[PATCH 11/24] fs: add a kern_chmod helper
From: Christoph Hellwig <hch@lst.de>
Date: 2020-07-20 15:59:29
Also in:
linux-fsdevel, linux-raid, lkml
Subsystem:
abi/api, filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
Add a simple helper to chown with a kernel space name and use it in the early init code instead of relying on the implicit set_fs(KERNEL_DS) there. Remove the now unused ksys_chmod. Signed-off-by: Christoph Hellwig <hch@lst.de> --- fs/internal.h | 1 - fs/open.c | 28 +++++++++++++++++----------- include/linux/fs.h | 1 + include/linux/syscalls.h | 7 ------- init/initramfs.c | 4 ++-- 5 files changed, 20 insertions(+), 21 deletions(-)
diff --git a/fs/internal.h b/fs/internal.h
index ad62729e7ae587..1e2b425f56ee9e 100644
--- a/fs/internal.h
+++ b/fs/internal.h@@ -126,7 +126,6 @@ extern struct open_how build_open_how(int flags, umode_t mode); extern int build_open_flags(const struct open_how *how, struct open_flags *op); long do_sys_ftruncate(unsigned int fd, loff_t length, int small); -int do_fchmodat(int dfd, const char __user *filename, umode_t mode); extern int vfs_open(const struct path *, struct file *);
diff --git a/fs/open.c b/fs/open.c
index 8157db254c8f8a..bb8ffc24c4b034 100644
--- a/fs/open.c
+++ b/fs/open.c@@ -643,33 +643,39 @@ SYSCALL_DEFINE2(fchmod, unsigned int, fd, umode_t, mode) return err; } -int do_fchmodat(int dfd, const char __user *filename, umode_t mode) +static int do_fchmodat(int dfd, struct filename *name, umode_t mode) { struct path path; int error; unsigned int lookup_flags = LOOKUP_FOLLOW; retry: - error = user_path_at(dfd, filename, lookup_flags, &path); - if (!error) { - error = chmod_common(&path, mode); - path_put(&path); - if (retry_estale(error, lookup_flags)) { - lookup_flags |= LOOKUP_REVAL; - goto retry; - } + error = filename_lookup(dfd, name, lookup_flags, &path, NULL); + if (error) + return error; + error = chmod_common(&path, mode); + path_put(&path); + if (retry_estale(error, lookup_flags)) { + lookup_flags |= LOOKUP_REVAL; + goto retry; } + putname(name); return error; } +int __init kern_chmod(const char *filename, umode_t mode) +{ + return do_fchmodat(AT_FDCWD, getname_kernel(filename), mode); +} + SYSCALL_DEFINE3(fchmodat, int, dfd, const char __user *, filename, umode_t, mode) { - return do_fchmodat(dfd, filename, mode); + return do_fchmodat(dfd, getname(filename), mode); } SYSCALL_DEFINE2(chmod, const char __user *, filename, umode_t, mode) { - return do_fchmodat(AT_FDCWD, filename, mode); + return do_fchmodat(AT_FDCWD, getname(filename), mode); } static int chown_common(const struct path *path, uid_t user, gid_t group)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 75d6ef7e1de52b..ca034126cb0e4d 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h@@ -3675,5 +3675,6 @@ int kern_chdir(const char *filename); int kern_chroot(const char *filename); int __init kern_access(const char *filename, int mode); int __init kern_chown(const char *filename, uid_t user, gid_t group, int flag); +int __init kern_chmod(const char *filename, umode_t mode); #endif /* _LINUX_FS_H */
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 82346a68a73877..a2ece4cc8692f5 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h@@ -1318,13 +1318,6 @@ static inline long ksys_link(const char __user *oldname, return do_linkat(AT_FDCWD, oldname, AT_FDCWD, newname, 0); } -extern int do_fchmodat(int dfd, const char __user *filename, umode_t mode); - -static inline int ksys_chmod(const char __user *filename, umode_t mode) -{ - return do_fchmodat(AT_FDCWD, filename, mode); -} - extern long do_sys_ftruncate(unsigned int fd, loff_t length, int small); static inline long ksys_ftruncate(unsigned int fd, loff_t length)
diff --git a/init/initramfs.c b/init/initramfs.c
index 45e4ddb63caba1..2c2d4480d495e8 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c@@ -346,14 +346,14 @@ static int __init do_name(void) } else if (S_ISDIR(mode)) { ksys_mkdir(collected, mode); kern_chown(collected, uid, gid, 0); - ksys_chmod(collected, mode); + kern_chmod(collected, mode); dir_add(collected, mtime); } else if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) { if (maybe_link() == 0) { ksys_mknod(collected, mode, rdev); kern_chown(collected, uid, gid, 0); - ksys_chmod(collected, mode); + kern_chmod(collected, mode); do_utime(collected, mtime); } }
--
2.27.0