fs: add ksys_mount() helper; remove in-kernel calls to sys_mount()
Using this helper allows us to avoid the in-kernel calls to the sys_mount()
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_mount().
In the near future, all callers of ksys_mount() should be converted to call
do_mount() directly.
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 <viro@zeniv.linux.org.uk>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 6ab7ed7..3a9f9c5 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -946,4 +946,7 @@ asmlinkage long sys_statx(int dfd, const char __user *path, unsigned flags,
* the ksys_xyzyyz() functions prototyped below.
*/
+int ksys_mount(char __user *dev_name, char __user *dir_name, char __user *type,
+ unsigned long flags, void __user *data);
+
#endif