[tip:perf/core] tools lib traceevent: Fix off-by-one bug in pevent_strerror()

[tip-bot for Namhyung Kim <namhyung.kim@lge.com>]

Commit-ID:  f63fe79fa0b1362e8ea1c1e4996cf70d14917b02
Gitweb:     http://git.kernel.org/tip/f63fe79fa0b1362e8ea1c1e4996cf70d14917b02
Author:     Namhyung Kim <namhyung.kim@lge.com>
AuthorDate: Thu, 23 Aug 2012 16:37:00 +0900
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Thu, 23 Aug 2012 11:29:20 -0300

tools lib traceevent: Fix off-by-one bug in pevent_strerror()

As pevent_errno is defined using PEVENT_ERRORS which uses _PE macro
magic, the first errno is bigger than __PEVENT_ERRNO_START by 1. So we
need to subtract the 1 also when calculating the index of the error
strings.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1345707420-21767-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/lib/traceevent/event-parse.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index f978c59..b5b4d80 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -4822,7 +4822,7 @@ int pevent_strerror(struct pevent *pevent, enum pevent_errno errnum,
 	    errnum >= __PEVENT_ERRNO__END)
 		return -1;
 
-	idx = errnum - __PEVENT_ERRNO__START;
+	idx = errnum - __PEVENT_ERRNO__START - 1;
 	msg = pevent_error_str[idx];
 
 	switch (errnum) {