tests/tcg/aarch64: Add mte smoke tests

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210212184902.1251044-32-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

tests/tcg/aarch64/Makefile.target

@@ -35,6 +35,12 @@ endif
 # bti-2 tests PROT_BTI, so no special compiler support required.
 AARCH64_TESTS += bti-2
 
+# MTE Tests
+ifneq ($(DOCKER_IMAGE)$(CROSS_CC_HAS_ARMV8_MTE),)
+AARCH64_TESTS += mte-1 mte-2 mte-3 mte-4
+mte-%: CFLAGS += -march=armv8.5-a+memtag
+endif
+
 # Semihosting smoke test for linux-user
 AARCH64_TESTS += semihosting
 run-semihosting: semihosting

tests/tcg/aarch64/mte-1.c

@@ -0,0 +1,28 @@
+/*
+ * Memory tagging, basic pass cases.
+ *
+ * Copyright (c) 2021 Linaro Ltd
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "mte.h"
+
+int main(int ac, char **av)
+{
+    int *p0, *p1, *p2;
+    long c;
+
+    enable_mte(PR_MTE_TCF_NONE);
+    p0 = alloc_mte_mem(sizeof(*p0));
+
+    asm("irg %0,%1,%2" : "=r"(p1) : "r"(p0), "r"(1));
+    assert(p1 != p0);
+    asm("subp %0,%1,%2" : "=r"(c) : "r"(p0), "r"(p1));
+    assert(c == 0);
+
+    asm("stg %0, [%0]" : : "r"(p1));
+    asm("ldg %0, [%1]" : "=r"(p2) : "r"(p0), "0"(p0));
+    assert(p1 == p2);
+
+    return 0;
+}

tests/tcg/aarch64/mte-2.c

@@ -0,0 +1,45 @@
+/*
+ * Memory tagging, basic fail cases, synchronous signals.
+ *
+ * Copyright (c) 2021 Linaro Ltd
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "mte.h"
+
+void pass(int sig, siginfo_t *info, void *uc)
+{
+    assert(info->si_code == SEGV_MTESERR);
+    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);
+
+    *p2 = 0;
+
+    abort();
+}

tests/tcg/aarch64/mte-3.c

@@ -0,0 +1,51 @@
+/*
+ * Memory tagging, basic fail cases, asynchronous signals.
+ *
+ * Copyright (c) 2021 Linaro Ltd
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "mte.h"
+
+void pass(int sig, siginfo_t *info, void *uc)
+{
+    assert(info->si_code == SEGV_MTEAERR);
+    exit(0);
+}
+
+int main(int ac, char **av)
+{
+    struct sigaction sa;
+    long *p0, *p1, *p2;
+    long excl = 1;
+
+    enable_mte(PR_MTE_TCF_ASYNC);
+    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);
+
+    /*
+     * Signal for async error will happen eventually.
+     * For a real kernel this should be after the next IRQ (e.g. timer).
+     * For qemu linux-user, we kick the cpu and exit at the next TB.
+     * In either case, loop until this happens (or killed by timeout).
+     * For extra sauce, yield, producing EXCP_YIELD to cpu_loop().
+     */
+    asm("str %0, [%0]; yield" : : "r"(p2));
+    while (1);
+}

tests/tcg/aarch64/mte-4.c

@@ -0,0 +1,45 @@
+/*
+ * Memory tagging, re-reading tag checks.
+ *
+ * Copyright (c) 2021 Linaro Ltd
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "mte.h"
+
+void __attribute__((noinline)) tagset(void *p, size_t size)
+{
+    size_t i;
+    for (i = 0; i < size; i += 16) {
+        asm("stg %0, [%0]" : : "r"(p + i));
+    }
+}
+
+void __attribute__((noinline)) tagcheck(void *p, size_t size)
+{
+    size_t i;
+    void *c;
+
+    for (i = 0; i < size; i += 16) {
+        asm("ldg %0, [%1]" : "=r"(c) : "r"(p + i), "0"(p));
+        assert(c == p);
+    }
+}
+
+int main(int ac, char **av)
+{
+    size_t size = getpagesize() * 4;
+    long excl = 1;
+    int *p0, *p1;
+
+    enable_mte(PR_MTE_TCF_ASYNC);
+    p0 = alloc_mte_mem(size);
+
+    /* Tag the pointer. */
+    asm("irg %0,%1,%2" : "=r"(p1) : "r"(p0), "r"(excl));
+
+    tagset(p1, size);
+    tagcheck(p1, size);
+
+    return 0;
+}

tests/tcg/aarch64/mte.h

@@ -0,0 +1,60 @@
+/*
+ * Linux kernel fallback API definitions for MTE and test helpers.
+ *
+ * Copyright (c) 2021 Linaro Ltd
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include <assert.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <signal.h>
+#include <sys/mman.h>
+#include <sys/prctl.h>
+
+#ifndef PR_SET_TAGGED_ADDR_CTRL
+# define PR_SET_TAGGED_ADDR_CTRL  55
+#endif
+#ifndef PR_TAGGED_ADDR_ENABLE
+# define PR_TAGGED_ADDR_ENABLE    (1UL << 0)
+#endif
+#ifndef PR_MTE_TCF_SHIFT
+# define PR_MTE_TCF_SHIFT         1
+# define PR_MTE_TCF_NONE          (0UL << PR_MTE_TCF_SHIFT)
+# define PR_MTE_TCF_SYNC          (1UL << PR_MTE_TCF_SHIFT)
+# define PR_MTE_TCF_ASYNC         (2UL << PR_MTE_TCF_SHIFT)
+# define PR_MTE_TAG_SHIFT         3
+#endif
+
+#ifndef PROT_MTE
+# define PROT_MTE 0x20
+#endif
+
+#ifndef SEGV_MTEAERR
+# define SEGV_MTEAERR    8
+# define SEGV_MTESERR    9
+#endif
+
+static void enable_mte(int tcf)
+{
+    int r = prctl(PR_SET_TAGGED_ADDR_CTRL,
+                  PR_TAGGED_ADDR_ENABLE | tcf | (0xfffe << PR_MTE_TAG_SHIFT),
+                  0, 0, 0);
+    if (r < 0) {
+        perror("PR_SET_TAGGED_ADDR_CTRL");
+        exit(2);
+    }
+}
+
+static void *alloc_mte_mem(size_t size)
+{
+    void *p = mmap(NULL, size, PROT_READ | PROT_WRITE | PROT_MTE,
+                   MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+    if (p == MAP_FAILED) {
+        perror("mmap PROT_MTE");
+        exit(2);
+    }
+    return p;
+}

tests/tcg/configure.sh

@@ -244,6 +244,10 @@ for target in $target_list; do
                -mbranch-protection=standard -o $TMPE $TMPC; then
                 echo "CROSS_CC_HAS_ARMV8_BTI=y" >> $config_target_mak
             fi
+            if do_compiler "$target_compiler" $target_compiler_cflags \
+               -march=armv8.5-a+memtag -o $TMPE $TMPC; then
+                echo "CROSS_CC_HAS_ARMV8_MTE=y" >> $config_target_mak
+            fi
         ;;
     esac