1 files changed, 90 insertions, 0 deletions
diff --git a/tools/testing/selftests/arm64/signal/testcases/tpidr2_siginfo.c b/tools/testing/selftests/arm64/signal/testcases/tpidr2_siginfo.c
new file mode 100644
index 000000000000..6a2c82bf7ead
--- /dev/null
+++ b/tools/testing/selftests/arm64/signal/testcases/tpidr2_siginfo.c
@@ -0,0 +1,90 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2022 ARM Limited
+ *
+ * Verify that the TPIDR2 register context in signal frames is set up as
+ * expected.
+ */
+
+#include <signal.h>
+#include <ucontext.h>
+#include <sys/auxv.h>
+#include <sys/prctl.h>
+#include <unistd.h>
+#include <asm/sigcontext.h>
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+static union {
+	ucontext_t uc;
+	char buf[1024 * 128];
+} context;
+
+#define SYS_TPIDR2 "S3_3_C13_C0_5"
+
+static uint64_t get_tpidr2(void)
+{
+	uint64_t val;
+
+	asm volatile (
+		"mrs	%0, " SYS_TPIDR2 "\n"
+		: "=r"(val)
+		:
+		: "cc");
+
+	return val;
+}
+
+int tpidr2_present(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
+{
+	struct _aarch64_ctx *head = GET_BUF_RESV_HEAD(context);
+	struct tpidr2_context *tpidr2_ctx;
+	size_t offset;
+	bool in_sigframe;
+	bool have_sme;
+	__u64 orig_tpidr2;
+
+	have_sme = getauxval(AT_HWCAP2) & HWCAP2_SME;
+	if (have_sme)
+		orig_tpidr2 = get_tpidr2();
+
+	if (!get_current_context(td, &context.uc, sizeof(context)))
+		return 1;
+
+	tpidr2_ctx = (struct tpidr2_context *)
+		get_header(head, TPIDR2_MAGIC, td->live_sz, &offset);
+
+	in_sigframe = tpidr2_ctx != NULL;
+
+	fprintf(stderr, "TPIDR2 sigframe %s on system %s SME\n",
+		in_sigframe ? "present" : "absent",
+		have_sme ? "with" : "without");
+
+	td->pass = (in_sigframe == have_sme);
+
+	/*
+	 * Check that the value we read back was the one present at
+	 * the time that the signal was triggered.  TPIDR2 is owned by
+	 * libc so we can't safely choose the value and it is possible
+	 * that we may need to revisit this in future if something
+	 * starts deciding to set a new TPIDR2 between us reading and
+	 * the signal.
+	 */
+	if (have_sme && tpidr2_ctx) {
+		if (tpidr2_ctx->tpidr2 != orig_tpidr2) {
+			fprintf(stderr, "TPIDR2 in frame is %llx, was %llx\n",
+				tpidr2_ctx->tpidr2, orig_tpidr2);
+			td->pass = false;
+		}
+	}
+
+	return 0;
+}
+
+struct tdescr tde = {
+	.name = "TPIDR2",
+	.descr = "Validate that TPIDR2 is present as expected",
+	.timeout = 3,
+	.run = tpidr2_present,
+};