diff options
Diffstat (limited to 'mm/iov_iter.c')
| -rw-r--r-- | mm/iov_iter.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/mm/iov_iter.c b/mm/iov_iter.c index 7b5dbd1517b..9a09f2034fc 100644 --- a/mm/iov_iter.c +++ b/mm/iov_iter.c @@ -310,7 +310,7 @@ void iov_iter_init(struct iov_iter *i, int direction, EXPORT_SYMBOL(iov_iter_init); static ssize_t get_pages_iovec(struct iov_iter *i, - struct page **pages, size_t maxsize, + struct page **pages, size_t maxsize, unsigned maxpages, size_t *start) { size_t offset = i->iov_offset; @@ -327,6 +327,8 @@ static ssize_t get_pages_iovec(struct iov_iter *i, len = maxsize; addr = (unsigned long)iov->iov_base + offset; len += *start = addr & (PAGE_SIZE - 1); + if (len > maxpages * PAGE_SIZE) + len = maxpages * PAGE_SIZE; addr &= ~(PAGE_SIZE - 1); n = (len + PAGE_SIZE - 1) / PAGE_SIZE; res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, pages); @@ -588,7 +590,7 @@ static unsigned long alignment_bvec(const struct iov_iter *i) } static ssize_t get_pages_bvec(struct iov_iter *i, - struct page **pages, size_t maxsize, + struct page **pages, size_t maxsize, unsigned maxpages, size_t *start) { const struct bio_vec *bvec = i->bvec; @@ -597,6 +599,7 @@ static ssize_t get_pages_bvec(struct iov_iter *i, len = i->count; if (len > maxsize) len = maxsize; + /* can't be more than PAGE_SIZE */ *start = bvec->bv_offset + i->iov_offset; get_page(*pages = bvec->bv_page); @@ -712,13 +715,13 @@ unsigned long iov_iter_alignment(const struct iov_iter *i) EXPORT_SYMBOL(iov_iter_alignment); ssize_t iov_iter_get_pages(struct iov_iter *i, - struct page **pages, size_t maxsize, + struct page **pages, size_t maxsize, unsigned maxpages, size_t *start) { if (i->type & ITER_BVEC) - return get_pages_bvec(i, pages, maxsize, start); + return get_pages_bvec(i, pages, maxsize, maxpages, start); else - return get_pages_iovec(i, pages, maxsize, start); + return get_pages_iovec(i, pages, maxsize, maxpages, start); } EXPORT_SYMBOL(iov_iter_get_pages); |