fs: add do_faccessat() helper and ksys_access() wrapper; remove in-kernel calls to syscall

Using the fs-internal do_faccessat() helper allows us to get rid of
fs-internal calls to the sys_faccessat() syscall.

Introducing the ksys_access() wrapper allows us to avoid the in-kernel
calls to the sys_access() 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_access().

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/[email protected]

Cc: Al Viro <[email protected]>
Cc: Andrew Morton <[email protected]>
Signed-off-by: Dominik Brodowski <[email protected]>
This commit is contained in:
Dominik Brodowski 2018-03-11 11:34:54 +01:00
commit cbfe20f565
4 changed files with 17 additions and 3 deletions

View file

@ -119,6 +119,7 @@ extern struct file *do_filp_open(int dfd, struct filename *pathname,
extern struct file *do_file_open_root(struct dentry *, struct vfsmount *,
const char *, const struct open_flags *);
long do_faccessat(int dfd, const char __user *filename, int mode);
int do_fchmodat(int dfd, const char __user *filename, umode_t mode);
extern int open_check_o_direct(struct file *f);