[PATCH 04/10] perf tools: Fix proper buffer size for feature processing

From: Arnaldo Carvalho de Melo
Date: Tue Jul 23 2019 - 16:06:05 EST

From: Jiri Olsa <jolsa@xxxxxxxxxx>

After Song Liu's segfault fix for pipe mode, Arnaldo reported following

# perf record -o - | perf script
0x514 [0x1ac]: failed to process type: 80

It's caused by wrong buffer size setup in feature processing, which
makes cpu topology feature fail, because it's using buffer size to
recognize its header version.

Reported-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Tested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: David Carrillo-Cisneros <davidcc@xxxxxxxxxx>
Cc: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Song Liu <songliubraving@xxxxxx>
Fixes: e9def1b2e74e ("perf tools: Add feature header record to pipe-mode")
Link: http://lkml.kernel.org/r/20190715140426.32509-1-jolsa@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
tools/perf/util/header.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index c24db7f4909c..20111f8da5cb 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -3747,7 +3747,7 @@ int perf_event__process_feature(struct perf_session *session,
return 0;

ff.buf = (void *)fe->data;
- ff.size = event->header.size - sizeof(event->header);
+ ff.size = event->header.size - sizeof(*fe);
ff.ph = &session->header;

if (feat_ops[feat].process(&ff, NULL))