[tip:perf/core] perf: Fix dynamic field detection

From: tip-bot for Thomas Gleixner
Date: Wed Apr 14 2010 - 19:40:39 EST


Commit-ID: a1e2f60e3efc812bf66a2be0d8530ee175003f6d
Gitweb: http://git.kernel.org/tip/a1e2f60e3efc812bf66a2be0d8530ee175003f6d
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Wed, 14 Apr 2010 23:58:03 +0200
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Thu, 15 Apr 2010 01:34:46 +0200

perf: Fix dynamic field detection

Checking if a tracing field is an array with a dynamic length
requires to check the field type and seek the "__data_loc"
string that prepends the actual type, as can be found in a trace
event format file:

field:__data_loc char[] name; offset:16; size:4; signed:1;

But we actually use strcmp() to check if the field type fully
matches "__data_loc", which may fail as we trip over the rest of
the type.

To fix this, use strncmp to only check if it starts with
"__data_loc".

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Tom Zanussi <tzanussi@xxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
LKML-Reference: <1271282283-23721-1-git-send-regression-fweisbec@xxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
tools/perf/util/trace-event-parse.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/tools/perf/util/trace-event-parse.c b/tools/perf/util/trace-event-parse.c
index 17d6d66..d6ef414 100644
--- a/tools/perf/util/trace-event-parse.c
+++ b/tools/perf/util/trace-event-parse.c
@@ -761,7 +761,7 @@ static int field_is_string(struct format_field *field)

static int field_is_dynamic(struct format_field *field)
{
- if (!strcmp(field->type, "__data_loc"))
+ if (!strncmp(field->type, "__data_loc", 10))
return 1;

return 0;
--
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