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 #include "smatch_extra.h"
  16
  17 static sqlite3 *db;
  18
  19 struct def_callback {
  20         int hook_type;
  21         void (*callback)(const char *name, struct symbol *sym, char *key, char *value);
  22 };
  23 ALLOCATOR(def_callback, "definition db hook callbacks");
  24 DECLARE_PTR_LIST(callback_list, struct def_callback);
  25 static struct callback_list *callbacks;
  26
  27 struct member_info_callback {
  28         int owner;
  29         void (*callback)(char *fn, char *global_static, int param, char *printed_name, struct smatch_state *state);
  30 };
  31 ALLOCATOR(member_info_callback, "caller_info callbacks");
  32 DECLARE_PTR_LIST(member_info_cb_list, struct member_info_callback);
  33 static struct member_info_cb_list *member_callbacks;
  34
  35 struct returned_member_callback {
  36         int owner;
  37         void (*callback)(char *return_ranges, char *printed_name, struct smatch_state *state);
  38 };
  39 ALLOCATOR(returned_member_callback, "returned member callbacks");
  40 DECLARE_PTR_LIST(returned_member_cb_list, struct returned_member_callback);
  41 static struct returned_member_cb_list *returned_member_callbacks;
  42
  43 struct call_implies_callback {
  44         int type;
  45         void (*callback)(struct expression *arg, char *value);
  46 };
  47 ALLOCATOR(call_implies_callback, "call_implies callbacks");
  48 DECLARE_PTR_LIST(call_implies_cb_list, struct call_implies_callback);
  49 static struct call_implies_cb_list *call_implies_cb_list;
  50
  51 static int return_id;
  52 int get_return_id(void)
  53 {
  54         return return_id;
  55 }
  56
  57 void sql_exec(int (*callback)(void*, int, char**, char**), const char *sql)
  58 {
  59         char *err = NULL;
  60         int rc;
  61
  62         if (option_no_db || !db)
  63                 return;
  64
  65         rc = sqlite3_exec(db, sql, callback, 0, &err);
  66         if (rc != SQLITE_OK) {
  67                 fprintf(stderr, "SQL error #2: %s\n", err);
  68                 fprintf(stderr, "SQL: '%s'\n", sql);
  69         }
  70 }
  71
  72 void add_definition_db_callback(void (*callback)(const char *name, struct symbol *sym, char *key, char *value), int type)
  73 {
  74         struct def_callback *def_callback = __alloc_def_callback(0);
  75
  76         def_callback->hook_type = type;
  77         def_callback->callback = callback;
  78         add_ptr_list(&callbacks, def_callback);
  79 }
  80
  81 /*
  82  * These call backs are used when the --info option is turned on to print struct
  83  * member information.  For example foo->bar could have a state in
  84  * smatch_extra.c and also check_user.c.
  85  */
  86 void add_member_info_callback(int owner, void (*callback)(char *fn, char *global_static, int param, char *printed_name, struct smatch_state *state))
  87 {
  88         struct member_info_callback *member_callback = __alloc_member_info_callback(0);
  89
  90         member_callback->owner = owner;
  91         member_callback->callback = callback;
  92         add_ptr_list(&member_callbacks, member_callback);
  93 }
  94
  95 void add_returned_member_callback(int owner, void (*callback)(char *return_ranges, char *printed_name, struct smatch_state *state))
  96 {
  97         struct returned_member_callback *member_callback = __alloc_returned_member_callback(0);
  98
  99         member_callback->owner = owner;
 100         member_callback->callback = callback;
 101         add_ptr_list(&returned_member_callbacks, member_callback);
 102 }
 103
 104 void add_db_fn_call_callback(int type, void (*callback)(struct expression *arg, char *value))
 105 {
 106         struct call_implies_callback *cb = __alloc_call_implies_callback(0);
 107
 108         cb->type = type;
 109         cb->callback = callback;
 110         add_ptr_list(&call_implies_cb_list, cb);
 111 }
 112
 113 static struct symbol *return_type;
 114 static struct range_list *return_range_list;
 115 static int db_return_callback(void *unused, int argc, char **argv, char **azColName)
 116 {
 117         if (argc != 1)
 118                 return 0;
 119         if (option_debug)
 120                 sm_msg("return type %d", type_positive_bits(return_type));
 121         parse_value_ranges_type(return_type, argv[0], &return_range_list);
 122         return 0;
 123 }
 124
 125 struct range_list *db_return_vals(struct expression *expr)
 126 {
 127         struct symbol *sym;
 128         static char sql_filter[1024];
 129
 130         if (expr->type != EXPR_CALL)
 131                 return NULL;
 132         if (expr->fn->type != EXPR_SYMBOL)
 133                 return NULL;
 134         return_type = get_type(expr);
 135         if (!return_type)
 136                 return NULL;
 137         sym = expr->fn->symbol;
 138         if (!sym)
 139                 return NULL;
 140
 141         if (sym->ctype.modifiers & MOD_STATIC) {
 142                 snprintf(sql_filter, 1024, "file = '%s' and function = '%s';",
 143                          get_filename(), sym->ident->name);
 144         } else {
 145                 snprintf(sql_filter, 1024, "function = '%s' and static = 0;",
 146                                 sym->ident->name);
 147         }
 148
 149         return_range_list = NULL;
 150         run_sql(db_return_callback, "select return from return_values where %s",
 151                  sql_filter);
 152         return return_range_list;
 153 }
 154
 155 static void match_call_hack(struct expression *expr)
 156 {
 157         char *name;
 158
 159         /*
 160          * we just want to record something in the database so that if we have
 161          * two calls like:  frob(4); frob(some_unkown); then on the receiving
 162          * side we know that sometimes frob is called with unknown parameters.
 163          */
 164
 165         name = get_fnptr_name(expr->fn);
 166         if (!name)
 167                 return;
 168         sm_msg("info: call_marker '%s' %s", name, is_static(expr->fn) ? "static" : "global");
 169         free_string(name);
 170 }
 171
 172 static void print_struct_members(char *fn, char *global_static, struct expression *expr, int param, struct state_list *slist,
 173         void (*callback)(char *fn, char *global_static, int param, char *printed_name, struct smatch_state *state))
 174 {
 175         struct sm_state *sm;
 176         char *name;
 177         struct symbol *sym;
 178         int len;
 179         char printed_name[256];
 180         int is_address = 0;
 181
 182         expr = strip_expr(expr);
 183         if (expr->type == EXPR_PREOP && expr->op == '&') {
 184                 expr = strip_expr(expr->unop);
 185                 is_address = 1;
 186         }
 187
 188         name = get_variable_from_expr(expr, &sym);
 189         if (!name || !sym)
 190                 goto free;
 191
 192         len = strlen(name);
 193         FOR_EACH_PTR(slist, sm) {
 194                 if (sm->sym != sym)
 195                         continue;
 196                 if (strncmp(name, sm->name, len) || sm->name[len] == '\0')
 197                         continue;
 198                 if (is_address)
 199                         snprintf(printed_name, sizeof(printed_name), "$$->%s", sm->name + len + 1);
 200                 else
 201                         snprintf(printed_name, sizeof(printed_name), "$$%s", sm->name + len);
 202                 callback(fn, global_static, param, printed_name, sm->state);
 203         } END_FOR_EACH_PTR(sm);
 204 free:
 205         free_string(name);
 206 }
 207
 208 static void match_call_info(struct expression *expr)
 209 {
 210         struct member_info_callback *cb;
 211         struct expression *arg;
 212         struct state_list *slist;
 213         char *name;
 214         int i;
 215         char *gs;
 216
 217         name = get_fnptr_name(expr->fn);
 218         if (!name)
 219                 return;
 220
 221         if (is_static(expr->fn))
 222                 gs = (char *)"static";
 223         else
 224                 gs = (char *)"global";
 225
 226         FOR_EACH_PTR(member_callbacks, cb) {
 227                 slist = get_all_states(cb->owner);
 228                 i = 0;
 229                 FOR_EACH_PTR(expr->args, arg) {
 230                         print_struct_members(name, gs, arg, i, slist, cb->callback);
 231                         i++;
 232                 } END_FOR_EACH_PTR(arg);
 233                 free_slist(&slist);
 234         } END_FOR_EACH_PTR(cb);
 235
 236         free_string(name);
 237 }
 238
 239 static int get_param(int param, char **name, struct symbol **sym)
 240 {
 241         struct symbol *arg;
 242         int i;
 243
 244         i = 0;
 245         FOR_EACH_PTR(cur_func_sym->ctype.base_type->arguments, arg) {
 246                 /*
 247                  * this is a temporary hack to work around a bug (I think in sparse?)
 248                  * 2.6.37-rc1:fs/reiserfs/journal.o
 249                  * If there is a function definition without parameter name found
 250                  * after a function implementation then it causes a crash.
 251                  * int foo() {}
 252                  * int bar(char *);
 253                  */
 254                 if (arg->ident->name < (char *)100)
 255                         continue;
 256                 if (i == param && arg->ident->name) {
 257                         *name = arg->ident->name;
 258                         *sym = arg;
 259                         return TRUE;
 260                 }
 261                 i++;
 262         } END_FOR_EACH_PTR(arg);
 263
 264         return FALSE;
 265 }
 266
 267 static struct state_list *final_states;
 268 static int prev_func_id = -1;
 269 static int db_callback(void *unused, int argc, char **argv, char **azColName)
 270 {
 271         int func_id;
 272         long type;
 273         long param;
 274         char *name = NULL;
 275         struct symbol *sym = NULL;
 276         struct def_callback *def_callback;
 277
 278         if (argc != 5)
 279                 return 0;
 280
 281         func_id = atoi(argv[0]);
 282         errno = 0;
 283         type = strtol(argv[1], NULL, 10);
 284         param = strtol(argv[2], NULL, 10);
 285         if (errno)
 286                 return 0;
 287
 288         if (prev_func_id == -1)
 289                 prev_func_id = func_id;
 290         if (func_id != prev_func_id) {
 291                 merge_slist(&final_states, __pop_fake_cur_slist());
 292                 __push_fake_cur_slist();
 293                 __unnullify_path();
 294                 prev_func_id = func_id;
 295         }
 296
 297         if (type == INTERNAL)
 298                 return 0;
 299         if (param >= 0 && !get_param(param, &name, &sym))
 300                 return 0;
 301
 302         FOR_EACH_PTR(callbacks, def_callback) {
 303                 if (def_callback->hook_type == type)
 304                         def_callback->callback(name, sym, argv[3], argv[4]);
 305         } END_FOR_EACH_PTR(def_callback);
 306
 307         return 0;
 308 }
 309
 310 static void get_direct_callers(struct symbol *sym)
 311 {
 312         char sql_filter[1024];
 313
 314         if (sym->ctype.modifiers & MOD_STATIC) {
 315                 snprintf(sql_filter, 1024,
 316                          "file = '%s' and function = '%s' order by function_id;",
 317                          get_filename(), sym->ident->name);
 318         } else {
 319                 snprintf(sql_filter, 1024,
 320                          "function = '%s' and static = 0 order by function_id;",
 321                          sym->ident->name);
 322         }
 323
 324         run_sql(db_callback, "select function_id, type, parameter, key, value from caller_info"
 325                 " where %s", sql_filter);
 326 }
 327
 328 static char *ptr_name;
 329 static int get_ptr_name(void *unused, int argc, char **argv, char **azColName)
 330 {
 331         if (!ptr_name)
 332                 ptr_name = alloc_string(argv[0]);
 333         return 0;
 334 }
 335
 336 static void get_function_pointer_callers(struct symbol *sym)
 337 {
 338         ptr_name = NULL;
 339         run_sql(get_ptr_name, "select ptr from function_ptr where function = '%s'",
 340                 sym->ident->name);
 341         if (!ptr_name)
 342                 return;
 343
 344         run_sql(db_callback, "select function_id, type, parameter, key, value from caller_info"
 345                 " where function = '%s' order by function_id", ptr_name);
 346 }
 347
 348 static void match_data_from_db(struct symbol *sym)
 349 {
 350         struct sm_state *sm;
 351
 352         if (!sym || !sym->ident || !sym->ident->name)
 353                 return;
 354
 355         __push_fake_cur_slist();
 356         __unnullify_path();
 357         prev_func_id = -1;
 358
 359         get_direct_callers(sym);
 360         get_function_pointer_callers(sym);
 361
 362         merge_slist(&final_states, __pop_fake_cur_slist());
 363
 364         FOR_EACH_PTR(final_states, sm) {
 365                 __set_sm(sm);
 366         } END_FOR_EACH_PTR(sm);
 367
 368         free_slist(&final_states);
 369 }
 370
 371 static void match_function_assign(struct expression *expr)
 372 {
 373         struct expression *right = expr->right;
 374         struct symbol *sym;
 375         char *fn_name;
 376         char *ptr_name;
 377
 378         if (right->type == EXPR_PREOP && right->op == '&')
 379                 right = right->unop;
 380         if (right->type != EXPR_SYMBOL)
 381                 return;
 382         sym = get_type(right);
 383         if (!sym || sym->type != SYM_FN)
 384                 return;
 385
 386         fn_name = get_variable_from_expr(right, NULL);
 387         ptr_name = get_fnptr_name(expr->left);
 388         if (!fn_name || !ptr_name)
 389                 goto free;
 390
 391         sm_msg("info: sets_fn_ptr '%s' '%s'", ptr_name, fn_name);
 392
 393 free:
 394         free_string(fn_name);
 395         free_string(ptr_name);
 396 }
 397
 398 static struct expression *call_implies_call_expr;
 399 static int call_implies_callbacks(void *unused, int argc, char **argv, char **azColName)
 400 {
 401         struct call_implies_callback *cb;
 402         struct expression *arg = NULL;
 403         int type;
 404         int param;
 405
 406         if (argc != 4)
 407                 return 0;
 408
 409         type = atoi(argv[1]);
 410         param = atoi(argv[2]);
 411
 412         FOR_EACH_PTR(call_implies_cb_list, cb) {
 413                 if (cb->type != type)
 414                         continue;
 415                 if (param != -1) {
 416                         arg = get_argument_from_call_expr(call_implies_call_expr->args, param);
 417                         if (!arg)
 418                                 continue;
 419                 }
 420                 cb->callback(arg, argv[3]);
 421         } END_FOR_EACH_PTR(cb);
 422
 423         return 0;
 424 }
 425
 426 static void match_call_implies(struct expression *expr)
 427 {
 428         struct symbol *sym;
 429         static char sql_filter[1024];
 430
 431         if (expr->fn->type != EXPR_SYMBOL)
 432                 return;
 433         sym = expr->fn->symbol;
 434         if (!sym)
 435                 return;
 436
 437         if (sym->ctype.modifiers & MOD_STATIC) {
 438                 snprintf(sql_filter, 1024, "file = '%s' and function = '%s';",
 439                          get_filename(), sym->ident->name);
 440         } else {
 441                 snprintf(sql_filter, 1024, "function = '%s' and static = 0;",
 442                                 sym->ident->name);
 443         }
 444
 445         call_implies_call_expr = expr;
 446         run_sql(call_implies_callbacks,
 447                 "select function, type, parameter, value from call_implies where %s",
 448                 sql_filter);
 449         return;
 450 }
 451
 452 static void print_initializer_list(struct expression_list *expr_list,
 453                 struct symbol *struct_type)
 454 {
 455         struct expression *expr;
 456         struct symbol *base_type;
 457
 458         FOR_EACH_PTR(expr_list, expr) {
 459                 if (expr->type == EXPR_INDEX && expr->idx_expression && expr->idx_expression->type == EXPR_INITIALIZER) {
 460                         print_initializer_list(expr->idx_expression->expr_list, struct_type);
 461                         continue;
 462                 }
 463                 if (expr->type != EXPR_IDENTIFIER)
 464                         continue;
 465                 if (!expr->expr_ident)
 466                         continue;
 467                 if (!expr->ident_expression || !expr->ident_expression->symbol_name)
 468                         continue;
 469                 base_type = get_type(expr->ident_expression);
 470                 if (!base_type || base_type->type != SYM_FN)
 471                         continue;
 472                 sm_msg("info: sets_fn_ptr '(struct %s)->%s' '%s'", struct_type->ident->name,
 473                        expr->expr_ident->name,
 474                        expr->ident_expression->symbol_name->name);
 475         } END_FOR_EACH_PTR(expr);
 476 }
 477
 478 static void global_variable(struct symbol *sym)
 479 {
 480         struct symbol *struct_type;
 481
 482         if (!sym->ident)
 483                 return;
 484         if (!sym->initializer || sym->initializer->type != EXPR_INITIALIZER)
 485                 return;
 486         struct_type = get_base_type(sym);
 487         if (!struct_type)
 488                 return;
 489         if (struct_type->type == SYM_ARRAY) {
 490                 struct_type = get_base_type(struct_type);
 491                 if (!struct_type)
 492                         return;
 493         }
 494         if (struct_type->type != SYM_STRUCT || !struct_type->ident)
 495                 return;
 496         print_initializer_list(sym->initializer->expr_list, struct_type);
 497 }
 498
 499 static void match_return_info(struct expression *ret_value)
 500 {
 501         struct range_list *rl;
 502
 503         get_implied_range_list(ret_value, &rl);
 504         rl = cast_rl(cur_func_return_type(), rl);
 505         sm_msg("info: return_marker %d '%s' %s",
 506                get_return_id(), show_ranges(rl), global_static());
 507 }
 508
 509 static void print_returned_struct_members(struct expression *expr)
 510 {
 511         struct returned_member_callback *cb;
 512         struct state_list *slist;
 513         struct sm_state *sm;
 514         struct symbol *type;
 515         struct range_list *rl;
 516         char *return_ranges;
 517         char *name;
 518         char member_name[256];
 519         int len;
 520
 521         type = get_type(expr);
 522         if (!type || type->type != SYM_PTR)
 523                 return;
 524         type = get_real_base_type(type);
 525         if (!type || type->type != SYM_STRUCT)
 526                 return;
 527         name = get_variable_from_expr(expr, NULL);
 528         if (!name)
 529                 return;
 530
 531         if (!get_implied_range_list(expr, &rl))
 532                 return;
 533         return_ranges = show_ranges(rl);
 534
 535         member_name[sizeof(member_name) - 1] = '\0';
 536         strcpy(member_name, "$$");
 537
 538         len = strlen(name);
 539         FOR_EACH_PTR(returned_member_callbacks, cb) {
 540                 slist = get_all_states(cb->owner);
 541                 FOR_EACH_PTR(slist, sm) {
 542                         if (strncmp(sm->name, name, len) != 0)
 543                                 continue;
 544                         if (strncmp(sm->name + len, "->", 2) != 0)
 545                                 continue;
 546                         strncpy(member_name + 2, sm->name + len, sizeof(member_name) - 2);
 547                         cb->callback(return_ranges, member_name, sm->state);
 548                 } END_FOR_EACH_PTR(sm);
 549                 free_slist(&slist);
 550         } END_FOR_EACH_PTR(cb);
 551
 552         free_string(name);
 553 }
 554
 555 static void match_end_func_info(struct symbol *sym)
 556 {
 557         if (__path_is_null())
 558                 return;
 559         sm_msg("info: return_marker %d '' %s", get_return_id(), global_static());
 560 }
 561
 562 static void match_function_def(struct symbol *sym)
 563 {
 564         return_id = 0;
 565 }
 566
 567 static void match_return(struct expression *ret_value)
 568 {
 569         return_id++;
 570 }
 571
 572 static void match_end_func(struct symbol *sym)
 573 {
 574         return_id++;
 575 }
 576
 577 void open_smatch_db(void)
 578 {
 579 #ifdef SQLITE_OPEN_READONLY
 580         int rc;
 581
 582         if (option_no_db)
 583                 return;
 584
 585         rc = sqlite3_open_v2("smatch_db.sqlite", &db, SQLITE_OPEN_READONLY, NULL);
 586         if (rc != SQLITE_OK) {
 587                 option_no_db = 1;
 588                 return;
 589         }
 590         return;
 591 #else
 592         option_no_db = 1;
 593         return;
 594 #endif
 595 }
 596
 597 void register_definition_db_callbacks(int id)
 598 {
 599         add_hook(&match_function_def, FUNC_DEF_HOOK);
 600         add_hook(&match_return, RETURN_HOOK);
 601         add_hook(&match_end_func, END_FUNC_HOOK);
 602
 603         if (option_info) {
 604                 add_hook(&match_call_info, FUNCTION_CALL_HOOK);
 605                 add_hook(&match_call_hack, FUNCTION_CALL_HOOK);
 606                 add_hook(&match_function_assign, ASSIGNMENT_HOOK);
 607                 add_hook(&global_variable, BASE_HOOK);
 608                 add_hook(&global_variable, DECLARATION_HOOK);
 609                 add_hook(&match_return_info, RETURN_HOOK);
 610                 add_hook(&print_returned_struct_members, RETURN_HOOK);
 611                 add_hook(&match_end_func_info, END_FUNC_HOOK);
 612         }
 613
 614         if (option_no_db)
 615                 return;
 616
 617         add_hook(&match_data_from_db, FUNC_DEF_HOOK);
 618         add_hook(&match_call_implies, FUNCTION_CALL_HOOK);
 619 }