mtd: speedtest: fix integer overflow
32-bit integers used in 'calc_speed()' may overflow and lead to
incorrect results. Use 64-bit integers instead.
Signed-off-by: David Lambert <dave@lambsys.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/mtd/tests/mtd_speedtest.c b/drivers/mtd/tests/mtd_speedtest.c
index 3ce6fce..627d4e2 100644
--- a/drivers/mtd/tests/mtd_speedtest.c
+++ b/drivers/mtd/tests/mtd_speedtest.c
@@ -314,16 +314,16 @@
static long calc_speed(void)
{
- long ms, k, speed;
+ uint64_t k;
+ long ms;
ms = (finish.tv_sec - start.tv_sec) * 1000 +
(finish.tv_usec - start.tv_usec) / 1000;
- k = goodebcnt * mtd->erasesize / 1024;
- if (ms)
- speed = (k * 1000) / ms;
- else
- speed = 0;
- return speed;
+ if (ms == 0)
+ return 0;
+ k = goodebcnt * (mtd->erasesize / 1024) * 1000;
+ do_div(k, ms);
+ return k;
}
static int scan_for_bad_eraseblocks(void)