Commit 78b562fb authored Apr 15, 2018 by Jiri Olsa Committed by Arnaldo Carvalho de Melo Apr 17, 2018

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: 60e2364e ("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>

parent 038586c3

kernel/events/core.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -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)

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