linux-kernel - [PATCH 12/43] perf utils: Silence "Couldn't synthesize bpf events" warning for EPERM

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Date:   Thu, 14 Feb 2019 21:45:08 -0300
From:   Arnaldo Carvalho de Melo <acme@...nel.org>
To:     Ingo Molnar <mingo@...nel.org>
Cc:     Jiri Olsa <jolsa@...nel.org>, Namhyung Kim <namhyung@...nel.org>,
        Clark Williams <williams@...hat.com>,
        linux-kernel@...r.kernel.org, linux-perf-users@...r.kernel.org,
        Song Liu <songliubraving@...com>, kernel-team@...com,
        Arnaldo Carvalho de Melo <acme@...hat.com>
Subject: [PATCH 12/43] perf utils: Silence "Couldn't synthesize bpf events" warning for EPERM

From: Song Liu <songliubraving@...com>

Synthesizing BPF events is only supported for root. Silent warning msg
when non-root user runs perf-record.

Reported-by: David Carrillo-Cisneros <davidca@...com>
Signed-off-by: Song Liu <songliubraving@...com>
Tested-by: David Carrillo-Cisneros <davidca@...com>
Acked-by: Jiri Olsa <jolsa@...nel.org>
Cc: kernel-team@...com
Link: http://lkml.kernel.org/r/20190204193140.719740-1-songliubraving@fb.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@...hat.com>
---
 tools/perf/util/bpf-event.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
index 796ef793f4ce..62dda96b0096 100644
--- a/tools/perf/util/bpf-event.c
+++ b/tools/perf/util/bpf-event.c
@@ -236,8 +236,8 @@ int perf_event__synthesize_bpf_events(struct perf_tool *tool,
 			pr_debug("%s: can't get next program: %s%s",
 				 __func__, strerror(errno),
 				 errno == EINVAL ? " -- kernel too old?" : "");
-			/* don't report error on old kernel */
-			err = (errno == EINVAL) ? 0 : -1;
+			/* don't report error on old kernel or EPERM  */
+			err = (errno == EINVAL || errno == EPERM) ? 0 : -1;
 			break;
 		}
 		fd = bpf_prog_get_fd_by_id(id);
-- 
2.19.1