1 /*
2 * Copyright (C) 2016 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 /*
19 * What we're doing here is saving all the possible values for static variables.
20 * Later on we might do globals as well.
21 *
22 */
23
24 #include "smatch.h"
25 #include "smatch_slist.h"
26 #include "smatch_extra.h"
27
28 static int my_id;
29 static struct stree *vals;
30
31 static int save_rl(void *_rl, int argc, char **argv, char **azColName)
32 {
33 unsigned long *rl = _rl;
34
35 *rl = strtoul(argv[0], NULL, 10);
36 return 0;
37 }
38
39 static struct range_list *select_orig(mtag_t tag, int offset)
40 {
41 struct range_list *rl = NULL;
42
43 mem_sql(&save_rl, &rl, "select value from mtag_data where tag = %lld and offset = %d;",
44 tag, offset);
45 return rl;
46 }
47
48 static int is_kernel_param(const char *name)
49 {
50 struct sm_state *tmp;
51 char buf[256];
52
53 /*
54 * I'm ignoring these because otherwise Smatch thinks that kernel
55 * parameters are always set to the default.
56 *
57 */
58
59 if (option_project != PROJ_KERNEL)
60 return 0;
61
62 snprintf(buf, sizeof(buf), "__param_%s.arg", name);
63
64 FOR_EACH_SM(vals, tmp) {
65 if (strcmp(tmp->name, buf) == 0)
66 return 1;
67 } END_FOR_EACH_SM(tmp);
68
69 return 0;
70 }
71
72 static bool is_ignored_macro(struct expression *expr)
73 {
74 char *macro;
75
76 macro = get_macro_name(expr->pos);
77 if (!macro)
78 return false;
79 if (strcmp(macro, "EXPORT_SYMBOL") == 0)
80 return true;
81 return false;
82 }
83
84 static void insert_mtag_data(mtag_t tag, int offset, struct range_list *rl)
85 {
86 rl = clone_rl_permanent(rl);
87
88 mem_sql(NULL, NULL, "delete from mtag_data where tag = %lld and offset = %d and type = %d",
89 tag, offset, DATA_VALUE);
90 mem_sql(NULL, NULL, "insert into mtag_data values (%lld, %d, %d, '%lu');",
91 tag, offset, DATA_VALUE, (unsigned long)rl);
92 }
93
94 static bool invalid_type(struct symbol *type)
95 {
96 if (!type)
97 return true;
98 if (type == &void_ctype)
99 return true;
100 if (type->type == SYM_STRUCT ||
101 type->type == SYM_ARRAY ||
102 type->type == SYM_UNION)
103 return true;
104 return false;
105 }
106
107 void update_mtag_data(struct expression *expr, struct smatch_state *state)
108 {
109 struct range_list *orig, *new;
110 struct symbol *type;
111 char *name;
112 mtag_t tag;
113 int offset;
114
115 if (!expr)
116 return;
117 if (is_local_variable(expr))
118 return;
119 if (is_ignored_macro(expr))
120 return;
121 name = expr_to_var(expr);
122 if (is_kernel_param(name)) {
123 free_string(name);
124 return;
125 }
126 free_string(name);
127
128 if (!expr_to_mtag_offset(expr, &tag, &offset))
129 return;
130
131 type = get_type(expr);
132 if (offset == 0 && invalid_type(type))
133 return;
134
135 orig = select_orig(tag, offset);
136 new = rl_union(orig, estate_rl(state));
137 insert_mtag_data(tag, offset, new);
138 }
139
140 static void match_global_assign(struct expression *expr)
141 {
142 struct range_list *rl;
143 mtag_t tag;
144 int offset;
145 char *name;
146
147 if (is_ignored_macro(expr))
148 return;
149 name = expr_to_var(expr->left);
150 if (is_kernel_param(name)) {
151 free_string(name);
152 return;
153 }
154 free_string(name);
155
156 if (!expr_to_mtag_offset(expr->left, &tag, &offset))
157 return;
158
159 get_absolute_rl(expr->right, &rl);
160 insert_mtag_data(tag, offset, rl);
161 }
162
163 static int save_mtag_data(void *_unused, int argc, char **argv, char **azColName)
164 {
165 struct range_list *rl;
166
167 if (argc != 4) {
168 sm_msg("Error saving mtag data");
169 return 0;
170 }
171 if (!option_info)
172 return 0;
173
174 rl = (struct range_list *)strtoul(argv[3], NULL, 10);
175 sm_msg("SQL: insert into mtag_data values ('%s', '%s', '%s', '%s');",
176 argv[0], argv[1], argv[2], show_rl(rl));
177
178 return 0;
179 }
180
181 static void match_end_file(struct symbol_list *sym_list)
182 {
183 mem_sql(&save_mtag_data, NULL, "select * from mtag_data where type = %d;",
184 DATA_VALUE);
185 }
186
187 struct db_info {
188 struct symbol *type;
189 struct range_list *rl;
190 };
191
192 static int get_vals(void *_db_info, int argc, char **argv, char **azColName)
193 {
194 struct db_info *db_info = _db_info;
195 struct range_list *tmp;
196
197 str_to_rl(db_info->type, argv[0], &tmp);
198 if (db_info->rl)
199 db_info->rl = rl_union(db_info->rl, tmp);
200 else
201 db_info->rl = tmp;
202
203 return 0;
204 }
205
206 struct db_cache_results {
207 mtag_t tag;
208 struct range_list *rl;
209 };
210 static struct db_cache_results cached_results[8];
211
212 static int get_rl_from_mtag_offset(mtag_t tag, int offset, struct symbol *type, struct range_list **rl)
213 {
214 struct db_info db_info = {};
215 mtag_t merged = tag | offset;
216 static int idx;
217 int ret;
218 int i;
219
220 for (i = 0; i < ARRAY_SIZE(cached_results); i++) {
221 if (merged == cached_results[i].tag) {
222 if (cached_results[i].rl) {
223 *rl = cached_results[i].rl;
224 return 1;
225 }
226 return 0;
227 }
228 }
229
230 db_info.type = type;
231
232 run_sql(get_vals, &db_info,
233 "select value from mtag_data where tag = %lld and offset = %d and type = %d;",
234 tag, offset, DATA_VALUE);
235 if (!db_info.rl || is_whole_rl(db_info.rl)) {
236 db_info.rl = NULL;
237 ret = 0;
238 goto update_cache;
239 }
240
241 *rl = db_info.rl;
242 ret = 1;
243
244 update_cache:
245 cached_results[idx].tag = merged;
246 cached_results[idx].rl = db_info.rl;
247 idx = (idx + 1) % ARRAY_SIZE(cached_results);
248
249 return ret;
250 }
251
252 static void clear_cache(struct symbol *sym)
253 {
254 memset(cached_results, 0, sizeof(cached_results));
255 }
256
257 int get_mtag_rl(struct expression *expr, struct range_list **rl)
258 {
259 struct symbol *type;
260 mtag_t tag;
261 int offset;
262
263 if (is_local_variable(expr))
264 return 0;
265 if (!expr_to_mtag_offset(expr, &tag, &offset))
266 return 0;
267 if (offset >= MTAG_OFFSET_MASK)
268 return 0;
269
270 type = get_type(expr);
271 if (invalid_type(type))
272 return 0;
273
274 return get_rl_from_mtag_offset(tag, offset, type, rl);
275 }
276
277 void register_mtag_data(int id)
278 {
279 my_id = id;
280
281 add_hook(&clear_cache, FUNC_DEF_HOOK);
282
283 // if (!option_info)
284 // return;
285 add_hook(&match_global_assign, GLOBAL_ASSIGNMENT_HOOK);
286 add_hook(&match_end_file, END_FILE_HOOK);
287 }
288