From: Al Viro Date: Fri, 17 Jun 2022 19:15:14 +0000 (-0400) Subject: iov_iter_get_pages(): sanity-check arguments X-Git-Tag: v6.1-rc5~645^2~18 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=c81ce28df500b04444ef97dc82a7b0299ce717e8;p=platform%2Fkernel%2Flinux-starfive.git 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 Signed-off-by: Al Viro --- diff --git a/lib/iov_iter.c b/lib/iov_iter.c index e147497..7d3158d 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;