From: kemal <kmal@cock.li>

Support aarch64 to test "Syscall User Dispatch" with sud_test
selftest testcase.

Signed-off-by: kemal <kmal@cock.li>
---
 tools/testing/selftests/syscall_user_dispatch/sud_test.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/testing/selftests/syscall_user_dispatch/sud_test.c b/tools/testing/selftests/syscall_user_dispatch/sud_test.c
index 2eb2c06303f2..f53ebc89befc 100644
--- a/tools/testing/selftests/syscall_user_dispatch/sud_test.c
+++ b/tools/testing/selftests/syscall_user_dispatch/sud_test.c
@@ -192,6 +192,10 @@ static void handle_sigsys(int sig, siginfo_t *info, void *ucontext)
 	((ucontext_t *)ucontext)->uc_mcontext.__gregs[REG_A0] =
 			((ucontext_t *)ucontext)->uc_mcontext.__gregs[REG_A7];
 #endif
+#ifdef __aarch64__
+	((ucontext_t *)ucontext)->uc_mcontext.regs[0] = (unsigned int)
+			((ucontext_t *)ucontext)->uc_mcontext.regs[8];
+#endif
 }
 
 int setup_sigsys_handler(void)
-- 
2.34.1

You should also make sure TEST_BLOCKED_RETURN is defined in
sud_benchmark.c:

/*
 * To test returning from a sigsys with selector blocked, the test
 * requires some per-architecture support (i.e. knowledge about the
 * signal trampoline address).  On i386, we know it is on the vdso, and
 * a small trampoline is open-coded for x86_64.  Other architectures
 * that have a trampoline in the vdso will support TEST_BLOCKED_RETURN
 * out of the box, but don't enable them until they support syscall user
 * dispatch.
 */
#if defined(__x86_64__) || defined(__i386__) || defined(__aarch64__)
#define TEST_BLOCKED_RETURN
#endif