[tip:perf/core] perf tools: Fix strlen() bug in perf_event__synthesize_event_type()

From: tip-bot for Stephane Eranian
Date: Tue Jan 31 2012 - 08:25:17 EST


Commit-ID: d8d9c282a1abbe2baf6d22f959e6adf4c90629bf
Gitweb: http://git.kernel.org/tip/d8d9c282a1abbe2baf6d22f959e6adf4c90629bf
Author: Stephane Eranian <eranian@xxxxxxxxxx>
AuthorDate: Fri, 20 Jan 2012 10:49:12 +0100
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Mon, 30 Jan 2012 22:29:12 -0200

perf tools: Fix strlen() bug in perf_event__synthesize_event_type()

The event_type record has a max length for the event name.

It's called MAX_EVENT_NAME.

The name may be truncated to fit the max length. But the header.size still
reflects the original name length. If that length is > MAX_EVENT_NAME, then the
header.size field is bogus. Fix this by using the length of the name after the
potential truncation.

Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/20120120094912.GA4882@quad
Signed-off-by: Stephane Eranian <eranian@xxxxxxxxxx>
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/util/header.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 3e7e0b0..ecd7f4d 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -2105,7 +2105,7 @@ int perf_event__synthesize_event_type(struct perf_tool *tool,
strncpy(ev.event_type.event_type.name, name, MAX_EVENT_NAME - 1);

ev.event_type.header.type = PERF_RECORD_HEADER_EVENT_TYPE;
- size = strlen(name);
+ size = strlen(ev.event_type.event_type.name);
size = ALIGN(size, sizeof(u64));
ev.event_type.header.size = sizeof(ev.event_type) -
(sizeof(ev.event_type.event_type.name) - size);
--
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