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_state_callback {
  36         void (*callback)(int return_id, char *return_ranges, struct expression *return_expr, struct state_list *slist);
  37 };
  38 ALLOCATOR(returned_state_callback, "returned state callbacks");
  39 DECLARE_PTR_LIST(returned_state_cb_list, struct returned_state_callback);
  40 static struct returned_state_cb_list *returned_state_callbacks;
  41
  42 struct returned_member_callback {
  43         int owner;
  44         void (*callback)(int return_id, char *return_ranges, char *printed_name, struct smatch_state *state);
  45 };
  46 ALLOCATOR(returned_member_callback, "returned member callbacks");
  47 DECLARE_PTR_LIST(returned_member_cb_list, struct returned_member_callback);
  48 static struct returned_member_cb_list *returned_member_callbacks;
  49
  50 struct call_implies_callback {
  51         int type;
  52         void (*callback)(struct expression *arg, char *value);
  53 };
  54 ALLOCATOR(call_implies_callback, "call_implies callbacks");
  55 DECLARE_PTR_LIST(call_implies_cb_list, struct call_implies_callback);
  56 static struct call_implies_cb_list *call_implies_cb_list;
  57
  58 void sql_exec(int (*callback)(void*, int, char**, char**), const char *sql)
  59 {
  60         char *err = NULL;
  61         int rc;
  62
  63         if (option_no_db || !db)
  64                 return;
  65
  66         rc = sqlite3_exec(db, sql, callback, 0, &err);
  67         if (rc != SQLITE_OK) {
  68                 fprintf(stderr, "SQL error #2: %s\n", err);
  69                 fprintf(stderr, "SQL: '%s'\n", sql);
  70         }
  71 }
  72
  73 void add_definition_db_callback(void (*callback)(const char *name, struct symbol *sym, char *key, char *value), int type)
  74 {
  75         struct def_callback *def_callback = __alloc_def_callback(0);
  76
  77         def_callback->hook_type = type;
  78         def_callback->callback = callback;
  79         add_ptr_list(&callbacks, def_callback);
  80 }
  81
  82 /*
  83  * These call backs are used when the --info option is turned on to print struct
  84  * member information.  For example foo->bar could have a state in
  85  * smatch_extra.c and also check_user.c.
  86  */
  87 void add_member_info_callback(int owner, void (*callback)(char *fn, char *global_static, int param, char *printed_name, struct smatch_state *state))
  88 {
  89         struct member_info_callback *member_callback = __alloc_member_info_callback(0);
  90
  91         member_callback->owner = owner;
  92         member_callback->callback = callback;
  93         add_ptr_list(&member_callbacks, member_callback);
  94 }
  95
  96 void add_returned_state_callback(void (*fn)(int return_id, char *return_ranges, struct expression *returned_expr, struct state_list *slist))
  97 {
  98         struct returned_state_callback *callback = __alloc_returned_state_callback(0);
  99
 100         callback->callback = fn;
 101         add_ptr_list(&returned_state_callbacks, callback);
 102 }
 103
 104 void add_returned_member_callback(int owner, void (*callback)(int return_id, char *return_ranges, char *printed_name, struct smatch_state *state))
 105 {
 106         struct returned_member_callback *member_callback = __alloc_returned_member_callback(0);
 107
 108         member_callback->owner = owner;
 109         member_callback->callback = callback;
 110         add_ptr_list(&returned_member_callbacks, member_callback);
 111 }
 112
 113 void add_db_fn_call_callback(int type, void (*callback)(struct expression *arg, char *value))
 114 {
 115         struct call_implies_callback *cb = __alloc_call_implies_callback(0);
 116
 117         cb->type = type;
 118         cb->callback = callback;
 119         add_ptr_list(&call_implies_cb_list, cb);
 120 }
 121
 122 static struct symbol *return_type;
 123 static struct range_list *return_range_list;
 124 static int db_return_callback(void *unused, int argc, char **argv, char **azColName)
 125 {
 126         if (argc != 1)
 127                 return 0;
 128         if (option_debug)
 129                 sm_msg("return type %d", type_positive_bits(return_type));
 130         parse_value_ranges_type(return_type, argv[0], &return_range_list);
 131         return 0;
 132 }
 133
 134 struct range_list *db_return_vals(struct expression *expr)
 135 {
 136         struct symbol *sym;
 137         static char sql_filter[1024];
 138
 139         if (expr->type != EXPR_CALL)
 140                 return NULL;
 141         if (expr->fn->type != EXPR_SYMBOL)
 142                 return NULL;
 143         return_type = get_type(expr);
 144         if (!return_type)
 145                 return NULL;
 146         sym = expr->fn->symbol;
 147         if (!sym)
 148                 return NULL;
 149
 150         if (sym->ctype.modifiers & MOD_STATIC) {
 151                 snprintf(sql_filter, 1024, "file = '%s' and function = '%s';",
 152                          get_filename(), sym->ident->name);
 153         } else {
 154                 snprintf(sql_filter, 1024, "function = '%s' and static = 0;",
 155                                 sym->ident->name);
 156         }
 157
 158         return_range_list = NULL;
 159         run_sql(db_return_callback, "select return from return_values where %s",
 160                  sql_filter);
 161         return return_range_list;
 162 }
 163
 164 static void match_call_hack(struct expression *expr)
 165 {
 166         char *name;
 167
 168         /*
 169          * we just want to record something in the database so that if we have
 170          * two calls like:  frob(4); frob(some_unkown); then on the receiving
 171          * side we know that sometimes frob is called with unknown parameters.
 172          */
 173
 174         name = get_fnptr_name(expr->fn);
 175         if (!name)
 176                 return;
 177         sm_msg("info: call_marker '%s' %s", name, is_static(expr->fn) ? "static" : "global");
 178         free_string(name);
 179 }
 180
 181 static void print_struct_members(char *fn, char *global_static, struct expression *expr, int param, struct state_list *slist,
 182         void (*callback)(char *fn, char *global_static, int param, char *printed_name, struct smatch_state *state))
 183 {
 184         struct sm_state *sm;
 185         char *name;
 186         struct symbol *sym;
 187         int len;
 188         char printed_name[256];
 189         int is_address = 0;
 190
 191         expr = strip_expr(expr);
 192         if (expr->type == EXPR_PREOP && expr->op == '&') {
 193                 expr = strip_expr(expr->unop);
 194                 is_address = 1;
 195         }
 196
 197         name = get_variable_from_expr(expr, &sym);
 198         if (!name || !sym)
 199                 goto free;
 200
 201         len = strlen(name);
 202         FOR_EACH_PTR(slist, sm) {
 203                 if (sm->sym != sym)
 204                         continue;
 205                 if (strncmp(name, sm->name, len) || sm->name[len] == '\0')
 206                         continue;
 207                 if (is_address)
 208                         snprintf(printed_name, sizeof(printed_name), "$$->%s", sm->name + len + 1);
 209                 else
 210                         snprintf(printed_name, sizeof(printed_name), "$$%s", sm->name + len);
 211                 callback(fn, global_static, param, printed_name, sm->state);
 212         } END_FOR_EACH_PTR(sm);
 213 free:
 214         free_string(name);
 215 }
 216
 217 static void match_call_info(struct expression *expr)
 218 {
 219         struct member_info_callback *cb;
 220         struct expression *arg;
 221         struct state_list *slist;
 222         char *name;
 223         int i;
 224         char *gs;
 225
 226         name = get_fnptr_name(expr->fn);
 227         if (!name)
 228                 return;
 229
 230         if (is_static(expr->fn))
 231                 gs = (char *)"static";
 232         else
 233                 gs = (char *)"global";
 234
 235         FOR_EACH_PTR(member_callbacks, cb) {
 236                 slist = get_all_states(cb->owner);
 237                 i = 0;
 238                 FOR_EACH_PTR(expr->args, arg) {
 239                         print_struct_members(name, gs, arg, i, slist, cb->callback);
 240                         i++;
 241                 } END_FOR_EACH_PTR(arg);
 242                 free_slist(&slist);
 243         } END_FOR_EACH_PTR(cb);
 244
 245         free_string(name);
 246 }
 247
 248 static int get_param(int param, char **name, struct symbol **sym)
 249 {
 250         struct symbol *arg;
 251         int i;
 252
 253         i = 0;
 254         FOR_EACH_PTR(cur_func_sym->ctype.base_type->arguments, arg) {
 255                 /*
 256                  * this is a temporary hack to work around a bug (I think in sparse?)
 257                  * 2.6.37-rc1:fs/reiserfs/journal.o
 258                  * If there is a function definition without parameter name found
 259                  * after a function implementation then it causes a crash.
 260                  * int foo() {}
 261                  * int bar(char *);
 262                  */
 263                 if (arg->ident->name < (char *)100)
 264                         continue;
 265                 if (i == param && arg->ident->name) {
 266                         *name = arg->ident->name;
 267                         *sym = arg;
 268                         return TRUE;
 269                 }
 270                 i++;
 271         } END_FOR_EACH_PTR(arg);
 272
 273         return FALSE;
 274 }
 275
 276 static struct state_list *final_states;
 277 static int prev_func_id = -1;
 278 static int db_callback(void *unused, int argc, char **argv, char **azColName)
 279 {
 280         int func_id;
 281         long type;
 282         long param;
 283         char *name = NULL;
 284         struct symbol *sym = NULL;
 285         struct def_callback *def_callback;
 286
 287         if (argc != 5)
 288                 return 0;
 289
 290         func_id = atoi(argv[0]);
 291         errno = 0;
 292         type = strtol(argv[1], NULL, 10);
 293         param = strtol(argv[2], NULL, 10);
 294         if (errno)
 295                 return 0;
 296
 297         if (prev_func_id == -1)
 298                 prev_func_id = func_id;
 299         if (func_id != prev_func_id) {
 300                 merge_slist(&final_states, __pop_fake_cur_slist());
 301                 __push_fake_cur_slist();
 302                 __unnullify_path();
 303                 prev_func_id = func_id;
 304         }
 305
 306         if (type == INTERNAL)
 307                 return 0;
 308         if (param >= 0 && !get_param(param, &name, &sym))
 309                 return 0;
 310
 311         FOR_EACH_PTR(callbacks, def_callback) {
 312                 if (def_callback->hook_type == type)
 313                         def_callback->callback(name, sym, argv[3], argv[4]);
 314         } END_FOR_EACH_PTR(def_callback);
 315
 316         return 0;
 317 }
 318
 319 static void get_direct_callers(struct symbol *sym)
 320 {
 321         char sql_filter[1024];
 322
 323         if (sym->ctype.modifiers & MOD_STATIC) {
 324                 snprintf(sql_filter, 1024,
 325                          "file = '%s' and function = '%s' order by function_id;",
 326                          get_filename(), sym->ident->name);
 327         } else {
 328                 snprintf(sql_filter, 1024,
 329                          "function = '%s' and static = 0 order by function_id;",
 330                          sym->ident->name);
 331         }
 332
 333         run_sql(db_callback, "select function_id, type, parameter, key, value from caller_info"
 334                 " where %s", sql_filter);
 335 }
 336
 337 static char *ptr_name;
 338 static int get_ptr_name(void *unused, int argc, char **argv, char **azColName)
 339 {
 340         if (!ptr_name)
 341                 ptr_name = alloc_string(argv[0]);
 342         return 0;
 343 }
 344
 345 static void get_function_pointer_callers(struct symbol *sym)
 346 {
 347         ptr_name = NULL;
 348         run_sql(get_ptr_name, "select ptr from function_ptr where function = '%s'",
 349                 sym->ident->name);
 350         if (!ptr_name)
 351                 return;
 352
 353         run_sql(db_callback, "select function_id, type, parameter, key, value from caller_info"
 354                 " where function = '%s' order by function_id", ptr_name);
 355 }
 356
 357 static void match_data_from_db(struct symbol *sym)
 358 {
 359         struct sm_state *sm;
 360
 361         if (!sym || !sym->ident || !sym->ident->name)
 362                 return;
 363
 364         __push_fake_cur_slist();
 365         __unnullify_path();
 366         prev_func_id = -1;
 367
 368         get_direct_callers(sym);
 369         get_function_pointer_callers(sym);
 370
 371         merge_slist(&final_states, __pop_fake_cur_slist());
 372
 373         FOR_EACH_PTR(final_states, sm) {
 374                 __set_sm(sm);
 375         } END_FOR_EACH_PTR(sm);
 376
 377         free_slist(&final_states);
 378 }
 379
 380 static void match_function_assign(struct expression *expr)
 381 {
 382         struct expression *right = expr->right;
 383         struct symbol *sym;
 384         char *fn_name;
 385         char *ptr_name;
 386
 387         if (right->type == EXPR_PREOP && right->op == '&')
 388                 right = strip_expr(right->unop);
 389         if (right->type != EXPR_SYMBOL)
 390                 return;
 391         sym = get_type(right);
 392         if (!sym || sym->type != SYM_FN)
 393                 return;
 394
 395         fn_name = get_variable_from_expr(right, NULL);
 396         ptr_name = get_fnptr_name(expr->left);
 397         if (!fn_name || !ptr_name)
 398                 goto free;
 399
 400         sm_msg("info: sets_fn_ptr '%s' '%s'", ptr_name, fn_name);
 401
 402 free:
 403         free_string(fn_name);
 404         free_string(ptr_name);
 405 }
 406
 407 static struct expression *call_implies_call_expr;
 408 static int call_implies_callbacks(void *unused, int argc, char **argv, char **azColName)
 409 {
 410         struct call_implies_callback *cb;
 411         struct expression *arg = NULL;
 412         int type;
 413         int param;
 414
 415         if (argc != 4)
 416                 return 0;
 417
 418         type = atoi(argv[1]);
 419         param = atoi(argv[2]);
 420
 421         FOR_EACH_PTR(call_implies_cb_list, cb) {
 422                 if (cb->type != type)
 423                         continue;
 424                 if (param != -1) {
 425                         arg = get_argument_from_call_expr(call_implies_call_expr->args, param);
 426                         if (!arg)
 427                                 continue;
 428                 }
 429                 cb->callback(arg, argv[3]);
 430         } END_FOR_EACH_PTR(cb);
 431
 432         return 0;
 433 }
 434
 435 static void match_call_implies(struct expression *expr)
 436 {
 437         struct symbol *sym;
 438         static char sql_filter[1024];
 439
 440         if (expr->fn->type != EXPR_SYMBOL)
 441                 return;
 442         sym = expr->fn->symbol;
 443         if (!sym)
 444                 return;
 445
 446         if (sym->ctype.modifiers & MOD_STATIC) {
 447                 snprintf(sql_filter, 1024, "file = '%s' and function = '%s';",
 448                          get_filename(), sym->ident->name);
 449         } else {
 450                 snprintf(sql_filter, 1024, "function = '%s' and static = 0;",
 451                                 sym->ident->name);
 452         }
 453
 454         call_implies_call_expr = expr;
 455         run_sql(call_implies_callbacks,
 456                 "select function, type, parameter, value from call_implies where %s",
 457                 sql_filter);
 458         return;
 459 }
 460
 461 static void print_initializer_list(struct expression_list *expr_list,
 462                 struct symbol *struct_type)
 463 {
 464         struct expression *expr;
 465         struct symbol *base_type;
 466
 467         FOR_EACH_PTR(expr_list, expr) {
 468                 if (expr->type == EXPR_INDEX && expr->idx_expression && expr->idx_expression->type == EXPR_INITIALIZER) {
 469                         print_initializer_list(expr->idx_expression->expr_list, struct_type);
 470                         continue;
 471                 }
 472                 if (expr->type != EXPR_IDENTIFIER)
 473                         continue;
 474                 if (!expr->expr_ident)
 475                         continue;
 476                 if (!expr->ident_expression || !expr->ident_expression->symbol_name)
 477                         continue;
 478                 base_type = get_type(expr->ident_expression);
 479                 if (!base_type || base_type->type != SYM_FN)
 480                         continue;
 481                 sm_msg("info: sets_fn_ptr '(struct %s)->%s' '%s'", struct_type->ident->name,
 482                        expr->expr_ident->name,
 483                        expr->ident_expression->symbol_name->name);
 484         } END_FOR_EACH_PTR(expr);
 485 }
 486
 487 static void global_variable(struct symbol *sym)
 488 {
 489         struct symbol *struct_type;
 490
 491         if (!sym->ident)
 492                 return;
 493         if (!sym->initializer || sym->initializer->type != EXPR_INITIALIZER)
 494                 return;
 495         struct_type = get_base_type(sym);
 496         if (!struct_type)
 497                 return;
 498         if (struct_type->type == SYM_ARRAY) {
 499                 struct_type = get_base_type(struct_type);
 500                 if (!struct_type)
 501                         return;
 502         }
 503         if (struct_type->type != SYM_STRUCT || !struct_type->ident)
 504                 return;
 505         print_initializer_list(sym->initializer->expr_list, struct_type);
 506 }
 507
 508 static void match_return_info(int return_id, char *return_ranges, struct expression *expr, struct state_list *slist)
 509 {
 510         sm_msg("info: return_marker %d '%s' %s", return_id, return_ranges,
 511                global_static());
 512 }
 513
 514 static int return_id;
 515 static void match_function_def(struct symbol *sym)
 516 {
 517         return_id = 0;
 518 }
 519
 520 static void call_return_state_hooks(struct expression *expr)
 521 {
 522         struct returned_state_callback *cb;
 523         struct state_list *slist;
 524         struct range_list *rl;
 525         char *return_ranges;
 526
 527         if (!expr) {
 528                 return_ranges = alloc_sname("");
 529         } else if (get_implied_range_list(expr, &rl)) {
 530                 rl = cast_rl(cur_func_return_type(), rl);
 531                 return_ranges = show_ranges(rl);
 532         } else {
 533                 rl = whole_range_list(cur_func_return_type());
 534                 return_ranges = show_ranges(rl);
 535         }
 536
 537         return_id++;
 538         slist = __get_cur_slist();
 539         FOR_EACH_PTR(returned_state_callbacks, cb) {
 540                 cb->callback(return_id, return_ranges, expr, slist);
 541         } END_FOR_EACH_PTR(cb);
 542 }
 543
 544 static void print_returned_struct_members(int return_id, char *return_ranges, struct expression *expr, struct state_list *slist)
 545 {
 546         struct returned_member_callback *cb;
 547         struct state_list *my_slist;
 548         struct sm_state *sm;
 549         struct symbol *type;
 550         char *name;
 551         char member_name[256];
 552         int len;
 553
 554         type = get_type(expr);
 555         if (!type || type->type != SYM_PTR)
 556                 return;
 557         type = get_real_base_type(type);
 558         if (!type || type->type != SYM_STRUCT)
 559                 return;
 560         name = get_variable_from_expr(expr, NULL);
 561         if (!name)
 562                 return;
 563
 564         member_name[sizeof(member_name) - 1] = '\0';
 565         strcpy(member_name, "$$");
 566
 567         len = strlen(name);
 568         FOR_EACH_PTR(returned_member_callbacks, cb) {
 569                 my_slist = get_all_states_slist(cb->owner, slist);
 570                 FOR_EACH_PTR(my_slist, sm) {
 571                         if (strncmp(sm->name, name, len) != 0)
 572                                 continue;
 573                         if (strncmp(sm->name + len, "->", 2) != 0)
 574                                 continue;
 575                         strncpy(member_name + 2, sm->name + len, sizeof(member_name) - 2);
 576                         cb->callback(return_id, return_ranges, member_name, sm->state);
 577                 } END_FOR_EACH_PTR(sm);
 578                 free_slist(&my_slist);
 579         } END_FOR_EACH_PTR(cb);
 580
 581         free_string(name);
 582 }
 583
 584 static void match_end_func_info(struct symbol *sym)
 585 {
 586         if (__path_is_null())
 587                 return;
 588         call_return_state_hooks(NULL);
 589 }
 590
 591 void open_smatch_db(void)
 592 {
 593 #ifdef SQLITE_OPEN_READONLY
 594         int rc;
 595
 596         if (option_no_db)
 597                 return;
 598
 599         rc = sqlite3_open_v2("smatch_db.sqlite", &db, SQLITE_OPEN_READONLY, NULL);
 600         if (rc != SQLITE_OK) {
 601                 option_no_db = 1;
 602                 return;
 603         }
 604         return;
 605 #else
 606         option_no_db = 1;
 607         return;
 608 #endif
 609 }
 610
 611 void register_definition_db_callbacks(int id)
 612 {
 613         add_hook(&match_function_def, FUNC_DEF_HOOK);
 614
 615         if (option_info) {
 616                 add_hook(&match_call_info, FUNCTION_CALL_HOOK);
 617                 add_hook(&match_call_hack, FUNCTION_CALL_HOOK);
 618                 add_hook(&match_function_assign, ASSIGNMENT_HOOK);
 619                 add_hook(&match_function_assign, GLOBAL_ASSIGNMENT_HOOK);
 620                 add_hook(&global_variable, BASE_HOOK);
 621                 add_hook(&global_variable, DECLARATION_HOOK);
 622                 add_returned_state_callback(match_return_info);
 623                 add_returned_state_callback(print_returned_struct_members);
 624                 add_hook(&call_return_state_hooks, RETURN_HOOK);
 625                 add_hook(&match_end_func_info, END_FUNC_HOOK);
 626         }
 627
 628         if (option_no_db)
 629                 return;
 630
 631         add_hook(&match_data_from_db, FUNC_DEF_HOOK);
 632         add_hook(&match_call_implies, FUNCTION_CALL_HOOK);
 633 }