static int debugfs_parse_options(char *data, struct debugfs_mount_opts *opts)
{
	substring_t args[MAX_OPT_ARGS];
	int option;
	int token;
	kuid_t uid;
	kgid_t gid;
	char *p;

	opts->mode = DEBUGFS_DEFAULT_MODE;

	while ((p = strsep(&data, ",")) != NULL) {
		if (!*p)
			continue;

		token = match_token(p, tokens, args);
		switch (token) {
		case Opt_uid:
			if (match_int(&args[0], &option))
				return -EINVAL;
			uid = make_kuid(current_user_ns(), option);
			if (!uid_valid(uid))
				return -EINVAL;
			opts->uid = uid;
			break;
		case Opt_gid:
			if (match_int(&args[0], &option))
				return -EINVAL;
			gid = make_kgid(current_user_ns(), option);
			if (!gid_valid(gid))
				return -EINVAL;
			opts->gid = gid;
			break;
		case Opt_mode:
			if (match_octal(&args[0], &option))
				return -EINVAL;
			opts->mode = option & S_IALLUGO;
			break;
		/*
		 * We might like to report bad mount options here;
		 * but traditionally debugfs has ignored all mount options
		 */
		}
	}

	return 0;
}

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.