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-rw-r--r--lib/iov_iter.c236
1 files changed, 166 insertions, 70 deletions
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 8be175df3075..be4bd627caf0 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -6,6 +6,7 @@
#include <linux/vmalloc.h>
#include <linux/splice.h>
#include <net/checksum.h>
+#include <linux/scatterlist.h>
#define PIPE_PARANOIA /* for now */
@@ -83,6 +84,7 @@
const struct kvec *kvec; \
struct kvec v; \
iterate_kvec(i, n, v, kvec, skip, (K)) \
+ } else if (unlikely(i->type & ITER_DISCARD)) { \
} else { \
const struct iovec *iov; \
struct iovec v; \
@@ -114,6 +116,8 @@
} \
i->nr_segs -= kvec - i->kvec; \
i->kvec = kvec; \
+ } else if (unlikely(i->type & ITER_DISCARD)) { \
+ skip += n; \
} else { \
const struct iovec *iov; \
struct iovec v; \
@@ -132,7 +136,7 @@
static int copyout(void __user *to, const void *from, size_t n)
{
- if (access_ok(VERIFY_WRITE, to, n)) {
+ if (access_ok(to, n)) {
kasan_check_read(from, n);
n = raw_copy_to_user(to, from, n);
}
@@ -141,7 +145,7 @@ static int copyout(void __user *to, const void *from, size_t n)
static int copyin(void *to, const void __user *from, size_t n)
{
- if (access_ok(VERIFY_READ, from, n)) {
+ if (access_ok(from, n)) {
kasan_check_write(to, n);
n = raw_copy_from_user(to, from, n);
}
@@ -428,17 +432,19 @@ int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes)
}
EXPORT_SYMBOL(iov_iter_fault_in_readable);
-void iov_iter_init(struct iov_iter *i, int direction,
+void iov_iter_init(struct iov_iter *i, unsigned int direction,
const struct iovec *iov, unsigned long nr_segs,
size_t count)
{
+ WARN_ON(direction & ~(READ | WRITE));
+ direction &= READ | WRITE;
+
/* It will get better. Eventually... */
if (uaccess_kernel()) {
- direction |= ITER_KVEC;
- i->type = direction;
+ i->type = ITER_KVEC | direction;
i->kvec = (struct kvec *)iov;
} else {
- i->type = direction;
+ i->type = ITER_IOVEC | direction;
i->iov = iov;
}
i->nr_segs = nr_segs;
@@ -555,10 +561,48 @@ static size_t copy_pipe_to_iter(const void *addr, size_t bytes,
return bytes;
}
+static __wsum csum_and_memcpy(void *to, const void *from, size_t len,
+ __wsum sum, size_t off)
+{
+ __wsum next = csum_partial_copy_nocheck(from, to, len, 0);
+ return csum_block_add(sum, next, off);
+}
+
+static size_t csum_and_copy_to_pipe_iter(const void *addr, size_t bytes,
+ __wsum *csum, struct iov_iter *i)
+{
+ struct pipe_inode_info *pipe = i->pipe;
+ size_t n, r;
+ size_t off = 0;
+ __wsum sum = *csum;
+ int idx;
+
+ if (!sanity(i))
+ return 0;
+
+ bytes = n = push_pipe(i, bytes, &idx, &r);
+ if (unlikely(!n))
+ return 0;
+ for ( ; n; idx = next_idx(idx, pipe), r = 0) {
+ size_t chunk = min_t(size_t, n, PAGE_SIZE - r);
+ char *p = kmap_atomic(pipe->bufs[idx].page);
+ sum = csum_and_memcpy(p + r, addr, chunk, sum, off);
+ kunmap_atomic(p);
+ i->idx = idx;
+ i->iov_offset = r + chunk;
+ n -= chunk;
+ off += chunk;
+ addr += chunk;
+ }
+ i->count -= bytes;
+ *csum = sum;
+ return bytes;
+}
+
size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
{
const char *from = addr;
- if (unlikely(i->type & ITER_PIPE))
+ if (unlikely(iov_iter_is_pipe(i)))
return copy_pipe_to_iter(addr, bytes, i);
if (iter_is_iovec(i))
might_fault();
@@ -576,7 +620,7 @@ EXPORT_SYMBOL(_copy_to_iter);
#ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE
static int copyout_mcsafe(void __user *to, const void *from, size_t n)
{
- if (access_ok(VERIFY_WRITE, to, n)) {
+ if (access_ok(to, n)) {
kasan_check_read(from, n);
n = copy_to_user_mcsafe((__force void *) to, from, n);
}
@@ -658,7 +702,7 @@ size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i)
const char *from = addr;
unsigned long rem, curr_addr, s_addr = (unsigned long) addr;
- if (unlikely(i->type & ITER_PIPE))
+ if (unlikely(iov_iter_is_pipe(i)))
return copy_pipe_to_iter_mcsafe(addr, bytes, i);
if (iter_is_iovec(i))
might_fault();
@@ -692,7 +736,7 @@ EXPORT_SYMBOL_GPL(_copy_to_iter_mcsafe);
size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
{
char *to = addr;
- if (unlikely(i->type & ITER_PIPE)) {
+ if (unlikely(iov_iter_is_pipe(i))) {
WARN_ON(1);
return 0;
}
@@ -712,7 +756,7 @@ EXPORT_SYMBOL(_copy_from_iter);
bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i)
{
char *to = addr;
- if (unlikely(i->type & ITER_PIPE)) {
+ if (unlikely(iov_iter_is_pipe(i))) {
WARN_ON(1);
return false;
}
@@ -739,7 +783,7 @@ EXPORT_SYMBOL(_copy_from_iter_full);
size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i)
{
char *to = addr;
- if (unlikely(i->type & ITER_PIPE)) {
+ if (unlikely(iov_iter_is_pipe(i))) {
WARN_ON(1);
return 0;
}
@@ -773,7 +817,7 @@ EXPORT_SYMBOL(_copy_from_iter_nocache);
size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i)
{
char *to = addr;
- if (unlikely(i->type & ITER_PIPE)) {
+ if (unlikely(iov_iter_is_pipe(i))) {
WARN_ON(1);
return 0;
}
@@ -794,7 +838,7 @@ EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache);
bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i)
{
char *to = addr;
- if (unlikely(i->type & ITER_PIPE)) {
+ if (unlikely(iov_iter_is_pipe(i))) {
WARN_ON(1);
return false;
}
@@ -836,7 +880,9 @@ size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
size_t wanted = copy_to_iter(kaddr + offset, bytes, i);
kunmap_atomic(kaddr);
return wanted;
- } else if (likely(!(i->type & ITER_PIPE)))
+ } else if (unlikely(iov_iter_is_discard(i)))
+ return bytes;
+ else if (likely(!iov_iter_is_pipe(i)))
return copy_page_to_iter_iovec(page, offset, bytes, i);
else
return copy_page_to_iter_pipe(page, offset, bytes, i);
@@ -848,7 +894,7 @@ size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes,
{
if (unlikely(!page_copy_sane(page, offset, bytes)))
return 0;
- if (unlikely(i->type & ITER_PIPE)) {
+ if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) {
WARN_ON(1);
return 0;
}
@@ -888,7 +934,7 @@ static size_t pipe_zero(size_t bytes, struct iov_iter *i)
size_t iov_iter_zero(size_t bytes, struct iov_iter *i)
{
- if (unlikely(i->type & ITER_PIPE))
+ if (unlikely(iov_iter_is_pipe(i)))
return pipe_zero(bytes, i);
iterate_and_advance(i, bytes, v,
clear_user(v.iov_base, v.iov_len),
@@ -908,7 +954,7 @@ size_t iov_iter_copy_from_user_atomic(struct page *page,
kunmap_atomic(kaddr);
return 0;
}
- if (unlikely(i->type & ITER_PIPE)) {
+ if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) {
kunmap_atomic(kaddr);
WARN_ON(1);
return 0;
@@ -972,10 +1018,14 @@ static void pipe_advance(struct iov_iter *i, size_t size)
void iov_iter_advance(struct iov_iter *i, size_t size)
{
- if (unlikely(i->type & ITER_PIPE)) {
+ if (unlikely(iov_iter_is_pipe(i))) {
pipe_advance(i, size);
return;
}
+ if (unlikely(iov_iter_is_discard(i))) {
+ i->count -= size;
+ return;
+ }
iterate_and_advance(i, size, v, 0, 0, 0)
}
EXPORT_SYMBOL(iov_iter_advance);
@@ -987,7 +1037,7 @@ void iov_iter_revert(struct iov_iter *i, size_t unroll)
if (WARN_ON(unroll > MAX_RW_COUNT))
return;
i->count += unroll;
- if (unlikely(i->type & ITER_PIPE)) {
+ if (unlikely(iov_iter_is_pipe(i))) {
struct pipe_inode_info *pipe = i->pipe;
int idx = i->idx;
size_t off = i->iov_offset;
@@ -1011,12 +1061,14 @@ void iov_iter_revert(struct iov_iter *i, size_t unroll)
pipe_truncate(i);
return;
}
+ if (unlikely(iov_iter_is_discard(i)))
+ return;
if (unroll <= i->iov_offset) {
i->iov_offset -= unroll;
return;
}
unroll -= i->iov_offset;
- if (i->type & ITER_BVEC) {
+ if (iov_iter_is_bvec(i)) {
const struct bio_vec *bvec = i->bvec;
while (1) {
size_t n = (--bvec)->bv_len;
@@ -1049,23 +1101,25 @@ EXPORT_SYMBOL(iov_iter_revert);
*/
size_t iov_iter_single_seg_count(const struct iov_iter *i)
{
- if (unlikely(i->type & ITER_PIPE))
+ if (unlikely(iov_iter_is_pipe(i)))
return i->count; // it is a silly place, anyway
if (i->nr_segs == 1)
return i->count;
- else if (i->type & ITER_BVEC)
+ if (unlikely(iov_iter_is_discard(i)))
+ return i->count;
+ else if (iov_iter_is_bvec(i))
return min(i->count, i->bvec->bv_len - i->iov_offset);
else
return min(i->count, i->iov->iov_len - i->iov_offset);
}
EXPORT_SYMBOL(iov_iter_single_seg_count);
-void iov_iter_kvec(struct iov_iter *i, int direction,
+void iov_iter_kvec(struct iov_iter *i, unsigned int direction,
const struct kvec *kvec, unsigned long nr_segs,
size_t count)
{
- BUG_ON(!(direction & ITER_KVEC));
- i->type = direction;
+ WARN_ON(direction & ~(READ | WRITE));
+ i->type = ITER_KVEC | (direction & (READ | WRITE));
i->kvec = kvec;
i->nr_segs = nr_segs;
i->iov_offset = 0;
@@ -1073,12 +1127,12 @@ void iov_iter_kvec(struct iov_iter *i, int direction,
}
EXPORT_SYMBOL(iov_iter_kvec);
-void iov_iter_bvec(struct iov_iter *i, int direction,
+void iov_iter_bvec(struct iov_iter *i, unsigned int direction,
const struct bio_vec *bvec, unsigned long nr_segs,
size_t count)
{
- BUG_ON(!(direction & ITER_BVEC));
- i->type = direction;
+ WARN_ON(direction & ~(READ | WRITE));
+ i->type = ITER_BVEC | (direction & (READ | WRITE));
i->bvec = bvec;
i->nr_segs = nr_segs;
i->iov_offset = 0;
@@ -1086,13 +1140,13 @@ void iov_iter_bvec(struct iov_iter *i, int direction,
}
EXPORT_SYMBOL(iov_iter_bvec);
-void iov_iter_pipe(struct iov_iter *i, int direction,
+void iov_iter_pipe(struct iov_iter *i, unsigned int direction,
struct pipe_inode_info *pipe,
size_t count)
{
- BUG_ON(direction != ITER_PIPE);
+ BUG_ON(direction != READ);
WARN_ON(pipe->nrbufs == pipe->buffers);
- i->type = direction;
+ i->type = ITER_PIPE | READ;
i->pipe = pipe;
i->idx = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1);
i->iov_offset = 0;
@@ -1101,12 +1155,30 @@ void iov_iter_pipe(struct iov_iter *i, int direction,
}
EXPORT_SYMBOL(iov_iter_pipe);
+/**
+ * iov_iter_discard - Initialise an I/O iterator that discards data
+ * @i: The iterator to initialise.
+ * @direction: The direction of the transfer.
+ * @count: The size of the I/O buffer in bytes.
+ *
+ * Set up an I/O iterator that just discards everything that's written to it.
+ * It's only available as a READ iterator.
+ */
+void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count)
+{
+ BUG_ON(direction != READ);
+ i->type = ITER_DISCARD | READ;
+ i->count = count;
+ i->iov_offset = 0;
+}
+EXPORT_SYMBOL(iov_iter_discard);
+
unsigned long iov_iter_alignment(const struct iov_iter *i)
{
unsigned long res = 0;
size_t size = i->count;
- if (unlikely(i->type & ITER_PIPE)) {
+ if (unlikely(iov_iter_is_pipe(i))) {
if (size && i->iov_offset && allocated(&i->pipe->bufs[i->idx]))
return size | i->iov_offset;
return size;
@@ -1125,7 +1197,7 @@ unsigned long iov_iter_gap_alignment(const struct iov_iter *i)
unsigned long res = 0;
size_t size = i->count;
- if (unlikely(i->type & ITER_PIPE)) {
+ if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) {
WARN_ON(1);
return ~0U;
}
@@ -1193,8 +1265,11 @@ ssize_t iov_iter_get_pages(struct iov_iter *i,
if (maxsize > i->count)
maxsize = i->count;
- if (unlikely(i->type & ITER_PIPE))
+ if (unlikely(iov_iter_is_pipe(i)))
return pipe_get_pages(i, pages, maxsize, maxpages, start);
+ if (unlikely(iov_iter_is_discard(i)))
+ return -EFAULT;
+
iterate_all_kinds(i, maxsize, v, ({
unsigned long addr = (unsigned long)v.iov_base;
size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1));
@@ -1205,7 +1280,7 @@ ssize_t iov_iter_get_pages(struct iov_iter *i,
len = maxpages * PAGE_SIZE;
addr &= ~(PAGE_SIZE - 1);
n = DIV_ROUND_UP(len, PAGE_SIZE);
- res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, pages);
+ res = get_user_pages_fast(addr, n, iov_iter_rw(i) != WRITE, pages);
if (unlikely(res < 0))
return res;
return (res == n ? len : res * PAGE_SIZE) - *start;
@@ -1270,8 +1345,11 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i,
if (maxsize > i->count)
maxsize = i->count;
- if (unlikely(i->type & ITER_PIPE))
+ if (unlikely(iov_iter_is_pipe(i)))
return pipe_get_pages_alloc(i, pages, maxsize, start);
+ if (unlikely(iov_iter_is_discard(i)))
+ return -EFAULT;
+
iterate_all_kinds(i, maxsize, v, ({
unsigned long addr = (unsigned long)v.iov_base;
size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1));
@@ -1283,7 +1361,7 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i,
p = get_pages_array(n);
if (!p)
return -ENOMEM;
- res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, p);
+ res = get_user_pages_fast(addr, n, iov_iter_rw(i) != WRITE, p);
if (unlikely(res < 0)) {
kvfree(p);
return res;
@@ -1313,7 +1391,7 @@ size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum,
__wsum sum, next;
size_t off = 0;
sum = *csum;
- if (unlikely(i->type & ITER_PIPE)) {
+ if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) {
WARN_ON(1);
return 0;
}
@@ -1329,17 +1407,15 @@ size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum,
err ? v.iov_len : 0;
}), ({
char *p = kmap_atomic(v.bv_page);
- next = csum_partial_copy_nocheck(p + v.bv_offset,
- (to += v.bv_len) - v.bv_len,
- v.bv_len, 0);
+ sum = csum_and_memcpy((to += v.bv_len) - v.bv_len,
+ p + v.bv_offset, v.bv_len,
+ sum, off);
kunmap_atomic(p);
- sum = csum_block_add(sum, next, off);
off += v.bv_len;
}),({
- next = csum_partial_copy_nocheck(v.iov_base,
- (to += v.iov_len) - v.iov_len,
- v.iov_len, 0);
- sum = csum_block_add(sum, next, off);
+ sum = csum_and_memcpy((to += v.iov_len) - v.iov_len,
+ v.iov_base, v.iov_len,
+ sum, off);
off += v.iov_len;
})
)
@@ -1355,7 +1431,7 @@ bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum,
__wsum sum, next;
size_t off = 0;
sum = *csum;
- if (unlikely(i->type & ITER_PIPE)) {
+ if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) {
WARN_ON(1);
return false;
}
@@ -1373,17 +1449,15 @@ bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum,
0;
}), ({
char *p = kmap_atomic(v.bv_page);
- next = csum_partial_copy_nocheck(p + v.bv_offset,
- (to += v.bv_len) - v.bv_len,
- v.bv_len, 0);
+ sum = csum_and_memcpy((to += v.bv_len) - v.bv_len,
+ p + v.bv_offset, v.bv_len,
+ sum, off);
kunmap_atomic(p);
- sum = csum_block_add(sum, next, off);
off += v.bv_len;
}),({
- next = csum_partial_copy_nocheck(v.iov_base,
- (to += v.iov_len) - v.iov_len,
- v.iov_len, 0);
- sum = csum_block_add(sum, next, off);
+ sum = csum_and_memcpy((to += v.iov_len) - v.iov_len,
+ v.iov_base, v.iov_len,
+ sum, off);
off += v.iov_len;
})
)
@@ -1393,14 +1467,19 @@ bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum,
}
EXPORT_SYMBOL(csum_and_copy_from_iter_full);
-size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum,
+size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csump,
struct iov_iter *i)
{
const char *from = addr;
+ __wsum *csum = csump;
__wsum sum, next;
size_t off = 0;
+
+ if (unlikely(iov_iter_is_pipe(i)))
+ return csum_and_copy_to_pipe_iter(addr, bytes, csum, i);
+
sum = *csum;
- if (unlikely(i->type & ITER_PIPE)) {
+ if (unlikely(iov_iter_is_discard(i))) {
WARN_ON(1); /* for now */
return 0;
}
@@ -1416,17 +1495,15 @@ size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum,
err ? v.iov_len : 0;
}), ({
char *p = kmap_atomic(v.bv_page);
- next = csum_partial_copy_nocheck((from += v.bv_len) - v.bv_len,
- p + v.bv_offset,
- v.bv_len, 0);
+ sum = csum_and_memcpy(p + v.bv_offset,
+ (from += v.bv_len) - v.bv_len,
+ v.bv_len, sum, off);
kunmap_atomic(p);
- sum = csum_block_add(sum, next, off);
off += v.bv_len;
}),({
- next = csum_partial_copy_nocheck((from += v.iov_len) - v.iov_len,
- v.iov_base,
- v.iov_len, 0);
- sum = csum_block_add(sum, next, off);
+ sum = csum_and_memcpy(v.iov_base,
+ (from += v.iov_len) - v.iov_len,
+ v.iov_len, sum, off);
off += v.iov_len;
})
)
@@ -1435,6 +1512,21 @@ size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum,
}
EXPORT_SYMBOL(csum_and_copy_to_iter);
+size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp,
+ struct iov_iter *i)
+{
+ struct ahash_request *hash = hashp;
+ struct scatterlist sg;
+ size_t copied;
+
+ copied = copy_to_iter(addr, bytes, i);
+ sg_init_one(&sg, addr, copied);
+ ahash_request_set_crypt(hash, &sg, NULL, copied);
+ crypto_ahash_update(hash);
+ return copied;
+}
+EXPORT_SYMBOL(hash_and_copy_to_iter);
+
int iov_iter_npages(const struct iov_iter *i, int maxpages)
{
size_t size = i->count;
@@ -1442,8 +1534,10 @@ int iov_iter_npages(const struct iov_iter *i, int maxpages)
if (!size)
return 0;
+ if (unlikely(iov_iter_is_discard(i)))
+ return 0;
- if (unlikely(i->type & ITER_PIPE)) {
+ if (unlikely(iov_iter_is_pipe(i))) {
struct pipe_inode_info *pipe = i->pipe;
size_t off;
int idx;
@@ -1481,11 +1575,13 @@ EXPORT_SYMBOL(iov_iter_npages);
const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags)
{
*new = *old;
- if (unlikely(new->type & ITER_PIPE)) {
+ if (unlikely(iov_iter_is_pipe(new))) {
WARN_ON(1);
return NULL;
}
- if (new->type & ITER_BVEC)
+ if (unlikely(iov_iter_is_discard(new)))
+ return NULL;
+ if (iov_iter_is_bvec(new))
return new->bvec = kmemdup(new->bvec,
new->nr_segs * sizeof(struct bio_vec),
flags);
@@ -1567,7 +1663,7 @@ int import_single_range(int rw, void __user *buf, size_t len,
{
if (len > MAX_RW_COUNT)
len = MAX_RW_COUNT;
- if (unlikely(!access_ok(!rw, buf, len)))
+ if (unlikely(!access_ok(buf, len)))
return -EFAULT;
iov->iov_base = buf;
generated by cgit v1.2.3-70-g09d2 (git 2.48.1) at 2025-04-15 21:26:50 +0000