[PATCH v8 07/11] namei: add getname_uflags()

Dmitry Kadashev
2021-07-07T12:28:15Z

There are a couple of places where we already open-code the (flags &
AT_EMPTY_PATH) check and io_uring will likely add another one in the
future. Let's just add a simple helper getname_uflags() that handles
this directly and use it.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/io-uring/20210415100815.edrn4a7cy26wkowe@wittgenstein/
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Dmitry Kadashev <dkadashev@gmail.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
---
fs/exec.c | 8 ++------
fs/namei.c | 8 ++++++++
include/linux/fs.h | 1 +
3 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/fs/exec.c b/fs/exec.c
index 18594f11c31f..df33ecaf2111 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -2069,10 +2069,8 @@ SYSCALL_DEFINE5(execveat,
const char __user *const __user *, envp,
int, flags)
{
- int lookup_flags = (flags & AT_EMPTY_PATH) ? LOOKUP_EMPTY : 0;
-
return do_execveat(fd,
- getname_flags(filename, lookup_flags, NULL),
+ getname_uflags(filename, flags),
argv, envp, flags);
}

@@ -2090,10 +2088,8 @@ COMPAT_SYSCALL_DEFINE5(execveat, int, fd,
const compat_uptr_t __user *, envp,
int, flags)
{
- int lookup_flags = (flags & AT_EMPTY_PATH) ? LOOKUP_EMPTY : 0;
-
return compat_do_execveat(fd,
- getname_flags(filename, lookup_flags, NULL),
+ getname_uflags(filename, flags),
argv, envp, flags);
}
#endif
diff --git a/fs/namei.c b/fs/namei.c
index add984e4bfd0..ab7979f9daaa 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -203,6 +203,14 @@ getname_flags(const char __user *filename, int flags, int *empty)
return result;
}

+struct filename *
+getname_uflags(const char __user *filename, int uflags)
+{
+ int flags = (uflags & AT_EMPTY_PATH) ? LOOKUP_EMPTY : 0;
+
+ return getname_flags(filename, flags, NULL);
+}
+
struct filename *
getname(const char __user * filename)
{
diff --git a/include/linux/fs.h b/include/linux/fs.h
index c3c88fdb9b2a..5885a68d2c12 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2781,6 +2781,7 @@ static inline struct file *file_clone_open(struct file *file)
extern int filp_close(struct file *, fl_owner_t id);

extern struct filename *getname_flags(const char __user *, int, int *);
+extern struct filename *getname_uflags(const char __user *, int);
extern struct filename *getname(const char __user *);
extern struct filename *getname_kernel(const char *);
extern void putname(struct filename *name);
--
2.30.2