6 files changed, 144 insertions, 3 deletions
diff --git a/tests/tcg/Makefile.target b/tests/tcg/Makefile.target
index 2da70b2fcf..9722145b97 100644
--- a/tests/tcg/Makefile.target
+++ b/tests/tcg/Makefile.target
@@ -103,9 +103,14 @@ ifeq ($(filter %-softmmu, $(TARGET)),)
 # then the target. If there are common tests shared between
 # sub-targets (e.g. ARM & AArch64) then it is up to
 # $(TARGET_NAME)/Makefile.target to include the common parent
-# architecture in its VPATH.
+# architecture in its VPATH. However some targets are so minimal we
+# can't even build the multiarch tests.
+ifneq ($(filter $(TARGET_NAME),aarch64_be),)
+-include $(SRC_PATH)/tests/tcg/$(TARGET_NAME)/Makefile.target
+else
 -include $(SRC_PATH)/tests/tcg/multiarch/Makefile.target
 -include $(SRC_PATH)/tests/tcg/$(TARGET_NAME)/Makefile.target
+endif
 
 # Add the common build options
 CFLAGS+=-Wall -Werror -O0 -g -fno-strict-aliasing
diff --git a/tests/tcg/aarch64/gdbstub/test-mte.py b/tests/tcg/aarch64/gdbstub/test-mte.py
index a4cae6caa0..9ad98e7a54 100644
--- a/tests/tcg/aarch64/gdbstub/test-mte.py
+++ b/tests/tcg/aarch64/gdbstub/test-mte.py
@@ -23,8 +23,8 @@ from sys import argv
 from test_gdbstub import arg_parser, main, report
 
 
-PATTERN_0 = "Memory tags for address 0x[0-9a-f]+ match \\(0x[0-9a-f]+\\)."
-PATTERN_1 = ".*(0x[0-9a-f]+)"
+PATTERN_0 = r"Memory tags for address 0x[0-9a-f]+ match \(0x[0-9a-f]+\)."
+PATTERN_1 = r".*(0x[0-9a-f]+)"
 
 
 def run_test():
diff --git a/tests/tcg/aarch64_be/Makefile.target b/tests/tcg/aarch64_be/Makefile.target
new file mode 100644
index 0000000000..cbe5fa0b2d
--- /dev/null
+++ b/tests/tcg/aarch64_be/Makefile.target
@@ -0,0 +1,17 @@
+# -*- Mode: makefile -*-
+#
+# A super basic AArch64 BE makefile. As we don't have any big-endian
+# libc available the best we can do is a basic Hello World.
+
+AARCH64BE_SRC=$(SRC_PATH)/tests/tcg/aarch64_be
+VPATH += $(AARCH64BE_SRC)
+
+AARCH64BE_TEST_SRCS=$(notdir $(wildcard $(AARCH64BE_SRC)/*.c))
+AARCH64BE_TESTS=$(AARCH64BE_TEST_SRCS:.c=)
+#MULTIARCH_TESTS = $(MULTIARCH_SRCS:.c=)
+
+# We need to specify big-endian cflags
+CFLAGS +=-mbig-endian -ffreestanding
+LDFLAGS +=-nostdlib
+
+TESTS += $(AARCH64BE_TESTS)
diff --git a/tests/tcg/aarch64_be/hello.c b/tests/tcg/aarch64_be/hello.c
new file mode 100644
index 0000000000..a9b2ab45de
--- /dev/null
+++ b/tests/tcg/aarch64_be/hello.c
@@ -0,0 +1,35 @@
+/*
+ * Non-libc syscall hello world for Aarch64 BE
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#define __NR_write 64
+#define __NR_exit 93
+
+int write(int fd, char *buf, int len)
+{
+    register int x0 __asm__("x0") = fd;
+    register char *x1 __asm__("x1") = buf;
+    register int x2 __asm__("x2") = len;
+    register int x8 __asm__("x8") = __NR_write;
+
+    asm volatile("svc #0" : : "r"(x0), "r"(x1), "r"(x2), "r"(x8));
+
+    return len;
+}
+
+void exit(int ret)
+{
+    register int x0 __asm__("x0") = ret;
+    register int x8 __asm__("x8") = __NR_exit;
+
+    asm volatile("svc #0" : : "r"(x0), "r"(x8));
+    __builtin_unreachable();
+}
+
+void _start(void)
+{
+    write(1, "Hello World\n", 12);
+    exit(0);
+}
diff --git a/tests/tcg/x86_64/Makefile.target b/tests/tcg/x86_64/Makefile.target
index 783ab5b21a..d6dff559c7 100644
--- a/tests/tcg/x86_64/Makefile.target
+++ b/tests/tcg/x86_64/Makefile.target
@@ -17,6 +17,7 @@ X86_64_TESTS += cmpxchg
 X86_64_TESTS += adox
 X86_64_TESTS += test-1648
 X86_64_TESTS += test-2175
+X86_64_TESTS += cross-modifying-code
 TESTS=$(MULTIARCH_TESTS) $(X86_64_TESTS) test-x86_64
 else
 TESTS=$(MULTIARCH_TESTS)
@@ -27,6 +28,9 @@ adox: CFLAGS=-O2
 run-test-i386-ssse3: QEMU_OPTS += -cpu max
 run-plugin-test-i386-ssse3-%: QEMU_OPTS += -cpu max
 
+cross-modifying-code: CFLAGS+=-pthread
+cross-modifying-code: LDFLAGS+=-pthread
+
 test-x86_64: LDFLAGS+=-lm -lc
 test-x86_64: test-i386.c test-i386.h test-i386-shift.h test-i386-muldiv.h
 	$(CC) $(CFLAGS) $< -o $@ $(LDFLAGS)
diff --git a/tests/tcg/x86_64/cross-modifying-code.c b/tests/tcg/x86_64/cross-modifying-code.c
new file mode 100644
index 0000000000..2704df6061
--- /dev/null
+++ b/tests/tcg/x86_64/cross-modifying-code.c
@@ -0,0 +1,80 @@
+/*
+ * Test patching code, running in one thread, from another thread.
+ *
+ * Intel SDM calls this "cross-modifying code" and recommends a special
+ * sequence, which requires both threads to cooperate.
+ *
+ * Linux kernel uses a different sequence that does not require cooperation and
+ * involves patching the first byte with int3.
+ *
+ * Finally, there is user-mode software out there that simply uses atomics, and
+ * that seems to be good enough in practice. Test that QEMU has no problems
+ * with this as well.
+ */
+
+#include <assert.h>
+#include <pthread.h>
+#include <stdbool.h>
+#include <stdlib.h>
+
+void add1_or_nop(long *x);
+asm(".pushsection .rwx,\"awx\",@progbits\n"
+    ".globl add1_or_nop\n"
+    /* addq $0x1,(%rdi) */
+    "add1_or_nop: .byte 0x48, 0x83, 0x07, 0x01\n"
+    "ret\n"
+    ".popsection\n");
+
+#define THREAD_WAIT 0
+#define THREAD_PATCH 1
+#define THREAD_STOP 2
+
+static void *thread_func(void *arg)
+{
+    int val = 0x0026748d; /* nop */
+
+    while (true) {
+        switch (__atomic_load_n((int *)arg, __ATOMIC_SEQ_CST)) {
+        case THREAD_WAIT:
+            break;
+        case THREAD_PATCH:
+            val = __atomic_exchange_n((int *)&add1_or_nop, val,
+                                      __ATOMIC_SEQ_CST);
+            break;
+        case THREAD_STOP:
+            return NULL;
+        default:
+            assert(false);
+            __builtin_unreachable();
+        }
+    }
+}
+
+#define INITIAL 42
+#define COUNT 1000000
+
+int main(void)
+{
+    int command = THREAD_WAIT;
+    pthread_t thread;
+    long x = 0;
+    int err;
+    int i;
+
+    err = pthread_create(&thread, NULL, &thread_func, &command);
+    assert(err == 0);
+
+    __atomic_store_n(&command, THREAD_PATCH, __ATOMIC_SEQ_CST);
+    for (i = 0; i < COUNT; i++) {
+        add1_or_nop(&x);
+    }
+    __atomic_store_n(&command, THREAD_STOP, __ATOMIC_SEQ_CST);
+
+    err = pthread_join(thread, NULL);
+    assert(err == 0);
+
+    assert(x >= INITIAL);
+    assert(x <= INITIAL + COUNT);
+
+    return EXIT_SUCCESS;
+}