[PATCH v4 12/13] tests/tcg: add test for MTE FAR

[Gabriel Brookman <brookmangabriel@gmail.com>]

This functionality was previously enabled but not advertised or tested.
This commit adds a new test, mte-9, that tests the code for proper
full-address reporting. FEAT_MTE_TAGGED_FAR requires that FAR_ELx
report the full logical address, including tag bits.

Signed-off-by: Gabriel Brookman <brookmangabriel@gmail.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
 tests/tcg/aarch64/Makefile.target |  2 +-
 tests/tcg/aarch64/mte-9.c         | 48 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/tests/tcg/aarch64/Makefile.target b/tests/tcg/aarch64/Makefile.target
index 9fa8687453..b491cfb5e1 100644
--- a/tests/tcg/aarch64/Makefile.target
+++ b/tests/tcg/aarch64/Makefile.target
@@ -64,7 +64,7 @@ AARCH64_TESTS += bti-2
 
 # MTE Tests
 ifneq ($(CROSS_CC_HAS_ARMV8_MTE),)
-AARCH64_TESTS += mte-1 mte-2 mte-3 mte-4 mte-5 mte-6 mte-7 mte-8
+AARCH64_TESTS += mte-1 mte-2 mte-3 mte-4 mte-5 mte-6 mte-7 mte-8 mte-9
 mte-%: CFLAGS += $(CROSS_CC_HAS_ARMV8_MTE)
 endif
 
diff --git a/tests/tcg/aarch64/mte-9.c b/tests/tcg/aarch64/mte-9.c
new file mode 100644
index 0000000000..9626a90c13
--- /dev/null
+++ b/tests/tcg/aarch64/mte-9.c
@@ -0,0 +1,48 @@
+/*
+ * Memory tagging, full-address reporting.
+ *
+ * Copyright (c) 2021 Linaro Ltd
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "mte.h"
+
+static void *faulting_ptr;
+
+void pass(int sig, siginfo_t *info, void *uc)
+{
+    assert(faulting_ptr == info->si_addr);
+    exit(0);
+}
+
+int main(int ac, char **av)
+{
+    struct sigaction sa;
+    int *p0, *p1, *p2;
+    long excl = 1;
+
+    enable_mte(PR_MTE_TCF_SYNC);
+    p0 = alloc_mte_mem(sizeof(*p0));
+
+    /* Create two differently tagged pointers. */
+    asm("irg %0,%1,%2" : "=r"(p1) : "r"(p0), "r"(excl));
+    asm("gmi %0,%1,%0" : "+r"(excl) : "r" (p1));
+    assert(excl != 1);
+    asm("irg %0,%1,%2" : "=r"(p2) : "r"(p0), "r"(excl));
+    assert(p1 != p2);
+
+    /* Store the tag from the first pointer.  */
+    asm("stg %0, [%0]" : : "r"(p1));
+
+    *p1 = 0;
+
+    memset(&sa, 0, sizeof(sa));
+    sa.sa_sigaction = pass;
+    sa.sa_flags = SA_SIGINFO;
+    sigaction(SIGSEGV, &sa, NULL);
+
+    faulting_ptr = p2;
+    *p2 = 0;
+
+    abort();
+}

-- 
2.52.0