Commit c81ce28d authored by Al Viro's avatar Al Viro
Browse files

iov_iter_get_pages(): sanity-check arguments 



zero maxpages is bogus, but best treated as "just return 0";
NULL pages, OTOH, should be treated as a hard bug.

get rid of now completely useless checks in xarray_get_pages{,_alloc}().

Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 91329559

lib/iov_iter.c

+2 −7
Original line number Diff line number Diff line
@@ -1368,9 +1368,6 @@ static ssize_t iter_xarray_get_pages(struct iov_iter *i, 
	size_t size = maxsize;

	loff_t pos;



	if (!size || !maxpages)

		return 0;



	pos = i->xarray_start + i->iov_offset;

	index = pos >> PAGE_SHIFT;

	offset = pos & ~PAGE_MASK;
@@ -1440,10 +1437,11 @@ ssize_t iov_iter_get_pages(struct iov_iter *i, 


	if (maxsize > i->count)

		maxsize = i->count;

	if (!maxsize)

	if (!maxsize || !maxpages)

		return 0;

	if (maxsize > MAX_RW_COUNT)

		maxsize = MAX_RW_COUNT;

	BUG_ON(!pages);



	if (likely(user_backed_iter(i))) {

		unsigned int gup_flags = 0;
@@ -1522,9 +1520,6 @@ static ssize_t iter_xarray_get_pages_alloc(struct iov_iter *i, 
	size_t size = maxsize;

	loff_t pos;



	if (!size)

		return 0;



	pos = i->xarray_start + i->iov_offset;

	index = pos >> PAGE_SHIFT;

	offset = pos & ~PAGE_MASK;