ARM: 9309/1: add missing syscall prototypes

All architecture-independent system calls have prototypes in
include/linux/syscalls.h, but there are a few that only exist
on arm or that take the pt_regs directly. These cause a W=1
warning such as:

arch/arm/kernel/signal.c:186:16: error: no previous prototype for 'sys_sigreturn' [-Werror=missing-prototypes]
arch/arm/kernel/signal.c:216:16: error: no previous prototype for 'sys_rt_sigreturn' [-Werror=missing-prototypes]
arch/arm/kernel/sys_arm.c:32:17: error: no previous prototype for 'sys_arm_fadvise64_64' [-Werror=missing-prototypes]

Add prototypes for all custom syscalls on arm and add them
to asm/syscalls.h.

Reviewed-by: Kees Cook <[e-mail]>
Signed-off-by: Arnd Bergmann <[e-mail]>
Signed-off-by: Russell King (Oracle) <[e-mail]>

arch/arm/include/asm/syscalls.h

···
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __ASM_SYSCALLS_H
+#define __ASM_SYSCALLS_H
+
+#include <linux/linkage.h>
+#include <linux/types.h>
+
+struct pt_regs;
+asmlinkage int sys_sigreturn(struct pt_regs *regs);
+asmlinkage int sys_rt_sigreturn(struct pt_regs *regs);
+asmlinkage long sys_arm_fadvise64_64(int fd, int advice,
+				     loff_t offset, loff_t len);
+
+struct oldabi_stat64;
+asmlinkage long sys_oabi_stat64(const char __user * filename,
+				struct oldabi_stat64 __user * statbuf);
+asmlinkage long sys_oabi_lstat64(const char __user * filename,
+				 struct oldabi_stat64 __user * statbuf);
+asmlinkage long sys_oabi_fstat64(unsigned long fd,
+				 struct oldabi_stat64 __user * statbuf);
+asmlinkage long sys_oabi_fstatat64(int dfd,
+				   const char __user *filename,
+				   struct oldabi_stat64  __user *statbuf,
+				   int flag);
+asmlinkage long sys_oabi_fcntl64(unsigned int fd, unsigned int cmd,
+				 unsigned long arg);
+struct oabi_epoll_event;
+asmlinkage long sys_oabi_epoll_ctl(int epfd, int op, int fd,
+				   struct oabi_epoll_event __user *event);
+struct oabi_sembuf;
+struct old_timespec32;
+asmlinkage long sys_oabi_semtimedop(int semid,
+				    struct oabi_sembuf __user *tsops,
+				    unsigned nsops,
+				    const struct old_timespec32 __user *timeout);
+asmlinkage long sys_oabi_semop(int semid, struct oabi_sembuf __user *tsops,
+			       unsigned nsops);
+asmlinkage int sys_oabi_ipc(uint call, int first, int second, int third,
+			    void __user *ptr, long fifth);
+struct sockaddr;
+asmlinkage long sys_oabi_bind(int fd, struct sockaddr __user *addr, int addrlen);
+asmlinkage long sys_oabi_connect(int fd, struct sockaddr __user *addr, int addrlen);
+asmlinkage long sys_oabi_sendto(int fd, void __user *buff,
+				size_t len, unsigned flags,
+				struct sockaddr __user *addr,
+				int addrlen);
+struct user_msghdr;
+asmlinkage long sys_oabi_sendmsg(int fd, struct user_msghdr __user *msg, unsigned flags);
+asmlinkage long sys_oabi_socketcall(int call, unsigned long __user *args);
+
+#endif

arch/arm/kernel/signal.c

···
 #include <asm/traps.h>
 #include <asm/unistd.h>
 #include <asm/vfp.h>
+#include <asm/syscalls.h>
 
 #include "signal.h"
 

arch/arm/kernel/sys_arm.c

···
 #include <linux/ipc.h>
 #include <linux/uaccess.h>
 #include <linux/slab.h>
+#include <asm/syscalls.h>
 
 /*
  * Since loff_t is a 64 bit type we avoid a lot of ABI hassle

arch/arm/kernel/sys_oabi-compat.c

···
  *  Copyright:	MontaVista Software, Inc.
  */
 
+#include <asm/syscalls.h>
+
 /*
  * The legacy ABI and the new ARM EABI have different rules making some
  * syscalls incompatible especially with structure arguments.