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 void insert_mtag_data(mtag_t tag, int offset, struct range_list *rl)
73 {
74 rl = clone_rl_permanent(rl);
75
76 mem_sql(NULL, NULL, "delete from mtag_data where tag = %lld and offset = %d and type = %d",
77 tag, offset, DATA_VALUE);
78 mem_sql(NULL, NULL, "insert into mtag_data values (%lld, %d, %d, '%lu');",
79 tag, offset, DATA_VALUE, (unsigned long)rl);
80 }
81
82 void update_mtag_data(struct expression *expr)
83 {
84 struct range_list *orig, *new, *rl;
85 struct symbol *type;
86 char *name;
87 mtag_t tag;
88 int offset;
89
90 name = expr_to_var(expr);
91 if (is_kernel_param(name)) {
92 free_string(name);
93 return;
94 }
95 free_string(name);
96
97 if (!expr_to_mtag_offset(expr, &tag, &offset))
98 return;
99
100 type = get_type(expr);
101 if ((offset == 0) &&
102 (!type || type == &void_ctype ||
103 type->type == SYM_STRUCT || type->type == SYM_UNION || type->type == SYM_ARRAY))
104 return;
105
106 get_absolute_rl(expr, &rl);
107
108 orig = select_orig(tag, offset);
109 new = rl_union(orig, rl);
110 insert_mtag_data(tag, offset, new);
111 }
112
113 static void match_global_assign(struct expression *expr)
114 {
115 struct range_list *rl;
116 mtag_t tag;
117 int offset;
118 char *name;
119
120 name = expr_to_var(expr->left);
121 if (is_kernel_param(name)) {
122 free_string(name);
123 return;
124 }
125 free_string(name);
126
127 if (!expr_to_mtag_offset(expr->left, &tag, &offset))
128 return;
129
130 get_absolute_rl(expr->right, &rl);
131 insert_mtag_data(tag, offset, rl);
132 }
133
134 static int save_mtag_data(void *_unused, int argc, char **argv, char **azColName)
135 {
136 struct range_list *rl;
137
138 if (argc != 4) {
139 sm_msg("Error saving mtag data");
140 return 0;
141 }
142 if (!option_info)
143 return 0;
144
145 rl = (struct range_list *)strtoul(argv[3], NULL, 10);
146 sm_msg("SQL: insert into mtag_data values ('%s', '%s', '%s', '%s');",
147 argv[0], argv[1], argv[2], show_rl(rl));
148
149 return 0;
150 }
151
152 static void match_end_file(struct symbol_list *sym_list)
153 {
154 mem_sql(&save_mtag_data, NULL, "select * from mtag_data where type = %d;",
155 DATA_VALUE);
156 }
157
158 struct db_info {
159 struct symbol *type;
160 struct range_list *rl;
161 };
162
163 static int get_vals(void *_db_info, int argc, char **argv, char **azColName)
164 {
165 struct db_info *db_info = _db_info;
166 struct range_list *tmp;
167
168 str_to_rl(db_info->type, argv[0], &tmp);
169 if (db_info->rl)
170 db_info->rl = rl_union(db_info->rl, tmp);
171 else
172 db_info->rl = tmp;
173
174 return 0;
175 }
176
177 struct db_cache_results {
178 mtag_t tag;
179 struct range_list *rl;
180 };
181 static struct db_cache_results cached_results[8];
182
183 static int get_rl_from_mtag_offset(mtag_t tag, int offset, struct symbol *type, struct range_list **rl)
184 {
185 struct db_info db_info = {};
186 mtag_t merged = tag | offset;
187 static int idx;
188 int ret;
189 int i;
190
191 if (!type || type == &void_ctype ||
192 (type->type == SYM_STRUCT || type->type == SYM_ARRAY || type->type == SYM_UNION))
193 return 0;
194
195 for (i = 0; i < ARRAY_SIZE(cached_results); i++) {
196 if (merged == cached_results[i].tag) {
197 if (cached_results[i].rl) {
198 *rl = cached_results[i].rl;
199 return 1;
200 }
201 return 0;
202 }
203 }
204
205 db_info.type = type;
206
207 run_sql(get_vals, &db_info,
208 "select value from mtag_data where tag = %lld and offset = %d and type = %d;",
209 tag, offset, DATA_VALUE);
210 if (!db_info.rl || is_whole_rl(db_info.rl)) {
211 db_info.rl = NULL;
212 ret = 0;
213 goto update_cache;
214 }
215
216 *rl = db_info.rl;
217 ret = 1;
218
219 update_cache:
220 cached_results[idx].tag = merged;
221 cached_results[idx].rl = db_info.rl;
222 idx = (idx + 1) % ARRAY_SIZE(cached_results);
223
224 return ret;
225 }
226
227 static void clear_cache(struct symbol *sym)
228 {
229 memset(cached_results, 0, sizeof(cached_results));
230 }
231
232 int get_mtag_rl(struct expression *expr, struct range_list **rl)
233 {
234 struct symbol *type;
235 mtag_t tag;
236 int offset;
237
238 if (!expr_to_mtag_offset(expr, &tag, &offset))
239 return 0;
240 if (offset >= MTAG_OFFSET_MASK)
241 return 0;
242
243 type = get_type(expr);
244 if (!type)
245 return 0;
246
247 return get_rl_from_mtag_offset(tag, offset, type, rl);
248 }
249
250 void register_mtag_data(int id)
251 {
252 my_id = id;
253
254 add_hook(&clear_cache, FUNC_DEF_HOOK);
255
256 // if (!option_info)
257 // return;
258 add_hook(&match_global_assign, GLOBAL_ASSIGNMENT_HOOK);
259 add_hook(&match_end_file, END_FILE_HOOK);
260 }
261