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 * The kernel has a small stack so putting huge structs and arrays on the
20 * stack is a bug.
21 *
22 */
23
24 #include "smatch.h"
25
26 static int my_id;
27
28 static int total_size;
29 static int max_size;
30 static int max_lineno;
31 static int complained;
32
33 #define MAX_ALLOWED 1000
34
scope_end(void * _size)35 static void scope_end(void *_size)
36 {
37 int size = PTR_INT(_size);
38 total_size -= size;
39 }
40
match_declarations(struct symbol * sym)41 static void match_declarations(struct symbol *sym)
42 {
43 struct symbol *base;
44 const char *name;
45
46 base = get_base_type(sym);
47 if (sym->ctype.modifiers & MOD_STATIC)
48 return;
49 name = sym->ident->name;
50 total_size += type_bytes(base);
51 if (total_size > max_size) {
52 max_size = total_size;
53 max_lineno = get_lineno();
54 }
55 if (type_bytes(base) >= MAX_ALLOWED) {
56 complained = 1;
57 sm_warning("'%s' puts %d bytes on stack", name, type_bytes(base));
58 }
59 add_scope_hook(&scope_end, INT_PTR(type_bytes(base)));
60 }
61
match_end_func(struct symbol * sym)62 static void match_end_func(struct symbol *sym)
63 {
64 if (__inline_fn)
65 return;
66
67 if ((max_size >= MAX_ALLOWED) && !complained) {
68 sm_printf("%s:%d %s() ", get_filename(), max_lineno, get_function());
69 sm_printf("warn: function puts %d bytes on stack\n", max_size);
70 }
71 total_size = 0;
72 complained = 0;
73 max_size = 0;
74 max_lineno = 0;
75 }
76
check_stack(int id)77 void check_stack(int id)
78 {
79 if (option_project != PROJ_KERNEL || !option_spammy)
80 return;
81
82 my_id = id;
83 add_hook(&match_declarations, DECLARATION_HOOK);
84 add_hook(&match_end_func, END_FUNC_HOOK);
85 }
86