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author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-05-21 08:46:08 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-05-21 08:46:08 -0700 |
commit | 7e5cb5e151c5474b4a468f437f5038ba9f67ef4d (patch) | |
tree | 899f42e88f926fb4501402cf4ee4aa0903421ef5 /fs/namei.c | |
parent | 8c12fec90c54cfabdd57b2726a1defbc07c19a55 (diff) | |
parent | e994defb7b6813ba6fa7a2a36e86d2455ad1dc35 (diff) | |
download | linux-stable-7e5cb5e151c5474b4a468f437f5038ba9f67ef4d.tar.gz linux-stable-7e5cb5e151c5474b4a468f437f5038ba9f67ef4d.tar.bz2 linux-stable-7e5cb5e151c5474b4a468f437f5038ba9f67ef4d.zip |
Merge branch 'vfs-cleanups' (random vfs cleanups)
This teaches vfs_fstat() to use the appropriate f[get|put]_light
functions, allowing it to avoid some unnecessary locking for the common
case.
More noticeably, it also cleans up and simplifies the "getname_flags()"
function, which now relies on the architecture strncpy_from_user() doing
all the user access checks properly, instead of hacking around the fact
that on x86 it didn't use to do it right (see commit 92ae03f2ef99: "x86:
merge 32/64-bit versions of 'strncpy_from_user()' and speed it up").
* vfs-cleanups:
VFS: make vfs_fstat() use f[get|put]_light()
VFS: clean up and simplify getname_flags()
x86: make word-at-a-time strncpy_from_user clear bytes at the end
Diffstat (limited to 'fs/namei.c')
-rw-r--r-- | fs/namei.c | 58 |
1 files changed, 24 insertions, 34 deletions
diff --git a/fs/namei.c b/fs/namei.c index c42791914f82..709fb2c17b5f 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -116,47 +116,37 @@ * POSIX.1 2.4: an empty pathname is invalid (ENOENT). * PATH_MAX includes the nul terminator --RR. */ -static int do_getname(const char __user *filename, char *page) -{ - int retval; - unsigned long len = PATH_MAX; - - if (!segment_eq(get_fs(), KERNEL_DS)) { - if ((unsigned long) filename >= TASK_SIZE) - return -EFAULT; - if (TASK_SIZE - (unsigned long) filename < PATH_MAX) - len = TASK_SIZE - (unsigned long) filename; - } - - retval = strncpy_from_user(page, filename, len); - if (retval > 0) { - if (retval < len) - return 0; - return -ENAMETOOLONG; - } else if (!retval) - retval = -ENOENT; - return retval; -} - static char *getname_flags(const char __user *filename, int flags, int *empty) { - char *result = __getname(); - int retval; + char *result = __getname(), *err; + int len; - if (!result) + if (unlikely(!result)) return ERR_PTR(-ENOMEM); - retval = do_getname(filename, result); - if (retval < 0) { - if (retval == -ENOENT && empty) + len = strncpy_from_user(result, filename, PATH_MAX); + err = ERR_PTR(len); + if (unlikely(len < 0)) + goto error; + + /* The empty path is special. */ + if (unlikely(!len)) { + if (empty) *empty = 1; - if (retval != -ENOENT || !(flags & LOOKUP_EMPTY)) { - __putname(result); - return ERR_PTR(retval); - } + err = ERR_PTR(-ENOENT); + if (!(flags & LOOKUP_EMPTY)) + goto error; } - audit_getname(result); - return result; + + err = ERR_PTR(-ENAMETOOLONG); + if (likely(len < PATH_MAX)) { + audit_getname(result); + return result; + } + +error: + __putname(result); + return err; } char *getname(const char __user * filename) |