[PATCH 3/3] tests/tcg/s390x: Test BRASL and BRCL with large negative offsets

[Ilya Leoshkevich]

Add a small test in order to prevent regressions.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 tests/tcg/s390x/Makefile.target        |  1 +
 tests/tcg/s390x/branch-relative-long.c | 29 ++++++++++++++++++++++++++
 2 files changed, 30 insertions(+)
 create mode 100644 tests/tcg/s390x/branch-relative-long.c

diff --git a/tests/tcg/s390x/Makefile.target b/tests/tcg/s390x/Makefile.target
index 257c568c58..fd34b130f7 100644
--- a/tests/tcg/s390x/Makefile.target
+++ b/tests/tcg/s390x/Makefile.target
@@ -15,6 +15,7 @@ TESTS+=mvc
 TESTS+=shift
 TESTS+=trap
 TESTS+=signals-s390x
+TESTS+=branch-relative-long
 
 ifneq ($(HAVE_GDB_BIN),)
 GDB_SCRIPT=$(SRC_PATH)/tests/guest-debug/run-test.py
diff --git a/tests/tcg/s390x/branch-relative-long.c 
b/tests/tcg/s390x/branch-relative-long.c
new file mode 100644
index 0000000000..b9fcee9873
--- /dev/null
+++ b/tests/tcg/s390x/branch-relative-long.c
@@ -0,0 +1,29 @@
+#include <assert.h>
+#include <stddef.h>
+#include <sys/mman.h>
+
+int main(void)
+{
+    const unsigned short opcodes[] = {
+        0xc005,  /* brasl %r0 */
+        0xc0f4,  /* brcl 0xf */
+    };
+    size_t length = 0x100000006;
+    unsigned char *buf;
+    int i;
+
+    buf = mmap(NULL, length, PROT_READ | PROT_WRITE | PROT_EXEC,
+               MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+    assert(buf != MAP_FAILED);
+
+    *(unsigned short *)&buf[0] = 0x07fe;  /* br %r14 */
+    *(unsigned int *)&buf[0x100000002] = 0x80000000;
+    for (i = 0; i < sizeof(opcodes) / sizeof(opcodes[0]); i++) {
+        *(unsigned short *)&buf[0x100000000] = opcodes[i];
+        ((void (*)(void))&buf[0x100000000])();
+    }
+
+    munmap(buf, length);
+
+    return 0;
+}
-- 
2.35.1