From e70727e442eb61581f836a9a0ca0c3b70d8a3ff2 Mon Sep 17 00:00:00 2001 From: David Lambert Date: Mon, 7 Mar 2011 12:00:46 +0200 Subject: [PATCH] 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 Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse --- drivers/mtd/tests/mtd_speedtest.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/mtd/tests/mtd_speedtest.c b/drivers/mtd/tests/mtd_speedtest.c index 3ce6fce75e07..627d4e2466a3 100644 --- a/drivers/mtd/tests/mtd_speedtest.c +++ b/drivers/mtd/tests/mtd_speedtest.c @@ -314,16 +314,16 @@ static inline void stop_timing(void) 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)