From 5fee64fcde0770c41e926ff981022eaa512d8980 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 22 Jul 2020 11:41:20 +0200 Subject: [PATCH] init: add an init_mknod helper Add a simple helper to mknod with a kernel space file name and switch the early init code over to it. Remove the now unused ksys_mknod. Signed-off-by: Christoph Hellwig --- fs/init.c | 25 +++++++++++++++++++++++++ fs/internal.h | 2 -- fs/namei.c | 2 +- include/linux/init_syscalls.h | 1 + include/linux/syscalls.h | 9 --------- init/do_mounts.h | 2 +- init/initramfs.c | 2 +- init/noinitramfs.c | 3 +-- 8 files changed, 30 insertions(+), 16 deletions(-) diff --git a/fs/init.c b/fs/init.c index 127033d..145fb31 100644 --- a/fs/init.c +++ b/fs/init.c @@ -122,6 +122,31 @@ int __init init_eaccess(const char *filename) return error; } +int __init init_mknod(const char *filename, umode_t mode, unsigned int dev) +{ + struct dentry *dentry; + struct path path; + int error; + + if (S_ISFIFO(mode) || S_ISSOCK(mode)) + dev = 0; + else if (!(S_ISBLK(mode) || S_ISCHR(mode))) + return -EINVAL; + + dentry = kern_path_create(AT_FDCWD, filename, &path, 0); + if (IS_ERR(dentry)) + return PTR_ERR(dentry); + + if (!IS_POSIXACL(path.dentry->d_inode)) + mode &= ~current_umask(); + error = security_path_mknod(&path, dentry, mode, dev); + if (!error) + error = vfs_mknod(path.dentry->d_inode, dentry, mode, + new_decode_dev(dev)); + done_path_create(&path, dentry); + return error; +} + int __init init_link(const char *oldname, const char *newname) { struct dentry *new_dentry; diff --git a/fs/internal.h b/fs/internal.h index 4741e59..07e145b 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -62,8 +62,6 @@ extern int filename_lookup(int dfd, struct filename *name, unsigned flags, struct path *path, struct path *root); extern int vfs_path_lookup(struct dentry *, struct vfsmount *, const char *, unsigned int, struct path *); -long do_mknodat(int dfd, const char __user *filename, umode_t mode, - unsigned int dev); long do_rmdir(int dfd, struct filename *name); long do_unlinkat(int dfd, struct filename *name); int may_linkat(struct path *link); diff --git a/fs/namei.c b/fs/namei.c index d6b25dd..fde8fe0 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -3564,7 +3564,7 @@ static int may_mknod(umode_t mode) } } -long do_mknodat(int dfd, const char __user *filename, umode_t mode, +static long do_mknodat(int dfd, const char __user *filename, umode_t mode, unsigned int dev) { struct dentry *dentry; diff --git a/include/linux/init_syscalls.h b/include/linux/init_syscalls.h index d808985..fa1fe7a 100644 --- a/include/linux/init_syscalls.h +++ b/include/linux/init_syscalls.h @@ -8,6 +8,7 @@ int __init init_chroot(const char *filename); int __init init_chown(const char *filename, uid_t user, gid_t group, int flags); int __init init_chmod(const char *filename, umode_t mode); int __init init_eaccess(const char *filename); +int __init init_mknod(const char *filename, umode_t mode, unsigned int dev); int __init init_link(const char *oldname, const char *newname); int __init init_symlink(const char *oldname, const char *newname); int __init init_unlink(const char *pathname); diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 5ef77a9..63046c5 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -1270,15 +1270,6 @@ int compat_ksys_ipc(u32 call, int first, int second, * The following kernel syscall equivalents are just wrappers to fs-internal * functions. Therefore, provide stubs to be inlined at the callsites. */ -extern long do_mknodat(int dfd, const char __user *filename, umode_t mode, - unsigned int dev); - -static inline long ksys_mknod(const char __user *filename, umode_t mode, - unsigned int dev) -{ - return do_mknodat(AT_FDCWD, filename, mode, dev); -} - extern int do_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group, int flag); diff --git a/init/do_mounts.h b/init/do_mounts.h index 104d843..7a29ac3 100644 --- a/init/do_mounts.h +++ b/init/do_mounts.h @@ -17,7 +17,7 @@ extern int root_mountflags; static inline __init int create_dev(char *name, dev_t dev) { init_unlink(name); - return ksys_mknod(name, S_IFBLK|0600, new_encode_dev(dev)); + return init_mknod(name, S_IFBLK | 0600, new_encode_dev(dev)); } #ifdef CONFIG_BLK_DEV_RAM diff --git a/init/initramfs.c b/init/initramfs.c index 0489eb6..425adda 100644 --- a/init/initramfs.c +++ b/init/initramfs.c @@ -355,7 +355,7 @@ static int __init do_name(void) } else if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) { if (maybe_link() == 0) { - ksys_mknod(collected, mode, rdev); + init_mknod(collected, mode, rdev); init_chown(collected, uid, gid, 0); init_chmod(collected, mode); do_utime(collected, mtime); diff --git a/init/noinitramfs.c b/init/noinitramfs.c index 94cc4df..3d62b07 100644 --- a/init/noinitramfs.c +++ b/init/noinitramfs.c @@ -22,8 +22,7 @@ static int __init default_rootfs(void) if (err < 0) goto out; - err = ksys_mknod((const char __user __force *) "/dev/console", - S_IFCHR | S_IRUSR | S_IWUSR, + err = init_mknod("/dev/console", S_IFCHR | S_IRUSR | S_IWUSR, new_encode_dev(MKDEV(5, 1))); if (err < 0) goto out; -- 2.7.4