Commit dc2b3e5c authored by yangerkun's avatar yangerkun Committed by Miquel Raynal
Browse files

mtd: phram: use div_u64_rem to stop overwrite len in phram_setup 



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: ffad5603 ("mtd: phram: Allow the user to set the erase page size.")
Signed-off-by: default avataryangerkun <yangerkun@huawei.com>
Signed-off-by: default avatarMiquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210125124936.651812-1-yangerkun@huawei.com
parent b81770a7

drivers/mtd/devices/phram.c

+5 −1
Original line number Diff line number Diff line
@@ -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;

	}