1 /*
2 * Copyright (C) 2010 Dan Carpenter.
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 /*
19 * Complains about places that return -1 instead of -ENOMEM
20 */
21
22 #include "smatch.h"
23 #include "smatch_slist.h"
24 #include "smatch_extra.h"
25
26 static int my_id;
27
match_return(struct expression * ret_value)28 static void match_return(struct expression *ret_value)
29 {
30 struct expression *expr;
31 struct sm_state *sm;
32 struct stree *stree;
33 sval_t sval;
34
35 if (!ret_value)
36 return;
37 if (returns_unsigned(cur_func_sym))
38 return;
39 if (returns_pointer(cur_func_sym))
40 return;
41 if (!get_value(ret_value, &sval) || sval.value != -1)
42 return;
43 if (get_macro_name(ret_value->pos))
44 return;
45
46 stree = __get_cur_stree();
47
48 FOR_EACH_MY_SM(SMATCH_EXTRA, stree, sm) {
49 if (!estate_get_single_value(sm->state, &sval) || sval.value != 0)
50 continue;
51 expr = get_assigned_expr_name_sym(sm->name, sm->sym);
52 if (!expr)
53 continue;
54 if (expr->type != EXPR_CALL || expr->fn->type != EXPR_SYMBOL)
55 continue;
56 if (!expr->fn->symbol_name)
57 continue;
58 /* To be honest the correct check is:
59 * if (strstr(expr->fn->symbol_name->name, "alloc"))
60 * complain();
61 * But it generates too many warnings and it's too depressing.
62 */
63 if (strcmp(expr->fn->symbol_name->name, "kmalloc") != 0 &&
64 strcmp(expr->fn->symbol_name->name, "kzalloc") != 0)
65 continue;
66
67 sm_warning("returning -1 instead of -ENOMEM is sloppy");
68 return;
69
70 } END_FOR_EACH_SM(sm);
71 }
72
check_return_enomem(int id)73 void check_return_enomem(int id)
74 {
75 if (option_project != PROJ_KERNEL)
76 return;
77
78 my_id = id;
79 add_hook(&match_return, RETURN_HOOK);
80 }
81