From: Bart Van Assche <bvanassche@acm.org>
Date: Sat, 11 Jan 2020 23:42:49 +0000 (-0800)
Subject: t/read-to-pipe-async: Do not divide by zero
X-Git-Tag: fio-3.18~12^2~1
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=b38cc6cb679e2f48dbdef43b1d70b7a1f9278945;p=fio.git

t/read-to-pipe-async: Do not divide by zero

This patch fixes the following Coverity complaint:

23. zero_return: Function call utime_since(&s, &re) returns 0.
CID 280732 (#2 of 2): Division or modulo by zero (DIVIDE_BY_ZERO)
24. divide_by_zero: In expression bytes * 1000UL * 1000UL / utime_since(&s, &re), division by expression utime_since(&s, &re) which may be zero has undefined behavior.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---

diff --git a/t/read-to-pipe-async.c b/t/read-to-pipe-async.c
index bc7986f7..1370ef08 100644
--- a/t/read-to-pipe-async.c
+++ b/t/read-to-pipe-async.c
@@ -581,6 +581,7 @@ int main(int argc, char *argv[])
 	struct reader_thread *rt;
 	struct writer_thread *wt;
 	unsigned long rate;
+	uint64_t elapsed;
 	struct stat sb;
 	size_t bytes;
 	off_t off;
@@ -684,9 +685,11 @@ int main(int argc, char *argv[])
 	show_latencies(&wt->s, "WRITERS");
 
 	bytes /= 1024;
-	rate = (bytes * 1000UL * 1000UL) / utime_since(&s, &re);
+	elapsed = utime_since(&s, &re);
+	rate = elapsed ? (bytes * 1000UL * 1000UL) / elapsed : 0;
 	fprintf(stderr, "Read rate (KiB/sec) : %lu\n", rate);
-	rate = (bytes * 1000UL * 1000UL) / utime_since(&s, &we);
+	elapsed = utime_since(&s, &we);
+	rate = elapsed ? (bytes * 1000UL * 1000UL) / elapsed : 0;
 	fprintf(stderr, "Write rate (KiB/sec): %lu\n", rate);
 
 	close(fd);