smatch_buf_size.c

   1 /*
   2  * Copyright (C) 2010 Dan Carpenter.
   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 #include <stdlib.h>
  19 #include <errno.h>
  20 #include "parse.h"
  21 #include "smatch.h"
  22 #include "smatch_slist.h"
  23 #include "smatch_extra.h"
  24 #include "smatch_function_hashtable.h"
  25
  26 #define UNKNOWN_SIZE -1
  27
  28 static int my_size_id;
  29
  30 static DEFINE_HASHTABLE_INSERT(insert_func, char, int);
  31 static DEFINE_HASHTABLE_SEARCH(search_func, char, int);
  32 static struct hashtable *allocation_funcs;
  33
  34 static char *get_fn_name(struct expression *expr)
  35 {
  36         if (expr->type != EXPR_CALL)
  37                 return NULL;
  38         if (expr->fn->type != EXPR_SYMBOL)
  39                 return NULL;
  40         return expr_to_var(expr->fn);
  41 }
  42
  43 static int is_allocation_function(struct expression *expr)
  44 {
  45         char *func;
  46         int ret = 0;
  47
  48         func = get_fn_name(expr);
  49         if (!func)
  50                 return 0;
  51         if (search_func(allocation_funcs, func))
  52                 ret = 1;
  53         free_string(func);
  54         return ret;
  55 }
  56
  57 static void add_allocation_function(const char *func, void *call_back, int param)
  58 {
  59         insert_func(allocation_funcs, (char *)func, (int *)1);
  60         add_function_assign_hook(func, call_back, INT_PTR(param));
  61 }
  62
  63 static struct smatch_state *size_to_estate(int size)
  64 {
  65         sval_t sval;
  66
  67         sval.type = &int_ctype;
  68         sval.value = size;
  69
  70         return alloc_estate_sval(sval);
  71 }
  72
  73 static struct range_list *size_to_rl(int size)
  74 {
  75         sval_t sval;
  76
  77         sval.type = &int_ctype;
  78         sval.value = size;
  79
  80         return alloc_rl(sval, sval);
  81 }
  82
  83 static struct smatch_state *unmatched_size_state(struct sm_state *sm)
  84 {
  85         return size_to_estate(UNKNOWN_SIZE);
  86 }
  87
  88 static void set_size_undefined(struct sm_state *sm, struct expression *mod_expr)
  89 {
  90         set_state(sm->owner, sm->name, sm->sym, size_to_estate(UNKNOWN_SIZE));
  91 }
  92
  93 static struct smatch_state *merge_size_func(struct smatch_state *s1, struct smatch_state *s2)
  94 {
  95         return merge_estates(s1, s2);
  96 }
  97
  98 void set_param_buf_size(const char *name, struct symbol *sym, char *key, char *value)
  99 {
 100         struct range_list *rl = NULL;
 101         struct smatch_state *state;
 102         char fullname[256];
 103
 104         if (strncmp(key, "$", 1) != 0)
 105                 return;
 106
 107         snprintf(fullname, 256, "%s%s", name, key + 1);
 108
 109         str_to_rl(&int_ctype, value, &rl);
 110         if (!rl || is_whole_rl(rl))
 111                 return;
 112         state = alloc_estate_rl(rl);
 113         set_state(my_size_id, fullname, sym, state);
 114 }
 115
 116 static int bytes_per_element(struct expression *expr)
 117 {
 118         struct symbol *type;
 119
 120         if (!expr)
 121                 return 0;
 122         if (expr->type == EXPR_STRING)
 123                 return 1;
 124         if (expr->type == EXPR_PREOP && expr->op == '&') {
 125                 type = get_type(expr->unop);
 126                 if (type && type->type == SYM_ARRAY)
 127                         expr = expr->unop;
 128         }
 129         type = get_type(expr);
 130         if (!type)
 131                 return 0;
 132
 133         if (type->type != SYM_PTR && type->type != SYM_ARRAY)
 134                 return 0;
 135
 136         type = get_base_type(type);
 137         return type_bytes(type);
 138 }
 139
 140 static int bytes_to_elements(struct expression *expr, int bytes)
 141 {
 142         int bpe;
 143
 144         bpe = bytes_per_element(expr);
 145         if (bpe == 0)
 146                 return 0;
 147         return bytes / bpe;
 148 }
 149
 150 static int elements_to_bytes(struct expression *expr, int elements)
 151 {
 152         int bpe;
 153
 154         bpe = bytes_per_element(expr);
 155         return elements * bpe;
 156 }
 157
 158 static int get_initializer_size(struct expression *expr)
 159 {
 160         switch (expr->type) {
 161         case EXPR_STRING:
 162                 return expr->string->length;
 163         case EXPR_INITIALIZER: {
 164                 struct expression *tmp;
 165                 int i = 0;
 166
 167                 FOR_EACH_PTR(expr->expr_list, tmp) {
 168                         if (tmp->type == EXPR_INDEX) {
 169                                 if (tmp->idx_to >= i)
 170                                         i = tmp->idx_to;
 171                                 else
 172                                         continue;
 173                         }
 174
 175                         i++;
 176                 } END_FOR_EACH_PTR(tmp);
 177                 return i;
 178         }
 179         case EXPR_SYMBOL:
 180                 return get_array_size(expr);
 181         }
 182         return 0;
 183 }
 184
 185 static struct range_list *db_size_rl;
 186 static int db_size_callback(void *unused, int argc, char **argv, char **azColName)
 187 {
 188         struct range_list *tmp = NULL;
 189
 190         if (!db_size_rl) {
 191                 str_to_rl(&int_ctype, argv[0], &db_size_rl);
 192         } else {
 193                 str_to_rl(&int_ctype, argv[0], &tmp);
 194                 db_size_rl = rl_union(db_size_rl, tmp);
 195         }
 196         return 0;
 197 }
 198
 199 static struct range_list *size_from_db_type(struct expression *expr)
 200 {
 201         int this_file_only = 0;
 202         char *name;
 203
 204         name = get_member_name(expr);
 205         if (!name && is_static(expr)) {
 206                 name = expr_to_var(expr);
 207                 this_file_only = 1;
 208         }
 209         if (!name)
 210                 return NULL;
 211
 212         if (this_file_only) {
 213                 db_size_rl = NULL;
 214                 run_sql(db_size_callback, NULL,
 215                         "select size from function_type_size where type = '%s' and file = '%s';",
 216                         name, get_filename());
 217                 if (db_size_rl)
 218                         return db_size_rl;
 219                 return NULL;
 220         }
 221
 222         db_size_rl = NULL;
 223         run_sql(db_size_callback, NULL,
 224                 "select size from type_size where type = '%s';",
 225                 name);
 226         return db_size_rl;
 227 }
 228
 229 static struct range_list *size_from_db_symbol(struct expression *expr)
 230 {
 231         struct symbol *sym;
 232
 233         if (expr->type != EXPR_SYMBOL)
 234                 return NULL;
 235         sym = expr->symbol;
 236         if (!sym || !sym->ident ||
 237             !(sym->ctype.modifiers & MOD_TOPLEVEL) ||
 238             sym->ctype.modifiers & MOD_STATIC)
 239                 return NULL;
 240
 241         db_size_rl = NULL;
 242         run_sql(db_size_callback, NULL,
 243                 "select value from data_info where file = 'extern' and data = '%s' and type = %d;",
 244                 sym->ident->name, BUF_SIZE);
 245         return db_size_rl;
 246 }
 247
 248 static struct range_list *size_from_db(struct expression *expr)
 249 {
 250         struct range_list *rl;
 251
 252         rl = size_from_db_symbol(expr);
 253         if (rl)
 254                 return rl;
 255         return size_from_db_type(expr);
 256 }
 257
 258 static void db_returns_buf_size(struct expression *expr, int param, char *unused, char *math)
 259 {
 260         struct expression *call;
 261         struct range_list *rl;
 262         sval_t sval;
 263
 264         if (expr->type != EXPR_ASSIGNMENT)
 265                 return;
 266         call = strip_expr(expr->right);
 267
 268         call_results_to_rl(call, &int_ctype, math, &rl);
 269         rl = cast_rl(&int_ctype, rl);
 270         if (rl_to_sval(rl, &sval) && sval.value == 0)
 271                 return;
 272         set_state_expr(my_size_id, expr->left, alloc_estate_rl(rl));
 273 }
 274
 275 static int get_real_array_size_from_type(struct symbol *type)
 276 {
 277         sval_t sval;
 278
 279         if (!type)
 280                 return 0;
 281         if (!type || type->type != SYM_ARRAY)
 282                 return 0;
 283
 284         if (!get_implied_value(type->array_size, &sval))
 285                 return 0;
 286
 287         return sval.value;
 288 }
 289
 290 int get_real_array_size(struct expression *expr)
 291 {
 292         if (!expr)
 293                 return 0;
 294         if (expr->type == EXPR_PREOP && expr->op == '&')
 295                 expr = expr->unop;
 296         if (expr->type == EXPR_BINOP) /* array elements foo[5] */
 297                 return 0;
 298         return get_real_array_size_from_type(get_type(expr));
 299 }
 300
 301 static int get_size_from_initializer(struct expression *expr)
 302 {
 303         if (expr->type != EXPR_SYMBOL || !expr->symbol || !expr->symbol->initializer)
 304                 return 0;
 305         if (expr->symbol->initializer == expr) /* int a = a; */
 306                 return 0;
 307         return get_initializer_size(expr->symbol->initializer);
 308 }
 309
 310 static struct range_list *get_stored_size_bytes(struct expression *expr)
 311 {
 312         struct smatch_state *state;
 313
 314         state = get_state_expr(my_size_id, expr);
 315         if (!state)
 316                 return NULL;
 317         return estate_rl(state);
 318 }
 319
 320 static int get_bytes_from_address(struct expression *expr)
 321 {
 322         struct symbol *type;
 323         int ret;
 324
 325         if (expr->type != EXPR_PREOP || expr->op != '&')
 326                 return 0;
 327         type = get_type(expr);
 328         if (!type)
 329                 return 0;
 330
 331         if (type->type == SYM_PTR)
 332                 type = get_base_type(type);
 333
 334         ret = type_bytes(type);
 335         if (ret == 1)
 336                 return 0;  /* ignore char pointers */
 337
 338         return ret;
 339 }
 340
 341 static struct expression *remove_addr_fluff(struct expression *expr)
 342 {
 343         struct expression *tmp;
 344         sval_t sval;
 345
 346         expr = strip_expr(expr);
 347
 348         /* remove '&' and '*' operations that cancel */
 349         while (expr && expr->type == EXPR_PREOP && expr->op == '&') {
 350                 tmp = strip_expr(expr->unop);
 351                 if (tmp->type != EXPR_PREOP)
 352                         break;
 353                 if (tmp->op != '*')
 354                         break;
 355                 expr = strip_expr(tmp->unop);
 356         }
 357
 358         if (!expr)
 359                 return NULL;
 360
 361         /* "foo + 0" is just "foo" */
 362         if (expr->type == EXPR_BINOP && expr->op == '+' &&
 363             get_value(expr->right, &sval) && sval.value == 0)
 364                 return expr->left;
 365
 366         return expr;
 367 }
 368
 369 static int is_last_member_of_struct(struct symbol *sym, struct ident *member)
 370 {
 371         struct symbol *tmp;
 372         int i;
 373
 374         if (sym->type != SYM_STRUCT)
 375                 return false;
 376
 377         i = 0;
 378         FOR_EACH_PTR_REVERSE(sym->symbol_list, tmp) {
 379                 if (i++ || !tmp->ident)
 380                         return 0;
 381                 if (tmp->ident == member)
 382                         return 1;
 383                 return 0;
 384         } END_FOR_EACH_PTR_REVERSE(tmp);
 385
 386         return 0;
 387 }
 388
 389 int last_member_is_resizable(struct symbol *sym)
 390 {
 391         struct symbol *last_member;
 392         struct symbol *type;
 393         sval_t sval;
 394
 395         if (!sym || sym->type != SYM_STRUCT)
 396                 return 0;
 397
 398         last_member = last_ptr_list((struct ptr_list *)sym->symbol_list);
 399         if (!last_member || !last_member->ident)
 400                 return 0;
 401
 402         type = get_real_base_type(last_member);
 403         if (type->type == SYM_STRUCT)
 404                 return last_member_is_resizable(type);
 405         if (type->type != SYM_ARRAY)
 406                 return 0;
 407
 408         if (!type->array_size)
 409                 return 1;
 410
 411         if (!get_implied_value(type->array_size, &sval))
 412                 return 0;
 413
 414         if (sval.value != 0 && sval.value != 1)
 415                 return 0;
 416
 417         return 1;
 418 }
 419
 420 static struct range_list *get_stored_size_end_struct_bytes(struct expression *expr)
 421 {
 422         struct symbol *sym;
 423         struct symbol *base_sym;
 424         struct smatch_state *state;
 425         sval_t base_size = {
 426                 .type = &int_ctype,
 427         };
 428
 429         if (expr->type == EXPR_BINOP) /* array elements foo[5] */
 430                 return NULL;
 431
 432         if (expr->type == EXPR_PREOP && expr->op == '&')
 433                 expr = strip_parens(expr->unop);
 434
 435         sym = expr_to_sym(expr);
 436         if (!sym || !sym->ident)
 437                 return NULL;
 438         if (!type_bytes(sym))
 439                 return NULL;
 440         if (sym->type != SYM_NODE)
 441                 return NULL;
 442
 443         base_sym = get_real_base_type(sym);
 444         if (!base_sym || base_sym->type != SYM_PTR)
 445                 return NULL;
 446         base_sym = get_real_base_type(base_sym);
 447         if (!base_sym || base_sym->type != SYM_STRUCT)
 448                 return NULL;
 449
 450         if (!is_last_member_of_struct(base_sym, expr->member))
 451                 return NULL;
 452         if (!last_member_is_resizable(base_sym))
 453                 return NULL;
 454
 455         state = get_state(my_size_id, sym->ident->name, sym);
 456         if (!estate_rl(state))
 457                 return NULL;
 458         base_size.value = type_bytes(base_sym) - type_bytes(get_type(expr));
 459         if (sval_cmp(estate_min(state), base_size) < 0)
 460                 return NULL;
 461
 462         return rl_binop(estate_rl(state), '-', alloc_rl(base_size, base_size));
 463 }
 464
 465 static int get_last_element_bytes(struct expression *expr)
 466 {
 467         struct symbol *type, *member, *member_type;
 468
 469         type = get_type(expr);
 470         if (!type || type->type != SYM_STRUCT)
 471                 return 0;
 472         member = last_ptr_list((struct ptr_list *)type->symbol_list);
 473         if (!member)
 474                 return 0;
 475         member_type = get_real_base_type(member);
 476         if (!member_type)
 477                 return 0;
 478         return type_bytes(member_type);
 479 }
 480
 481 static struct range_list *get_outer_end_struct_bytes(struct expression *expr)
 482 {
 483         struct expression *outer;
 484         int last_element_size;
 485         struct symbol *type;
 486         sval_t bytes = {
 487                 .type = &int_ctype,
 488         };
 489
 490         /*
 491          * What we're checking here is for when "u.bar.baz" is a zero element
 492          * array and "u" has a buffer to determine the space for baz.  Like
 493          * this:
 494          * struct { struct bar bar; char buf[256]; } u;
 495          *
 496          */
 497
 498         if (expr->type == EXPR_PREOP && expr->op == '&')
 499                 expr = strip_parens(expr->unop);
 500         if (expr->type != EXPR_DEREF)
 501                 return NULL;
 502         outer = expr->deref;
 503         if (outer->type != EXPR_DEREF)
 504                 return NULL;
 505         type = get_type(outer);
 506         if (!type)
 507                 return NULL;
 508
 509         if (!is_last_member_of_struct(type, expr->member))
 510                 return NULL;
 511         if (!last_member_is_resizable(type))
 512                 return NULL;
 513
 514         last_element_size = get_last_element_bytes(outer->deref);
 515         if (last_element_size == 0)
 516                 return NULL;
 517         if (type_bytes(get_type(outer)) + last_element_size !=
 518             type_bytes(get_type(outer->deref)))
 519                 return NULL;
 520
 521         bytes.value = last_element_size;
 522         return alloc_rl(bytes, bytes);
 523 }
 524
 525 static struct range_list *alloc_int_rl(int value)
 526 {
 527         sval_t sval = {
 528                 .type = &int_ctype,
 529                 {.value = value},
 530         };
 531
 532         return alloc_rl(sval, sval);
 533 }
 534
 535 struct range_list *get_array_size_bytes_rl(struct expression *expr)
 536 {
 537         struct range_list *ret = NULL;
 538         sval_t sval;
 539         int size;
 540
 541         if (is_fake_call(expr))
 542                 return NULL;
 543
 544         expr = remove_addr_fluff(expr);
 545         if (!expr)
 546                 return NULL;
 547
 548         /* "BAR" */
 549         if (expr->type == EXPR_STRING)
 550                 return alloc_int_rl(expr->string->length);
 551
 552         if (expr->type == EXPR_BINOP && expr->op == '+') {
 553                 sval_t offset;
 554                 struct symbol *type;
 555                 int bytes;
 556
 557                 if (!get_implied_value(expr->right, &offset))
 558                         return NULL;
 559                 type = get_type(expr->left);
 560                 if (!type)
 561                         return NULL;
 562                 if (type->type != SYM_ARRAY && type->type != SYM_PTR)
 563                         return NULL;
 564                 type = get_real_base_type(type);
 565                 bytes = type_bytes(type);
 566                 if (bytes == 0)
 567                         return NULL;
 568                 offset.value *= bytes;
 569                 size = get_array_size_bytes(expr->left);
 570                 if (size <= 0)
 571                         return NULL;
 572                 return alloc_int_rl(size - offset.value);
 573         }
 574
 575         /* buf = malloc(1024); */
 576         ret = get_stored_size_bytes(expr);
 577         if (ret)
 578                 return ret;
 579
 580         ret = get_stored_size_end_struct_bytes(expr);
 581         if (ret)
 582                 return ret;
 583
 584         ret = get_outer_end_struct_bytes(expr);
 585         if (ret)
 586                 return ret;
 587
 588         /* buf[4] */
 589         size = get_real_array_size(expr);
 590         if (size)
 591                 return alloc_int_rl(elements_to_bytes(expr, size));
 592
 593         /* char *foo = "BAR" */
 594         size = get_size_from_initializer(expr);
 595         if (size)
 596                 return alloc_int_rl(elements_to_bytes(expr, size));
 597
 598         size = get_bytes_from_address(expr);
 599         if (size)
 600                 return alloc_int_rl(size);
 601
 602         ret = size_from_db(expr);
 603         if (rl_to_sval(ret, &sval) && sval.value == -1)
 604                 return NULL;
 605         if (ret)
 606                 return ret;
 607
 608         return NULL;
 609 }
 610
 611 int get_array_size_bytes(struct expression *expr)
 612 {
 613         struct range_list *rl;
 614         sval_t sval;
 615
 616         rl = get_array_size_bytes_rl(expr);
 617         if (!rl_to_sval(rl, &sval))
 618                 return 0;
 619         if (sval.uvalue >= INT_MAX)
 620                 return 0;
 621         return sval.value;
 622 }
 623
 624 int get_array_size_bytes_max(struct expression *expr)
 625 {
 626         struct range_list *rl;
 627         sval_t bytes;
 628
 629         rl = get_array_size_bytes_rl(expr);
 630         if (!rl)
 631                 return 0;
 632         bytes = rl_min(rl);
 633         if (bytes.value < 0)
 634                 return 0;
 635         bytes = rl_max(rl);
 636         if (bytes.uvalue >= INT_MAX)
 637                 return 0;
 638         return bytes.value;
 639 }
 640
 641 int get_array_size_bytes_min(struct expression *expr)
 642 {
 643         struct range_list *rl;
 644         struct data_range *range;
 645
 646         rl = get_array_size_bytes_rl(expr);
 647         if (!rl)
 648                 return 0;
 649
 650         FOR_EACH_PTR(rl, range) {
 651                 if (range->min.value <= 0)
 652                         return 0;
 653                 if (range->max.value <= 0)
 654                         return 0;
 655                 if (range->min.uvalue >= INT_MAX)
 656                         return 0;
 657                 return range->min.value;
 658         } END_FOR_EACH_PTR(range);
 659
 660         return 0;
 661 }
 662
 663 int get_array_size(struct expression *expr)
 664 {
 665         if (!expr)
 666                 return 0;
 667         return bytes_to_elements(expr, get_array_size_bytes_max(expr));
 668 }
 669
 670 static struct expression *strip_ampersands(struct expression *expr)
 671 {
 672         struct symbol *type;
 673
 674         if (expr->type != EXPR_PREOP)
 675                 return expr;
 676         if (expr->op != '&')
 677                 return expr;
 678         type = get_type(expr->unop);
 679         if (!type || type->type != SYM_ARRAY)
 680                 return expr;
 681         return expr->unop;
 682 }
 683
 684 static void info_record_alloction(struct expression *buffer, struct range_list *rl)
 685 {
 686         char *name;
 687
 688         if (!option_info)
 689                 return;
 690
 691         name = get_member_name(buffer);
 692         if (!name && is_static(buffer))
 693                 name = expr_to_var(buffer);
 694         if (!name)
 695                 return;
 696         if (rl && !is_whole_rl(rl))
 697                 sql_insert_function_type_size(name, show_rl(rl));
 698         else
 699                 sql_insert_function_type_size(name, "(-1)");
 700
 701         free_string(name);
 702 }
 703
 704 static void store_alloc(struct expression *expr, struct range_list *rl)
 705 {
 706         struct symbol *type;
 707
 708         rl = clone_rl(rl); // FIXME!!!
 709         if (!rl)
 710                 rl = size_to_rl(UNKNOWN_SIZE);
 711
 712         if (rl_min(rl).value != UNKNOWN_SIZE ||
 713             rl_max(rl).value != UNKNOWN_SIZE ||
 714             get_state_expr(my_size_id, expr))
 715                 set_state_expr(my_size_id, expr, alloc_estate_rl(rl));
 716
 717         type = get_type(expr);
 718         if (!type)
 719                 return;
 720         if (type->type != SYM_PTR)
 721                 return;
 722         type = get_real_base_type(type);
 723         if (!type)
 724                 return;
 725         if (type == &void_ctype)
 726                 return;
 727         if (type->type != SYM_BASETYPE && type->type != SYM_PTR)
 728                 return;
 729
 730         info_record_alloction(expr, rl);
 731 }
 732
 733 static bool is_array_base(struct expression *expr)
 734 {
 735         struct symbol *type;
 736
 737         type = get_type(expr);
 738         if (type && type->type == SYM_ARRAY)
 739                 return true;
 740         return false;
 741 }
 742
 743 static void match_array_assignment(struct expression *expr)
 744 {
 745         struct expression *left;
 746         struct expression *right;
 747         char *left_member, *right_member;
 748         struct range_list *rl;
 749         sval_t sval;
 750
 751         if (expr->op != '=')
 752                 return;
 753
 754         left = strip_expr(expr->left);
 755         right = strip_expr(expr->right);
 756         right = strip_ampersands(right);
 757
 758         if (!is_pointer(left))
 759                 return;
 760         /* char buf[24] = "str"; */
 761         if (is_array_base(left))
 762                 return;
 763         if (is_allocation_function(right))
 764                 return;
 765
 766         left_member = get_member_name(left);
 767         right_member = get_member_name(right);
 768         if (left_member && right_member && strcmp(left_member, right_member) == 0) {
 769                 free_string(left_member);
 770                 free_string(right_member);
 771                 return;
 772         }
 773         free_string(left_member);
 774         free_string(right_member);
 775
 776         if (get_implied_value(right, &sval) && sval.value == 0) {
 777                 rl = alloc_int_rl(0);
 778                 goto store;
 779         }
 780
 781         rl = get_array_size_bytes_rl(right);
 782         if (!rl && __in_fake_assign)
 783                 return;
 784
 785 store:
 786         store_alloc(left, rl);
 787 }
 788
 789 static void match_alloc(const char *fn, struct expression *expr, void *_size_arg)
 790 {
 791         int size_arg = PTR_INT(_size_arg);
 792         struct expression *right;
 793         struct expression *arg;
 794         struct range_list *rl;
 795
 796         right = strip_expr(expr->right);
 797         arg = get_argument_from_call_expr(right->args, size_arg);
 798         get_absolute_rl(arg, &rl);
 799         rl = cast_rl(&int_ctype, rl);
 800         store_alloc(expr->left, rl);
 801 }
 802
 803 static void match_calloc(const char *fn, struct expression *expr, void *_param)
 804 {
 805         struct expression *right;
 806         struct expression *size, *nr, *mult;
 807         struct range_list *rl;
 808         int param = PTR_INT(_param);
 809
 810         right = strip_expr(expr->right);
 811         nr = get_argument_from_call_expr(right->args, param);
 812         size = get_argument_from_call_expr(right->args, param + 1);
 813         mult = binop_expression(nr, '*', size);
 814         if (get_implied_rl(mult, &rl))
 815                 store_alloc(expr->left, rl);
 816         else
 817                 store_alloc(expr->left, size_to_rl(UNKNOWN_SIZE));
 818 }
 819
 820 static void match_page(const char *fn, struct expression *expr, void *_unused)
 821 {
 822         sval_t page_size = {
 823                 .type = &int_ctype,
 824                 {.value = 4096},
 825         };
 826
 827         store_alloc(expr->left, alloc_rl(page_size, page_size));
 828 }
 829
 830 static void match_strndup(const char *fn, struct expression *expr, void *unused)
 831 {
 832         struct expression *fn_expr;
 833         struct expression *size_expr;
 834         sval_t size;
 835
 836         fn_expr = strip_expr(expr->right);
 837         size_expr = get_argument_from_call_expr(fn_expr->args, 1);
 838         if (get_implied_max(size_expr, &size)) {
 839                 size.value++;
 840                 store_alloc(expr->left, size_to_rl(size.value));
 841         } else {
 842                 store_alloc(expr->left, size_to_rl(UNKNOWN_SIZE));
 843         }
 844
 845 }
 846
 847 static void match_alloc_pages(const char *fn, struct expression *expr, void *_order_arg)
 848 {
 849         int order_arg = PTR_INT(_order_arg);
 850         struct expression *right;
 851         struct expression *arg;
 852         sval_t sval;
 853
 854         right = strip_expr(expr->right);
 855         arg = get_argument_from_call_expr(right->args, order_arg);
 856         if (!get_implied_value(arg, &sval))
 857                 return;
 858         if (sval.value < 0 || sval.value > 10)
 859                 return;
 860
 861         sval.type = &int_ctype;
 862         sval.value = 1 << sval.value;
 863         sval.value *= 4096;
 864
 865         store_alloc(expr->left, alloc_rl(sval, sval));
 866 }
 867
 868 static int is_type_bytes(struct range_list *rl, struct expression *call, int nr)
 869 {
 870         struct symbol *type;
 871         sval_t sval;
 872
 873         if (!rl_to_sval(rl, &sval))
 874                 return 0;
 875
 876         type = get_arg_type(call->fn, nr);
 877         if (!type)
 878                 return 0;
 879         if (type->type != SYM_PTR)
 880                 return 0;
 881         type = get_real_base_type(type);
 882         if (sval.value != type_bytes(type))
 883                 return 0;
 884         return 1;
 885 }
 886
 887 static void match_call(struct expression *expr)
 888 {
 889         struct expression *arg;
 890         struct symbol *type;
 891         struct range_list *rl;
 892         int i;
 893
 894         i = -1;
 895         FOR_EACH_PTR(expr->args, arg) {
 896                 i++;
 897                 type = get_type(arg);
 898                 if (!type || (type->type != SYM_PTR && type->type != SYM_ARRAY))
 899                         continue;
 900                 rl = get_array_size_bytes_rl(arg);
 901                 if (!rl)
 902                         continue;
 903                 if (rl_min(rl).value == UNKNOWN_SIZE &&
 904                     rl_max(rl).value == UNKNOWN_SIZE)
 905                         continue;
 906                 if (is_whole_rl(rl))
 907                         continue;
 908                 if (is_type_bytes(rl, expr, i))
 909                         continue;
 910                 sql_insert_caller_info(expr, BUF_SIZE, i, "$", show_rl(rl));
 911         } END_FOR_EACH_PTR(arg);
 912 }
 913
 914 static void struct_member_callback(struct expression *call, int param, char *printed_name, struct sm_state *sm)
 915 {
 916         sval_t sval;
 917
 918         if (!estate_rl(sm->state) ||
 919             (estate_get_single_value(sm->state, &sval) &&
 920              (sval.value == -1 || sval.value == 0)))
 921                 return;
 922
 923         sql_insert_caller_info(call, BUF_SIZE, param, printed_name, sm->state->name);
 924 }
 925
 926 /*
 927  * This is slightly (very) weird because half of this stuff is handled in
 928  * smatch_parse_call_math.c which is poorly named.  But anyway, add some buf
 929  * sizes here.
 930  *
 931  */
 932 static void print_returned_allocations(int return_id, char *return_ranges, struct expression *expr)
 933 {
 934         const char *param_math;
 935         struct range_list *rl;
 936         char buf[64];
 937         sval_t sval;
 938
 939         rl = get_array_size_bytes_rl(expr);
 940         param_math = get_allocation_math(expr);
 941         if (!rl && !param_math)
 942                 return;
 943
 944         if (!param_math &&
 945             rl_to_sval(rl, &sval) &&
 946             (sval.value == -1 || sval.value == 0))
 947                 return;
 948
 949         if (param_math)
 950                 snprintf(buf, sizeof(buf), "%s[%s]", show_rl(rl), param_math);
 951         else
 952                 snprintf(buf, sizeof(buf), "%s", show_rl(rl));
 953
 954         // FIXME: don't store if you can guess the size from the type
 955         // FIXME: return if we allocate a parameter $0->bar
 956         sql_insert_return_states(return_id, return_ranges, BUF_SIZE, -1, "", buf);
 957 }
 958
 959 static void record_global_size(struct symbol *sym)
 960 {
 961         int bytes;
 962         char buf[16];
 963
 964         if (!sym->ident)
 965                 return;
 966
 967         if (!(sym->ctype.modifiers & MOD_TOPLEVEL) ||
 968             sym->ctype.modifiers & MOD_STATIC)
 969                 return;
 970
 971         bytes = get_array_size_bytes(symbol_expression(sym));
 972         if (bytes <= 1)
 973                 return;
 974
 975         snprintf(buf, sizeof(buf), "%d", bytes);
 976         sql_insert_data_info_var_sym(sym->ident->name, sym, BUF_SIZE, buf);
 977 }
 978
 979 void register_buf_size(int id)
 980 {
 981         my_size_id = id;
 982
 983         set_dynamic_states(my_size_id);
 984
 985         add_unmatched_state_hook(my_size_id, &unmatched_size_state);
 986         add_merge_hook(my_size_id, &merge_estates);
 987
 988         select_caller_info_hook(set_param_buf_size, BUF_SIZE);
 989         select_return_states_hook(BUF_SIZE, &db_returns_buf_size);
 990         add_split_return_callback(print_returned_allocations);
 991
 992         allocation_funcs = create_function_hashtable(100);
 993         add_allocation_function("malloc", &match_alloc, 0);
 994         add_allocation_function("calloc", &match_calloc, 0);
 995         add_allocation_function("memdup", &match_alloc, 1);
 996         add_allocation_function("realloc", &match_alloc, 1);
 997         if (option_project == PROJ_KERNEL) {
 998                 add_allocation_function("kmalloc", &match_alloc, 0);
 999                 add_allocation_function("kmalloc_node", &match_alloc, 0);
1000                 add_allocation_function("kzalloc", &match_alloc, 0);
1001                 add_allocation_function("kzalloc_node", &match_alloc, 0);
1002                 add_allocation_function("vmalloc", &match_alloc, 0);
1003                 add_allocation_function("vzalloc", &match_alloc, 0);
1004                 add_allocation_function("__vmalloc", &match_alloc, 0);
1005                 add_allocation_function("kvmalloc", &match_alloc, 0);
1006                 add_allocation_function("kcalloc", &match_calloc, 0);
1007                 add_allocation_function("kvcalloc", &match_calloc, 0);
1008                 add_allocation_function("kmalloc_array", &match_calloc, 0);
1009                 add_allocation_function("devm_kmalloc_array", &match_calloc, 1);
1010                 add_allocation_function("sock_kmalloc", &match_alloc, 1);
1011                 add_allocation_function("kmemdup", &match_alloc, 1);
1012                 add_allocation_function("kmemdup_user", &match_alloc, 1);
1013                 add_allocation_function("dma_alloc_attrs", &match_alloc, 1);
1014                 add_allocation_function("pci_alloc_consistent", &match_alloc, 1);
1015                 add_allocation_function("pci_alloc_coherent", &match_alloc, 1);
1016                 add_allocation_function("devm_kmalloc", &match_alloc, 1);
1017                 add_allocation_function("devm_kzalloc", &match_alloc, 1);
1018                 add_allocation_function("krealloc", &match_alloc, 1);
1019                 add_allocation_function("__alloc_bootmem", &match_alloc, 0);
1020                 add_allocation_function("alloc_bootmem", &match_alloc, 0);
1021                 add_allocation_function("kmap", &match_page, 0);
1022                 add_allocation_function("kmap_atomic", &match_page, 0);
1023                 add_allocation_function("get_zeroed_page", &match_page, 0);
1024                 add_allocation_function("alloc_page", &match_page, 0);
1025                 add_allocation_function("alloc_pages", &match_alloc_pages, 1);
1026                 add_allocation_function("alloc_pages_current", &match_alloc_pages, 1);
1027                 add_allocation_function("__get_free_pages", &match_alloc_pages, 1);
1028                 add_allocation_function("dma_alloc_contiguous", &match_alloc, 1);
1029                 add_allocation_function("dma_alloc_coherent", &match_alloc, 1);
1030         }
1031
1032         add_allocation_function("strndup", match_strndup, 0);
1033         if (option_project == PROJ_KERNEL)
1034                 add_allocation_function("kstrndup", match_strndup, 0);
1035
1036         add_modification_hook(my_size_id, &set_size_undefined);
1037
1038         add_merge_hook(my_size_id, &merge_size_func);
1039
1040         if (option_info)
1041                 add_hook(record_global_size, BASE_HOOK);
1042 }
1043
1044 void register_buf_size_late(int id)
1045 {
1046         /* has to happen after match_alloc() */
1047         add_hook(&match_array_assignment, ASSIGNMENT_HOOK);
1048
1049         add_hook(&match_call, FUNCTION_CALL_HOOK);
1050         add_member_info_callback(my_size_id, struct_member_callback);
1051 }