From ee81feb64ead8e4bed0ebc94c980e6cd836aaafd Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Sun, 11 Mar 2018 11:34:28 +0100 Subject: fs: add do_renameat2() helper; remove internal call to sys_renameat2() Using this helper removes in-kernel calls to the sys_renameat2() syscall. 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: Alexander Viro Signed-off-by: Dominik Brodowski --- fs/namei.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) (limited to 'fs/namei.c') diff --git a/fs/namei.c b/fs/namei.c index 921ae32dbc80..524e829ffc7d 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -4478,8 +4478,8 @@ out: } EXPORT_SYMBOL(vfs_rename); -SYSCALL_DEFINE5(renameat2, int, olddfd, const char __user *, oldname, - int, newdfd, const char __user *, newname, unsigned int, flags) +static int do_renameat2(int olddfd, const char __user *oldname, int newdfd, + const char __user *newname, unsigned int flags) { struct dentry *old_dentry, *new_dentry; struct dentry *trap; @@ -4621,15 +4621,21 @@ exit: return error; } +SYSCALL_DEFINE5(renameat2, int, olddfd, const char __user *, oldname, + int, newdfd, const char __user *, newname, unsigned int, flags) +{ + return do_renameat2(olddfd, oldname, newdfd, newname, flags); +} + SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname, int, newdfd, const char __user *, newname) { - return sys_renameat2(olddfd, oldname, newdfd, newname, 0); + return do_renameat2(olddfd, oldname, newdfd, newname, 0); } SYSCALL_DEFINE2(rename, const char __user *, oldname, const char __user *, newname) { - return sys_renameat2(AT_FDCWD, oldname, AT_FDCWD, newname, 0); + return do_renameat2(AT_FDCWD, oldname, AT_FDCWD, newname, 0); } int vfs_whiteout(struct inode *dir, struct dentry *dentry) -- cgit v1.2.3 From f459dffae1c6026928bbe8e972daecb635b7b5e9 Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Sun, 11 Mar 2018 11:34:48 +0100 Subject: fs: add ksys_rmdir() wrapper; remove in-kernel calls to sys_rmdir() Using this wrapper allows us to avoid the in-kernel calls to the sys_rmdir() syscall. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as sys_rmdir(). 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 Cc: Andrew Morton Signed-off-by: Dominik Brodowski --- fs/internal.h | 1 + fs/namei.c | 2 +- include/linux/syscalls.h | 7 +++++++ init/initramfs.c | 4 ++-- 4 files changed, 11 insertions(+), 3 deletions(-) (limited to 'fs/namei.c') diff --git a/fs/internal.h b/fs/internal.h index df262f41a0ef..0eda35fa1743 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -55,6 +55,7 @@ extern void __init chrdev_init(void); extern int user_path_mountpoint_at(int, const char __user *, unsigned int, struct path *); extern int vfs_path_lookup(struct dentry *, struct vfsmount *, const char *, unsigned int, struct path *); +long do_rmdir(int dfd, const char __user *pathname); long do_unlinkat(int dfd, struct filename *name); /* diff --git a/fs/namei.c b/fs/namei.c index 524e829ffc7d..8545151f74e9 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -3872,7 +3872,7 @@ out: } EXPORT_SYMBOL(vfs_rmdir); -static long do_rmdir(int dfd, const char __user *pathname) +long do_rmdir(int dfd, const char __user *pathname) { int error = 0; struct filename *name; diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 7cbfb41e666b..746043a05884 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -965,4 +965,11 @@ static inline long ksys_unlink(const char __user *pathname) return do_unlinkat(AT_FDCWD, getname(pathname)); } +extern long do_rmdir(int dfd, const char __user *pathname); + +static inline long ksys_rmdir(const char __user *pathname) +{ + return do_rmdir(AT_FDCWD, pathname); +} + #endif diff --git a/init/initramfs.c b/init/initramfs.c index 08eb551168a8..73bbb227f868 100644 --- a/init/initramfs.c +++ b/init/initramfs.c @@ -317,7 +317,7 @@ static void __init clean_path(char *path, umode_t fmode) if (!vfs_lstat(path, &st) && (st.mode ^ fmode) & S_IFMT) { if (S_ISDIR(st.mode)) - sys_rmdir(path); + ksys_rmdir(path); else ksys_unlink(path); } @@ -589,7 +589,7 @@ static void __init clean_rootfs(void) WARN_ON_ONCE(ret); if (!ret) { if (S_ISDIR(st.mode)) - sys_rmdir(dirp->d_name); + ksys_rmdir(dirp->d_name); else ksys_unlink(dirp->d_name); } -- cgit v1.2.3 From 0101db7a301981a008296d522d8c1f456b0fe837 Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Sun, 11 Mar 2018 11:34:49 +0100 Subject: fs: add do_mkdirat() helper and ksys_mkdir() wrapper; remove in-kernel calls to syscall Using the fs-internal do_mkdirat() helper allows us to get rid of fs-internal calls to the sys_mkdirat() syscall. Introducing the ksys_mkdir() wrapper allows us to avoid the in-kernel calls to the sys_mkdir() syscall. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as sys_mkdir(). 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 Cc: Andrew Morton Signed-off-by: Dominik Brodowski --- fs/internal.h | 1 + fs/namei.c | 9 +++++++-- include/linux/syscalls.h | 7 +++++++ init/do_mounts_initrd.c | 2 +- init/initramfs.c | 2 +- init/noinitramfs.c | 4 ++-- 6 files changed, 19 insertions(+), 6 deletions(-) (limited to 'fs/namei.c') diff --git a/fs/internal.h b/fs/internal.h index 0eda35fa1743..53846bd4d9d7 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -55,6 +55,7 @@ extern void __init chrdev_init(void); extern int user_path_mountpoint_at(int, const char __user *, unsigned int, struct path *); extern int vfs_path_lookup(struct dentry *, struct vfsmount *, const char *, unsigned int, struct path *); +long do_mkdirat(int dfd, const char __user *pathname, umode_t mode); long do_rmdir(int dfd, const char __user *pathname); long do_unlinkat(int dfd, struct filename *name); diff --git a/fs/namei.c b/fs/namei.c index 8545151f74e9..dcf506227509 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -3803,7 +3803,7 @@ int vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) } EXPORT_SYMBOL(vfs_mkdir); -SYSCALL_DEFINE3(mkdirat, int, dfd, const char __user *, pathname, umode_t, mode) +long do_mkdirat(int dfd, const char __user *pathname, umode_t mode) { struct dentry *dentry; struct path path; @@ -3828,9 +3828,14 @@ retry: return error; } +SYSCALL_DEFINE3(mkdirat, int, dfd, const char __user *, pathname, umode_t, mode) +{ + return do_mkdirat(dfd, pathname, mode); +} + SYSCALL_DEFINE2(mkdir, const char __user *, pathname, umode_t, mode) { - return sys_mkdirat(AT_FDCWD, pathname, mode); + return do_mkdirat(AT_FDCWD, pathname, mode); } int vfs_rmdir(struct inode *dir, struct dentry *dentry) diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 746043a05884..c982cb5f4e50 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -972,4 +972,11 @@ static inline long ksys_rmdir(const char __user *pathname) return do_rmdir(AT_FDCWD, pathname); } +extern long do_mkdirat(int dfd, const char __user *pathname, umode_t mode); + +static inline long ksys_mkdir(const char __user *pathname, umode_t mode) +{ + return do_mkdirat(AT_FDCWD, pathname, mode); +} + #endif diff --git a/init/do_mounts_initrd.c b/init/do_mounts_initrd.c index e9e9e1c67d31..99922d1ebfe6 100644 --- a/init/do_mounts_initrd.c +++ b/init/do_mounts_initrd.c @@ -60,7 +60,7 @@ static void __init handle_initrd(void) create_dev("/dev/root.old", Root_RAM0); /* mount initrd on rootfs' /root */ mount_block_root("/dev/root.old", root_mountflags & ~MS_RDONLY); - sys_mkdir("/old", 0700); + ksys_mkdir("/old", 0700); ksys_chdir("/old"); /* try loading default modules from initrd */ diff --git a/init/initramfs.c b/init/initramfs.c index 73bbb227f868..ca538a5f9fa9 100644 --- a/init/initramfs.c +++ b/init/initramfs.c @@ -352,7 +352,7 @@ static int __init do_name(void) } } } else if (S_ISDIR(mode)) { - sys_mkdir(collected, mode); + ksys_mkdir(collected, mode); sys_chown(collected, uid, gid); sys_chmod(collected, mode); dir_add(collected, mtime); diff --git a/init/noinitramfs.c b/init/noinitramfs.c index 267739d85179..a08a9d937e60 100644 --- a/init/noinitramfs.c +++ b/init/noinitramfs.c @@ -29,7 +29,7 @@ static int __init default_rootfs(void) { int err; - err = sys_mkdir((const char __user __force *) "/dev", 0755); + err = ksys_mkdir((const char __user __force *) "/dev", 0755); if (err < 0) goto out; @@ -39,7 +39,7 @@ static int __init default_rootfs(void) if (err < 0) goto out; - err = sys_mkdir((const char __user __force *) "/root", 0700); + err = ksys_mkdir((const char __user __force *) "/root", 0700); if (err < 0) goto out; -- cgit v1.2.3 From b724e846b491ef8db943be8086226c9d8da31877 Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Sun, 11 Mar 2018 11:34:49 +0100 Subject: fs: add do_symlinkat() helper and ksys_symlink() wrapper; remove in-kernel calls to syscall Using the fs-internal do_symlinkat() helper allows us to get rid of fs-internal calls to the sys_symlinkat() syscall. Introducing the ksys_symlink() wrapper allows us to avoid the in-kernel calls to the sys_symlink() syscall. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as sys_symlink(). 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 Cc: Andrew Morton Signed-off-by: Dominik Brodowski --- fs/internal.h | 2 ++ fs/namei.c | 12 +++++++++--- include/linux/syscalls.h | 9 +++++++++ init/initramfs.c | 2 +- 4 files changed, 21 insertions(+), 4 deletions(-) (limited to 'fs/namei.c') diff --git a/fs/internal.h b/fs/internal.h index 53846bd4d9d7..a3f04ca2a08b 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -58,6 +58,8 @@ extern int vfs_path_lookup(struct dentry *, struct vfsmount *, long do_mkdirat(int dfd, const char __user *pathname, umode_t mode); long do_rmdir(int dfd, const char __user *pathname); long do_unlinkat(int dfd, struct filename *name); +long do_symlinkat(const char __user *oldname, int newdfd, + const char __user *newname); /* * namespace.c diff --git a/fs/namei.c b/fs/namei.c index dcf506227509..e15da92209d5 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -4113,8 +4113,8 @@ int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname) } EXPORT_SYMBOL(vfs_symlink); -SYSCALL_DEFINE3(symlinkat, const char __user *, oldname, - int, newdfd, const char __user *, newname) +long do_symlinkat(const char __user *oldname, int newdfd, + const char __user *newname) { int error; struct filename *from; @@ -4144,9 +4144,15 @@ out_putname: return error; } +SYSCALL_DEFINE3(symlinkat, const char __user *, oldname, + int, newdfd, const char __user *, newname) +{ + return do_symlinkat(oldname, newdfd, newname); +} + SYSCALL_DEFINE2(symlink, const char __user *, oldname, const char __user *, newname) { - return sys_symlinkat(oldname, AT_FDCWD, newname); + return do_symlinkat(oldname, AT_FDCWD, newname); } /** diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index c982cb5f4e50..39c5cef86a10 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -979,4 +979,13 @@ static inline long ksys_mkdir(const char __user *pathname, umode_t mode) return do_mkdirat(AT_FDCWD, pathname, mode); } +extern long do_symlinkat(const char __user *oldname, int newdfd, + const char __user *newname); + +static inline long ksys_symlink(const char __user *oldname, + const char __user *newname) +{ + return do_symlinkat(oldname, AT_FDCWD, newname); +} + #endif diff --git a/init/initramfs.c b/init/initramfs.c index ca538a5f9fa9..cd9571a113b6 100644 --- a/init/initramfs.c +++ b/init/initramfs.c @@ -392,7 +392,7 @@ static int __init do_symlink(void) { collected[N_ALIGN(name_len) + body_len] = '\0'; clean_path(collected, 0); - sys_symlink(collected + N_ALIGN(name_len), collected); + ksys_symlink(collected + N_ALIGN(name_len), collected); sys_lchown(collected, uid, gid); do_utime(collected, mtime); state = SkipIt; -- cgit v1.2.3 From 87c4e19262d81862886207be3c8795f6576d5a52 Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Sun, 11 Mar 2018 11:34:50 +0100 Subject: fs: add do_mknodat() helper and ksys_mknod() wrapper; remove in-kernel calls to syscall Using the fs-internal do_mknodat() helper allows us to get rid of fs-internal calls to the sys_mknodat() syscall. Introducing the ksys_mknod() wrapper allows us to avoid the in-kernel calls to sys_mknod() syscall. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as sys_mknod(). 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 Cc: Andrew Morton Signed-off-by: Dominik Brodowski --- fs/internal.h | 2 ++ fs/namei.c | 12 +++++++++--- include/linux/syscalls.h | 9 +++++++++ init/do_mounts.h | 2 +- init/initramfs.c | 2 +- init/noinitramfs.c | 2 +- 6 files changed, 23 insertions(+), 6 deletions(-) (limited to 'fs/namei.c') diff --git a/fs/internal.h b/fs/internal.h index a3f04ca2a08b..4f0b67054c54 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -55,6 +55,8 @@ extern void __init chrdev_init(void); extern int user_path_mountpoint_at(int, const char __user *, unsigned int, struct path *); 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_mkdirat(int dfd, const char __user *pathname, umode_t mode); long do_rmdir(int dfd, const char __user *pathname); long do_unlinkat(int dfd, struct filename *name); diff --git a/fs/namei.c b/fs/namei.c index e15da92209d5..8459a18cdd18 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -3728,8 +3728,8 @@ static int may_mknod(umode_t mode) } } -SYSCALL_DEFINE4(mknodat, int, dfd, const char __user *, filename, umode_t, mode, - unsigned, dev) +long do_mknodat(int dfd, const char __user *filename, umode_t mode, + unsigned int dev) { struct dentry *dentry; struct path path; @@ -3772,9 +3772,15 @@ out: return error; } +SYSCALL_DEFINE4(mknodat, int, dfd, const char __user *, filename, umode_t, mode, + unsigned int, dev) +{ + return do_mknodat(dfd, filename, mode, dev); +} + SYSCALL_DEFINE3(mknod, const char __user *, filename, umode_t, mode, unsigned, dev) { - return sys_mknodat(AT_FDCWD, filename, mode, dev); + return do_mknodat(AT_FDCWD, filename, mode, dev); } int vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 39c5cef86a10..0b4fd684f0f1 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -988,4 +988,13 @@ static inline long ksys_symlink(const char __user *oldname, return do_symlinkat(oldname, AT_FDCWD, newname); } +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); +} + #endif diff --git a/init/do_mounts.h b/init/do_mounts.h index 401f90ee1eeb..0bb0806de4ce 100644 --- a/init/do_mounts.h +++ b/init/do_mounts.h @@ -17,7 +17,7 @@ extern int root_mountflags; static inline int create_dev(char *name, dev_t dev) { ksys_unlink(name); - return sys_mknod(name, S_IFBLK|0600, new_encode_dev(dev)); + return ksys_mknod(name, S_IFBLK|0600, new_encode_dev(dev)); } static inline u32 bstat(char *name) diff --git a/init/initramfs.c b/init/initramfs.c index cd9571a113b6..2972ed0ab399 100644 --- a/init/initramfs.c +++ b/init/initramfs.c @@ -359,7 +359,7 @@ static int __init do_name(void) } else if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) { if (maybe_link() == 0) { - sys_mknod(collected, mode, rdev); + ksys_mknod(collected, mode, rdev); sys_chown(collected, uid, gid); sys_chmod(collected, mode); do_utime(collected, mtime); diff --git a/init/noinitramfs.c b/init/noinitramfs.c index a08a9d937e60..f4bad8436c93 100644 --- a/init/noinitramfs.c +++ b/init/noinitramfs.c @@ -33,7 +33,7 @@ static int __init default_rootfs(void) if (err < 0) goto out; - err = sys_mknod((const char __user __force *) "/dev/console", + err = ksys_mknod((const char __user __force *) "/dev/console", S_IFCHR | S_IRUSR | S_IWUSR, new_encode_dev(MKDEV(5, 1))); if (err < 0) -- cgit v1.2.3 From 46ea89eb652a365e10257016d09dcf1aaf23cf63 Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Sun, 11 Mar 2018 11:34:53 +0100 Subject: fs: add do_linkat() helper and ksys_link() wrapper; remove in-kernel calls to syscall Using the fs-internal do_linkat() helper allows us to get rid of fs-internal calls to the sys_linkat() syscall. Introducing the ksys_link() wrapper allows us to avoid the in-kernel calls to sys_link() syscall. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as sys_link(). In the near future, the only fs-external user of ksys_link() should be converted to use vfs_link() instead. 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 Cc: Andrew Morton Signed-off-by: Dominik Brodowski --- fs/internal.h | 2 ++ fs/namei.c | 12 +++++++++--- include/linux/syscalls.h | 9 +++++++++ init/initramfs.c | 2 +- 4 files changed, 21 insertions(+), 4 deletions(-) (limited to 'fs/namei.c') diff --git a/fs/internal.h b/fs/internal.h index 4f0b67054c54..91e6fc93fcb5 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -62,6 +62,8 @@ long do_rmdir(int dfd, const char __user *pathname); long do_unlinkat(int dfd, struct filename *name); long do_symlinkat(const char __user *oldname, int newdfd, const char __user *newname); +int do_linkat(int olddfd, const char __user *oldname, int newdfd, + const char __user *newname, int flags); /* * namespace.c diff --git a/fs/namei.c b/fs/namei.c index 8459a18cdd18..10148235829f 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -4250,8 +4250,8 @@ EXPORT_SYMBOL(vfs_link); * with linux 2.0, and to avoid hard-linking to directories * and other special files. --ADM */ -SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname, - int, newdfd, const char __user *, newname, int, flags) +int do_linkat(int olddfd, const char __user *oldname, int newdfd, + const char __user *newname, int flags) { struct dentry *new_dentry; struct path old_path, new_path; @@ -4315,9 +4315,15 @@ out: return error; } +SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname, + int, newdfd, const char __user *, newname, int, flags) +{ + return do_linkat(olddfd, oldname, newdfd, newname, flags); +} + SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname) { - return sys_linkat(AT_FDCWD, oldname, AT_FDCWD, newname, 0); + return do_linkat(AT_FDCWD, oldname, AT_FDCWD, newname, 0); } /** diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 0b4fd684f0f1..827ed917630c 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -997,4 +997,13 @@ static inline long ksys_mknod(const char __user *filename, umode_t mode, return do_mknodat(AT_FDCWD, filename, mode, dev); } +extern int do_linkat(int olddfd, const char __user *oldname, int newdfd, + const char __user *newname, int flags); + +static inline long ksys_link(const char __user *oldname, + const char __user *newname) +{ + return do_linkat(AT_FDCWD, oldname, AT_FDCWD, newname, 0); +} + #endif diff --git a/init/initramfs.c b/init/initramfs.c index 2972ed0ab399..5855ab632b4e 100644 --- a/init/initramfs.c +++ b/init/initramfs.c @@ -306,7 +306,7 @@ static int __init maybe_link(void) if (nlink >= 2) { char *old = find_link(major, minor, ino, mode, collected); if (old) - return (sys_link(old, collected) < 0) ? -1 : 1; + return (ksys_link(old, collected) < 0) ? -1 : 1; } return 0; } -- cgit v1.2.3