arm64: use the correct function type in SYSCALL_DEFINE0

[ Upstream commit 0e358bd7 ]

Although a syscall defined using SYSCALL_DEFINE0 doesn't accept
parameters, use the correct function type to avoid indirect call
type mismatches with Control-Flow Integrity checking.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

arch/arm64/include/asm/syscall_wrapper.h

@@ -31,9 +31,9 @@
 	static inline long __do_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))
 
 #define COMPAT_SYSCALL_DEFINE0(sname)							\
-	asmlinkage long __arm64_compat_sys_##sname(void);		\
+	asmlinkage long __arm64_compat_sys_##sname(const struct pt_regs *__unused);	\
 	ALLOW_ERROR_INJECTION(__arm64_compat_sys_##sname, ERRNO);			\
-	asmlinkage long __arm64_compat_sys_##sname(void)
+	asmlinkage long __arm64_compat_sys_##sname(const struct pt_regs *__unused)
 
 #define COND_SYSCALL_COMPAT(name) \
 	cond_syscall(__arm64_compat_sys_##name);
@@ -64,9 +64,9 @@
 #ifndef SYSCALL_DEFINE0
 #define SYSCALL_DEFINE0(sname)							\
 	SYSCALL_METADATA(_##sname, 0);						\
-	asmlinkage long __arm64_sys_##sname(void);		\
+	asmlinkage long __arm64_sys_##sname(const struct pt_regs *__unused);	\
 	ALLOW_ERROR_INJECTION(__arm64_sys_##sname, ERRNO);			\
-	asmlinkage long __arm64_sys_##sname(void)
+	asmlinkage long __arm64_sys_##sname(const struct pt_regs *__unused)
 #endif
 
 #ifndef COND_SYSCALL