[PATCH v4 4/4] tests/tcg/linux-test: Add linux-fork-trap test

[Ilya Leoshkevich]

Check that dying due to a signal does not deadlock.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 tests/tcg/multiarch/linux/linux-fork-trap.c | 51 +++++++++++++++++++++
 1 file changed, 51 insertions(+)
 create mode 100644 tests/tcg/multiarch/linux/linux-fork-trap.c

diff --git a/tests/tcg/multiarch/linux/linux-fork-trap.c 
b/tests/tcg/multiarch/linux/linux-fork-trap.c
new file mode 100644
index 00000000000..2bfef800c3e
--- /dev/null
+++ b/tests/tcg/multiarch/linux/linux-fork-trap.c
@@ -0,0 +1,51 @@
+/*
+ * Test that a fork()ed process terminates after __builtin_trap().
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/resource.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+int main(void)
+{
+    struct rlimit nodump;
+    pid_t err, pid;
+    int wstatus;
+
+    pid = fork();
+    assert(pid != -1);
+    if (pid == 0) {
+        /* We are about to crash on purpose; disable core dumps. */
+        if (getrlimit(RLIMIT_CORE, &nodump)) {
+            return EXIT_FAILURE;
+        }
+        nodump.rlim_cur = 0;
+        if (setrlimit(RLIMIT_CORE, &nodump)) {
+            return EXIT_FAILURE;
+        }
+        /*
+         * An alternative would be to dereference a NULL pointer, but that
+         * would be an UB in C.
+         */
+        printf("about to trigger fault...\n");
+#if defined(__MICROBLAZE__)
+        /*
+         * gcc emits "bri 0", which is an endless loop.
+         * Take glibc's ABORT_INSTRUCTION.
+         */
+        asm volatile("brki r0,-1");
+#else
+        __builtin_trap();
+#endif
+    }
+    err = waitpid(pid, &wstatus, 0);
+    assert(err == pid);
+    assert(WIFSIGNALED(wstatus));
+    printf("faulting thread exited cleanly\n");
+
+    return EXIT_SUCCESS;
+}
-- 
2.39.1