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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: ffad560394 ("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.com
This commit is contained in:
yangerkun 2021-01-25 20:49:36 +08:00 committed by Miquel Raynal
parent b81770a700
commit dc2b3e5cbc

View File

@ -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;
}