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Subject[PATCH 15/29] iov_iter: Split copy_from_user_atomic()
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Split copy_from_user_atomic() by type.

Signed-off-by: David Howells <dhowells@redhat.com>
---

lib/iov_iter.c | 53 ++++++++++++++++++++++++++++++++++++++++-------------
1 file changed, 40 insertions(+), 13 deletions(-)

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 9a167f53ecff..a626d41fef72 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -1195,7 +1195,7 @@ static size_t discard_zero(size_t bytes, struct iov_iter *i)
return bytes;
}

-static size_t xxx_copy_from_user_atomic(struct page *page,
+static size_t iovec_copy_from_user_atomic(struct page *page,
struct iov_iter *i, unsigned long offset, size_t bytes)
{
char *kaddr = kmap_atomic(page), *p = kaddr + offset;
@@ -1203,21 +1203,48 @@ static size_t xxx_copy_from_user_atomic(struct page *page,
kunmap_atomic(kaddr);
return 0;
}
- if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) {
+ iterate_over_iovec(i, bytes, v,
+ copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len));
+ kunmap_atomic(kaddr);
+ return bytes;
+}
+
+static size_t bvec_copy_from_user_atomic(struct page *page,
+ struct iov_iter *i, unsigned long offset, size_t bytes)
+{
+ char *kaddr = kmap_atomic(page), *p = kaddr + offset;
+ if (unlikely(!page_copy_sane(page, offset, bytes))) {
kunmap_atomic(kaddr);
- WARN_ON(1);
return 0;
}
- iterate_all_kinds(i, bytes, v,
- copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len),
+ iterate_over_bvec(i, bytes, v,
memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page,
- v.bv_offset, v.bv_len),
- memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len)
- )
+ v.bv_offset, v.bv_len));
kunmap_atomic(kaddr);
return bytes;
}

+static size_t kvec_copy_from_user_atomic(struct page *page,
+ struct iov_iter *i, unsigned long offset, size_t bytes)
+{
+ char *kaddr = kmap_atomic(page), *p = kaddr + offset;
+ if (unlikely(!page_copy_sane(page, offset, bytes))) {
+ kunmap_atomic(kaddr);
+ return 0;
+ }
+ iterate_over_kvec(i, bytes, v,
+ memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len));
+ kunmap_atomic(kaddr);
+ return bytes;
+}
+
+static size_t no_copy_from_user_atomic(struct page *page,
+ struct iov_iter *i, unsigned long offset, size_t bytes)
+{
+ WARN_ON(1);
+ return 0;
+}
+
static inline void pipe_truncate(struct iov_iter *i)
{
struct pipe_inode_info *pipe = i->pipe;
@@ -2046,7 +2073,7 @@ static int xxx_for_each_range(struct iov_iter *i, size_t bytes,

static const struct iov_iter_ops iovec_iter_ops = {
.type = ITER_IOVEC,
- .copy_from_user_atomic = xxx_copy_from_user_atomic,
+ .copy_from_user_atomic = iovec_copy_from_user_atomic,
.advance = xxx_advance,
.revert = xxx_revert,
.fault_in_readable = iovec_fault_in_readable,
@@ -2080,7 +2107,7 @@ static const struct iov_iter_ops iovec_iter_ops = {

static const struct iov_iter_ops kvec_iter_ops = {
.type = ITER_KVEC,
- .copy_from_user_atomic = xxx_copy_from_user_atomic,
+ .copy_from_user_atomic = kvec_copy_from_user_atomic,
.advance = xxx_advance,
.revert = xxx_revert,
.fault_in_readable = no_fault_in_readable,
@@ -2114,7 +2141,7 @@ static const struct iov_iter_ops kvec_iter_ops = {

static const struct iov_iter_ops bvec_iter_ops = {
.type = ITER_BVEC,
- .copy_from_user_atomic = xxx_copy_from_user_atomic,
+ .copy_from_user_atomic = bvec_copy_from_user_atomic,
.advance = xxx_advance,
.revert = xxx_revert,
.fault_in_readable = no_fault_in_readable,
@@ -2148,7 +2175,7 @@ static const struct iov_iter_ops bvec_iter_ops = {

static const struct iov_iter_ops pipe_iter_ops = {
.type = ITER_PIPE,
- .copy_from_user_atomic = xxx_copy_from_user_atomic,
+ .copy_from_user_atomic = no_copy_from_user_atomic,
.advance = xxx_advance,
.revert = xxx_revert,
.fault_in_readable = no_fault_in_readable,
@@ -2182,7 +2209,7 @@ static const struct iov_iter_ops pipe_iter_ops = {

static const struct iov_iter_ops discard_iter_ops = {
.type = ITER_DISCARD,
- .copy_from_user_atomic = xxx_copy_from_user_atomic,
+ .copy_from_user_atomic = no_copy_from_user_atomic,
.advance = xxx_advance,
.revert = xxx_revert,
.fault_in_readable = no_fault_in_readable,

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