perf trace: Use strerror_r instead of strerror

Use strerror_r instead of strerror in error message for thead-safety.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naohiro Aota <naota@elisp.net>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20140814022241.3545.97543.stgit@kbuild-fedora.novalocalSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-trace.c

@@ -1750,7 +1750,7 @@ static int trace__sys_exit(struct trace *trace, struct perf_evsel *evsel,
 signed_print:
 		fprintf(trace->output, ") = %d", ret);
 	} else if (ret < 0 && sc->fmt->errmsg) {
-		char bf[256];
+		char bf[STRERR_BUFSIZE];
 		const char *emsg = strerror_r(-ret, bf, sizeof(bf)),
 			   *e = audit_errno_to_name(-ret);
 
@@ -2044,6 +2044,7 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
 	int err = -1, i;
 	unsigned long before;
 	const bool forks = argc > 0;
+	char sbuf[STRERR_BUFSIZE];
 
 	trace->live = true;
 
@@ -2105,7 +2106,8 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
 
 	err = perf_evlist__mmap(evlist, trace->opts.mmap_pages, false);
 	if (err < 0) {
-		fprintf(trace->output, "Couldn't mmap the events: %s\n", strerror(errno));
+		fprintf(trace->output, "Couldn't mmap the events: %s\n",
+			strerror_r(errno, sbuf, sizeof(sbuf)));
 		goto out_delete_evlist;
 	}