From: yangerkun yangerkun@huawei.com
[ Upstream commit dc2b3e5cbc8087224fcd8698b0dc56131e0bf37d ]
We now support user to set erase page size, and use do_div between len and erase size to determine the reasonableness for the erase size. However, do_div is a macro and will overwrite the value of len. Which results a mtd device with unexcepted size. Fix it by use div_u64_rem.
Fixes: ffad560394de ("mtd: phram: Allow the user to set the erase page size.") Signed-off-by: yangerkun yangerkun@huawei.com Signed-off-by: Miquel Raynal miquel.raynal@bootlin.com Link: https://lore.kernel.org/linux-mtd/20210125124936.651812-1-yangerkun@huawei.c... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/mtd/devices/phram.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/mtd/devices/phram.c b/drivers/mtd/devices/phram.c index cfd170946ba48..5b04ae6c30573 100644 --- a/drivers/mtd/devices/phram.c +++ b/drivers/mtd/devices/phram.c @@ -222,6 +222,7 @@ static int phram_setup(const char *val) uint64_t start; uint64_t len; uint64_t erasesize = PAGE_SIZE; + uint32_t rem; int i, ret;
if (strnlen(val, sizeof(buf)) >= sizeof(buf)) @@ -263,8 +264,11 @@ static int phram_setup(const char *val) } }
+ if (erasesize) + div_u64_rem(len, (uint32_t)erasesize, &rem); + if (len == 0 || erasesize == 0 || erasesize > len - || erasesize > UINT_MAX || do_div(len, (uint32_t)erasesize) != 0) { + || erasesize > UINT_MAX || rem) { parse_err("illegal erasesize or len\n"); goto error; }