[PATCH 03/29] iov_iter: Split iov_iter_fault_in_readable

From: David Howells
Date: Sat Nov 21 2020 - 09:13:56 EST


Split iov_iter_fault_in_readable() by type.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---

lib/iov_iter.c | 29 ++++++++++++++++-------------
1 file changed, 16 insertions(+), 13 deletions(-)

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index fee8e99fbb9c..280b5c9c9a9c 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -439,20 +439,23 @@ static size_t pipe_copy_page_to_iter(struct page *page, size_t offset, size_t by
* Return 0 on success, or non-zero if the memory could not be accessed (i.e.
* because it is an invalid address).
*/
-static int xxx_fault_in_readable(struct iov_iter *i, size_t bytes)
+static int iovec_fault_in_readable(struct iov_iter *i, size_t bytes)
{
size_t skip = i->iov_offset;
const struct iovec *iov;
int err;
struct iovec v;

- if (!(iov_iter_type(i) & (ITER_BVEC|ITER_KVEC))) {
- iterate_iovec(i, bytes, v, iov, skip, ({
- err = fault_in_pages_readable(v.iov_base, v.iov_len);
- if (unlikely(err))
- return err;
- 0;}))
- }
+ iterate_iovec(i, bytes, v, iov, skip, ({
+ err = fault_in_pages_readable(v.iov_base, v.iov_len);
+ if (unlikely(err))
+ return err;
+ 0;}))
+ return 0;
+}
+
+static int no_fault_in_readable(struct iov_iter *i, size_t bytes)
+{
return 0;
}

@@ -1846,7 +1849,7 @@ static const struct iov_iter_ops iovec_iter_ops = {
.copy_from_user_atomic = xxx_copy_from_user_atomic,
.advance = xxx_advance,
.revert = xxx_revert,
- .fault_in_readable = xxx_fault_in_readable,
+ .fault_in_readable = iovec_fault_in_readable,
.single_seg_count = xxx_single_seg_count,
.copy_page_to_iter = iovec_copy_page_to_iter,
.copy_page_from_iter = xxx_copy_page_from_iter,
@@ -1880,7 +1883,7 @@ static const struct iov_iter_ops kvec_iter_ops = {
.copy_from_user_atomic = xxx_copy_from_user_atomic,
.advance = xxx_advance,
.revert = xxx_revert,
- .fault_in_readable = xxx_fault_in_readable,
+ .fault_in_readable = no_fault_in_readable,
.single_seg_count = xxx_single_seg_count,
.copy_page_to_iter = bkvec_copy_page_to_iter,
.copy_page_from_iter = xxx_copy_page_from_iter,
@@ -1914,7 +1917,7 @@ static const struct iov_iter_ops bvec_iter_ops = {
.copy_from_user_atomic = xxx_copy_from_user_atomic,
.advance = xxx_advance,
.revert = xxx_revert,
- .fault_in_readable = xxx_fault_in_readable,
+ .fault_in_readable = no_fault_in_readable,
.single_seg_count = xxx_single_seg_count,
.copy_page_to_iter = bkvec_copy_page_to_iter,
.copy_page_from_iter = xxx_copy_page_from_iter,
@@ -1948,7 +1951,7 @@ static const struct iov_iter_ops pipe_iter_ops = {
.copy_from_user_atomic = xxx_copy_from_user_atomic,
.advance = xxx_advance,
.revert = xxx_revert,
- .fault_in_readable = xxx_fault_in_readable,
+ .fault_in_readable = no_fault_in_readable,
.single_seg_count = xxx_single_seg_count,
.copy_page_to_iter = pipe_copy_page_to_iter,
.copy_page_from_iter = xxx_copy_page_from_iter,
@@ -1982,7 +1985,7 @@ static const struct iov_iter_ops discard_iter_ops = {
.copy_from_user_atomic = xxx_copy_from_user_atomic,
.advance = xxx_advance,
.revert = xxx_revert,
- .fault_in_readable = xxx_fault_in_readable,
+ .fault_in_readable = no_fault_in_readable,
.single_seg_count = xxx_single_seg_count,
.copy_page_to_iter = discard_copy_page_to_iter,
.copy_page_from_iter = xxx_copy_page_from_iter,