[PATCH v9 29/39] selftests/clone3: Enable arm64 shadow stack testing

[Mark Brown <broonie@kernel.org>]

In order to test shadow stack support in clone3() the clone3() selftests
need to have a fully inline clone3() call, provide one for arm64.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 tools/testing/selftests/clone3/clone3_selftests.h | 26 +++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/tools/testing/selftests/clone3/clone3_selftests.h b/tools/testing/selftests/clone3/clone3_selftests.h
index 38d82934668a..e32915085333 100644
--- a/tools/testing/selftests/clone3/clone3_selftests.h
+++ b/tools/testing/selftests/clone3/clone3_selftests.h
@@ -69,6 +69,32 @@ static pid_t __always_inline sys_clone3(struct __clone_args *args, size_t size)
 
 	return ret;
 }
+#elif defined(__aarch64__)
+static pid_t __always_inline sys_clone3(struct __clone_args *args, size_t size)
+{
+	register long _num  __asm__ ("x8") = __NR_clone3;
+	register long _args __asm__ ("x0") = (long)(args);
+	register long _size __asm__ ("x1") = (long)(size);
+	register long arg2 __asm__ ("x2") = 0;
+	register long arg3 __asm__ ("x3") = 0;
+	register long arg4 __asm__ ("x4") = 0;
+
+	__asm__ volatile (
+		"svc #0\n"
+		: "=r"(_args)
+		: "r"(_args), "r"(_size),
+		  "r"(_num), "r"(arg2),
+		  "r"(arg3), "r"(arg4)
+		: "memory", "cc"
+	);
+
+	if ((int)_args < 0) {
+		errno = -((int)_args);
+		return -1;
+	}
+
+	return _args;
+}
 #else
 static pid_t sys_clone3(struct __clone_args *args, size_t size)
 {

-- 
2.39.2