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.
Reviewed-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Mark Brown broonie@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..54f9c888249d 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 = EXIT_FAILURE; + } + + _exit(ret); + } + + /* + * In parent, check we can still do function calls then check + * on 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)