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authorLinus Torvalds <torvalds@linux-foundation.org>2016-05-18 11:46:23 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-05-18 11:46:23 -0700
commit69370471d0b2fc3020c60f5473b1eef5977d165a (patch)
treee0ba8b51204779afb17b5749657e9709e8a1ea3e
parente34df3344d7b6f284e958147d7225faa340a1f39 (diff)
parentdd254f5a382cc7879db7a07ed266b12d38fe3ab6 (diff)
downloadop-kernel-dev-69370471d0b2fc3020c60f5473b1eef5977d165a.zip
op-kernel-dev-69370471d0b2fc3020c60f5473b1eef5977d165a.tar.gz
Merge branch 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull iov_iter cleanups from Al Viro. * 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fold checks into iterate_and_advance() rw_verify_area(): saner calling conventions aio: remove a pointless assignment
-rw-r--r--fs/aio.c2
-rw-r--r--fs/read_write.c33
-rw-r--r--lib/iov_iter.c104
3 files changed, 50 insertions, 89 deletions
diff --git a/fs/aio.c b/fs/aio.c
index 155f842..a6deaa7 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1447,8 +1447,6 @@ rw_common:
return ret;
}
- len = ret;
-
if (rw == WRITE)
file_start_write(file);
diff --git a/fs/read_write.c b/fs/read_write.c
index 56425cd..933b53a 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -398,11 +398,6 @@ ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos)
}
EXPORT_SYMBOL(vfs_iter_write);
-/*
- * rw_verify_area doesn't like huge counts. We limit
- * them to something that fits in "int" so that others
- * won't have to do range checks all the time.
- */
int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count)
{
struct inode *inode;
@@ -429,11 +424,8 @@ int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t
if (retval < 0)
return retval;
}
- retval = security_file_permission(file,
+ return security_file_permission(file,
read_write == READ ? MAY_READ : MAY_WRITE);
- if (retval)
- return retval;
- return count > MAX_RW_COUNT ? MAX_RW_COUNT : count;
}
static ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos)
@@ -477,8 +469,9 @@ ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
return -EFAULT;
ret = rw_verify_area(READ, file, pos, count);
- if (ret >= 0) {
- count = ret;
+ if (!ret) {
+ if (count > MAX_RW_COUNT)
+ count = MAX_RW_COUNT;
ret = __vfs_read(file, buf, count, pos);
if (ret > 0) {
fsnotify_access(file);
@@ -560,8 +553,9 @@ ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_
return -EFAULT;
ret = rw_verify_area(WRITE, file, pos, count);
- if (ret >= 0) {
- count = ret;
+ if (!ret) {
+ if (count > MAX_RW_COUNT)
+ count = MAX_RW_COUNT;
file_start_write(file);
ret = __vfs_write(file, buf, count, pos);
if (ret > 0) {
@@ -1315,7 +1309,8 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
retval = rw_verify_area(READ, in.file, &pos, count);
if (retval < 0)
goto fput_in;
- count = retval;
+ if (count > MAX_RW_COUNT)
+ count = MAX_RW_COUNT;
/*
* Get output file, and verify that it is ok..
@@ -1333,7 +1328,6 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
retval = rw_verify_area(WRITE, out.file, &out_pos, count);
if (retval < 0)
goto fput_out;
- count = retval;
if (!max)
max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes);
@@ -1477,11 +1471,12 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in,
if (flags != 0)
return -EINVAL;
- /* copy_file_range allows full ssize_t len, ignoring MAX_RW_COUNT */
ret = rw_verify_area(READ, file_in, &pos_in, len);
- if (ret >= 0)
- ret = rw_verify_area(WRITE, file_out, &pos_out, len);
- if (ret < 0)
+ if (unlikely(ret))
+ return ret;
+
+ ret = rw_verify_area(WRITE, file_out, &pos_out, len);
+ if (unlikely(ret))
return ret;
if (!(file_in->f_mode & FMODE_READ) ||
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index ca5316e..28cb431 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -99,40 +99,44 @@
}
#define iterate_and_advance(i, n, v, I, B, K) { \
- size_t skip = i->iov_offset; \
- if (unlikely(i->type & ITER_BVEC)) { \
- const struct bio_vec *bvec; \
- struct bio_vec v; \
- iterate_bvec(i, n, v, bvec, skip, (B)) \
- if (skip == bvec->bv_len) { \
- bvec++; \
- skip = 0; \
- } \
- i->nr_segs -= bvec - i->bvec; \
- i->bvec = bvec; \
- } else if (unlikely(i->type & ITER_KVEC)) { \
- const struct kvec *kvec; \
- struct kvec v; \
- iterate_kvec(i, n, v, kvec, skip, (K)) \
- if (skip == kvec->iov_len) { \
- kvec++; \
- skip = 0; \
- } \
- i->nr_segs -= kvec - i->kvec; \
- i->kvec = kvec; \
- } else { \
- const struct iovec *iov; \
- struct iovec v; \
- iterate_iovec(i, n, v, iov, skip, (I)) \
- if (skip == iov->iov_len) { \
- iov++; \
- skip = 0; \
+ if (unlikely(i->count < n)) \
+ n = i->count; \
+ if (n) { \
+ size_t skip = i->iov_offset; \
+ if (unlikely(i->type & ITER_BVEC)) { \
+ const struct bio_vec *bvec; \
+ struct bio_vec v; \
+ iterate_bvec(i, n, v, bvec, skip, (B)) \
+ if (skip == bvec->bv_len) { \
+ bvec++; \
+ skip = 0; \
+ } \
+ i->nr_segs -= bvec - i->bvec; \
+ i->bvec = bvec; \
+ } else if (unlikely(i->type & ITER_KVEC)) { \
+ const struct kvec *kvec; \
+ struct kvec v; \
+ iterate_kvec(i, n, v, kvec, skip, (K)) \
+ if (skip == kvec->iov_len) { \
+ kvec++; \
+ skip = 0; \
+ } \
+ i->nr_segs -= kvec - i->kvec; \
+ i->kvec = kvec; \
+ } else { \
+ const struct iovec *iov; \
+ struct iovec v; \
+ iterate_iovec(i, n, v, iov, skip, (I)) \
+ if (skip == iov->iov_len) { \
+ iov++; \
+ skip = 0; \
+ } \
+ i->nr_segs -= iov - i->iov; \
+ i->iov = iov; \
} \
- i->nr_segs -= iov - i->iov; \
- i->iov = iov; \
+ i->count -= n; \
+ i->iov_offset = skip; \
} \
- i->count -= n; \
- i->iov_offset = skip; \
}
static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes,
@@ -386,12 +390,6 @@ static void memzero_page(struct page *page, size_t offset, size_t len)
size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
{
const char *from = addr;
- if (unlikely(bytes > i->count))
- bytes = i->count;
-
- if (unlikely(!bytes))
- return 0;
-
iterate_and_advance(i, bytes, v,
__copy_to_user(v.iov_base, (from += v.iov_len) - v.iov_len,
v.iov_len),
@@ -407,12 +405,6 @@ EXPORT_SYMBOL(copy_to_iter);
size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
{
char *to = addr;
- if (unlikely(bytes > i->count))
- bytes = i->count;
-
- if (unlikely(!bytes))
- return 0;
-
iterate_and_advance(i, bytes, v,
__copy_from_user((to += v.iov_len) - v.iov_len, v.iov_base,
v.iov_len),
@@ -428,12 +420,6 @@ EXPORT_SYMBOL(copy_from_iter);
size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i)
{
char *to = addr;
- if (unlikely(bytes > i->count))
- bytes = i->count;
-
- if (unlikely(!bytes))
- return 0;
-
iterate_and_advance(i, bytes, v,
__copy_from_user_nocache((to += v.iov_len) - v.iov_len,
v.iov_base, v.iov_len),
@@ -474,12 +460,6 @@ EXPORT_SYMBOL(copy_page_from_iter);
size_t iov_iter_zero(size_t bytes, struct iov_iter *i)
{
- if (unlikely(bytes > i->count))
- bytes = i->count;
-
- if (unlikely(!bytes))
- return 0;
-
iterate_and_advance(i, bytes, v,
__clear_user(v.iov_base, v.iov_len),
memzero_page(v.bv_page, v.bv_offset, v.bv_len),
@@ -685,12 +665,6 @@ size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum,
char *to = addr;
__wsum sum, next;
size_t off = 0;
- if (unlikely(bytes > i->count))
- bytes = i->count;
-
- if (unlikely(!bytes))
- return 0;
-
sum = *csum;
iterate_and_advance(i, bytes, v, ({
int err = 0;
@@ -729,12 +703,6 @@ size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum,
const char *from = addr;
__wsum sum, next;
size_t off = 0;
- if (unlikely(bytes > i->count))
- bytes = i->count;
-
- if (unlikely(!bytes))
- return 0;
-
sum = *csum;
iterate_and_advance(i, bytes, v, ({
int err = 0;
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