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 static int return_id;
  59 int get_return_id(void)
  60 {
  61         return return_id;
  62 }
  63
  64 void sql_exec(int (*callback)(void*, int, char**, char**), const char *sql)
  65 {
  66         char *err = NULL;
  67         int rc;
  68
  69         if (option_no_db || !db)
  70                 return;
  71
  72         rc = sqlite3_exec(db, sql, callback, 0, &err);
  73         if (rc != SQLITE_OK) {
  74                 fprintf(stderr, "SQL error #2: %s\n", err);
  75                 fprintf(stderr, "SQL: '%s'\n", sql);
  76         }
  77 }
  78
  79 void add_definition_db_callback(void (*callback)(const char *name, struct symbol *sym, char *key, char *value), int type)
  80 {
  81         struct def_callback *def_callback = __alloc_def_callback(0);
  82
  83         def_callback->hook_type = type;
  84         def_callback->callback = callback;
  85         add_ptr_list(&callbacks, def_callback);
  86 }
  87
  88 /*
  89  * These call backs are used when the --info option is turned on to print struct
  90  * member information.  For example foo->bar could have a state in
  91  * smatch_extra.c and also check_user.c.
  92  */
  93 void add_member_info_callback(int owner, void (*callback)(char *fn, char *global_static, int param, char *printed_name, struct smatch_state *state))
  94 {
  95         struct member_info_callback *member_callback = __alloc_member_info_callback(0);
  96
  97         member_callback->owner = owner;
  98         member_callback->callback = callback;
  99         add_ptr_list(&member_callbacks, member_callback);
 100 }
 101
 102 void add_returned_state_callback(void (*fn)(int return_id, char *return_ranges, struct expression *returned_expr, struct state_list *slist))
 103 {
 104         struct returned_state_callback *callback = __alloc_returned_state_callback(0);
 105
 106         callback->callback = fn;
 107         add_ptr_list(&returned_state_callbacks, callback);
 108 }
 109
 110 void add_returned_member_callback(int owner, void (*callback)(int return_id, char *return_ranges, char *printed_name, struct smatch_state *state))
 111 {
 112         struct returned_member_callback *member_callback = __alloc_returned_member_callback(0);
 113
 114         member_callback->owner = owner;
 115         member_callback->callback = callback;
 116         add_ptr_list(&returned_member_callbacks, member_callback);
 117 }
 118
 119 void add_db_fn_call_callback(int type, void (*callback)(struct expression *arg, char *value))
 120 {
 121         struct call_implies_callback *cb = __alloc_call_implies_callback(0);
 122
 123         cb->type = type;
 124         cb->callback = callback;
 125         add_ptr_list(&call_implies_cb_list, cb);
 126 }
 127
 128 static struct symbol *return_type;
 129 static struct range_list *return_range_list;
 130 static int db_return_callback(void *unused, int argc, char **argv, char **azColName)
 131 {
 132         if (argc != 1)
 133                 return 0;
 134         if (option_debug)
 135                 sm_msg("return type %d", type_positive_bits(return_type));
 136         parse_value_ranges_type(return_type, argv[0], &return_range_list);
 137         return 0;
 138 }
 139
 140 struct range_list *db_return_vals(struct expression *expr)
 141 {
 142         struct symbol *sym;
 143         static char sql_filter[1024];
 144
 145         if (expr->type != EXPR_CALL)
 146                 return NULL;
 147         if (expr->fn->type != EXPR_SYMBOL)
 148                 return NULL;
 149         return_type = get_type(expr);
 150         if (!return_type)
 151                 return NULL;
 152         sym = expr->fn->symbol;
 153         if (!sym)
 154                 return NULL;
 155
 156         if (sym->ctype.modifiers & MOD_STATIC) {
 157                 snprintf(sql_filter, 1024, "file = '%s' and function = '%s';",
 158                          get_filename(), sym->ident->name);
 159         } else {
 160                 snprintf(sql_filter, 1024, "function = '%s' and static = 0;",
 161                                 sym->ident->name);
 162         }
 163
 164         return_range_list = NULL;
 165         run_sql(db_return_callback, "select return from return_values where %s",
 166                  sql_filter);
 167         return return_range_list;
 168 }
 169
 170 static void match_call_hack(struct expression *expr)
 171 {
 172         char *name;
 173
 174         /*
 175          * we just want to record something in the database so that if we have
 176          * two calls like:  frob(4); frob(some_unkown); then on the receiving
 177          * side we know that sometimes frob is called with unknown parameters.
 178          */
 179
 180         name = get_fnptr_name(expr->fn);
 181         if (!name)
 182                 return;
 183         sm_msg("info: call_marker '%s' %s", name, is_static(expr->fn) ? "static" : "global");
 184         free_string(name);
 185 }
 186
 187 static void print_struct_members(char *fn, char *global_static, struct expression *expr, int param, struct state_list *slist,
 188         void (*callback)(char *fn, char *global_static, int param, char *printed_name, struct smatch_state *state))
 189 {
 190         struct sm_state *sm;
 191         char *name;
 192         struct symbol *sym;
 193         int len;
 194         char printed_name[256];
 195         int is_address = 0;
 196
 197         expr = strip_expr(expr);
 198         if (expr->type == EXPR_PREOP && expr->op == '&') {
 199                 expr = strip_expr(expr->unop);
 200                 is_address = 1;
 201         }
 202
 203         name = get_variable_from_expr(expr, &sym);
 204         if (!name || !sym)
 205                 goto free;
 206
 207         len = strlen(name);
 208         FOR_EACH_PTR(slist, sm) {
 209                 if (sm->sym != sym)
 210                         continue;
 211                 if (strncmp(name, sm->name, len) || sm->name[len] == '\0')
 212                         continue;
 213                 if (is_address)
 214                         snprintf(printed_name, sizeof(printed_name), "$$->%s", sm->name + len + 1);
 215                 else
 216                         snprintf(printed_name, sizeof(printed_name), "$$%s", sm->name + len);
 217                 callback(fn, global_static, param, printed_name, sm->state);
 218         } END_FOR_EACH_PTR(sm);
 219 free:
 220         free_string(name);
 221 }
 222
 223 static void match_call_info(struct expression *expr)
 224 {
 225         struct member_info_callback *cb;
 226         struct expression *arg;
 227         struct state_list *slist;
 228         char *name;
 229         int i;
 230         char *gs;
 231
 232         name = get_fnptr_name(expr->fn);
 233         if (!name)
 234                 return;
 235
 236         if (is_static(expr->fn))
 237                 gs = (char *)"static";
 238         else
 239                 gs = (char *)"global";
 240
 241         FOR_EACH_PTR(member_callbacks, cb) {
 242                 slist = get_all_states(cb->owner);
 243                 i = 0;
 244                 FOR_EACH_PTR(expr->args, arg) {
 245                         print_struct_members(name, gs, arg, i, slist, cb->callback);
 246                         i++;
 247                 } END_FOR_EACH_PTR(arg);
 248                 free_slist(&slist);
 249         } END_FOR_EACH_PTR(cb);
 250
 251         free_string(name);
 252 }
 253
 254 static int get_param(int param, char **name, struct symbol **sym)
 255 {
 256         struct symbol *arg;
 257         int i;
 258
 259         i = 0;
 260         FOR_EACH_PTR(cur_func_sym->ctype.base_type->arguments, arg) {
 261                 /*
 262                  * this is a temporary hack to work around a bug (I think in sparse?)
 263                  * 2.6.37-rc1:fs/reiserfs/journal.o
 264                  * If there is a function definition without parameter name found
 265                  * after a function implementation then it causes a crash.
 266                  * int foo() {}
 267                  * int bar(char *);
 268                  */
 269                 if (arg->ident->name < (char *)100)
 270                         continue;
 271                 if (i == param && arg->ident->name) {
 272                         *name = arg->ident->name;
 273                         *sym = arg;
 274                         return TRUE;
 275                 }
 276                 i++;
 277         } END_FOR_EACH_PTR(arg);
 278
 279         return FALSE;
 280 }
 281
 282 static struct state_list *final_states;
 283 static int prev_func_id = -1;
 284 static int db_callback(void *unused, int argc, char **argv, char **azColName)
 285 {
 286         int func_id;
 287         long type;
 288         long param;
 289         char *name = NULL;
 290         struct symbol *sym = NULL;
 291         struct def_callback *def_callback;
 292
 293         if (argc != 5)
 294                 return 0;
 295
 296         func_id = atoi(argv[0]);
 297         errno = 0;
 298         type = strtol(argv[1], NULL, 10);
 299         param = strtol(argv[2], NULL, 10);
 300         if (errno)
 301                 return 0;
 302
 303         if (prev_func_id == -1)
 304                 prev_func_id = func_id;
 305         if (func_id != prev_func_id) {
 306                 merge_slist(&final_states, __pop_fake_cur_slist());
 307                 __push_fake_cur_slist();
 308                 __unnullify_path();
 309                 prev_func_id = func_id;
 310         }
 311
 312         if (type == INTERNAL)
 313                 return 0;
 314         if (param >= 0 && !get_param(param, &name, &sym))
 315                 return 0;
 316
 317         FOR_EACH_PTR(callbacks, def_callback) {
 318                 if (def_callback->hook_type == type)
 319                         def_callback->callback(name, sym, argv[3], argv[4]);
 320         } END_FOR_EACH_PTR(def_callback);
 321
 322         return 0;
 323 }
 324
 325 static void get_direct_callers(struct symbol *sym)
 326 {
 327         char sql_filter[1024];
 328
 329         if (sym->ctype.modifiers & MOD_STATIC) {
 330                 snprintf(sql_filter, 1024,
 331                          "file = '%s' and function = '%s' order by function_id;",
 332                          get_filename(), sym->ident->name);
 333         } else {
 334                 snprintf(sql_filter, 1024,
 335                          "function = '%s' and static = 0 order by function_id;",
 336                          sym->ident->name);
 337         }
 338
 339         run_sql(db_callback, "select function_id, type, parameter, key, value from caller_info"
 340                 " where %s", sql_filter);
 341 }
 342
 343 static char *ptr_name;
 344 static int get_ptr_name(void *unused, int argc, char **argv, char **azColName)
 345 {
 346         if (!ptr_name)
 347                 ptr_name = alloc_string(argv[0]);
 348         return 0;
 349 }
 350
 351 static void get_function_pointer_callers(struct symbol *sym)
 352 {
 353         ptr_name = NULL;
 354         run_sql(get_ptr_name, "select ptr from function_ptr where function = '%s'",
 355                 sym->ident->name);
 356         if (!ptr_name)
 357                 return;
 358
 359         run_sql(db_callback, "select function_id, type, parameter, key, value from caller_info"
 360                 " where function = '%s' order by function_id", ptr_name);
 361 }
 362
 363 static void match_data_from_db(struct symbol *sym)
 364 {
 365         struct sm_state *sm;
 366
 367         if (!sym || !sym->ident || !sym->ident->name)
 368                 return;
 369
 370         __push_fake_cur_slist();
 371         __unnullify_path();
 372         prev_func_id = -1;
 373
 374         get_direct_callers(sym);
 375         get_function_pointer_callers(sym);
 376
 377         merge_slist(&final_states, __pop_fake_cur_slist());
 378
 379         FOR_EACH_PTR(final_states, sm) {
 380                 __set_sm(sm);
 381         } END_FOR_EACH_PTR(sm);
 382
 383         free_slist(&final_states);
 384 }
 385
 386 static void match_function_assign(struct expression *expr)
 387 {
 388         struct expression *right = expr->right;
 389         struct symbol *sym;
 390         char *fn_name;
 391         char *ptr_name;
 392
 393         if (right->type == EXPR_PREOP && right->op == '&')
 394                 right = strip_expr(right->unop);
 395         if (right->type != EXPR_SYMBOL)
 396                 return;
 397         sym = get_type(right);
 398         if (!sym || sym->type != SYM_FN)
 399                 return;
 400
 401         fn_name = get_variable_from_expr(right, NULL);
 402         ptr_name = get_fnptr_name(expr->left);
 403         if (!fn_name || !ptr_name)
 404                 goto free;
 405
 406         sm_msg("info: sets_fn_ptr '%s' '%s'", ptr_name, fn_name);
 407
 408 free:
 409         free_string(fn_name);
 410         free_string(ptr_name);
 411 }
 412
 413 static struct expression *call_implies_call_expr;
 414 static int call_implies_callbacks(void *unused, int argc, char **argv, char **azColName)
 415 {
 416         struct call_implies_callback *cb;
 417         struct expression *arg = NULL;
 418         int type;
 419         int param;
 420
 421         if (argc != 4)
 422                 return 0;
 423
 424         type = atoi(argv[1]);
 425         param = atoi(argv[2]);
 426
 427         FOR_EACH_PTR(call_implies_cb_list, cb) {
 428                 if (cb->type != type)
 429                         continue;
 430                 if (param != -1) {
 431                         arg = get_argument_from_call_expr(call_implies_call_expr->args, param);
 432                         if (!arg)
 433                                 continue;
 434                 }
 435                 cb->callback(arg, argv[3]);
 436         } END_FOR_EACH_PTR(cb);
 437
 438         return 0;
 439 }
 440
 441 static void match_call_implies(struct expression *expr)
 442 {
 443         struct symbol *sym;
 444         static char sql_filter[1024];
 445
 446         if (expr->fn->type != EXPR_SYMBOL)
 447                 return;
 448         sym = expr->fn->symbol;
 449         if (!sym)
 450                 return;
 451
 452         if (sym->ctype.modifiers & MOD_STATIC) {
 453                 snprintf(sql_filter, 1024, "file = '%s' and function = '%s';",
 454                          get_filename(), sym->ident->name);
 455         } else {
 456                 snprintf(sql_filter, 1024, "function = '%s' and static = 0;",
 457                                 sym->ident->name);
 458         }
 459
 460         call_implies_call_expr = expr;
 461         run_sql(call_implies_callbacks,
 462                 "select function, type, parameter, value from call_implies where %s",
 463                 sql_filter);
 464         return;
 465 }
 466
 467 static void print_initializer_list(struct expression_list *expr_list,
 468                 struct symbol *struct_type)
 469 {
 470         struct expression *expr;
 471         struct symbol *base_type;
 472
 473         FOR_EACH_PTR(expr_list, expr) {
 474                 if (expr->type == EXPR_INDEX && expr->idx_expression && expr->idx_expression->type == EXPR_INITIALIZER) {
 475                         print_initializer_list(expr->idx_expression->expr_list, struct_type);
 476                         continue;
 477                 }
 478                 if (expr->type != EXPR_IDENTIFIER)
 479                         continue;
 480                 if (!expr->expr_ident)
 481                         continue;
 482                 if (!expr->ident_expression || !expr->ident_expression->symbol_name)
 483                         continue;
 484                 base_type = get_type(expr->ident_expression);
 485                 if (!base_type || base_type->type != SYM_FN)
 486                         continue;
 487                 sm_msg("info: sets_fn_ptr '(struct %s)->%s' '%s'", struct_type->ident->name,
 488                        expr->expr_ident->name,
 489                        expr->ident_expression->symbol_name->name);
 490         } END_FOR_EACH_PTR(expr);
 491 }
 492
 493 static void global_variable(struct symbol *sym)
 494 {
 495         struct symbol *struct_type;
 496
 497         if (!sym->ident)
 498                 return;
 499         if (!sym->initializer || sym->initializer->type != EXPR_INITIALIZER)
 500                 return;
 501         struct_type = get_base_type(sym);
 502         if (!struct_type)
 503                 return;
 504         if (struct_type->type == SYM_ARRAY) {
 505                 struct_type = get_base_type(struct_type);
 506                 if (!struct_type)
 507                         return;
 508         }
 509         if (struct_type->type != SYM_STRUCT || !struct_type->ident)
 510                 return;
 511         print_initializer_list(sym->initializer->expr_list, struct_type);
 512 }
 513
 514 static void match_return_info(int return_id, char *return_ranges, struct expression *expr, struct state_list *slist)
 515 {
 516         sm_msg("info: return_marker %d '%s' %s", return_id, return_ranges,
 517                global_static());
 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         slist = __get_cur_slist();
 538         FOR_EACH_PTR(returned_state_callbacks, cb) {
 539                 cb->callback(get_return_id(), return_ranges, expr, slist);
 540         } END_FOR_EACH_PTR(cb);
 541 }
 542
 543 struct state_list *get_my_states(int owner, struct state_list *source)
 544 {
 545         struct state_list *slist = NULL;
 546         struct sm_state *tmp;
 547
 548         FOR_EACH_PTR(source, tmp) {
 549                 if (tmp->owner == owner)
 550                         add_ptr_list(&slist, tmp);
 551         } END_FOR_EACH_PTR(tmp);
 552
 553         return slist;
 554 }
 555
 556 static void print_returned_struct_members(int return_id, char *return_ranges, struct expression *expr, struct state_list *slist)
 557 {
 558         struct returned_member_callback *cb;
 559         struct state_list *my_slist;
 560         struct sm_state *sm;
 561         struct symbol *type;
 562         char *name;
 563         char member_name[256];
 564         int len;
 565
 566         type = get_type(expr);
 567         if (!type || type->type != SYM_PTR)
 568                 return;
 569         type = get_real_base_type(type);
 570         if (!type || type->type != SYM_STRUCT)
 571                 return;
 572         name = get_variable_from_expr(expr, NULL);
 573         if (!name)
 574                 return;
 575
 576         member_name[sizeof(member_name) - 1] = '\0';
 577         strcpy(member_name, "$$");
 578
 579         len = strlen(name);
 580         FOR_EACH_PTR(returned_member_callbacks, cb) {
 581                 my_slist = get_my_states(cb->owner, slist);
 582                 FOR_EACH_PTR(my_slist, sm) {
 583                         if (strncmp(sm->name, name, len) != 0)
 584                                 continue;
 585                         if (strncmp(sm->name + len, "->", 2) != 0)
 586                                 continue;
 587                         strncpy(member_name + 2, sm->name + len, sizeof(member_name) - 2);
 588                         cb->callback(return_id, return_ranges, member_name, sm->state);
 589                 } END_FOR_EACH_PTR(sm);
 590                 free_slist(&my_slist);
 591         } END_FOR_EACH_PTR(cb);
 592
 593         free_string(name);
 594 }
 595
 596 static void match_end_func_info(struct symbol *sym)
 597 {
 598         if (__path_is_null())
 599                 return;
 600         sm_msg("info: return_marker %d '' %s", get_return_id(), global_static());
 601 }
 602
 603 static void match_function_def(struct symbol *sym)
 604 {
 605         return_id = 0;
 606 }
 607
 608 static void match_return(struct expression *ret_value)
 609 {
 610         return_id++;
 611 }
 612
 613 static void match_end_func(struct symbol *sym)
 614 {
 615         return_id++;
 616 }
 617
 618 void open_smatch_db(void)
 619 {
 620 #ifdef SQLITE_OPEN_READONLY
 621         int rc;
 622
 623         if (option_no_db)
 624                 return;
 625
 626         rc = sqlite3_open_v2("smatch_db.sqlite", &db, SQLITE_OPEN_READONLY, NULL);
 627         if (rc != SQLITE_OK) {
 628                 option_no_db = 1;
 629                 return;
 630         }
 631         return;
 632 #else
 633         option_no_db = 1;
 634         return;
 635 #endif
 636 }
 637
 638 void register_definition_db_callbacks(int id)
 639 {
 640         add_hook(&match_function_def, FUNC_DEF_HOOK);
 641         add_hook(&match_return, RETURN_HOOK);
 642         add_hook(&match_end_func, END_FUNC_HOOK);
 643
 644         if (option_info) {
 645                 add_hook(&match_call_info, FUNCTION_CALL_HOOK);
 646                 add_hook(&match_call_hack, FUNCTION_CALL_HOOK);
 647                 add_hook(&match_function_assign, ASSIGNMENT_HOOK);
 648                 add_hook(&match_function_assign, GLOBAL_ASSIGNMENT_HOOK);
 649                 add_hook(&global_variable, BASE_HOOK);
 650                 add_hook(&global_variable, DECLARATION_HOOK);
 651                 add_returned_state_callback(match_return_info);
 652                 add_returned_state_callback(print_returned_struct_members);
 653                 add_hook(&call_return_state_hooks, RETURN_HOOK);
 654                 add_hook(&match_end_func_info, END_FUNC_HOOK);
 655         }
 656
 657         if (option_no_db)
 658                 return;
 659
 660         add_hook(&match_data_from_db, FUNC_DEF_HOOK);
 661         add_hook(&match_call_implies, FUNCTION_CALL_HOOK);
 662 }