-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 1bae80a..67612ce 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -10209,9 +10209,9 @@ static int perf_copy_attr(struct perf_event_attr __user *uattr,
 		 * __u16 sample size limit.
 		 */
 		if (attr->sample_stack_user >= USHRT_MAX)
-			ret = -EINVAL;
+			return -EINVAL;
 		else if (!IS_ALIGNED(attr->sample_stack_user, sizeof(u64)))
-			ret = -EINVAL;
+			return -EINVAL;
 	}
 
 	if (!attr->sample_max_stack)