/*
 * Copyright 2024 Linaro Ltd.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see http://www.gnu.org/copyleft/gpl.txt
 */

#include "smatch.h"
#include "smatch_slist.h"
#include "smatch_extra.h"

static int my_id;

static unsigned long is_ioctl;

static void function_start(struct symbol *sym)
{
	struct string_list *ptrs;
	char *ptr;

	ptrs = get_caller_ptrs(sym);
	FOR_EACH_PTR(ptrs, ptr) {
		if (strcmp(ptr, "(struct file_operations)->unlocked_ioctl") == 0 ||
		    strcmp(ptr, "(struct file_operations)->compat_ioctl") == 0) {
			is_ioctl = true;
			return;
		}
	} END_FOR_EACH_PTR(ptr);
}

static void match_return(struct expression *expr)
{
	char *name;

	if (!is_ioctl)
		return;
	if (!is_EPROBE_DEFER(expr))
		return;

	name = expr_to_str(expr);
	sm_warning("EPROBE_DEFER is only for probe functions '%s'", name);
	free_string(name);
}

void check_returning_EPROBE_DEFER(int id)
{
	my_id = id;

	if (option_project != PROJ_KERNEL)
		return;

	add_function_data(&is_ioctl);

	add_hook(&function_start, FUNC_DEF_HOOK);
	add_hook(&match_return, RETURN_HOOK);
}