Function fail_point_sysctl

freebsd/kern/kern_fail.c:867–921

* Handle kernel failpoint set/get. */

 * Handle kernel failpoint set/get.
 */
int
fail_point_sysctl(SYSCTL_HANDLER_ARGS)
{
	struct fail_point *fp;
	char *buf;
	struct sbuf sb, *sb_check;
	int error;

	buf = NULL;
	error = 0;
	fp = arg1;

	sb_check = sbuf_new(&sb, NULL, 1024, SBUF_AUTOEXTEND);
	if (sb_check != &sb)
		return (ENOMEM);

	sbuf_set_drain(&sb, (sbuf_drain_func *)fail_sysctl_drain_func, req);

	/* Setting */
	/**
	 * Lock protects any new entries from being garbage collected before we
	 * can link them to the fail point.
	 */
	sx_xlock(&sx_fp_set);
	if (req->newptr) {
		if (req->newlen > MAX_FAIL_POINT_BUF) {
			error = EINVAL;
			goto out;
		}

		buf = fp_malloc(req->newlen + 1, M_WAITOK);

		error = SYSCTL_IN(req, buf, req->newlen);
		if (error)
			goto out;
		buf[req->newlen] = '\0';

		error = fail_point_set(fp, buf);
	}

	fail_point_garbage_collect();
	sx_xunlock(&sx_fp_set);

	/* Retrieving. */
	fail_point_get(fp, &sb, false);

out:
	sbuf_finish(&sb);
	sbuf_delete(&sb);

	if (buf)
		fp_free(buf);

	return (error);
}

int
fail_point_sysctl_status(SYSCTL_HANDLER_ARGS)