[PATCH 5.4 091/155] perf probe: Fix to delete multiple probe event

Greg Kroah-Hartman
2020-03-31T09:15:34Z

From: Masami Hiramatsu <mhiramat@kernel.org>

commit 6b8d68f1ce9266b05a55e93c62923ff51daae4c1 upstream.

When we put an event with multiple probes, perf-probe fails to delete
with filters. This comes from a failure to list up the event name
because of overwrapping its name.

To fix this issue, skip to list up the event which has same name.

Without this patch:

# perf probe -l \*
probe_perf:map__map_ip (on perf_sample__fprintf_brstackoff:21@
probe_perf:map__map_ip (on perf_sample__fprintf_brstackoff:25@
probe_perf:map__map_ip (on append_inlines:12@util/machine.c in
probe_perf:map__map_ip (on unwind_entry:19@util/machine.c in /
probe_perf:map__map_ip (on map__map_ip@util/map.h in /home/mhi
probe_perf:map__map_ip (on map__map_ip@util/map.h in /home/mhi
# perf probe -d \*
"*" does not hit any event.
Error: Failed to delete events. Reason: No such file or directory (Code: -2)

With it:

# perf probe -d \*
Removed event: probe_perf:map__map_ip
#

Fixes: 72363540c009 ("perf probe: Support multiprobe event")
Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Reported-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: stable@vger.kernel.org
Link: http://lore.kernel.org/lkml/158287666197.16697.7514373548551863562.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c
index 0f5fda11675f..8c852948513e 100644
--- a/tools/perf/util/probe-file.c
+++ b/tools/perf/util/probe-file.c
@@ -206,6 +206,9 @@ static struct strlist *__probe_file__get_namelist(int fd, bool include_group)
} else
ret = strlist__add(sl, tev.event);
clear_probe_trace_event(&tev);
+ /* Skip if there is same name multi-probe event in the list */
+ if (ret == -EEXIST)
+ ret = 0;
if (ret < 0)
break;
}