1 files changed, 100 insertions, 0 deletions
diff --git a/tools/testing/selftests/arm64/fp/za-fork.c b/tools/testing/selftests/arm64/fp/za-fork.c
new file mode 100644
index 000000000000..587b94648222
--- /dev/null
+++ b/tools/testing/selftests/arm64/fp/za-fork.c
@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2022 ARM Limited.
+ * Original author: Mark Brown <broonie@kernel.org>
+ */
+
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/sched.h>
+#include <linux/wait.h>
+
+#include "kselftest.h"
+
+#define EXPECTED_TESTS 1
+
+int fork_test(void);
+int verify_fork(void);
+
+/*
+ * If we fork the value in the parent should be unchanged and the
+ * child should start with the same value.  This is called from the
+ * fork_test() asm function.
+ */
+int fork_test_c(void)
+{
+	pid_t newpid, waiting;
+	int child_status, parent_result;
+
+	newpid = fork();
+	if (newpid == 0) {
+		/* In child */
+		if (!verify_fork()) {
+			ksft_print_msg("ZA state invalid in child\n");
+			exit(0);
+		} else {
+			exit(1);
+		}
+	}
+	if (newpid < 0) {
+		ksft_print_msg("fork() failed: %d\n", newpid);
+
+		return 0;
+	}
+
+	parent_result = verify_fork();
+	if (!parent_result)
+		ksft_print_msg("ZA state invalid in parent\n");
+
+	for (;;) {
+		waiting = waitpid(newpid, &child_status, 0);
+
+		if (waiting < 0) {
+			if (errno == EINTR)
+				continue;
+			ksft_print_msg("waitpid() failed: %d\n", errno);
+			return 0;
+		}
+		if (waiting != newpid) {
+			ksft_print_msg("waitpid() returned wrong PID\n");
+			return 0;
+		}
+
+		if (!WIFEXITED(child_status)) {
+			ksft_print_msg("child did not exit\n");
+			return 0;
+		}
+
+		return WEXITSTATUS(child_status) && parent_result;
+	}
+}
+
+int main(int argc, char **argv)
+{
+	int ret, i;
+
+	ksft_print_header();
+	ksft_set_plan(EXPECTED_TESTS);
+
+	ksft_print_msg("PID: %d\n", getpid());
+
+	/*
+	 * This test is run with nolibc which doesn't support hwcap and
+	 * it's probably disproportionate to implement so instead check
+	 * for the default vector length configuration in /proc.
+	 */
+	ret = open("/proc/sys/abi/sme_default_vector_length", O_RDONLY, 0);
+	if (ret >= 0) {
+		ksft_test_result(fork_test(), "fork_test\n");
+
+	} else {
+		ksft_print_msg("SME not supported\n");
+		for (i = 0; i < EXPECTED_TESTS; i++) {
+			ksft_test_result_skip("fork_test\n");
+		}
+	}
+
+	ksft_finished();
+
+	return 0;
+}