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| author | Dominik Brodowski <linux@dominikbrodowski.net> | 2018-03-11 11:34:55 +0100 |
|---|---|---|
| committer | Dominik Brodowski <linux@dominikbrodowski.net> | 2018-04-02 20:15:59 +0200 |
| commit | 55731b3cda3a85ee888dac3bf1f36489f275c187 (patch) | |
| tree | a322dc9efdd89932a35b294d221f90eccad45f23 /fs | |
| parent | cbfe20f565228966f0249f016752437df95df679 (diff) | |
| download | linux-rpi-55731b3cda3a85ee888dac3bf1f36489f275c187.tar.gz linux-rpi-55731b3cda3a85ee888dac3bf1f36489f275c187.tar.bz2 linux-rpi-55731b3cda3a85ee888dac3bf1f36489f275c187.zip | |
fs: add do_fchownat(), ksys_fchown() helpers and ksys_{,l}chown() wrappers
Using the fs-interal do_fchownat() wrapper allows us to get rid of
fs-internal calls to the sys_fchownat() syscall.
Introducing the ksys_fchown() helper and the ksys_{,}chown() wrappers
allows us to avoid the in-kernel calls to the sys_{,l,f}chown() syscalls.
The ksys_ prefix denotes that these functions are meant as a drop-in
replacement for the syscalls. In particular, they use the same calling
convention as sys_{,l,f}chown().
This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/internal.h | 2 | ||||
| -rw-r--r-- | fs/open.c | 23 |
2 files changed, 19 insertions, 6 deletions
diff --git a/fs/internal.h b/fs/internal.h index 26f4f05b52ef..c797480cbd6f 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -121,6 +121,8 @@ extern struct file *do_file_open_root(struct dentry *, struct vfsmount *, long do_faccessat(int dfd, const char __user *filename, int mode); int do_fchmodat(int dfd, const char __user *filename, umode_t mode); +int do_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group, + int flag); extern int open_check_o_direct(struct file *f); extern int vfs_open(const struct path *, struct file *, const struct cred *); diff --git a/fs/open.c b/fs/open.c index 0fc8188be31a..7b2eccb541f2 100644 --- a/fs/open.c +++ b/fs/open.c @@ -645,8 +645,8 @@ retry_deleg: return error; } -SYSCALL_DEFINE5(fchownat, int, dfd, const char __user *, filename, uid_t, user, - gid_t, group, int, flag) +int do_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group, + int flag) { struct path path; int error = -EINVAL; @@ -677,18 +677,24 @@ out: return error; } +SYSCALL_DEFINE5(fchownat, int, dfd, const char __user *, filename, uid_t, user, + gid_t, group, int, flag) +{ + return do_fchownat(dfd, filename, user, group, flag); +} + SYSCALL_DEFINE3(chown, const char __user *, filename, uid_t, user, gid_t, group) { - return sys_fchownat(AT_FDCWD, filename, user, group, 0); + return do_fchownat(AT_FDCWD, filename, user, group, 0); } SYSCALL_DEFINE3(lchown, const char __user *, filename, uid_t, user, gid_t, group) { - return sys_fchownat(AT_FDCWD, filename, user, group, - AT_SYMLINK_NOFOLLOW); + return do_fchownat(AT_FDCWD, filename, user, group, + AT_SYMLINK_NOFOLLOW); } -SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group) +int ksys_fchown(unsigned int fd, uid_t user, gid_t group) { struct fd f = fdget(fd); int error = -EBADF; @@ -708,6 +714,11 @@ out: return error; } +SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group) +{ + return ksys_fchown(fd, user, group); +} + int open_check_o_direct(struct file *f) { /* NB: we're sure to have correct a_ops only after f_op->open */ |