diff options
| -rw-r--r-- | include/linux/uio.h | 2 | ||||
| -rw-r--r-- | lib/iov_iter.c | 26 |
2 files changed, 17 insertions, 11 deletions
diff --git a/include/linux/uio.h b/include/linux/uio.h index ad76eef356b0..b5cf54859109 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -119,7 +119,7 @@ size_t iov_iter_copy_from_user_atomic(struct page *page, struct iov_iter *i, unsigned long offset, size_t bytes); void iov_iter_advance(struct iov_iter *i, size_t bytes); void iov_iter_revert(struct iov_iter *i, size_t bytes); -int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes); +int iov_iter_fault_in_readable(const struct iov_iter *i, size_t bytes); size_t iov_iter_single_seg_count(const struct iov_iter *i); size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, struct iov_iter *i); diff --git a/lib/iov_iter.c b/lib/iov_iter.c index cd23c79acb94..2b543bea1e0d 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -466,19 +466,25 @@ out: * Return 0 on success, or non-zero if the memory could not be accessed (i.e. * because it is an invalid address). */ -int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) +int iov_iter_fault_in_readable(const struct iov_iter *i, size_t bytes) { - size_t skip = i->iov_offset; - const struct iovec *iov; - int err; - struct iovec v; - if (iter_is_iovec(i)) { - iterate_iovec(i, bytes, v, iov, skip, ({ - err = fault_in_pages_readable(v.iov_base, v.iov_len); + const struct iovec *p; + size_t skip; + + if (bytes > i->count) + bytes = i->count; + for (p = i->iov, skip = i->iov_offset; bytes; p++, skip = 0) { + size_t len = min(bytes, p->iov_len - skip); + int err; + + if (unlikely(!len)) + continue; + err = fault_in_pages_readable(p->iov_base + skip, len); if (unlikely(err)) - return err; - 0;})) + return err; + bytes -= len; + } } return 0; } |