linux-kernel - [PATCH] perf utils: silent "Couldn't synthesize bpf events" warning for EPERM

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Message-ID: <20190204193140.719740-1-songliubraving@fb.com>
Date:   Mon, 4 Feb 2019 11:31:40 -0800
From:   Song Liu <songliubraving@...com>
To:     <linux-kernel@...r.kernel.org>
CC:     Song Liu <songliubraving@...com>, <kernel-team@...com>,
        Arnaldo Carvalho de Melo <acme@...hat.com>,
        Jiri Olsa <jolsa@...hat.com>
Subject: [PATCH] perf utils: silent "Couldn't synthesize bpf events" warning for EPERM

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

Cc: Arnaldo Carvalho de Melo <acme@...hat.com>
Cc: Jiri Olsa <jolsa@...hat.com>
Reported-by: David Carrillo-Cisneros <davidca@...com>
Tested-by: David Carrillo-Cisneros <davidca@...com>
Signed-off-by: Song Liu <songliubraving@...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);
-- 
2.17.1