1 files changed, 48 insertions, 0 deletions
diff --git a/tests/tcg/aarch64/gcsstr.c b/tests/tcg/aarch64/gcsstr.c
new file mode 100644
index 0000000..b045aee
--- /dev/null
+++ b/tests/tcg/aarch64/gcsstr.c
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include "gcs.h"
+
+/*
+ * A single garbage store to the gcs stack.
+ * The asm inside must be unique, so disallow inlining.
+ */
+void __attribute__((noinline))
+test_gcsstr(void)
+{
+    register uint64_t *ptr __asm__("x0") = gcspr();
+    /* GCSSTR x1, x0 */
+    __asm__("inst_gcsstr: .inst 0xd91f1c01" : : "r"(--ptr));
+}
+
+static void test_sigsegv(int sig, siginfo_t *info, void *vuc)
+{
+    ucontext_t *uc = vuc;
+    uint64_t inst_gcsstr;
+
+    __asm__("adr %0, inst_gcsstr" : "=r"(inst_gcsstr));
+    assert(uc->uc_mcontext.pc == inst_gcsstr);
+    assert(info->si_code == SEGV_CPERR);
+    /* TODO: Dig for ESR and verify syndrome. */
+    exit(0);
+}
+
+int main()
+{
+    struct sigaction sa = {
+        .sa_sigaction = test_sigsegv,
+        .sa_flags = SA_SIGINFO,
+    };
+
+    /* Enable GCSSTR and test the store succeeds. */
+    enable_gcs(PR_SHADOW_STACK_WRITE);
+    test_gcsstr();
+
+    /* Disable GCSSTR and test the resulting sigsegv. */
+    enable_gcs(0);
+    if (sigaction(SIGSEGV, &sa, NULL) < 0) {
+        perror("sigaction");
+        exit(1);
+    }
+    test_gcsstr();
+    abort();
+}