From f459dffae1c6026928bbe8e972daecb635b7b5e9 Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Sun, 11 Mar 2018 11:34:48 +0100 Subject: [PATCH] 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(-) diff --git a/fs/internal.h b/fs/internal.h index df262f4..0eda35f 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 524e829..8545151 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 7cbfb41..746043a 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 08eb551..73bbb22 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); } -- 2.7.4