* [PATCH 01/14] cachefiles: switch to kernel_write
2020-06-24 16:13 clean up kernel_{read,write} & friends v5 Christoph Hellwig
@ 2020-06-24 16:13 ` Christoph Hellwig
2020-06-24 16:13 ` [PATCH 02/14] autofs: " Christoph Hellwig
` (12 subsequent siblings)
13 siblings, 0 replies; 17+ messages in thread
From: Christoph Hellwig @ 2020-06-24 16:13 UTC (permalink / raw)
To: Al Viro
Cc: Linus Torvalds, Ian Kent, David Howells, linux-kernel,
linux-fsdevel, linux-security-module, netfilter-devel
__kernel_write doesn't take a sb_writers references, which we need here.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Howells <dhowells@redhat.com>
---
fs/cachefiles/rdwr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/cachefiles/rdwr.c b/fs/cachefiles/rdwr.c
index e7726f5f1241c2..3080cda9e82457 100644
--- a/fs/cachefiles/rdwr.c
+++ b/fs/cachefiles/rdwr.c
@@ -937,7 +937,7 @@ int cachefiles_write_page(struct fscache_storage *op, struct page *page)
}
data = kmap(page);
- ret = __kernel_write(file, data, len, &pos);
+ ret = kernel_write(file, data, len, &pos);
kunmap(page);
fput(file);
if (ret != len)
--
2.26.2
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [PATCH 02/14] autofs: switch to kernel_write
2020-06-24 16:13 clean up kernel_{read,write} & friends v5 Christoph Hellwig
2020-06-24 16:13 ` [PATCH 01/14] cachefiles: switch to kernel_write Christoph Hellwig
@ 2020-06-24 16:13 ` Christoph Hellwig
2020-06-24 16:13 ` [PATCH 03/14] bpfilter: " Christoph Hellwig
` (11 subsequent siblings)
13 siblings, 0 replies; 17+ messages in thread
From: Christoph Hellwig @ 2020-06-24 16:13 UTC (permalink / raw)
To: Al Viro
Cc: Linus Torvalds, Ian Kent, David Howells, linux-kernel,
linux-fsdevel, linux-security-module, netfilter-devel
While pipes don't really need sb_writers projection, __kernel_write is an
interface better kept private, and the additional rw_verify_area does not
hurt here.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Ian Kent <raven@themaw.net>
---
fs/autofs/waitq.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/autofs/waitq.c b/fs/autofs/waitq.c
index b04c528b19d342..74c886f7c51cbe 100644
--- a/fs/autofs/waitq.c
+++ b/fs/autofs/waitq.c
@@ -53,7 +53,7 @@ static int autofs_write(struct autofs_sb_info *sbi,
mutex_lock(&sbi->pipe_mutex);
while (bytes) {
- wr = __kernel_write(file, data, bytes, &file->f_pos);
+ wr = kernel_write(file, data, bytes, &file->f_pos);
if (wr <= 0)
break;
data += wr;
--
2.26.2
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [PATCH 03/14] bpfilter: switch to kernel_write
2020-06-24 16:13 clean up kernel_{read,write} & friends v5 Christoph Hellwig
2020-06-24 16:13 ` [PATCH 01/14] cachefiles: switch to kernel_write Christoph Hellwig
2020-06-24 16:13 ` [PATCH 02/14] autofs: " Christoph Hellwig
@ 2020-06-24 16:13 ` Christoph Hellwig
2020-06-24 16:13 ` [PATCH 04/14] fs: unexport __kernel_write Christoph Hellwig
` (10 subsequent siblings)
13 siblings, 0 replies; 17+ messages in thread
From: Christoph Hellwig @ 2020-06-24 16:13 UTC (permalink / raw)
To: Al Viro
Cc: Linus Torvalds, Ian Kent, David Howells, linux-kernel,
linux-fsdevel, linux-security-module, netfilter-devel
While pipes don't really need sb_writers projection, __kernel_write is an
interface better kept private, and the additional rw_verify_area does not
hurt here.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
net/bpfilter/bpfilter_kern.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/bpfilter/bpfilter_kern.c b/net/bpfilter/bpfilter_kern.c
index c0f0990f30b604..1905e01c3aa9a7 100644
--- a/net/bpfilter/bpfilter_kern.c
+++ b/net/bpfilter/bpfilter_kern.c
@@ -50,7 +50,7 @@ static int __bpfilter_process_sockopt(struct sock *sk, int optname,
req.len = optlen;
if (!bpfilter_ops.info.pid)
goto out;
- n = __kernel_write(bpfilter_ops.info.pipe_to_umh, &req, sizeof(req),
+ n = kernel_write(bpfilter_ops.info.pipe_to_umh, &req, sizeof(req),
&pos);
if (n != sizeof(req)) {
pr_err("write fail %zd\n", n);
--
2.26.2
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [PATCH 04/14] fs: unexport __kernel_write
2020-06-24 16:13 clean up kernel_{read,write} & friends v5 Christoph Hellwig
` (2 preceding siblings ...)
2020-06-24 16:13 ` [PATCH 03/14] bpfilter: " Christoph Hellwig
@ 2020-06-24 16:13 ` Christoph Hellwig
2020-06-24 16:13 ` [PATCH 05/14] fs: check FMODE_WRITE in __kernel_write Christoph Hellwig
` (9 subsequent siblings)
13 siblings, 0 replies; 17+ messages in thread
From: Christoph Hellwig @ 2020-06-24 16:13 UTC (permalink / raw)
To: Al Viro
Cc: Linus Torvalds, Ian Kent, David Howells, linux-kernel,
linux-fsdevel, linux-security-module, netfilter-devel
This is a very special interface that skips sb_writes protection, and not
used by modules anymore.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/read_write.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/fs/read_write.c b/fs/read_write.c
index bbfa9b12b15eb7..2c601d853ff3d8 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -522,7 +522,6 @@ ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t
inc_syscw(current);
return ret;
}
-EXPORT_SYMBOL(__kernel_write);
ssize_t kernel_write(struct file *file, const void *buf, size_t count,
loff_t *pos)
--
2.26.2
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [PATCH 05/14] fs: check FMODE_WRITE in __kernel_write
2020-06-24 16:13 clean up kernel_{read,write} & friends v5 Christoph Hellwig
` (3 preceding siblings ...)
2020-06-24 16:13 ` [PATCH 04/14] fs: unexport __kernel_write Christoph Hellwig
@ 2020-06-24 16:13 ` Christoph Hellwig
2020-06-24 16:13 ` [PATCH 06/14] fs: implement kernel_write using __kernel_write Christoph Hellwig
` (8 subsequent siblings)
13 siblings, 0 replies; 17+ messages in thread
From: Christoph Hellwig @ 2020-06-24 16:13 UTC (permalink / raw)
To: Al Viro
Cc: Linus Torvalds, Ian Kent, David Howells, linux-kernel,
linux-fsdevel, linux-security-module, netfilter-devel
Add a WARN_ON_ONCE if the file isn't actually open for write. This
matches the check done in vfs_write, but actually warn warns as a
kernel user calling write on a file not opened for writing is a pretty
obvious programming error.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/read_write.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/read_write.c b/fs/read_write.c
index 2c601d853ff3d8..8f9fc05990ae8b 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -505,6 +505,8 @@ ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t
const char __user *p;
ssize_t ret;
+ if (WARN_ON_ONCE(!(file->f_mode & FMODE_WRITE)))
+ return -EBADF;
if (!(file->f_mode & FMODE_CAN_WRITE))
return -EINVAL;
--
2.26.2
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [PATCH 06/14] fs: implement kernel_write using __kernel_write
2020-06-24 16:13 clean up kernel_{read,write} & friends v5 Christoph Hellwig
` (4 preceding siblings ...)
2020-06-24 16:13 ` [PATCH 05/14] fs: check FMODE_WRITE in __kernel_write Christoph Hellwig
@ 2020-06-24 16:13 ` Christoph Hellwig
2020-06-24 16:13 ` [PATCH 07/14] fs: remove __vfs_write Christoph Hellwig
` (7 subsequent siblings)
13 siblings, 0 replies; 17+ messages in thread
From: Christoph Hellwig @ 2020-06-24 16:13 UTC (permalink / raw)
To: Al Viro
Cc: Linus Torvalds, Ian Kent, David Howells, linux-kernel,
linux-fsdevel, linux-security-module, netfilter-devel
Consolidate the two in-kernel write helpers to make upcoming changes
easier. The only difference are the missing call to rw_verify_area
in kernel_write, and an access_ok check that doesn't make sense for
kernel buffers to start with.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/read_write.c | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)
diff --git a/fs/read_write.c b/fs/read_write.c
index 8f9fc05990ae8b..5110cd1e6e2771 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -499,6 +499,7 @@ static ssize_t __vfs_write(struct file *file, const char __user *p,
return -EINVAL;
}
+/* caller is responsible for file_start_write/file_end_write */
ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t *pos)
{
mm_segment_t old_fs;
@@ -528,16 +529,16 @@ ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t
ssize_t kernel_write(struct file *file, const void *buf, size_t count,
loff_t *pos)
{
- mm_segment_t old_fs;
- ssize_t res;
+ ssize_t ret;
- old_fs = get_fs();
- set_fs(KERNEL_DS);
- /* The cast to a user pointer is valid due to the set_fs() */
- res = vfs_write(file, (__force const char __user *)buf, count, pos);
- set_fs(old_fs);
+ ret = rw_verify_area(WRITE, file, pos, count);
+ if (ret)
+ return ret;
- return res;
+ file_start_write(file);
+ ret = __kernel_write(file, buf, count, pos);
+ file_end_write(file);
+ return ret;
}
EXPORT_SYMBOL(kernel_write);
--
2.26.2
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [PATCH 07/14] fs: remove __vfs_write
2020-06-24 16:13 clean up kernel_{read,write} & friends v5 Christoph Hellwig
` (5 preceding siblings ...)
2020-06-24 16:13 ` [PATCH 06/14] fs: implement kernel_write using __kernel_write Christoph Hellwig
@ 2020-06-24 16:13 ` Christoph Hellwig
2020-06-24 16:13 ` [PATCH 08/14] fs: don't change the address limit for ->write_iter in __kernel_write Christoph Hellwig
` (6 subsequent siblings)
13 siblings, 0 replies; 17+ messages in thread
From: Christoph Hellwig @ 2020-06-24 16:13 UTC (permalink / raw)
To: Al Viro
Cc: Linus Torvalds, Ian Kent, David Howells, linux-kernel,
linux-fsdevel, linux-security-module, netfilter-devel
Fold it into the two callers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/read_write.c | 46 ++++++++++++++++++++++------------------------
1 file changed, 22 insertions(+), 24 deletions(-)
diff --git a/fs/read_write.c b/fs/read_write.c
index 5110cd1e6e2771..96e8e354f99b45 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -488,17 +488,6 @@ static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t
return ret;
}
-static ssize_t __vfs_write(struct file *file, const char __user *p,
- size_t count, loff_t *pos)
-{
- if (file->f_op->write)
- return file->f_op->write(file, p, count, pos);
- else if (file->f_op->write_iter)
- return new_sync_write(file, p, count, pos);
- else
- return -EINVAL;
-}
-
/* caller is responsible for file_start_write/file_end_write */
ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t *pos)
{
@@ -516,7 +505,12 @@ ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t
p = (__force const char __user *)buf;
if (count > MAX_RW_COUNT)
count = MAX_RW_COUNT;
- ret = __vfs_write(file, p, count, pos);
+ if (file->f_op->write)
+ ret = file->f_op->write(file, p, count, pos);
+ else if (file->f_op->write_iter)
+ ret = new_sync_write(file, p, count, pos);
+ else
+ ret = -EINVAL;
set_fs(old_fs);
if (ret > 0) {
fsnotify_modify(file);
@@ -554,19 +548,23 @@ 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) {
- if (count > MAX_RW_COUNT)
- count = MAX_RW_COUNT;
- file_start_write(file);
- ret = __vfs_write(file, buf, count, pos);
- if (ret > 0) {
- fsnotify_modify(file);
- add_wchar(current, ret);
- }
- inc_syscw(current);
- file_end_write(file);
+ if (ret)
+ return ret;
+ if (count > MAX_RW_COUNT)
+ count = MAX_RW_COUNT;
+ file_start_write(file);
+ if (file->f_op->write)
+ ret = file->f_op->write(file, buf, count, pos);
+ else if (file->f_op->write_iter)
+ ret = new_sync_write(file, buf, count, pos);
+ else
+ ret = -EINVAL;
+ if (ret > 0) {
+ fsnotify_modify(file);
+ add_wchar(current, ret);
}
-
+ inc_syscw(current);
+ file_end_write(file);
return ret;
}
--
2.26.2
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [PATCH 08/14] fs: don't change the address limit for ->write_iter in __kernel_write
2020-06-24 16:13 clean up kernel_{read,write} & friends v5 Christoph Hellwig
` (6 preceding siblings ...)
2020-06-24 16:13 ` [PATCH 07/14] fs: remove __vfs_write Christoph Hellwig
@ 2020-06-24 16:13 ` Christoph Hellwig
2020-06-24 16:13 ` [PATCH 09/14] fs: add a __kernel_read helper Christoph Hellwig
` (5 subsequent siblings)
13 siblings, 0 replies; 17+ messages in thread
From: Christoph Hellwig @ 2020-06-24 16:13 UTC (permalink / raw)
To: Al Viro
Cc: Linus Torvalds, Ian Kent, David Howells, linux-kernel,
linux-fsdevel, linux-security-module, netfilter-devel
If we write to a file that implements ->write_iter there is no need
to change the address limit if we send a kvec down. Implement that
case, and prefer it over using plain ->write with a changed address
limit if available.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/read_write.c | 34 ++++++++++++++++++++++------------
1 file changed, 22 insertions(+), 12 deletions(-)
diff --git a/fs/read_write.c b/fs/read_write.c
index 96e8e354f99b45..bd46c959799e97 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -489,10 +489,9 @@ static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t
}
/* caller is responsible for file_start_write/file_end_write */
-ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t *pos)
+ssize_t __kernel_write(struct file *file, const void *buf, size_t count,
+ loff_t *pos)
{
- mm_segment_t old_fs;
- const char __user *p;
ssize_t ret;
if (WARN_ON_ONCE(!(file->f_mode & FMODE_WRITE)))
@@ -500,18 +499,29 @@ ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t
if (!(file->f_mode & FMODE_CAN_WRITE))
return -EINVAL;
- old_fs = get_fs();
- set_fs(KERNEL_DS);
- p = (__force const char __user *)buf;
if (count > MAX_RW_COUNT)
count = MAX_RW_COUNT;
- if (file->f_op->write)
- ret = file->f_op->write(file, p, count, pos);
- else if (file->f_op->write_iter)
- ret = new_sync_write(file, p, count, pos);
- else
+ if (file->f_op->write_iter) {
+ struct kvec iov = { .iov_base = (void *)buf, .iov_len = count };
+ struct kiocb kiocb;
+ struct iov_iter iter;
+
+ init_sync_kiocb(&kiocb, file);
+ kiocb.ki_pos = *pos;
+ iov_iter_kvec(&iter, WRITE, &iov, 1, count);
+ ret = file->f_op->write_iter(&kiocb, &iter);
+ if (ret > 0)
+ *pos = kiocb.ki_pos;
+ } else if (file->f_op->write) {
+ mm_segment_t old_fs = get_fs();
+
+ set_fs(KERNEL_DS);
+ ret = file->f_op->write(file, (__force const char __user *)buf,
+ count, pos);
+ set_fs(old_fs);
+ } else {
ret = -EINVAL;
- set_fs(old_fs);
+ }
if (ret > 0) {
fsnotify_modify(file);
add_wchar(current, ret);
--
2.26.2
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [PATCH 09/14] fs: add a __kernel_read helper
2020-06-24 16:13 clean up kernel_{read,write} & friends v5 Christoph Hellwig
` (7 preceding siblings ...)
2020-06-24 16:13 ` [PATCH 08/14] fs: don't change the address limit for ->write_iter in __kernel_write Christoph Hellwig
@ 2020-06-24 16:13 ` Christoph Hellwig
2020-06-24 16:13 ` [PATCH 10/14] integrity/ima: switch to using __kernel_read Christoph Hellwig
` (4 subsequent siblings)
13 siblings, 0 replies; 17+ messages in thread
From: Christoph Hellwig @ 2020-06-24 16:13 UTC (permalink / raw)
To: Al Viro
Cc: Linus Torvalds, Ian Kent, David Howells, linux-kernel,
linux-fsdevel, linux-security-module, netfilter-devel
This is the counterpart to __kernel_write, and skip the rw_verify_area
call compared to kernel_read.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/read_write.c | 23 +++++++++++++++++++++++
include/linux/fs.h | 1 +
2 files changed, 24 insertions(+)
diff --git a/fs/read_write.c b/fs/read_write.c
index bd46c959799e97..cc8e0b4f3cd697 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -430,6 +430,29 @@ ssize_t __vfs_read(struct file *file, char __user *buf, size_t count,
return -EINVAL;
}
+ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)
+{
+ mm_segment_t old_fs = get_fs();
+ ssize_t ret;
+
+ if (WARN_ON_ONCE(!(file->f_mode & FMODE_READ)))
+ return -EINVAL;
+ if (!(file->f_mode & FMODE_CAN_READ))
+ return -EINVAL;
+
+ if (count > MAX_RW_COUNT)
+ count = MAX_RW_COUNT;
+ set_fs(KERNEL_DS);
+ ret = __vfs_read(file, (void __user *)buf, count, pos);
+ set_fs(old_fs);
+ if (ret > 0) {
+ fsnotify_access(file);
+ add_rchar(current, ret);
+ }
+ inc_syscr(current);
+ return ret;
+}
+
ssize_t kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)
{
mm_segment_t old_fs;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 3f881a892ea746..22cbe7b2e91994 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -3033,6 +3033,7 @@ extern int kernel_read_file_from_path_initns(const char *, void **, loff_t *, lo
extern int kernel_read_file_from_fd(int, void **, loff_t *, loff_t,
enum kernel_read_file_id);
extern ssize_t kernel_read(struct file *, void *, size_t, loff_t *);
+ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos);
extern ssize_t kernel_write(struct file *, const void *, size_t, loff_t *);
extern ssize_t __kernel_write(struct file *, const void *, size_t, loff_t *);
extern struct file * open_exec(const char *);
--
2.26.2
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [PATCH 10/14] integrity/ima: switch to using __kernel_read
2020-06-24 16:13 clean up kernel_{read,write} & friends v5 Christoph Hellwig
` (8 preceding siblings ...)
2020-06-24 16:13 ` [PATCH 09/14] fs: add a __kernel_read helper Christoph Hellwig
@ 2020-06-24 16:13 ` Christoph Hellwig
2020-06-24 16:13 ` [PATCH 11/14] fs: implement kernel_read " Christoph Hellwig
` (3 subsequent siblings)
13 siblings, 0 replies; 17+ messages in thread
From: Christoph Hellwig @ 2020-06-24 16:13 UTC (permalink / raw)
To: Al Viro
Cc: Linus Torvalds, Ian Kent, David Howells, linux-kernel,
linux-fsdevel, linux-security-module, netfilter-devel
__kernel_read has a bunch of additional sanity checks, and this moves
the set_fs out of non-core code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
security/integrity/iint.c | 14 +-------------
1 file changed, 1 insertion(+), 13 deletions(-)
diff --git a/security/integrity/iint.c b/security/integrity/iint.c
index e12c4900510f60..1d20003243c3fb 100644
--- a/security/integrity/iint.c
+++ b/security/integrity/iint.c
@@ -188,19 +188,7 @@ DEFINE_LSM(integrity) = {
int integrity_kernel_read(struct file *file, loff_t offset,
void *addr, unsigned long count)
{
- mm_segment_t old_fs;
- char __user *buf = (char __user *)addr;
- ssize_t ret;
-
- if (!(file->f_mode & FMODE_READ))
- return -EBADF;
-
- old_fs = get_fs();
- set_fs(KERNEL_DS);
- ret = __vfs_read(file, buf, count, &offset);
- set_fs(old_fs);
-
- return ret;
+ return __kernel_read(file, addr, count, &offset);
}
/*
--
2.26.2
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [PATCH 11/14] fs: implement kernel_read using __kernel_read
2020-06-24 16:13 clean up kernel_{read,write} & friends v5 Christoph Hellwig
` (9 preceding siblings ...)
2020-06-24 16:13 ` [PATCH 10/14] integrity/ima: switch to using __kernel_read Christoph Hellwig
@ 2020-06-24 16:13 ` Christoph Hellwig
2020-06-24 16:13 ` [PATCH 12/14] fs: remove __vfs_read Christoph Hellwig
` (2 subsequent siblings)
13 siblings, 0 replies; 17+ messages in thread
From: Christoph Hellwig @ 2020-06-24 16:13 UTC (permalink / raw)
To: Al Viro
Cc: Linus Torvalds, Ian Kent, David Howells, linux-kernel,
linux-fsdevel, linux-security-module, netfilter-devel
Consolidate the two in-kernel read helpers to make upcoming changes
easier. The only difference are the missing call to rw_verify_area
in kernel_read, and an access_ok check that doesn't make sense for
kernel buffers to start with.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/read_write.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)
diff --git a/fs/read_write.c b/fs/read_write.c
index cc8e0b4f3cd697..a0a0b5d1d9249c 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -455,15 +455,12 @@ ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)
ssize_t kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)
{
- mm_segment_t old_fs;
- ssize_t result;
+ ssize_t ret;
- old_fs = get_fs();
- set_fs(KERNEL_DS);
- /* The cast to a user pointer is valid due to the set_fs() */
- result = vfs_read(file, (void __user *)buf, count, pos);
- set_fs(old_fs);
- return result;
+ ret = rw_verify_area(READ, file, pos, count);
+ if (ret)
+ return ret;
+ return __kernel_read(file, buf, count, pos);
}
EXPORT_SYMBOL(kernel_read);
--
2.26.2
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [PATCH 12/14] fs: remove __vfs_read
2020-06-24 16:13 clean up kernel_{read,write} & friends v5 Christoph Hellwig
` (10 preceding siblings ...)
2020-06-24 16:13 ` [PATCH 11/14] fs: implement kernel_read " Christoph Hellwig
@ 2020-06-24 16:13 ` Christoph Hellwig
2020-06-24 16:13 ` [PATCH 13/14] fs: implement default_file_splice_read using __kernel_read Christoph Hellwig
2020-06-24 16:13 ` [PATCH 14/14] fs: don't change the address limit for ->read_iter in __kernel_read Christoph Hellwig
13 siblings, 0 replies; 17+ messages in thread
From: Christoph Hellwig @ 2020-06-24 16:13 UTC (permalink / raw)
To: Al Viro
Cc: Linus Torvalds, Ian Kent, David Howells, linux-kernel,
linux-fsdevel, linux-security-module, netfilter-devel
Fold it into the two callers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/read_write.c | 43 +++++++++++++++++++++----------------------
include/linux/fs.h | 1 -
2 files changed, 21 insertions(+), 23 deletions(-)
diff --git a/fs/read_write.c b/fs/read_write.c
index a0a0b5d1d9249c..6a2170eaee64f9 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -419,17 +419,6 @@ static ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, lo
return ret;
}
-ssize_t __vfs_read(struct file *file, char __user *buf, size_t count,
- loff_t *pos)
-{
- if (file->f_op->read)
- return file->f_op->read(file, buf, count, pos);
- else if (file->f_op->read_iter)
- return new_sync_read(file, buf, count, pos);
- else
- return -EINVAL;
-}
-
ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)
{
mm_segment_t old_fs = get_fs();
@@ -443,7 +432,12 @@ ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)
if (count > MAX_RW_COUNT)
count = MAX_RW_COUNT;
set_fs(KERNEL_DS);
- ret = __vfs_read(file, (void __user *)buf, count, pos);
+ if (file->f_op->read)
+ ret = file->f_op->read(file, (void __user *)buf, count, pos);
+ else if (file->f_op->read_iter)
+ ret = new_sync_read(file, (void __user *)buf, count, pos);
+ else
+ ret = -EINVAL;
set_fs(old_fs);
if (ret > 0) {
fsnotify_access(file);
@@ -476,17 +470,22 @@ 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) {
- if (count > MAX_RW_COUNT)
- count = MAX_RW_COUNT;
- ret = __vfs_read(file, buf, count, pos);
- if (ret > 0) {
- fsnotify_access(file);
- add_rchar(current, ret);
- }
- inc_syscr(current);
- }
+ if (ret)
+ return ret;
+ if (count > MAX_RW_COUNT)
+ count = MAX_RW_COUNT;
+ if (file->f_op->read)
+ ret = file->f_op->read(file, buf, count, pos);
+ else if (file->f_op->read_iter)
+ ret = new_sync_read(file, buf, count, pos);
+ else
+ ret = -EINVAL;
+ if (ret > 0) {
+ fsnotify_access(file);
+ add_rchar(current, ret);
+ }
+ inc_syscr(current);
return ret;
}
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 22cbe7b2e91994..0c0ec76b600b50 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1917,7 +1917,6 @@ ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
struct iovec *fast_pointer,
struct iovec **ret_pointer);
-extern ssize_t __vfs_read(struct file *, char __user *, size_t, loff_t *);
extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *);
extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *);
extern ssize_t vfs_readv(struct file *, const struct iovec __user *,
--
2.26.2
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [PATCH 13/14] fs: implement default_file_splice_read using __kernel_read
2020-06-24 16:13 clean up kernel_{read,write} & friends v5 Christoph Hellwig
` (11 preceding siblings ...)
2020-06-24 16:13 ` [PATCH 12/14] fs: remove __vfs_read Christoph Hellwig
@ 2020-06-24 16:13 ` Christoph Hellwig
[not found] ` <20200701091943.GC3874@shao2-debian>
2020-06-24 16:13 ` [PATCH 14/14] fs: don't change the address limit for ->read_iter in __kernel_read Christoph Hellwig
13 siblings, 1 reply; 17+ messages in thread
From: Christoph Hellwig @ 2020-06-24 16:13 UTC (permalink / raw)
To: Al Viro
Cc: Linus Torvalds, Ian Kent, David Howells, linux-kernel,
linux-fsdevel, linux-security-module, netfilter-devel
default_file_splice_read goes through great lenght to create an
iovec array and iov_iter for all the reads, but is a helper only
useful for files not implementing ->read_iter as we have the much
better generic_file_splice_read version available for those. Remove
the iters and just call __kernel_read in a loop instead.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/read_write.c | 2 +-
fs/splice.c | 53 +++++++++++++---------------------------------
include/linux/fs.h | 2 --
3 files changed, 16 insertions(+), 41 deletions(-)
diff --git a/fs/read_write.c b/fs/read_write.c
index 6a2170eaee64f9..1c41c25e548d8c 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1070,7 +1070,7 @@ ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos,
}
EXPORT_SYMBOL(vfs_iter_write);
-ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,
+static ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,
unsigned long vlen, loff_t *pos, rwf_t flags)
{
struct iovec iovstack[UIO_FASTIOV];
diff --git a/fs/splice.c b/fs/splice.c
index d7c8a7c4db07ff..d1efc53875bd93 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -342,38 +342,26 @@ const struct pipe_buf_operations nosteal_pipe_buf_ops = {
};
EXPORT_SYMBOL(nosteal_pipe_buf_ops);
-static ssize_t kernel_readv(struct file *file, const struct kvec *vec,
- unsigned long vlen, loff_t offset)
-{
- mm_segment_t old_fs;
- loff_t pos = offset;
- ssize_t res;
-
- old_fs = get_fs();
- set_fs(KERNEL_DS);
- /* The cast to a user pointer is valid due to the set_fs() */
- res = vfs_readv(file, (const struct iovec __user *)vec, vlen, &pos, 0);
- set_fs(old_fs);
-
- return res;
-}
-
static ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
struct pipe_inode_info *pipe, size_t len,
unsigned int flags)
{
- struct kvec *vec, __vec[PIPE_DEF_BUFFERS];
struct iov_iter to;
struct page **pages;
unsigned int nr_pages;
unsigned int mask;
size_t offset, base, copied = 0;
+ loff_t pos;
ssize_t res;
int i;
if (pipe_full(pipe->head, pipe->tail, pipe->max_usage))
return -EAGAIN;
+ res = rw_verify_area(READ, in, ppos, len);
+ if (res < 0)
+ return res;
+
/*
* Try to keep page boundaries matching to source pagecache ones -
* it probably won't be much help, but...
@@ -386,37 +374,26 @@ static ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
if (res <= 0)
return -ENOMEM;
- nr_pages = DIV_ROUND_UP(res + base, PAGE_SIZE);
-
- vec = __vec;
- if (nr_pages > PIPE_DEF_BUFFERS) {
- vec = kmalloc_array(nr_pages, sizeof(struct kvec), GFP_KERNEL);
- if (unlikely(!vec)) {
- res = -ENOMEM;
- goto out;
- }
- }
-
mask = pipe->ring_size - 1;
pipe->bufs[to.head & mask].offset = offset;
pipe->bufs[to.head & mask].len -= offset;
+ nr_pages = DIV_ROUND_UP(res + base, PAGE_SIZE);
+
+ pos = *ppos;
for (i = 0; i < nr_pages; i++) {
size_t this_len = min_t(size_t, len, PAGE_SIZE - offset);
- vec[i].iov_base = page_address(pages[i]) + offset;
- vec[i].iov_len = this_len;
+
+ res = __kernel_read(in, page_address(pages[i]) + offset,
+ this_len, &pos);
+ if (res < 0)
+ goto out;
len -= this_len;
offset = 0;
}
+ copied = pos - *ppos;
+ *ppos = pos;
- res = kernel_readv(in, vec, nr_pages, *ppos);
- if (res > 0) {
- copied = res;
- *ppos += res;
- }
-
- if (vec != __vec)
- kfree(vec);
out:
for (i = 0; i < nr_pages; i++)
put_page(pages[i]);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 0c0ec76b600b50..fac6aead402a98 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1919,8 +1919,6 @@ ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *);
extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *);
-extern ssize_t vfs_readv(struct file *, const struct iovec __user *,
- unsigned long, loff_t *, rwf_t);
extern ssize_t vfs_copy_file_range(struct file *, loff_t , struct file *,
loff_t, size_t, unsigned int);
extern ssize_t generic_copy_file_range(struct file *file_in, loff_t pos_in,
--
2.26.2
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [PATCH 14/14] fs: don't change the address limit for ->read_iter in __kernel_read
2020-06-24 16:13 clean up kernel_{read,write} & friends v5 Christoph Hellwig
` (12 preceding siblings ...)
2020-06-24 16:13 ` [PATCH 13/14] fs: implement default_file_splice_read using __kernel_read Christoph Hellwig
@ 2020-06-24 16:13 ` Christoph Hellwig
13 siblings, 0 replies; 17+ messages in thread
From: Christoph Hellwig @ 2020-06-24 16:13 UTC (permalink / raw)
To: Al Viro
Cc: Linus Torvalds, Ian Kent, David Howells, linux-kernel,
linux-fsdevel, linux-security-module, netfilter-devel
If we read to a file that implements ->read_iter there is no need
to change the address limit if we send a kvec down.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/read_write.c | 40 +++++++++++++++++++++++++---------------
1 file changed, 25 insertions(+), 15 deletions(-)
diff --git a/fs/read_write.c b/fs/read_write.c
index 1c41c25e548d8c..e7f36b15683049 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -421,7 +421,6 @@ static ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, lo
ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)
{
- mm_segment_t old_fs = get_fs();
ssize_t ret;
if (WARN_ON_ONCE(!(file->f_mode & FMODE_READ)))
@@ -431,14 +430,25 @@ ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)
if (count > MAX_RW_COUNT)
count = MAX_RW_COUNT;
- set_fs(KERNEL_DS);
- if (file->f_op->read)
+ if (file->f_op->read) {
+ mm_segment_t old_fs = get_fs();
+
+ set_fs(KERNEL_DS);
ret = file->f_op->read(file, (void __user *)buf, count, pos);
- else if (file->f_op->read_iter)
- ret = new_sync_read(file, (void __user *)buf, count, pos);
- else
+ set_fs(old_fs);
+ } else if (file->f_op->read_iter) {
+ struct kvec iov = { .iov_base = buf, .iov_len = count };
+ struct kiocb kiocb;
+ struct iov_iter iter;
+
+ init_sync_kiocb(&kiocb, file);
+ kiocb.ki_pos = *pos;
+ iov_iter_kvec(&iter, READ, &iov, 1, count);
+ ret = file->f_op->read_iter(&kiocb, &iter);
+ *pos = kiocb.ki_pos;
+ } else {
ret = -EINVAL;
- set_fs(old_fs);
+ }
if (ret > 0) {
fsnotify_access(file);
add_rchar(current, ret);
@@ -520,7 +530,14 @@ ssize_t __kernel_write(struct file *file, const void *buf, size_t count,
if (count > MAX_RW_COUNT)
count = MAX_RW_COUNT;
- if (file->f_op->write_iter) {
+ if (file->f_op->write) {
+ mm_segment_t old_fs = get_fs();
+
+ set_fs(KERNEL_DS);
+ ret = file->f_op->write(file, (__force const char __user *)buf,
+ count, pos);
+ set_fs(old_fs);
+ } else if (file->f_op->write_iter) {
struct kvec iov = { .iov_base = (void *)buf, .iov_len = count };
struct kiocb kiocb;
struct iov_iter iter;
@@ -531,13 +548,6 @@ ssize_t __kernel_write(struct file *file, const void *buf, size_t count,
ret = file->f_op->write_iter(&kiocb, &iter);
if (ret > 0)
*pos = kiocb.ki_pos;
- } else if (file->f_op->write) {
- mm_segment_t old_fs = get_fs();
-
- set_fs(KERNEL_DS);
- ret = file->f_op->write(file, (__force const char __user *)buf,
- count, pos);
- set_fs(old_fs);
} else {
ret = -EINVAL;
}
--
2.26.2
^ permalink raw reply related [flat|nested] 17+ messages in thread