diff options
Diffstat (limited to 'lib/iov_iter.c')
| -rw-r--r-- | lib/iov_iter.c | 29 |
1 files changed, 25 insertions, 4 deletions
diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 48b8c27acabb..f0c7f1481bae 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -396,8 +396,7 @@ int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) if (!(i->type & (ITER_BVEC|ITER_KVEC))) { iterate_iovec(i, bytes, v, iov, skip, ({ - err = fault_in_multipages_readable(v.iov_base, - v.iov_len); + err = fault_in_pages_readable(v.iov_base, v.iov_len); if (unlikely(err)) return err; 0;})) @@ -834,13 +833,13 @@ static inline size_t __pipe_get_pages(struct iov_iter *i, size_t *start) { struct pipe_inode_info *pipe = i->pipe; - size_t n = push_pipe(i, maxsize, &idx, start); + ssize_t n = push_pipe(i, maxsize, &idx, start); if (!n) return -EFAULT; maxsize = n; n += *start; - while (n >= PAGE_SIZE) { + while (n > 0) { get_page(*pages++ = pipe->bufs[idx].page); idx = next_idx(idx, pipe); n -= PAGE_SIZE; @@ -1140,6 +1139,28 @@ const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) } EXPORT_SYMBOL(dup_iter); +/** + * import_iovec() - Copy an array of &struct iovec from userspace + * into the kernel, check that it is valid, and initialize a new + * &struct iov_iter iterator to access it. + * + * @type: One of %READ or %WRITE. + * @uvector: Pointer to the userspace array. + * @nr_segs: Number of elements in userspace array. + * @fast_segs: Number of elements in @iov. + * @iov: (input and output parameter) Pointer to pointer to (usually small + * on-stack) kernel array. + * @i: Pointer to iterator that will be initialized on success. + * + * If the array pointed to by *@iov is large enough to hold all @nr_segs, + * then this function places %NULL in *@iov on return. Otherwise, a new + * array will be allocated and the result placed in *@iov. This means that + * the caller may call kfree() on *@iov regardless of whether the small + * on-stack array was used or not (and regardless of whether this function + * returns an error or not). + * + * Return: 0 on success or negative error code on error. + */ int import_iovec(int type, const struct iovec __user * uvector, unsigned nr_segs, unsigned fast_segs, struct iovec **iov, struct iov_iter *i) |