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authorAlexey Dobriyan <adobriyan@gmail.com>2021-05-07 04:02:16 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-05-07 05:24:11 +0300
commitd4455faccd6cbe11ddfdbe28723a2122453b4f4e (patch)
tree259db030de708622b3215088c3eb664c36b85a4b
parentb793cd9ab34da3c571a038219d1d6315f91e5afd (diff)
downloadlinux-d4455faccd6cbe11ddfdbe28723a2122453b4f4e.tar.xz
proc: mandate ->proc_lseek in "struct proc_ops"
Now that proc_ops are separate from file_operations and other operations it easy to check all instances to have ->proc_lseek hook and remove check in main code. Note: nonseekable_open() files naturally don't require ->proc_lseek. Garbage collect pde_lseek() function. [adobriyan@gmail.com: smoke test lseek()] Link: https://lkml.kernel.org/r/YG4OIhChOrVTPgdN@localhost.localdomain Link: https://lkml.kernel.org/r/YFYX0Bzwxlc7aBa/@localhost.localdomain Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--drivers/isdn/capi/kcapi_proc.c1
-rw-r--r--drivers/net/wireless/intersil/hostap/hostap_proc.c1
-rw-r--r--drivers/scsi/esas2r/esas2r_main.c1
-rw-r--r--fs/proc/inode.c14
-rw-r--r--include/linux/proc_fs.h1
-rw-r--r--tools/testing/selftests/proc/read.c4
6 files changed, 9 insertions, 13 deletions
diff --git a/drivers/isdn/capi/kcapi_proc.c b/drivers/isdn/capi/kcapi_proc.c
index b5ed4ea145cb..77e951206809 100644
--- a/drivers/isdn/capi/kcapi_proc.c
+++ b/drivers/isdn/capi/kcapi_proc.c
@@ -201,6 +201,7 @@ static ssize_t empty_read(struct file *file, char __user *buf,
static const struct proc_ops empty_proc_ops = {
.proc_read = empty_read,
+ .proc_lseek = default_llseek,
};
// ---------------------------------------------------------------------------
diff --git a/drivers/net/wireless/intersil/hostap/hostap_proc.c b/drivers/net/wireless/intersil/hostap/hostap_proc.c
index 97c270845fd1..51c847d98755 100644
--- a/drivers/net/wireless/intersil/hostap/hostap_proc.c
+++ b/drivers/net/wireless/intersil/hostap/hostap_proc.c
@@ -227,6 +227,7 @@ static ssize_t prism2_aux_dump_proc_no_read(struct file *file, char __user *buf,
static const struct proc_ops prism2_aux_dump_proc_ops = {
.proc_read = prism2_aux_dump_proc_no_read,
+ .proc_lseek = default_llseek,
};
diff --git a/drivers/scsi/esas2r/esas2r_main.c b/drivers/scsi/esas2r/esas2r_main.c
index 5d9eeac6717a..45ec9f16c085 100644
--- a/drivers/scsi/esas2r/esas2r_main.c
+++ b/drivers/scsi/esas2r/esas2r_main.c
@@ -616,6 +616,7 @@ static const struct file_operations esas2r_proc_fops = {
};
static const struct proc_ops esas2r_proc_ops = {
+ .proc_lseek = default_llseek,
.proc_ioctl = esas2r_proc_ioctl,
#ifdef CONFIG_COMPAT
.proc_compat_ioctl = compat_ptr_ioctl,
diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index bde6b6f69852..2ea8aaa7206e 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -273,25 +273,15 @@ void proc_entry_rundown(struct proc_dir_entry *de)
spin_unlock(&de->pde_unload_lock);
}
-static loff_t pde_lseek(struct proc_dir_entry *pde, struct file *file, loff_t offset, int whence)
-{
- typeof_member(struct proc_ops, proc_lseek) lseek;
-
- lseek = pde->proc_ops->proc_lseek;
- if (!lseek)
- lseek = default_llseek;
- return lseek(file, offset, whence);
-}
-
static loff_t proc_reg_llseek(struct file *file, loff_t offset, int whence)
{
struct proc_dir_entry *pde = PDE(file_inode(file));
loff_t rv = -EINVAL;
if (pde_is_permanent(pde)) {
- return pde_lseek(pde, file, offset, whence);
+ return pde->proc_ops->proc_lseek(file, offset, whence);
} else if (use_pde(pde)) {
- rv = pde_lseek(pde, file, offset, whence);
+ rv = pde->proc_ops->proc_lseek(file, offset, whence);
unuse_pde(pde);
}
return rv;
diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h
index 000cc0533c33..069c7fd95396 100644
--- a/include/linux/proc_fs.h
+++ b/include/linux/proc_fs.h
@@ -32,6 +32,7 @@ struct proc_ops {
ssize_t (*proc_read)(struct file *, char __user *, size_t, loff_t *);
ssize_t (*proc_read_iter)(struct kiocb *, struct iov_iter *);
ssize_t (*proc_write)(struct file *, const char __user *, size_t, loff_t *);
+ /* mandatory unless nonseekable_open() or equivalent is used */
loff_t (*proc_lseek)(struct file *, loff_t, int);
int (*proc_release)(struct inode *, struct file *);
__poll_t (*proc_poll)(struct file *, struct poll_table_struct *);
diff --git a/tools/testing/selftests/proc/read.c b/tools/testing/selftests/proc/read.c
index b3ef9e14d6cc..35ee78dff144 100644
--- a/tools/testing/selftests/proc/read.c
+++ b/tools/testing/selftests/proc/read.c
@@ -14,7 +14,7 @@
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
// Test
-// 1) read of every file in /proc
+// 1) read and lseek on every file in /proc
// 2) readlink of every symlink in /proc
// 3) recursively (1) + (2) for every directory in /proc
// 4) write to /proc/*/clear_refs and /proc/*/task/*/clear_refs
@@ -45,6 +45,8 @@ static void f_reg(DIR *d, const char *filename)
fd = openat(dirfd(d), filename, O_RDONLY|O_NONBLOCK);
if (fd == -1)
return;
+ /* struct proc_ops::proc_lseek is mandatory if file is seekable. */
+ (void)lseek(fd, 0, SEEK_SET);
rv = read(fd, buf, sizeof(buf));
assert((0 <= rv && rv <= sizeof(buf)) || rv == -1);
close(fd);