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authorAl Viro <viro@zeniv.linux.org.uk>2022-06-17 15:15:14 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2022-08-08 22:37:20 -0400
commitc81ce28df500b04444ef97dc82a7b0299ce717e8 (patch)
treee7987013cb4c73a500219d7d80eda6b692b030ad /lib
parent91329559eb07c9b12c7ce80e893ad39579c40aa2 (diff)
downloadlwn-c81ce28df500b04444ef97dc82a7b0299ce717e8.tar.gz
lwn-c81ce28df500b04444ef97dc82a7b0299ce717e8.zip
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: Jeff Layton <jlayton@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'lib')
-rw-r--r--lib/iov_iter.c9
1 files changed, 2 insertions, 7 deletions
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index e14749711e34..7d3158d1f8ea 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -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;