[PATCH 2/2] perf tools: Fix find_perf_probe_point_from_map() which incorrectly returns success

From: Wang Nan
Date: Thu Nov 05 2015 - 08:20:12 EST


It is possible that find_perf_probe_point_from_map() fails to find
symbol but still returns 0 because of an small error when coding:
find_perf_probe_point_from_map() set 'ret' to error code at first,
but also use it to hold return value of
kernel_get_symbol_address_by_name().

This patch resets 'ret' to error even kernel_get_symbol_address_by_name()
success, so if !sym, the whole function returns error correctly.

Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/util/probe-event.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index b51a8bf..e659c4f 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -1905,6 +1905,9 @@ static int find_perf_probe_point_from_map(struct probe_trace_point *tp,
sym = __find_kernel_function(addr, &map);
}
}
+
+ /* ret may has be overwritten so reset it */
+ ret = -ENOENT;
if (!sym)
goto out;

--
1.8.3.4

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