smatch_db.c

   1 /*
   2  * smatch/smatch_db.c
   3  *
   4  * Copyright (C) 2010 Dan Carpenter.
   5  *
   6  * Licensed under the Open Software License version 1.1
   7  *
   8  */
   9
  10 #include <string.h>
  11 #include <errno.h>
  12 #include <sqlite3.h>
  13 #include "smatch.h"
  14 #include "smatch_slist.h"
  15
  16 static sqlite3 *db;
  17
  18 struct def_callback {
  19         int hook_type;
  20         void (*callback)(const char *name, struct symbol *sym, char *key, char *value);
  21 };
  22 ALLOCATOR(def_callback, "definition db hook callbacks");
  23 DECLARE_PTR_LIST(callback_list, struct def_callback);
  24 static struct callback_list *callbacks;
  25
  26 struct member_info_callback {
  27         int owner;
  28         void (*callback)(char *fn, int param, char *printed_name, struct smatch_state *state);
  29 };
  30 ALLOCATOR(member_info_callback, "caller_info callbacks");
  31 DECLARE_PTR_LIST(member_info_cb_list, struct member_info_callback);
  32 static struct member_info_cb_list *member_callbacks;
  33
  34 void sql_exec(int (*callback)(void*, int, char**, char**), const char *sql)
  35 {
  36         char *err = NULL;
  37         int rc;
  38
  39         if (option_no_db || !db)
  40                 return;
  41
  42         rc = sqlite3_exec(db, sql, callback, 0, &err);
  43         if (rc != SQLITE_OK) {
  44                 fprintf(stderr, "SQL error #2: %s\n", err);
  45                 exit(1);
  46         }
  47 }
  48
  49 void add_definition_db_callback(void (*callback)(const char *name, struct symbol *sym, char *key, char *value), int type)
  50 {
  51         struct def_callback *def_callback = __alloc_def_callback(0);
  52
  53         def_callback->hook_type = type;
  54         def_callback->callback = callback;
  55         add_ptr_list(&callbacks, def_callback);
  56 }
  57
  58 void add_member_info_callback(int owner, void (*callback)(char *fn, int param, char *printed_name, struct smatch_state *state))
  59 {
  60         struct member_info_callback *member_callback = __alloc_member_info_callback(0);
  61
  62         member_callback->owner = owner;
  63         member_callback->callback = callback;
  64         add_ptr_list(&member_callbacks, member_callback);
  65 }
  66
  67 static void match_call_hack(struct expression *expr)
  68 {
  69         char *name;
  70
  71         /*
  72          * we just want to record something in the database so that if we have
  73          * two calls like:  frob(4); frob(some_unkown); then on the recieving
  74          * side we know that sometimes frob is called with unknown parameters.
  75          */
  76
  77         name = get_fnptr_name(expr->fn);
  78         if (!name)
  79                 return;
  80         if (ptr_list_empty(expr->args))
  81                 return;
  82         sm_msg("info: passes param_value '%s' -1 '$$' min-max", name);
  83         free_string(name);
  84 }
  85
  86 static void print_struct_members(char *fn, struct expression *expr, int param, struct state_list *slist,
  87         void (*callback)(char *fn, int param, char *printed_name, struct smatch_state *state))
  88 {
  89         struct sm_state *sm;
  90         char *name;
  91         struct symbol *sym;
  92         int len;
  93         char printed_name[256];
  94         int is_address = 0;
  95
  96         expr = strip_expr(expr);
  97         if (expr->type == EXPR_PREOP && expr->op == '&') {
  98                 expr = strip_expr(expr->unop);
  99                 is_address = 1;
 100         }
 101
 102         name = get_variable_from_expr(expr, &sym);
 103         if (!name || !sym)
 104                 goto free;
 105
 106         len = strlen(name);
 107         FOR_EACH_PTR(slist, sm) {
 108                 if (sm->sym != sym)
 109                         continue;
 110                 if (strncmp(name, sm->name, len) || sm->name[len] == '\0')
 111                         continue;
 112                 if (is_address)
 113                         snprintf(printed_name, sizeof(printed_name), "$$->%s", sm->name + len + 1);
 114                 else
 115                         snprintf(printed_name, sizeof(printed_name), "$$%s", sm->name + len);
 116                 callback(fn, param, printed_name, sm->state);
 117         } END_FOR_EACH_PTR(sm);
 118 free:
 119         free_string(name);
 120 }
 121
 122 static void match_call_info(struct expression *expr)
 123 {
 124         struct member_info_callback *cb;
 125         struct expression *arg;
 126         struct state_list *slist;
 127         char *name;
 128         int i;
 129
 130         name = get_fnptr_name(expr->fn);
 131         if (!name)
 132                 return;
 133
 134         FOR_EACH_PTR(member_callbacks, cb) {
 135                 slist = get_all_states(cb->owner);
 136                 i = 0;
 137                 FOR_EACH_PTR(expr->args, arg) {
 138                         print_struct_members(name, arg, i, slist, cb->callback);
 139                         i++;
 140                 } END_FOR_EACH_PTR(arg);
 141         } END_FOR_EACH_PTR(cb);
 142
 143         free_string(name);
 144         free_slist(&slist);
 145 }
 146
 147 static unsigned long call_count;
 148 static int db_count_callback(void *unused, int argc, char **argv, char **azColName)
 149 {
 150         call_count += strtoul(argv[0], NULL, 10);
 151         return 0;
 152 }
 153
 154 static int get_param(int param, char **name, struct symbol **sym)
 155 {
 156         struct symbol *arg;
 157         int i;
 158
 159         i = 0;
 160         FOR_EACH_PTR(cur_func_sym->ctype.base_type->arguments, arg) {
 161                 /*
 162                  * this is a temporary hack to work around a bug (I think in sparse?)
 163                  * 2.6.37-rc1:fs/reiserfs/journal.o
 164                  * If there is a function definition without parameter name found
 165                  * after a function implementation then it causes a crash.
 166                  * int foo() {}
 167                  * int bar(char *);
 168                  */
 169                 if (arg->ident->name < (char *)100)
 170                         continue;
 171                 if (i == param && arg->ident->name) {
 172                         *name = arg->ident->name;
 173                         *sym = arg;
 174                         return TRUE;
 175                 }
 176                 i++;
 177         } END_FOR_EACH_PTR(arg);
 178
 179         return FALSE;
 180 }
 181
 182 static struct state_list *final_states;
 183 static int prev_func_id = -1;
 184 static int db_callback(void *unused, int argc, char **argv, char **azColName)
 185 {
 186         int func_id;
 187         long type;
 188         long param;
 189         char *name;
 190         struct symbol *sym;
 191         struct def_callback *def_callback;
 192
 193         if (argc != 5)
 194                 return 0;
 195
 196         func_id = atoi(argv[0]);
 197         errno = 0;
 198         type = strtol(argv[1], NULL, 10);
 199         param = strtol(argv[2], NULL, 10);
 200         if (errno)
 201                 return 0;
 202
 203         if (prev_func_id == -1)
 204                 prev_func_id = func_id;
 205         if (func_id != prev_func_id) {
 206                 merge_slist(&final_states, __pop_fake_cur_slist());
 207                 __push_fake_cur_slist();
 208                 prev_func_id = func_id;
 209         }
 210
 211         if (param == -1 || !get_param(param, &name, &sym))
 212                 return 0;
 213
 214         FOR_EACH_PTR(callbacks, def_callback) {
 215                 if (def_callback->hook_type == type)
 216                         def_callback->callback(name, sym, argv[3], argv[4]);
 217         } END_FOR_EACH_PTR(def_callback);
 218
 219         return 0;
 220 }
 221
 222 static void get_direct_callers(struct symbol *sym)
 223 {
 224         char sql_filter[1024];
 225
 226         if (sym->ctype.modifiers & MOD_STATIC) {
 227                 snprintf(sql_filter, 1024,
 228                          "file = '%s' and function = '%s' order by function_id;",
 229                          get_filename(), sym->ident->name);
 230         } else {
 231                 snprintf(sql_filter, 1024,
 232                          "function = '%s' order by function_id;",
 233                          sym->ident->name);
 234         }
 235
 236         run_sql(db_count_callback, "select count(*) from caller_info where %s",
 237                  sql_filter);
 238         if (call_count == 0 || call_count > 100)
 239                 return;
 240
 241         run_sql(db_callback, "select function_id, type, parameter, key, value from caller_info"
 242                 " where %s", sql_filter);
 243 }
 244
 245 static char *ptr_name;
 246 static int get_ptr_name(void *unused, int argc, char **argv, char **azColName)
 247 {
 248         if (!ptr_name)
 249                 ptr_name = alloc_string(argv[0]);
 250         return 0;
 251 }
 252
 253 static void get_function_pointer_callers(struct symbol *sym)
 254 {
 255         ptr_name = NULL;
 256         run_sql(get_ptr_name, "select ptr from function_ptr where function = '%s'",
 257                 sym->ident->name);
 258         if (!ptr_name)
 259                 return;
 260
 261         run_sql(db_count_callback, "select count(*) from caller_info where function = '%s'",
 262                  ptr_name);
 263         if (call_count == 0 || call_count > 100)
 264                 return;
 265
 266         run_sql(db_callback, "select function_id, type, parameter, key, value from caller_info"
 267                 " where function = '%s' order by function_id", ptr_name);
 268 }
 269
 270 static void match_data_from_db(struct symbol *sym)
 271 {
 272         struct sm_state *sm;
 273
 274         if (!sym || !sym->ident || !sym->ident->name)
 275                 return;
 276
 277         __push_fake_cur_slist();
 278         prev_func_id = -1;
 279
 280         call_count = 0;
 281         get_direct_callers(sym);
 282         get_function_pointer_callers(sym);
 283
 284         merge_slist(&final_states, __pop_fake_cur_slist());
 285
 286         if (call_count > 100) {
 287                 free_slist(&final_states);
 288                 return;
 289         }
 290         FOR_EACH_PTR(final_states, sm) {
 291                 __set_sm(sm);
 292         } END_FOR_EACH_PTR(sm);
 293
 294         free_slist(&final_states);
 295 }
 296
 297 static void match_function_assign(struct expression *expr)
 298 {
 299         struct expression *right = expr->right;
 300         struct symbol *sym;
 301         char *fn_name;
 302         char *ptr_name;
 303
 304         if (right->type == EXPR_PREOP && right->op == '&')
 305                 right = right->unop;
 306         if (right->type != EXPR_SYMBOL)
 307                 return;
 308         sym = get_type(right);
 309         if (!sym || sym->type != SYM_FN)
 310                 return;
 311
 312         fn_name = get_variable_from_expr(right, NULL);
 313         ptr_name = get_fnptr_name(expr->left);
 314         if (!fn_name || !ptr_name)
 315                 goto free;
 316
 317         sm_msg("info: sets_fn_ptr '%s' '%s'", ptr_name, fn_name);
 318
 319 free:
 320         free_string(fn_name);
 321         free_string(ptr_name);
 322 }
 323
 324 static void print_initializer_list(struct expression_list *expr_list,
 325                 struct symbol *struct_type)
 326 {
 327         struct expression *expr;
 328         struct symbol *base_type;
 329
 330         FOR_EACH_PTR(expr_list, expr) {
 331                 if (expr->type == EXPR_INDEX && expr->idx_expression && expr->idx_expression->type == EXPR_INITIALIZER) {
 332                         print_initializer_list(expr->idx_expression->expr_list, struct_type);
 333                         continue;
 334                 }
 335                 if (expr->type != EXPR_IDENTIFIER)
 336                         continue;
 337                 if (!expr->expr_ident)
 338                         continue;
 339                 if (!expr->ident_expression || !expr->ident_expression->symbol_name)
 340                         continue;
 341                 base_type = get_type(expr->ident_expression);
 342                 if (!base_type || base_type->type != SYM_FN)
 343                         continue;
 344                 sm_msg("info: sets_fn_ptr '(struct %s)->%s' '%s'", struct_type->ident->name,
 345                        expr->expr_ident->name,
 346                        expr->ident_expression->symbol_name->name);
 347         } END_FOR_EACH_PTR(expr);
 348
 349 }
 350
 351 static void global_variable(struct symbol *sym)
 352 {
 353         struct symbol *struct_type;
 354
 355         if (!sym->ident)
 356                 return;
 357         if (!sym->initializer || sym->initializer->type != EXPR_INITIALIZER)
 358                 return;
 359         struct_type = get_base_type(sym);
 360         if (!struct_type)
 361                 return;
 362         if (struct_type->type == SYM_ARRAY) {
 363                 struct_type = get_base_type(struct_type);
 364                 if (!struct_type)
 365                         return;
 366                 sm_msg("here in sets_fn_ptr %d %p", struct_type->type, struct_type->ident);
 367         }
 368         if (struct_type->type != SYM_STRUCT || !struct_type->ident)
 369                 return;
 370         print_initializer_list(sym->initializer->expr_list, struct_type);
 371 }
 372
 373 void open_smatch_db(void)
 374 {
 375 #ifdef SQLITE_OPEN_READONLY
 376         int rc;
 377
 378         if (option_no_db)
 379                 return;
 380
 381         rc = sqlite3_open_v2("smatch_db.sqlite", &db, SQLITE_OPEN_READONLY, NULL);
 382         if (rc != SQLITE_OK) {
 383                 option_no_db = 1;
 384                 return;
 385         }
 386         return;
 387 #else
 388         option_no_db = 1;
 389         return;
 390 #endif
 391 }
 392
 393 void register_definition_db_callbacks(int id)
 394 {
 395         if (option_info) {
 396                 add_hook(&match_call_info, FUNCTION_CALL_HOOK);
 397                 add_hook(&match_call_hack, FUNCTION_CALL_HOOK);
 398                 add_hook(&match_function_assign, ASSIGNMENT_HOOK);
 399                 add_hook(&global_variable, BASE_HOOK);
 400                 add_hook(&global_variable, DECLARATION_HOOK);
 401         }
 402
 403         if (option_no_db)
 404                 return;
 405
 406         add_hook(&match_data_from_db, FUNC_DEF_HOOK);
 407 }