From 371ea1951bdf66fa58af984ce1c86f85c5e12b6e Mon Sep 17 00:00:00 2001
From: rls1004 <98nba@naver.com>
Date: Mon, 9 Sep 2019 09:57:01 +0000
Subject: [PATCH] uftrace: Fix segfault when using --logfile

This patch is to fix segfault in --logfile.
If logfd is NULL, set logfd to stderr before calling pr_err().

Fixed: #853

Signed-off-by: MinJeong Kim <98nba@naver.com>
---
 uftrace.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/uftrace.c b/uftrace.c
index 536d33b2f..099e8bbef 100644
--- a/uftrace.c
+++ b/uftrace.c
@@ -1082,8 +1082,10 @@ int main(int argc, char *argv[])
 
 	if (opts.logfile) {
 		logfp = fopen(opts.logfile, "a");
-		if (logfp == NULL)
+		if (logfp == NULL) {
+			logfp = stderr;
 			pr_err("cannot open log file");
+		}
 
 		setvbuf(logfp, NULL, _IOLBF, 1024);
 	}