tools/testing/selftests/timens/vfork_exec.c

Source file repositories/reference/linux-study-clean/tools/testing/selftests/timens/vfork_exec.c

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/timens/vfork_exec.c
Extension
.c
Size
2772 bytes
Lines
142
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

struct thread_args {
	char *tst_name;
	struct timespec *now;
};

static void *tcheck(void *_args)
{
	struct thread_args *args = _args;
	struct timespec *now = args->now, tst;
	int i;

	for (i = 0; i < 2; i++) {
		_gettime(CLOCK_MONOTONIC, &tst, i);
		if (labs(tst.tv_sec - now->tv_sec) > 5) {
			pr_fail("%s: in-thread: unexpected value: %ld (%ld)\n",
				args->tst_name, tst.tv_sec, now->tv_sec);
			return (void *)1UL;
		}
	}
	return NULL;
}

static int check_in_thread(char *tst_name, struct timespec *now)
{
	struct thread_args args = {
		.tst_name = tst_name,
		.now = now,
	};
	pthread_t th;
	void *retval;

	if (pthread_create(&th, NULL, tcheck, &args))
		return pr_perror("thread");
	if (pthread_join(th, &retval))
		return pr_perror("pthread_join");
	return !(retval == NULL);
}

static int check(char *tst_name, struct timespec *now)
{
	struct timespec tst;
	int i;

	for (i = 0; i < 2; i++) {
		_gettime(CLOCK_MONOTONIC, &tst, i);
		if (labs(tst.tv_sec - now->tv_sec) > 5)
			return pr_fail("%s: unexpected value: %ld (%ld)\n",
					tst_name, tst.tv_sec, now->tv_sec);
	}
	if (check_in_thread(tst_name, now))
		return 1;
	ksft_test_result_pass("%s\n", tst_name);
	return 0;
}

int main(int argc, char *argv[])
{
	struct timespec now;
	int status;
	pid_t pid;

	if (argc > 1) {
		char *endptr;

		ksft_cnt.ksft_pass = 1;
		now.tv_sec = strtoul(argv[1], &endptr, 0);
		if (*endptr != 0)
			return pr_perror("strtoul");

		return check("child after exec", &now);
	}

	ksft_print_header();

	nscheck();

	ksft_set_plan(4);

	clock_gettime(CLOCK_MONOTONIC, &now);

	if (unshare_timens())
		return 1;

	if (_settime(CLOCK_MONOTONIC, OFFSET))
		return 1;

	if (check("parent before vfork", &now))
		return 1;

	pid = vfork();

Annotation

Implementation Notes