/*
 * Copyright (C) 2013 Oracle.
 *
 * 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"

STATE(devm);

static int my_id;

static void match_assign(const char *fn, struct expression *expr, void *unused)
{
        set_state_expr(my_id, expr->left, &devm);
}

static void match_free_func(const char *fn, struct expression *expr, void *_arg)
{
        struct expression *arg_expr;
        int arg = PTR_INT(_arg);
        char *name;

        arg_expr = get_argument_from_call_expr(expr->args, arg);
        if (!get_state_expr(my_id, arg_expr))
                return;
        name = expr_to_str(arg_expr);
        sm_warning("passing devm_ allocated variable to kfree. '%s'", name);
        free_string(name);
}

static void register_funcs_from_file(void)
{
        struct token *token;
        const char *func;
        int arg;

        token = get_tokens_file("kernel.frees_argument");
        if (!token)
                return;
        if (token_type(token) != TOKEN_STREAMBEGIN)
                return;
        token = token->next;
        while (token_type(token) != TOKEN_STREAMEND) {
                if (token_type(token) != TOKEN_IDENT)
                        return;
                func = show_ident(token->ident);
                token = token->next;
                if (token_type(token) != TOKEN_NUMBER)
                        return;
                arg = atoi(token->number);
                add_function_hook(func, &match_free_func, INT_PTR(arg));
                token = token->next;
        }
        clear_token_alloc();
}

void check_freeing_devm(int id)
{
        if (option_project != PROJ_KERNEL)
                return;

        my_id = id;

        add_function_assign_hook("devm_kmalloc", &match_assign, NULL);
        add_function_assign_hook("devm_kzalloc", &match_assign, NULL);
        add_function_assign_hook("devm_kcalloc", &match_assign, NULL);
        add_function_assign_hook("devm_kmalloc_array", &match_assign, NULL);


        add_function_hook("kfree", &match_free_func, INT_PTR(0));
        add_function_hook("krealloc", &match_free_func, INT_PTR(0));
        register_funcs_from_file();
}