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11506 smatch resync
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--- old/usr/src/tools/smatch/src/smatch_param_limit.c
+++ new/usr/src/tools/smatch/src/smatch_param_limit.c
1 1 /*
2 2 * Copyright (C) 2012 Oracle.
3 3 *
4 4 * This program is free software; you can redistribute it and/or
5 5 * modify it under the terms of the GNU General Public License
6 6 * as published by the Free Software Foundation; either version 2
7 7 * of the License, or (at your option) any later version.
8 8 *
9 9 * This program is distributed in the hope that it will be useful,
10 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 12 * GNU General Public License for more details.
13 13 *
14 14 * You should have received a copy of the GNU General Public License
15 15 * along with this program; if not, see http://www.gnu.org/copyleft/gpl.txt
16 16 */
17 17
18 18 /*
19 19 * This is almost the same as smatch_param_filter.c. The difference is that
20 20 * this only deals with values passed on the stack and param filter only deals
21 21 * with values changed so that the caller sees the new value. It other words
22 22 * the key for these should always be "$" and the key for param_filter should
23 23 * never be "$". Also smatch_param_set() should never use "$" as the key.
24 24 * Param set should work together with param_filter to determine the value that
25 25 * the caller sees at the end.
26 26 *
27 27 * This is for functions like this:
28 28 *
29 29 * int foo(int a)
30 30 * {
31 31 * if (a >= 0 && a < 10) {
32 32 * a = 42;
33 33 * return 1;
34 34 * }
35 35 * return 0;
36 36 * }
37 37 *
38 38 * If we pass in 5, it returns 1.
39 39 *
40 40 * It's a bit complicated because we can't just consider the final value, we
41 41 * have to always consider the passed in value.
42 42 *
43 43 */
44 44
45 45 #include "scope.h"
46 46 #include "smatch.h"
47 47 #include "smatch_extra.h"
48 48 #include "smatch_slist.h"
49 49
50 50 static int my_id;
51 51
52 52 static struct stree *start_states;
53 53 static struct stree_stack *saved_stack;
54 54
55 55 static void save_start_states(struct statement *stmt)
56 56 {
57 57 start_states = get_all_states_stree(SMATCH_EXTRA);
58 58 }
59 59
60 60 static void free_start_states(void)
61 61 {
62 62 free_stree(&start_states);
63 63 }
64 64
65 65 static struct smatch_state *unmatched_state(struct sm_state *sm)
66 66 {
67 67 struct smatch_state *state;
68 68
69 69 state = get_state(SMATCH_EXTRA, sm->name, sm->sym);
70 70 if (state)
71 71 return state;
72 72 return alloc_estate_whole(estate_type(sm->state));
73 73 }
74 74
75 75 struct smatch_state *get_orig_estate(const char *name, struct symbol *sym)
76 76 {
77 77 struct smatch_state *state;
78 78
79 79 state = get_state(my_id, name, sym);
80 80 if (state)
81 81 return state;
82 82
83 83 state = get_state(SMATCH_EXTRA, name, sym);
84 84 if (state)
85 85 return state;
86 86 return alloc_estate_rl(alloc_whole_rl(get_real_base_type(sym)));
87 87 }
88 88
89 89 struct smatch_state *get_orig_estate_type(const char *name, struct symbol *sym, struct symbol *type)
90 90 {
91 91 struct smatch_state *state;
92 92
93 93 state = get_state(my_id, name, sym);
94 94 if (state)
95 95 return state;
96 96
97 97 state = get_state(SMATCH_EXTRA, name, sym);
98 98 if (state)
99 99 return state;
100 100 return alloc_estate_rl(alloc_whole_rl(type));
101 101 }
102 102
103 103 static struct range_list *generify_mtag_range(struct smatch_state *state)
104 104 {
105 105 struct range_list *rl;
106 106 struct data_range *drange;
107 107
108 108 if (!estate_type(state) || estate_type(state)->type != SYM_PTR)
109 109 return estate_rl(state);
110 110
111 111 /*
112 112 * The problem is that we get too specific on our param limits when we
113 113 * know exactly what pointers are passed to a function. It gets to the
114 114 * point where we say "pointer x will succeed, but everything else will
115 115 * fail." And then we introduce a new caller which passes a different
116 116 * pointer and it's like, "Sorry bro, that's not possible."
117 117 *
118 118 */
119 119 rl = rl_intersection(estate_rl(state), valid_ptr_rl);
120 120 if (!rl)
121 121 return estate_rl(state);
122 122
123 123 FOR_EACH_PTR(rl, drange) {
124 124 if (drange->min.value != drange->max.value)
125 125 continue;
126 126 if (drange->min.value > -4096 && drange->min.value <= 0)
127 127 continue;
128 128 return rl_union(valid_ptr_rl, rl);
129 129 } END_FOR_EACH_PTR(drange);
130 130
131 131 return estate_rl(state);
132 132 }
133 133
134 134 static void print_return_value_param(int return_id, char *return_ranges, struct expression *expr)
135 135 {
136 136 struct smatch_state *state, *old;
137 137 struct sm_state *tmp;
138 138 struct range_list *rl;
139 139 const char *param_name;
140 140 int param;
141 141
142 142 FOR_EACH_MY_SM(SMATCH_EXTRA, __get_cur_stree(), tmp) {
143 143 param = get_param_num_from_sym(tmp->sym);
144 144 if (param < 0)
145 145 continue;
146 146
147 147 param_name = get_param_name(tmp);
148 148 if (!param_name)
149 149 continue;
150 150
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151 151 state = __get_state(my_id, tmp->name, tmp->sym);
152 152 if (!state)
153 153 state = tmp->state;
154 154
155 155 if (estate_is_whole(state) || estate_is_empty(state))
156 156 continue;
157 157 old = get_state_stree(start_states, SMATCH_EXTRA, tmp->name, tmp->sym);
158 158 if (old && rl_equiv(estate_rl(old), estate_rl(state)))
159 159 continue;
160 160
161 + if (is_ignored_kernel_data(param_name))
162 + continue;
163 +
161 164 rl = generify_mtag_range(state);
162 165 sql_insert_return_states(return_id, return_ranges, PARAM_LIMIT,
163 166 param, param_name, show_rl(rl));
164 167 } END_FOR_EACH_SM(tmp);
165 168 }
166 169
167 170 static void extra_mod_hook(const char *name, struct symbol *sym, struct expression *expr, struct smatch_state *state)
168 171 {
169 172 struct smatch_state *orig_vals;
170 173 int param;
171 174
172 175 param = get_param_num_from_sym(sym);
173 176 if (param < 0)
174 177 return;
175 178
176 179 orig_vals = get_orig_estate_type(name, sym, estate_type(state));
177 180 set_state(my_id, name, sym, orig_vals);
178 181 }
179 182
180 183 static void match_save_states(struct expression *expr)
181 184 {
182 185 push_stree(&saved_stack, start_states);
183 186 start_states = NULL;
184 187 }
185 188
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186 189 static void match_restore_states(struct expression *expr)
187 190 {
188 191 free_stree(&start_states);
189 192 start_states = pop_stree(&saved_stack);
190 193 }
191 194
192 195 void register_param_limit(int id)
193 196 {
194 197 my_id = id;
195 198
199 + set_dynamic_states(my_id);
196 200 add_hook(&save_start_states, AFTER_DEF_HOOK);
197 201 add_hook(&free_start_states, AFTER_FUNC_HOOK);
198 202
199 203 add_extra_mod_hook(&extra_mod_hook);
200 204 add_unmatched_state_hook(my_id, &unmatched_state);
201 205 add_merge_hook(my_id, &merge_estates);
202 206
203 207 add_hook(&match_save_states, INLINE_FN_START);
204 208 add_hook(&match_restore_states, INLINE_FN_END);
205 209
206 210 add_split_return_callback(&print_return_value_param);
207 211 }
208 212
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