From 91329559eb07c9b12c7ce80e893ad39579c40aa2 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 10 Jun 2022 20:38:20 -0400 Subject: [PATCH] iov_iter_get_pages_alloc(): lift freeing pages array on failure exits into wrapper Incidentally, ITER_XARRAY did *not* free the sucker in case when iter_xarray_populate_pages() returned 0... Reviewed-by: Jeff Layton Signed-off-by: Al Viro --- lib/iov_iter.c | 38 ++++++++++++++++++++++---------------- 1 file changed, 22 insertions(+), 16 deletions(-) diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 12dda10..e147497 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -1506,15 +1506,10 @@ static ssize_t pipe_get_pages_alloc(struct iov_iter *i, maxsize = n; else npages = DIV_ROUND_UP(maxsize + off, PAGE_SIZE); - p = get_pages_array(npages); + *pages = p = get_pages_array(npages); if (!p) return -ENOMEM; - n = __pipe_get_pages(i, maxsize, p, off); - if (n > 0) - *pages = p; - else - kvfree(p); - return n; + return __pipe_get_pages(i, maxsize, p, off); } static ssize_t iter_xarray_get_pages_alloc(struct iov_iter *i, @@ -1544,10 +1539,9 @@ static ssize_t iter_xarray_get_pages_alloc(struct iov_iter *i, count++; } - p = get_pages_array(count); + *pages = p = get_pages_array(count); if (!p) return -ENOMEM; - *pages = p; nr = iter_xarray_populate_pages(p, i->xarray, index, count); if (nr == 0) @@ -1556,7 +1550,7 @@ static ssize_t iter_xarray_get_pages_alloc(struct iov_iter *i, return min_t(size_t, nr * PAGE_SIZE - offset, maxsize); } -ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, +static ssize_t __iov_iter_get_pages_alloc(struct iov_iter *i, struct page ***pages, size_t maxsize, size_t *start) { @@ -1583,16 +1577,12 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, *start = addr % PAGE_SIZE; addr &= PAGE_MASK; n = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); - p = get_pages_array(n); + *pages = p = get_pages_array(n); if (!p) return -ENOMEM; res = get_user_pages_fast(addr, n, gup_flags, p); - if (unlikely(res <= 0)) { - kvfree(p); - *pages = NULL; + if (unlikely(res <= 0)) return res; - } - *pages = p; return min_t(size_t, maxsize, res * PAGE_SIZE - *start); } if (iov_iter_is_bvec(i)) { @@ -1613,6 +1603,22 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, return iter_xarray_get_pages_alloc(i, pages, maxsize, start); return -EFAULT; } + +ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, + struct page ***pages, size_t maxsize, + size_t *start) +{ + ssize_t len; + + *pages = NULL; + + len = __iov_iter_get_pages_alloc(i, pages, maxsize, start); + if (len <= 0) { + kvfree(*pages); + *pages = NULL; + } + return len; +} EXPORT_SYMBOL(iov_iter_get_pages_alloc); size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, -- 2.7.4