Ensure that we've got at least some coverage of the special cases around
vfork() by adding a test case in basic-gcs doing the same thing as the
plain fork() one - vfork(), do a few checks and then return to the parent.
Signed-off-by: Mark Brown <broo...@kernel.org>
---
tools/testing/selftests/arm64/gcs/basic-gcs.c | 63 +++++++++++++++++++++++++++
1 file changed, 63 insertions(+)
diff --git a/tools/testing/selftests/arm64/gcs/basic-gcs.c
b/tools/testing/selftests/arm64/gcs/basic-gcs.c
index 3fb9742342a3..96ea51cf7163 100644
--- a/tools/testing/selftests/arm64/gcs/basic-gcs.c
+++ b/tools/testing/selftests/arm64/gcs/basic-gcs.c
@@ -298,6 +298,68 @@ static bool test_fork(void)
return pass;
}
+/* A vfork()ed process can run and exit */
+static bool test_vfork(void)
+{
+ unsigned long child_mode;
+ int ret, status;
+ pid_t pid;
+ bool pass = true;
+
+ pid = vfork();
+ if (pid == -1) {
+ ksft_print_msg("vfork() failed: %d\n", errno);
+ pass = false;
+ goto out;
+ }
+ if (pid == 0) {
+ /* In child, make sure we can call a function, read
+ * the GCS pointer and status and then exit */
+ valid_gcs_function();
+ get_gcspr();
+
+ ret = my_syscall5(__NR_prctl, PR_GET_SHADOW_STACK_STATUS,
+ &child_mode, 0, 0, 0);
+ if (ret == 0 && !(child_mode & PR_SHADOW_STACK_ENABLE)) {
+ ksft_print_msg("GCS not enabled in child\n");
+ ret = -EINVAL;
+ }
+
+ exit(ret);
+ }
+
+ /*
+ * In parent, check we can still do function calls then block
+ * for the child.
+ */
+ valid_gcs_function();
+
+ ksft_print_msg("Waiting for child %d\n", pid);
+
+ ret = waitpid(pid, &status, 0);
+ if (ret == -1) {
+ ksft_print_msg("Failed to wait for child: %d\n",
+ errno);
+ return false;
+ }
+
+ if (!WIFEXITED(status)) {
+ ksft_print_msg("Child exited due to signal %d\n",
+ WTERMSIG(status));
+ pass = false;
+ } else {
+ if (WEXITSTATUS(status)) {
+ ksft_print_msg("Child exited with status %d\n",
+ WEXITSTATUS(status));
+ pass = false;
+ }
+ }
+
+out:
+
+ return pass;
+}
+
typedef bool (*gcs_test)(void);
static struct {
@@ -314,6 +376,7 @@ static struct {
{ "enable_invalid", enable_invalid, true },
{ "map_guarded_stack", map_guarded_stack },
{ "fork", test_fork },
+ { "vfork", test_vfork },
};
int main(void)
--
2.39.5
