tests/tcg/s390x: Test CLC with inaccessible second operand

Add a small test to prevent regressions.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20231106093605.1349201-3-iii@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
(cherry picked from commit 43fecbe7a53fe8e5a6aff0d6471b1cc624e26b51)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

2 files changed, 49 insertions, 0 deletions

diff --git a/tests/tcg/s390x/Makefile.target b/tests/tcg/s390x/Makefile.target
index 1fc9809907..3ddbde1a9d 100644
--- a/tests/tcg/s390x/Makefile.target
+++ b/tests/tcg/s390x/Makefile.target
@@ -41,6 +41,7 @@ TESTS+=larl
 TESTS+=mdeb
 TESTS+=cgebra
 TESTS+=clgebr
+TESTS+=clc
 
 cdsg: CFLAGS+=-pthread
 cdsg: LDFLAGS+=-pthread
diff --git a/tests/tcg/s390x/clc.c b/tests/tcg/s390x/clc.c
new file mode 100644
index 0000000000..e14189bd75
--- /dev/null
+++ b/tests/tcg/s390x/clc.c
@@ -0,0 +1,48 @@
+/*
+ * Test the CLC instruction.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+#include <assert.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+static void handle_sigsegv(int sig, siginfo_t *info, void *ucontext)
+{
+    mcontext_t *mcontext = &((ucontext_t *)ucontext)->uc_mcontext;
+    if (mcontext->gregs[0] != 600) {
+        write(STDERR_FILENO, "bad r0\n", 7);
+        _exit(EXIT_FAILURE);
+    }
+    if (((mcontext->psw.mask >> 44) & 3) != 1) {
+        write(STDERR_FILENO, "bad cc\n", 7);
+        _exit(EXIT_FAILURE);
+    }
+    _exit(EXIT_SUCCESS);
+}
+
+int main(void)
+{
+    register unsigned long r0 asm("r0");
+    unsigned long mem = 42, rhs = 500;
+    struct sigaction act;
+    int err;
+
+    memset(&act, 0, sizeof(act));
+    act.sa_sigaction = handle_sigsegv;
+    act.sa_flags = SA_SIGINFO;
+    err = sigaction(SIGSEGV, &act, NULL);
+    assert(err == 0);
+
+    r0 = 100;
+    asm("algr %[r0],%[rhs]\n"
+        "clc 0(8,%[mem]),0(0)\n"  /* The 2nd operand will cause a SEGV. */
+        : [r0] "+r" (r0)
+        : [mem] "r" (&mem)
+        , [rhs] "r" (rhs)
+        : "cc", "memory");
+
+    return EXIT_FAILURE;
+}