[tip:perf/urgent] perf tools: Fix proper buffer size for feature processing

[tip-bot for Jiri Olsa]

Commit-ID:  79b2fe5e756163897175a8f57d66b26cd9befd59
Gitweb:     https://git.kernel.org/tip/79b2fe5e756163897175a8f57d66b26cd9befd59
Author:     Jiri Olsa <jolsa@xxxxxxxxxx>
AuthorDate: Mon, 15 Jul 2019 16:04:26 +0200
Committer:  Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Tue, 23 Jul 2019 08:59:49 -0300

perf tools: Fix proper buffer size for feature processing

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

  # 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))