diff options
| author | Al Viro <viro@zeniv.linux.org.uk> | 2024-10-07 23:08:34 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2024-10-19 20:33:34 -0400 |
| commit | e896474fe4851ffc4dd860c92daa906783090346 (patch) | |
| tree | 190f43b0cad7d3754b88e3f3f3b9d4f365408bc1 /include | |
| parent | 5b313bcb6e3597dacd893ae9545fd087df46db45 (diff) | |
getname_maybe_null() - the third variant of pathname copy-in
Semantics used by statx(2) (and later *xattrat(2)): without AT_EMPTY_PATH
it's standard getname() (i.e. ERR_PTR(-ENOENT) on empty string,
ERR_PTR(-EFAULT) on NULL), with AT_EMPTY_PATH both empty string and
NULL are accepted.
Calling conventions: getname_maybe_null(user_pointer, flags) returns
* pointer to struct filename when non-empty string had been
successfully read
* ERR_PTR(...) on error
* NULL if an empty string or NULL pointer had been given
with AT_EMPTY_PATH in the flags argument.
It tries to avoid allocation in the last case; it's not always
able to do so, in which case the temporary struct filename instance
is freed and NULL returned anyway.
Fast path is inlined.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/fs.h | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h index e3c603d01337..403258ac2ea2 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2766,6 +2766,16 @@ extern struct filename *getname_flags(const char __user *, 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 struct filename *__getname_maybe_null(const char __user *); +static inline struct filename *getname_maybe_null(const char __user *name, int flags) +{ + if (!(flags & AT_EMPTY_PATH)) + return getname(name); + + if (!name) + return NULL; + return __getname_maybe_null(name); +} extern void putname(struct filename *name); extern int finish_open(struct file *file, struct dentry *dentry, |