s390: wire up userfaultfd system call

Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/include/uapi/asm/unistd.h

@@ -290,7 +290,8 @@
 #define __NR_s390_pci_mmio_write	352
 #define __NR_s390_pci_mmio_read		353
 #define __NR_execveat		354
-#define NR_syscalls 355
+#define __NR_userfaultfd	355
+#define NR_syscalls 356
 
 /* 
  * There are some system calls that are not present on 64 bit, some

arch/s390/kernel/syscalls.S

@@ -363,3 +363,4 @@ SYSCALL(sys_bpf,compat_sys_bpf)
 SYSCALL(sys_s390_pci_mmio_write,compat_sys_s390_pci_mmio_write)
 SYSCALL(sys_s390_pci_mmio_read,compat_sys_s390_pci_mmio_read)
 SYSCALL(sys_execveat,compat_sys_execveat)
+SYSCALL(sys_userfaultfd,sys_userfaultfd)		/* 355 */

tools/testing/selftests/vm/userfaultfd.c

@@ -72,6 +72,8 @@
 #define __NR_userfaultfd 374
 #elif defined(__powewrpc__)
 #define __NR_userfaultfd 364
+#elif defined(__s390__)
+#define __NR_userfaultfd 355
 #else
 #error "missing __NR_userfaultfd definition"
 #endif