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 <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
This commit is contained in:
Dominik Brodowski
2018-03-11 11:34:50 +01:00
parent b724e846b4
commit 87c4e19262
6 changed files with 23 additions and 6 deletions

View File

@@ -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);