ipc: add shmdt syscall wrapper
Provide ksys_shmdt() wrapper to avoid in-kernel calls to this 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_shmdt().
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>
diff --git a/ipc/shm.c b/ipc/shm.c
index 9f3cdb2..e5838e3 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -1481,7 +1481,7 @@ COMPAT_SYSCALL_DEFINE3(shmat, int, shmid, compat_uptr_t, shmaddr, int, shmflg)
* detach and kill segment if marked destroyed.
* The work is done in shm_close.
*/
-SYSCALL_DEFINE1(shmdt, char __user *, shmaddr)
+long ksys_shmdt(char __user *shmaddr)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
@@ -1588,6 +1588,11 @@ SYSCALL_DEFINE1(shmdt, char __user *, shmaddr)
return retval;
}
+SYSCALL_DEFINE1(shmdt, char __user *, shmaddr)
+{
+ return ksys_shmdt(shmaddr);
+}
+
#ifdef CONFIG_PROC_FS
static int sysvipc_shm_proc_show(struct seq_file *s, void *it)
{