1 /*
2 * Copyright (C) 2009 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 #include <fcntl.h>
19 #include <unistd.h>
20 #include "parse.h"
21 #include "smatch.h"
22 #include "smatch_slist.h"
23
24 static int my_id;
25
26 /*
27 * Print a list of functions that return newly allocated memory.
28 */
29
30 static struct tracker_list *allocated;
31
32 static const char *allocation_funcs[] = {
33 "kmalloc",
34 "kzalloc",
35 "kcalloc",
36 "__alloc_skb",
37 NULL,
38 };
39
match_allocation(const char * fn,struct expression * expr,void * info)40 static void match_allocation(const char *fn, struct expression *expr,
41 void *info)
42 {
43 char *left_name;
44 struct symbol *left_sym;
45
46 left_name = expr_to_var_sym(expr->left, &left_sym);
47 if (!left_name || !left_sym)
48 goto free;
49 if (left_sym->ctype.modifiers &
50 (MOD_NONLOCAL | MOD_STATIC | MOD_ADDRESSABLE))
51 goto free;
52 add_tracker(&allocated, my_id, left_name, left_sym);
53 free:
54 free_string(left_name);
55 }
56
57 static int returns_new_stuff = 0;
58 static int returns_old_stuff = 0;
match_return(struct expression * ret_value)59 static void match_return(struct expression *ret_value)
60 {
61 char *name;
62 struct symbol *sym;
63 sval_t tmp;
64
65 if (__inline_fn)
66 return;
67 if (get_value(ret_value, &tmp) && tmp.value == 0)
68 return;
69 returns_new_stuff = 1;
70 name = expr_to_var_sym(ret_value, &sym);
71 if (!name || !sym) {
72 returns_old_stuff = 1;
73 goto free;
74 }
75 if (!in_tracker_list(allocated, my_id, name, sym))
76 returns_old_stuff = 1;
77 free:
78 free_string(name);
79 }
80
match_end_func(struct symbol * sym)81 static void match_end_func(struct symbol *sym)
82 {
83 if (__inline_fn)
84 return;
85 if (returns_new_stuff && !returns_old_stuff)
86 sm_info("allocation func");
87 free_trackers_and_list(&allocated);
88 returns_new_stuff = 0;
89 returns_old_stuff = 0;
90 }
91
check_allocation_funcs(int id)92 void check_allocation_funcs(int id)
93 {
94 int i;
95
96 if (!option_info || option_project != PROJ_KERNEL)
97 return;
98
99 my_id = id;
100 add_hook(&match_return, RETURN_HOOK);
101 add_hook(&match_end_func, AFTER_FUNC_HOOK);
102 for (i = 0; allocation_funcs[i]; i++) {
103 add_function_assign_hook(allocation_funcs[i],
104 &match_allocation, NULL);
105 }
106 }
107