diff options
Diffstat (limited to 'lib/iov_iter.c')
| -rw-r--r-- | lib/iov_iter.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 7312e7784611..f0c7f1481bae 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -1139,6 +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) |