ARM: add seccomp syscall

Wires up the new seccomp syscall.
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>

arch/arm/include/uapi/asm/unistd.h

@@ -409,6 +409,7 @@
 #define __NR_sched_setattr		(__NR_SYSCALL_BASE+380)
 #define __NR_sched_getattr		(__NR_SYSCALL_BASE+381)
 #define __NR_renameat2			(__NR_SYSCALL_BASE+382)
+#define __NR_seccomp			(__NR_SYSCALL_BASE+383)
 
 /*
  * This may need to be greater than __NR_last_syscall+1 in order to

arch/arm/kernel/calls.S

@@ -392,6 +392,7 @@
 /* 380 */	CALL(sys_sched_setattr)
 		CALL(sys_sched_getattr)
 		CALL(sys_renameat2)
+		CALL(sys_seccomp)
 #ifndef syscalls_counted
 .equ syscalls_padding, ((NR_syscalls + 3) & ~3) - NR_syscalls
 #define syscalls_counted