Add a simple helper for a chdir 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_chdir.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
drivers/base/devtmpfs.c | 2 +-
fs/open.c | 15 ++++++++++-----
include/linux/fs.h | 2 ++
include/linux/syscalls.h | 1 -
init/do_mounts.c | 2 +-
init/do_mounts_initrd.c | 8 ++++----
6 files changed, 18 insertions(+), 12 deletions(-)
diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
index 03221ca708c91c..2cedeb62706f18 100644
--- a/drivers/base/devtmpfs.c
+++ b/drivers/base/devtmpfs.c
@@ -388,7 +388,7 @@ static int devtmpfs_setup(void *p)
err = do_kern_mount("devtmpfs", "/", "devtmpfs", MS_SILENT, NULL);
if (err)
goto out;
- ksys_chdir("/.."); /* will traverse into overmounted root */
+ kern_chdir("/.."); /* will traverse into overmounted root */
ksys_chroot(".");
out:
*(int *)p = err;
diff --git a/fs/open.c b/fs/open.c
index b316dd6a86a8b9..3d62f4d2604739 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -482,15 +482,15 @@ SYSCALL_DEFINE2(access, const char __user *, filename, int, mode)
return do_faccessat(AT_FDCWD, filename, mode, 0);
}
-int ksys_chdir(const char __user *filename)
+static int do_chdir(struct filename *name)
{
struct path path;
int error;
unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
retry:
- error = user_path_at(AT_FDCWD, filename, lookup_flags, &path);
+ error = filename_lookup(AT_FDCWD, name, lookup_flags, &path, NULL);
if (error)
- goto out;
+ return error;
error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR);
if (error)
@@ -504,13 +504,18 @@ int ksys_chdir(const char __user *filename)
lookup_flags |= LOOKUP_REVAL;
goto retry;
}
-out:
+ putname(name);
return error;
}
+int kern_chdir(const char *filename)
+{
+ return do_chdir(getname_kernel(filename));
+}
+
SYSCALL_DEFINE1(chdir, const char __user *, filename)
{
- return ksys_chdir(filename);
+ return do_chdir(getname(filename));
}
SYSCALL_DEFINE1(fchdir, unsigned int, fd)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index fbeadaa1a185fb..dccb37407e9bad 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -3671,4 +3671,6 @@ static inline int inode_drain_writes(struct inode *inode)
return filemap_write_and_wait(inode->i_mapping);
}
+int kern_chdir(const char *filename);
+
#endif /* _LINUX_FS_H */
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 3b1b8ebcda1d8c..f2a181776b0409 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -1238,7 +1238,6 @@ asmlinkage long sys_ni_syscall(void);
int ksys_chroot(const char __user *filename);
ssize_t ksys_write(unsigned int fd, const char __user *buf, size_t count);
-int ksys_chdir(const char __user *filename);
int ksys_fchown(unsigned int fd, uid_t user, gid_t group);
ssize_t ksys_read(unsigned int fd, char __user *buf, size_t count);
void ksys_sync(void);
diff --git a/init/do_mounts.c b/init/do_mounts.c
index 2fef92a8ed3c15..8c3fca8e2d3c6e 100644
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -408,7 +408,7 @@ static int __init do_mount_root(const char *name, const char *fs,
if (ret)
goto out;
- ksys_chdir("/root");
+ kern_chdir("/root");
s = current->fs->pwd.dentry->d_sb;
ROOT_DEV = s->s_dev;
printk(KERN_INFO
diff --git a/init/do_mounts_initrd.c b/init/do_mounts_initrd.c
index d3858620707893..522554d703b785 100644
--- a/init/do_mounts_initrd.c
+++ b/init/do_mounts_initrd.c
@@ -61,7 +61,7 @@ static int __init init_linuxrc(struct subprocess_info *info, struct cred *new)
ksys_unshare(CLONE_FS | CLONE_FILES);
console_on_rootfs();
/* move initrd over / and chdir/chroot in initrd root */
- ksys_chdir("/root");
+ kern_chdir("/root");
do_kern_mount(".", "/", NULL, MS_MOVE, NULL);
ksys_chroot(".");
ksys_setsid();
@@ -82,7 +82,7 @@ static void __init handle_initrd(void)
/* mount initrd on rootfs' /root */
mount_block_root("/dev/root.old", root_mountflags & ~MS_RDONLY);
ksys_mkdir("/old", 0700);
- ksys_chdir("/old");
+ kern_chdir("/old");
/*
* In case that a resume from disk is carried out by linuxrc or one of
@@ -104,11 +104,11 @@ static void __init handle_initrd(void)
ksys_chroot("..");
if (new_decode_dev(real_root_dev) == Root_RAM0) {
- ksys_chdir("/old");
+ kern_chdir("/old");
return;
}
- ksys_chdir("/");
+ kern_chdir("/");
ROOT_DEV = new_decode_dev(real_root_dev);
mount_root();
--
2.27.0
