Add a simple helper for a access with a kernelspace 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_access.
Signed-off-by: Christoph Hellwig <[email protected]> --- fs/open.c | 37 +++++++++++++++++++++++++------------ include/linux/fs.h | 1 + include/linux/syscalls.h | 7 ------- init/main.c | 3 +-- 4 files changed, 27 insertions(+), 21 deletions(-) diff --git a/fs/open.c b/fs/open.c index 424db905da5f18..2a9457a16b2be2 100644 --- a/fs/open.c +++ b/fs/open.c @@ -394,19 +394,19 @@ static const struct cred *access_override_creds(void) return old_cred; } -long do_faccessat(int dfd, const char __user *filename, int mode, int flags) +static int do_faccessat(int dfd, struct filename *name, int mode, int flags) { struct path path; struct inode *inode; - int res; + int res = -EINVAL; unsigned int lookup_flags = LOOKUP_FOLLOW; const struct cred *old_cred = NULL; if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */ - return -EINVAL; + goto out_putname; if (flags & ~(AT_EACCESS | AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) - return -EINVAL; + goto out_putname; if (flags & AT_SYMLINK_NOFOLLOW) lookup_flags &= ~LOOKUP_FOLLOW; @@ -414,15 +414,16 @@ long do_faccessat(int dfd, const char __user *filename, int mode, int flags) lookup_flags |= LOOKUP_EMPTY; if (!(flags & AT_EACCESS)) { + res = -ENOMEM; old_cred = access_override_creds(); if (!old_cred) - return -ENOMEM; + goto out_putname; } retry: - res = user_path_at(dfd, filename, lookup_flags, &path); + res = filename_lookup(dfd, name, lookup_flags, &path, NULL); if (res) - goto out; + goto out_revert_creds; inode = d_backing_inode(path.dentry); @@ -459,27 +460,39 @@ long do_faccessat(int dfd, const char __user *filename, int mode, int flags) lookup_flags |= LOOKUP_REVAL; goto retry; } -out: + putname(name); +out_revert_creds: if (old_cred) revert_creds(old_cred); - return res; +out_putname: + if (!IS_ERR(name)) + putname(name); + return res; +} + +int __init kern_access(const char __user *filename, int mode) +{ + return do_faccessat(AT_FDCWD, getname_kernel(filename), mode, 0); } SYSCALL_DEFINE3(faccessat, int, dfd, const char __user *, filename, int, mode) { - return do_faccessat(dfd, filename, mode, 0); + return do_faccessat(dfd, getname(filename), mode, 0); } SYSCALL_DEFINE4(faccessat2, int, dfd, const char __user *, filename, int, mode, int, flags) { - return do_faccessat(dfd, filename, mode, flags); + unsigned int lookup_flags = (flags & AT_EMPTY_PATH) ? LOOKUP_EMPTY : 0; + struct filename *name = getname_flags(filename, lookup_flags, NULL); + + return do_faccessat(dfd, name, mode, flags); } SYSCALL_DEFINE2(access, const char __user *, filename, int, mode) { - return do_faccessat(AT_FDCWD, filename, mode, 0); + return do_faccessat(AT_FDCWD, getname(filename), mode, 0); } static int do_chdir(struct filename *name) diff --git a/include/linux/fs.h b/include/linux/fs.h index 0205355bffb1bc..0c7672d3f1172f 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3673,5 +3673,6 @@ static inline int inode_drain_writes(struct inode *inode) int kern_chdir(const char *filename); int kern_chroot(const char *filename); +int __init kern_access(const char *filename, int mode); #endif /* _LINUX_FS_H */ diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index a3176d1a521467..b387e3700c68c5 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -1326,13 +1326,6 @@ static inline int ksys_chmod(const char __user *filename, umode_t mode) return do_fchmodat(AT_FDCWD, filename, mode); } -long do_faccessat(int dfd, const char __user *filename, int mode, int flags); - -static inline long ksys_access(const char __user *filename, int mode) -{ - return do_faccessat(AT_FDCWD, filename, mode, 0); -} - extern int do_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group, int flag); diff --git a/init/main.c b/init/main.c index c2c9143db96795..880f195b61abe1 100644 --- a/init/main.c +++ b/init/main.c @@ -1514,8 +1514,7 @@ static noinline void __init kernel_init_freeable(void) * check if there is an early userspace init. If yes, let it do all * the work */ - if (ksys_access((const char __user *) - ramdisk_execute_command, 0) != 0) { + if (kern_access(ramdisk_execute_command, 0) != 0) { ramdisk_execute_command = NULL; prepare_namespace(); } -- 2.27.0
