[PATCH v3 2/2] tests/tcg: Test that compare-and-trap raises SIGFPE

[Jonathan Albrecht <jonathan.albrecht@linux.vnet.ibm.com>]

Signed-off-by: Jonathan Albrecht <jonathan.albrecht@linux.vnet.ibm.com>
---
 tests/tcg/s390x/Makefile.target |   1 +
 tests/tcg/s390x/trap.c          | 102 ++++++++++++++++++++++++++++++++
 2 files changed, 103 insertions(+)
 create mode 100644 tests/tcg/s390x/trap.c

diff --git a/tests/tcg/s390x/Makefile.target b/tests/tcg/s390x/Makefile.target
index 0a5b25c156..d440ecd6f7 100644
--- a/tests/tcg/s390x/Makefile.target
+++ b/tests/tcg/s390x/Makefile.target
@@ -9,6 +9,7 @@ TESTS+=exrl-trtr
 TESTS+=pack
 TESTS+=mvo
 TESTS+=mvc
+TESTS+=trap
 
 # This triggers failures on s390x hosts about 4% of the time
 run-signals: signals
diff --git a/tests/tcg/s390x/trap.c b/tests/tcg/s390x/trap.c
new file mode 100644
index 0000000000..d4c61c7f52
--- /dev/null
+++ b/tests/tcg/s390x/trap.c
@@ -0,0 +1,102 @@
+/*
+ * Copyright 2021 IBM Corp.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or (at
+ * your option) any later version. See the COPYING file in the top-level
+ * directory.
+ */
+
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <signal.h>
+
+static void error1(const char *filename, int line, const char *fmt, ...)
+{
+    va_list ap;
+    va_start(ap, fmt);
+    fprintf(stderr, "%s:%d: ", filename, line);
+    vfprintf(stderr, fmt, ap);
+    fprintf(stderr, "\n");
+    va_end(ap);
+    exit(1);
+}
+
+static int __chk_error(const char *filename, int line, int ret)
+{
+    if (ret < 0) {
+        error1(filename, line, "%m (ret=%d, errno=%d/%s)",
+               ret, errno, strerror(errno));
+    }
+    return ret;
+}
+
+#define error(fmt, ...) error1(__FILE__, __LINE__, fmt, ## __VA_ARGS__)
+
+#define chk_error(ret) __chk_error(__FILE__, __LINE__, (ret))
+
+int sigfpe_count;
+int sigill_count;
+
+static void sig_handler(int sig, siginfo_t *si, void *puc)
+{
+    if (sig == SIGFPE) {
+        if (si->si_code != 0) {
+            error("unexpected si_code: 0x%x != 0", si->si_code);
+        }
+        ++sigfpe_count;
+        return;
+    }
+
+    if (sig == SIGILL) {
+        ++sigill_count;
+        return;
+    }
+
+    error("unexpected signal 0x%x\n", sig);
+}
+
+int main(int argc, char **argv)
+{
+    sigfpe_count = sigill_count = 0;
+
+    struct sigaction act;
+
+    /* Set up SIG handler */
+    act.sa_sigaction = sig_handler;
+    sigemptyset(&act.sa_mask);
+    act.sa_flags = SA_SIGINFO;
+    chk_error(sigaction(SIGFPE, &act, NULL));
+    chk_error(sigaction(SIGILL, &act, NULL));
+
+    uint64_t z = 0x0ull;
+    uint64_t lz = 0xffffffffffffffffull;
+    asm volatile (
+        "lg %%r13,%[lz]\n"
+        "cgitne %%r13,0\n" /* SIGFPE */
+        "lg %%r13,%[z]\n"
+        "cgitne %%r13,0\n" /* no trap */
+        "nopr\n"
+        "lg %%r13,%[lz]\n"
+        "citne %%r13,0\n" /* SIGFPE */
+        "lg %%r13,%[z]\n"
+        "citne %%r13,0\n" /* no trap */
+        "nopr\n"
+        :
+        : [z] "m" (z), [lz] "m" (lz)
+        : "memory", "r13");
+
+    if (sigfpe_count != 2) {
+        error("unexpected SIGFPE count: %d != 2", sigfpe_count);
+    }
+    if (sigill_count != 0) {
+        error("unexpected SIGILL count: %d != 0", sigill_count);
+    }
+
+    printf("PASS\n");
+    return 0;
+}
-- 
2.31.1