1/*
2 * Copyright (C) 2015 Oracle.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version 2
7 * of the License, or (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, see http://www.gnu.org/copyleft/gpl.txt
16 */
17
18#include "smatch.h"
19#include "smatch_slist.h"
20#include "smatch_extra.h"
21
22static int my_id;
23
24STATE(positive);
25STATE(ok);
26
27static void ok_to_use(struct sm_state *sm, struct expression *mod_expr)
28{
29	if (sm->state != &ok)
30		set_state(my_id, sm->name, sm->sym, &ok);
31}
32
33static void match_assign(const char *fn, struct expression *expr, void *unused)
34{
35	struct range_list *rl;
36
37	if (!get_implied_rl(expr->right, &rl))
38		return;
39	if (rl_max(rl).value != 1)
40		return;
41	set_state_expr(my_id, expr->left, &positive);
42}
43
44static void match_condition(struct expression *expr)
45{
46	if (!get_state_expr(my_id, expr))
47		return;
48	/* If the variable is zero that's ok */
49	set_true_false_states_expr(my_id, expr, NULL, &ok);
50}
51
52static void match_return(struct expression *ret_value)
53{
54	struct smatch_state *state;
55	struct sm_state *sm;
56	sval_t min;
57
58	sm = get_sm_state_expr(my_id, ret_value);
59	if (!sm)
60		return;
61	if (!slist_has_state(sm->possible, &positive))
62		return;
63	state = get_state_expr(SMATCH_EXTRA, ret_value);
64	if (!state)
65		return;
66	if (!get_absolute_min(ret_value, &min))
67		return;
68	if (min.value == 0)
69		return;
70	sm_warning("dma_mapping_error() doesn't return an error code");
71}
72
73void check_dma_mapping_error(int id)
74{
75	if (option_project != PROJ_KERNEL)
76		return;
77
78	my_id = id;
79	add_function_assign_hook("dma_mapping_error", &match_assign, NULL);
80	add_function_assign_hook("pci_dma_mapping_error", &match_assign, NULL);
81	add_hook(&match_condition, CONDITION_HOOK);
82	add_hook(&match_return, RETURN_HOOK);
83	add_modification_hook(my_id, &ok_to_use);
84}
85