kernel: add ksys_unshare() helper; remove in-kernel calls to sys_unshare()
Using this helper allows us to avoid the in-kernel calls to the
sys_unshare() 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_unshare().
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>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
diff --git a/init/do_mounts_initrd.c b/init/do_mounts_initrd.c
index 03ec0c1..d1d3e53 100644
--- a/init/do_mounts_initrd.c
+++ b/init/do_mounts_initrd.c
@@ -36,7 +36,7 @@
static int init_linuxrc(struct subprocess_info *info, struct cred *new)
{
- sys_unshare(CLONE_FS | CLONE_FILES);
+ ksys_unshare(CLONE_FS | CLONE_FILES);
/* stdin/stdout/stderr for /linuxrc */
ksys_open("/dev/console", O_RDWR, 0);
ksys_dup(0);