smatch_kernel_user_data.c

   1 /*
   2  * Copyright (C) 2011 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 /*
  19  * There are a couple checks that try to see if a variable
  20  * comes from the user.  It would be better to unify them
  21  * into one place.  Also it we should follow the data down
  22  * the call paths.  Hence this file.
  23  */
  24
  25 #include "smatch.h"
  26 #include "smatch_slist.h"
  27 #include "smatch_extra.h"
  28
  29 static int my_id;
  30 static int my_call_id;
  31
  32 STATE(called);
  33 static unsigned long func_gets_user_data;
  34
  35 static const char *kstr_funcs[] = {
  36         "kstrtoull", "kstrtoll", "kstrtoul", "kstrtol", "kstrtouint",
  37         "kstrtoint", "kstrtou64", "kstrtos64", "kstrtou32", "kstrtos32",
  38         "kstrtou16", "kstrtos16", "kstrtou8", "kstrtos8", "kstrtoull_from_user"
  39         "kstrtoll_from_user", "kstrtoul_from_user", "kstrtol_from_user",
  40         "kstrtouint_from_user", "kstrtoint_from_user", "kstrtou16_from_user",
  41         "kstrtos16_from_user", "kstrtou8_from_user", "kstrtos8_from_user",
  42         "kstrtou64_from_user", "kstrtos64_from_user", "kstrtou32_from_user",
  43         "kstrtos32_from_user",
  44 };
  45
  46 static const char *returns_user_data[] = {
  47         "simple_strtol", "simple_strtoll", "simple_strtoul", "simple_strtoull",
  48         "kvm_register_read", "xdr_inline_decode",
  49 };
  50
  51 static struct smatch_state *empty_state(struct sm_state *sm)
  52 {
  53         return alloc_estate_empty();
  54 }
  55
  56 static struct smatch_state *new_state(struct symbol *type)
  57 {
  58         struct smatch_state *state;
  59
  60         if (!type || type_is_ptr(type))
  61                 return NULL;
  62
  63         state = alloc_estate_whole(type);
  64         estate_set_new(state);
  65         return state;
  66 }
  67
  68 static void pre_merge_hook(struct sm_state *cur, struct sm_state *other)
  69 {
  70         struct smatch_state *user = cur->state;
  71         struct smatch_state *extra;
  72         struct smatch_state *state;
  73         struct range_list *rl;
  74
  75         extra = __get_state(SMATCH_EXTRA, cur->name, cur->sym);
  76         if (!extra)
  77                 return;
  78         rl = rl_intersection(estate_rl(user), estate_rl(extra));
  79         state = alloc_estate_rl(clone_rl(rl));
  80         if (estate_capped(user) || is_capped_var_sym(cur->name, cur->sym))
  81                 estate_set_capped(state);
  82         if (estate_treat_untagged(user))
  83                 estate_set_treat_untagged(state);
  84         if (estates_equiv(state, cur->state))
  85                 return;
  86         if (estate_new(cur->state))
  87                 estate_set_new(state);
  88         set_state(my_id, cur->name, cur->sym, state);
  89 }
  90
  91 static void extra_nomod_hook(const char *name, struct symbol *sym, struct expression *expr, struct smatch_state *state)
  92 {
  93         struct smatch_state *user, *new;
  94         struct range_list *rl;
  95
  96         user = __get_state(my_id, name, sym);
  97         if (!user)
  98                 return;
  99         rl = rl_intersection(estate_rl(user), estate_rl(state));
 100         if (rl_equiv(rl, estate_rl(user)))
 101                 return;
 102         new = alloc_estate_rl(rl);
 103         if (estate_capped(user))
 104                 estate_set_capped(new);
 105         if (estate_treat_untagged(user))
 106                 estate_set_treat_untagged(new);
 107         set_state(my_id, name, sym, new);
 108 }
 109
 110 static void store_type_info(struct expression *expr, struct smatch_state *state)
 111 {
 112         struct symbol *type;
 113         char *type_str, *member;
 114
 115         if (__in_fake_assign)
 116                 return;
 117
 118         if (!estate_rl(state))
 119                 return;
 120
 121         expr = strip_expr(expr);
 122         if (!expr || expr->type != EXPR_DEREF || !expr->member)
 123                 return;
 124
 125         type = get_type(expr->deref);
 126         if (!type || !type->ident)
 127                 return;
 128
 129         type_str = type_to_str(type);
 130         if (!type_str)
 131                 return;
 132         member = get_member_name(expr);
 133         if (!member)
 134                 return;
 135
 136         sql_insert_function_type_info(USER_DATA, type_str, member, state->name);
 137 }
 138
 139 static void set_user_data(struct expression *expr, struct smatch_state *state)
 140 {
 141         store_type_info(expr, state);
 142         set_state_expr(my_id, expr, state);
 143 }
 144
 145 static bool user_rl_known(struct expression *expr)
 146 {
 147         struct range_list *rl;
 148         sval_t close_to_max;
 149
 150         if (!get_user_rl(expr, &rl))
 151                 return true;
 152
 153         close_to_max = sval_type_max(rl_type(rl));
 154         close_to_max.value -= 100;
 155
 156         if (sval_cmp(rl_max(rl), close_to_max) >= 0)
 157                 return false;
 158         return true;
 159 }
 160
 161 static bool is_array_index_mask_nospec(struct expression *expr)
 162 {
 163         struct expression *orig;
 164
 165         orig = get_assigned_expr(expr);
 166         if (!orig || orig->type != EXPR_CALL)
 167                 return false;
 168         return sym_name_is("array_index_mask_nospec", orig->fn);
 169 }
 170
 171 static bool binop_capped(struct expression *expr)
 172 {
 173         struct range_list *left_rl;
 174         int comparison;
 175         sval_t sval;
 176
 177         if (expr->op == '-' && get_user_rl(expr->left, &left_rl)) {
 178                 if (user_rl_capped(expr->left))
 179                         return true;
 180                 comparison = get_comparison(expr->left, expr->right);
 181                 if (comparison && show_special(comparison)[0] == '>')
 182                         return true;
 183                 return false;
 184         }
 185
 186         if (expr->op == '&' || expr->op == '%') {
 187                 bool left_user, left_capped, right_user, right_capped;
 188
 189                 if (!get_value(expr->right, &sval) && is_capped(expr->right))
 190                         return true;
 191                 if (is_array_index_mask_nospec(expr->right))
 192                         return true;
 193                 if (is_capped(expr->left))
 194                         return true;
 195                 left_user = is_user_rl(expr->left);
 196                 right_user = is_user_rl(expr->right);
 197                 if (!left_user && !right_user)
 198                         return true;
 199
 200                 left_capped = user_rl_capped(expr->left);
 201                 right_capped = user_rl_capped(expr->right);
 202
 203                 if (left_user && left_capped) {
 204                         if (!right_user)
 205                                 return true;
 206                         if (right_user && right_capped)
 207                                 return true;
 208                         return false;
 209                 }
 210                 if (right_user && right_capped) {
 211                         if (!left_user)
 212                                 return true;
 213                         return false;
 214                 }
 215                 return false;
 216         }
 217
 218         /*
 219          * Generally "capped" means that we capped it to an unknown value.
 220          * This is useful because if Smatch doesn't know what the value is then
 221          * we have to trust that it is correct.  But if we known cap value is
 222          * 100 then we can check if 100 is correct and complain if it's wrong.
 223          *
 224          * So then the problem is with BINOP when we take a capped variable
 225          * plus a user variable which is clamped to a known range (uncapped)
 226          * the result should be capped.
 227          */
 228         if ((user_rl_capped(expr->left) || user_rl_known(expr->left)) &&
 229             (user_rl_capped(expr->right) || user_rl_known(expr->right)))
 230                 return true;
 231
 232         return false;
 233 }
 234
 235 bool user_rl_capped_var_sym(const char *name, struct symbol *sym)
 236 {
 237         struct smatch_state *state;
 238
 239         state = get_state(my_id, name, sym);
 240         if (state)
 241                 return estate_capped(state);
 242
 243         return true;
 244 }
 245
 246 bool user_rl_capped(struct expression *expr)
 247 {
 248         struct smatch_state *state;
 249         struct range_list *rl;
 250         sval_t sval;
 251
 252         expr = strip_expr(expr);
 253         if (!expr)
 254                 return false;
 255         if (get_value(expr, &sval))
 256                 return true;
 257         if (expr->type == EXPR_BINOP)
 258                 return binop_capped(expr);
 259         if ((expr->type == EXPR_PREOP || expr->type == EXPR_POSTOP) &&
 260             (expr->op == SPECIAL_INCREMENT || expr->op == SPECIAL_DECREMENT))
 261                 return user_rl_capped(expr->unop);
 262         state = get_state_expr(my_id, expr);
 263         if (state)
 264                 return estate_capped(state);
 265
 266         if (!get_user_rl(expr, &rl)) {
 267                 /*
 268                  * The non user data parts of a binop are capped and
 269                  * also empty user rl states are capped.
 270                  */
 271                 return true;
 272         }
 273
 274         if (rl_to_sval(rl, &sval))
 275                 return true;
 276
 277         return false;  /* uncapped user data */
 278 }
 279
 280 bool user_rl_treat_untagged(struct expression *expr)
 281 {
 282         struct smatch_state *state;
 283         struct range_list *rl;
 284         sval_t sval;
 285
 286         expr = strip_expr(expr);
 287         if (!expr)
 288                 return false;
 289         if (get_value(expr, &sval))
 290                 return true;
 291
 292         state = get_state_expr(my_id, expr);
 293         if (state)
 294                 return estate_treat_untagged(state);
 295
 296         if (get_user_rl(expr, &rl))
 297                 return false;  /* uncapped user data */
 298
 299         return true;  /* not actually user data */
 300 }
 301
 302 static void tag_inner_struct_members(struct expression *expr, struct symbol *member)
 303 {
 304         struct expression *edge_member;
 305         struct symbol *base = get_real_base_type(member);
 306         struct symbol *tmp;
 307
 308         if (member->ident)
 309                 expr = member_expression(expr, '.', member->ident);
 310
 311         FOR_EACH_PTR(base->symbol_list, tmp) {
 312                 struct symbol *type;
 313
 314                 type = get_real_base_type(tmp);
 315                 if (!type)
 316                         continue;
 317
 318                 if (type->type == SYM_UNION || type->type == SYM_STRUCT) {
 319                         tag_inner_struct_members(expr, tmp);
 320                         continue;
 321                 }
 322
 323                 if (!tmp->ident)
 324                         continue;
 325
 326                 edge_member = member_expression(expr, '.', tmp->ident);
 327                 set_user_data(edge_member, new_state(type));
 328         } END_FOR_EACH_PTR(tmp);
 329 }
 330
 331 void __set_user_string(struct expression *expr);
 332 static void tag_struct_members(struct symbol *type, struct expression *expr)
 333 {
 334         struct symbol *tmp;
 335         struct expression *member;
 336         int op = '*';
 337
 338         if (expr->type == EXPR_PREOP && expr->op == '&') {
 339                 expr = strip_expr(expr->unop);
 340                 op = '.';
 341         }
 342
 343         FOR_EACH_PTR(type->symbol_list, tmp) {
 344                 type = get_real_base_type(tmp);
 345                 if (!type)
 346                         continue;
 347
 348                 if (type->type == SYM_UNION || type->type == SYM_STRUCT) {
 349                         tag_inner_struct_members(expr, tmp);
 350                         continue;
 351                 }
 352
 353                 if (!tmp->ident)
 354                         continue;
 355
 356                 member = member_expression(expr, op, tmp->ident);
 357                 if (type->type == SYM_ARRAY) {
 358                         set_points_to_user_data(member, true);
 359                 } else {
 360                         set_user_data(member, new_state(get_type(member)));
 361                 }
 362         } END_FOR_EACH_PTR(tmp);
 363 }
 364
 365 static void tag_base_type(struct expression *expr)
 366 {
 367         if (expr->type == EXPR_PREOP && expr->op == '&')
 368                 expr = strip_expr(expr->unop);
 369         else
 370                 expr = deref_expression(expr);
 371         set_user_data(expr, new_state(get_type(expr)));
 372 }
 373
 374 static void tag_as_user_data(struct expression *expr)
 375 {
 376         struct symbol *type;
 377
 378         expr = strip_expr(expr);
 379
 380         type = get_type(expr);
 381         if (!type || type->type != SYM_PTR)
 382                 return;
 383         type = get_real_base_type(type);
 384         if (!type)
 385                 return;
 386         if (type == &void_ctype) {
 387                 set_user_data(deref_expression(expr), new_state(&ulong_ctype));
 388                 return;
 389         }
 390         if (type->type == SYM_BASETYPE) {
 391                 if (expr->type != EXPR_PREOP && expr->op != '&')
 392                         set_points_to_user_data(expr, true);
 393                 tag_base_type(expr);
 394                 return;
 395         }
 396         if (type->type == SYM_STRUCT || type->type == SYM_UNION) {
 397                 if (expr->type != EXPR_PREOP || expr->op != '&')
 398                         expr = deref_expression(expr);
 399                 else
 400                         set_user_data(deref_expression(expr), new_state(&ulong_ctype));
 401                 tag_struct_members(type, expr);
 402         }
 403 }
 404
 405 static struct expression *ignore_param_set;
 406 static void match_user_copy(const char *fn, struct expression *expr, void *_param)
 407 {
 408         int param = PTR_INT(_param);
 409         struct expression *dest;
 410
 411         func_gets_user_data = true;
 412         ignore_param_set = expr;
 413
 414         dest = get_argument_from_call_expr(expr->args, param);
 415         dest = strip_expr(dest);
 416         if (!dest)
 417                 return;
 418         tag_as_user_data(dest);
 419 }
 420
 421 static int is_dev_attr_name(struct expression *expr)
 422 {
 423         char *name;
 424         int ret = 0;
 425
 426         name = expr_to_str(expr);
 427         if (!name)
 428                 return 0;
 429         if (strstr(name, "->attr.name"))
 430                 ret = 1;
 431         free_string(name);
 432         return ret;
 433 }
 434
 435 static int ends_in_n(struct expression *expr)
 436 {
 437         struct string *str;
 438
 439         if (!expr)
 440                 return 0;
 441         if (expr->type != EXPR_STRING || !expr->string)
 442                 return 0;
 443
 444         str = expr->string;
 445         if (str->length < 3)
 446                 return 0;
 447
 448         if (str->data[str->length - 3] == '%' &&
 449             str->data[str->length - 2] == 'n')
 450                 return 1;
 451         return 0;
 452 }
 453
 454 static void match_sscanf(const char *fn, struct expression *expr, void *unused)
 455 {
 456         struct expression *str, *format, *arg;
 457         int i, last;
 458
 459         func_gets_user_data = true;
 460
 461         str = get_argument_from_call_expr(expr->args, 0);
 462         if (is_dev_attr_name(str))
 463                 return;
 464
 465         format = get_argument_from_call_expr(expr->args, 1);
 466         if (is_dev_attr_name(format))
 467                 return;
 468
 469         last = ptr_list_size((struct ptr_list *)expr->args) - 1;
 470
 471         i = -1;
 472         FOR_EACH_PTR(expr->args, arg) {
 473                 i++;
 474                 if (i < 2)
 475                         continue;
 476                 if (i == last && ends_in_n(format))
 477                         continue;
 478                 tag_as_user_data(arg);
 479         } END_FOR_EACH_PTR(arg);
 480 }
 481
 482 static int get_rl_from_function(struct expression *expr, struct range_list **rl)
 483 {
 484         int i;
 485
 486         if (expr->type != EXPR_CALL || expr->fn->type != EXPR_SYMBOL ||
 487             !expr->fn->symbol_name || !expr->fn->symbol_name->name)
 488                 return 0;
 489
 490         for (i = 0; i < ARRAY_SIZE(returns_user_data); i++) {
 491                 if (strcmp(expr->fn->symbol_name->name, returns_user_data[i]) == 0) {
 492                         *rl = alloc_whole_rl(get_type(expr));
 493                         return 1;
 494                 }
 495         }
 496         return 0;
 497 }
 498
 499 static int comes_from_skb_data(struct expression *expr)
 500 {
 501         expr = strip_expr(expr);
 502         if (!expr || expr->type != EXPR_PREOP || expr->op != '*')
 503                 return 0;
 504
 505         expr = strip_expr(expr->unop);
 506         if (!expr)
 507                 return 0;
 508         if (expr->type == EXPR_BINOP && expr->op == '+')
 509                 expr = strip_expr(expr->left);
 510
 511         return is_skb_data(expr);
 512 }
 513
 514 static int handle_get_user(struct expression *expr)
 515 {
 516         char *name;
 517         int ret = 0;
 518
 519         name = get_macro_name(expr->pos);
 520         if (!name || strcmp(name, "get_user") != 0)
 521                 return 0;
 522
 523         name = expr_to_var(expr->right);
 524         if (!name || (strcmp(name, "__val_gu") != 0 && strcmp(name, "__gu_val") != 0))
 525                 goto free;
 526         set_user_data(expr->left, new_state(get_type(expr->left)));
 527         ret = 1;
 528 free:
 529         free_string(name);
 530         return ret;
 531 }
 532
 533 static bool state_is_new(struct expression *expr)
 534 {
 535         struct smatch_state *state;
 536
 537         state = get_state_expr(my_id, expr);
 538         if (estate_new(state))
 539                 return true;
 540
 541         if (expr->type == EXPR_BINOP) {
 542                 if (state_is_new(expr->left))
 543                         return true;
 544                 if (state_is_new(expr->right))
 545                         return true;
 546         }
 547         return false;
 548 }
 549
 550 static bool handle_op_assign(struct expression *expr)
 551 {
 552         struct expression *binop_expr;
 553         struct smatch_state *state;
 554         struct range_list *rl;
 555
 556         switch (expr->op) {
 557         case SPECIAL_ADD_ASSIGN:
 558         case SPECIAL_SUB_ASSIGN:
 559         case SPECIAL_AND_ASSIGN:
 560         case SPECIAL_MOD_ASSIGN:
 561         case SPECIAL_SHL_ASSIGN:
 562         case SPECIAL_SHR_ASSIGN:
 563         case SPECIAL_OR_ASSIGN:
 564         case SPECIAL_XOR_ASSIGN:
 565         case SPECIAL_MUL_ASSIGN:
 566         case SPECIAL_DIV_ASSIGN:
 567                 binop_expr = binop_expression(expr->left,
 568                                               op_remove_assign(expr->op),
 569                                               expr->right);
 570                 if (!get_user_rl(binop_expr, &rl))
 571                         return true;
 572
 573                 rl = cast_rl(get_type(expr->left), rl);
 574                 state = alloc_estate_rl(rl);
 575                 if (expr->op == SPECIAL_AND_ASSIGN ||
 576                     expr->op == SPECIAL_MOD_ASSIGN ||
 577                     user_rl_capped(binop_expr))
 578                         estate_set_capped(state);
 579                 if (user_rl_treat_untagged(expr->left))
 580                         estate_set_treat_untagged(state);
 581                 if (state_is_new(binop_expr))
 582                         estate_set_new(state);
 583                 estate_set_assigned(state);
 584                 set_user_data(expr->left, state);
 585                 return true;
 586         }
 587         return false;
 588 }
 589
 590 static void handle_derefed_pointers(struct expression *expr, bool is_new)
 591 {
 592         expr = strip_expr(expr);
 593         if (expr->type != EXPR_PREOP ||
 594             expr->op != '*')
 595                 return;
 596         expr = strip_expr(expr->unop);
 597         set_points_to_user_data(expr, is_new);
 598 }
 599
 600 static void match_assign(struct expression *expr)
 601 {
 602         struct symbol *left_type, *right_type;
 603         struct range_list *rl = NULL;
 604         static struct expression *handled;
 605         struct smatch_state *state;
 606         struct expression *faked;
 607         bool is_capped = false;
 608         bool is_new = false;
 609
 610         left_type = get_type(expr->left);
 611         if (left_type == &void_ctype)
 612                 return;
 613
 614         faked = get_faked_expression();
 615
 616         /* FIXME: handle fake array assignments frob(&user_array[x]); */
 617
 618         if (faked &&
 619             faked->type == EXPR_ASSIGNMENT &&
 620             points_to_user_data(faked->right)) {
 621                 if (is_skb_data(faked->right))
 622                         func_gets_user_data = true;
 623                 rl = alloc_whole_rl(get_type(expr->left));
 624                 is_new = true;
 625                 goto set;
 626         }
 627
 628         if (faked && faked == handled)
 629                 return;
 630         if (is_fake_call(expr->right))
 631                 goto clear_old_state;
 632         if (handle_get_user(expr))
 633                 return;
 634         if (points_to_user_data(expr->right) &&
 635             is_struct_ptr(get_type(expr->left))) {
 636                 handled = expr;
 637                 // This should be handled by smatch_points_to_user_data.c
 638                 // set_points_to_user_data(expr->left);
 639         }
 640
 641         if (handle_op_assign(expr))
 642                 return;
 643         if (expr->op != '=')
 644                 goto clear_old_state;
 645
 646         /* Handled by DB code */
 647         if (expr->right->type == EXPR_CALL)
 648                 return;
 649
 650         if (faked)
 651                 disable_type_val_lookups();
 652         get_user_rl(expr->right, &rl);
 653         if (faked)
 654                 enable_type_val_lookups();
 655         if (!rl)
 656                 goto clear_old_state;
 657
 658         is_capped = user_rl_capped(expr->right);
 659         is_new = state_is_new(expr->right);
 660
 661 set:
 662         if (type_is_ptr(left_type)) {
 663                 right_type = get_type(expr->right);
 664                 if (right_type && right_type->type == SYM_ARRAY)
 665                         set_points_to_user_data(expr->left, is_new);
 666                 return;
 667         }
 668
 669         rl = cast_rl(left_type, rl);
 670         state = alloc_estate_rl(rl);
 671         if (is_new)
 672                 estate_set_new(state);
 673         if (is_capped)
 674                 estate_set_capped(state);
 675         if (user_rl_treat_untagged(expr->right))
 676                 estate_set_treat_untagged(state);
 677         estate_set_assigned(state);
 678
 679         set_user_data(expr->left, state);
 680         handle_derefed_pointers(expr->left, is_new);
 681         return;
 682
 683 clear_old_state:
 684
 685         /*
 686          * HACK ALERT!!!  This should be at the start of the function.  The
 687          * the problem is that handling "pointer = array;" assignments is
 688          * handled in this function instead of in kernel_points_to_user_data.c.
 689          */
 690         if (type_is_ptr(left_type))
 691                 return;
 692
 693         if (get_state_expr(my_id, expr->left))
 694                 set_user_data(expr->left, alloc_estate_empty());
 695 }
 696
 697 static void handle_eq_noteq(struct expression *expr)
 698 {
 699         struct smatch_state *left_orig, *right_orig;
 700
 701         left_orig = get_state_expr(my_id, expr->left);
 702         right_orig = get_state_expr(my_id, expr->right);
 703
 704         if (!left_orig && !right_orig)
 705                 return;
 706         if (left_orig && right_orig)
 707                 return;
 708
 709         if (left_orig) {
 710                 set_true_false_states_expr(my_id, expr->left,
 711                                 expr->op == SPECIAL_EQUAL ? alloc_estate_empty() : NULL,
 712                                 expr->op == SPECIAL_EQUAL ? NULL : alloc_estate_empty());
 713         } else {
 714                 set_true_false_states_expr(my_id, expr->right,
 715                                 expr->op == SPECIAL_EQUAL ? alloc_estate_empty() : NULL,
 716                                 expr->op == SPECIAL_EQUAL ? NULL : alloc_estate_empty());
 717         }
 718 }
 719
 720 static struct range_list *strip_negatives(struct range_list *rl)
 721 {
 722         sval_t min = rl_min(rl);
 723         sval_t minus_one = { .type = rl_type(rl), .value = -1 };
 724         sval_t over = { .type = rl_type(rl), .value = INT_MAX + 1ULL };
 725         sval_t max = sval_type_max(rl_type(rl));
 726
 727         if (!rl)
 728                 return NULL;
 729
 730         if (type_unsigned(rl_type(rl)) && type_bits(rl_type(rl)) > 31)
 731                 return remove_range(rl, over, max);
 732
 733         return remove_range(rl, min, minus_one);
 734 }
 735
 736 static void handle_compare(struct expression *expr)
 737 {
 738         struct expression  *left, *right;
 739         struct range_list *left_rl = NULL;
 740         struct range_list *right_rl = NULL;
 741         struct range_list *user_rl;
 742         struct smatch_state *capped_state;
 743         struct smatch_state *left_true = NULL;
 744         struct smatch_state *left_false = NULL;
 745         struct smatch_state *right_true = NULL;
 746         struct smatch_state *right_false = NULL;
 747         struct symbol *type;
 748         sval_t sval;
 749
 750         left = strip_expr(expr->left);
 751         right = strip_expr(expr->right);
 752
 753         while (left->type == EXPR_ASSIGNMENT)
 754                 left = strip_expr(left->left);
 755
 756         /*
 757          * Conditions are mostly handled by smatch_extra.c, but there are some
 758          * times where the exact values are not known so we can't do that.
 759          *
 760          * Normally, we might consider using smatch_capped.c to supliment smatch
 761          * extra but that doesn't work when we merge unknown uncapped kernel
 762          * data with unknown capped user data.  The result is uncapped user
 763          * data.  We need to keep it separate and say that the user data is
 764          * capped.  In the past, I would have marked this as just regular
 765          * kernel data (not user data) but we can't do that these days because
 766          * we need to track user data for Spectre.
 767          *
 768          * The other situation which we have to handle is when we do have an
 769          * int and we compare against an unknown unsigned kernel variable.  In
 770          * that situation we assume that the kernel data is less than INT_MAX.
 771          * Otherwise then we get all sorts of array underflow false positives.
 772          *
 773          */
 774
 775         /* Handled in smatch_extra.c */
 776         if (get_implied_value(left, &sval) ||
 777             get_implied_value(right, &sval))
 778                 return;
 779
 780         get_user_rl(left, &left_rl);
 781         get_user_rl(right, &right_rl);
 782
 783         /* nothing to do */
 784         if (!left_rl && !right_rl)
 785                 return;
 786         /* if both sides are user data that's not a good limit */
 787         if (left_rl && right_rl)
 788                 return;
 789
 790         if (left_rl)
 791                 user_rl = left_rl;
 792         else
 793                 user_rl = right_rl;
 794
 795         type = get_type(expr);
 796         if (type_unsigned(type))
 797                 user_rl = strip_negatives(user_rl);
 798         capped_state = alloc_estate_rl(user_rl);
 799         estate_set_capped(capped_state);
 800
 801         switch (expr->op) {
 802         case '<':
 803         case SPECIAL_UNSIGNED_LT:
 804         case SPECIAL_LTE:
 805         case SPECIAL_UNSIGNED_LTE:
 806                 if (left_rl)
 807                         left_true = capped_state;
 808                 else
 809                         right_false = capped_state;
 810                 break;
 811         case '>':
 812         case SPECIAL_UNSIGNED_GT:
 813         case SPECIAL_GTE:
 814         case SPECIAL_UNSIGNED_GTE:
 815                 if (left_rl)
 816                         left_false = capped_state;
 817                 else
 818                         right_true = capped_state;
 819                 break;
 820         }
 821
 822         set_true_false_states_expr(my_id, left, left_true, left_false);
 823         set_true_false_states_expr(my_id, right, right_true, right_false);
 824 }
 825
 826 static void match_condition(struct expression *expr)
 827 {
 828         if (expr->type != EXPR_COMPARE)
 829                 return;
 830
 831         if (expr->op == SPECIAL_EQUAL ||
 832             expr->op == SPECIAL_NOTEQUAL) {
 833                 handle_eq_noteq(expr);
 834                 return;
 835         }
 836
 837         handle_compare(expr);
 838 }
 839
 840 static void match_returns_user_rl(const char *fn, struct expression *expr, void *unused)
 841 {
 842         func_gets_user_data = true;
 843 }
 844
 845 static int get_user_macro_rl(struct expression *expr, struct range_list **rl)
 846 {
 847         struct expression *parent;
 848         char *macro;
 849
 850         if (!expr)
 851                 return 0;
 852
 853         macro = get_macro_name(expr->pos);
 854         if (!macro)
 855                 return 0;
 856
 857         /* handle ntohl(foo[i]) where "i" is trusted */
 858         parent = expr_get_parent_expr(expr);
 859         while (parent && parent->type != EXPR_BINOP)
 860                 parent = expr_get_parent_expr(parent);
 861         if (parent && parent->type == EXPR_BINOP) {
 862                 char *parent_macro = get_macro_name(parent->pos);
 863
 864                 if (parent_macro && strcmp(macro, parent_macro) == 0)
 865                         return 0;
 866         }
 867
 868         if (strcmp(macro, "ntohl") == 0) {
 869                 *rl = alloc_whole_rl(&uint_ctype);
 870                 return 1;
 871         }
 872         if (strcmp(macro, "ntohs") == 0) {
 873                 *rl = alloc_whole_rl(&ushort_ctype);
 874                 return 1;
 875         }
 876         return 0;
 877 }
 878
 879 static int has_user_data(struct symbol *sym)
 880 {
 881         struct sm_state *tmp;
 882
 883         FOR_EACH_MY_SM(my_id, __get_cur_stree(), tmp) {
 884                 if (tmp->sym == sym)
 885                         return 1;
 886         } END_FOR_EACH_SM(tmp);
 887         return 0;
 888 }
 889
 890 bool we_pass_user_data(struct expression *call)
 891 {
 892         struct expression *arg;
 893         struct symbol *sym;
 894
 895         FOR_EACH_PTR(call->args, arg) {
 896                 if (points_to_user_data(arg))
 897                         return true;
 898                 sym = expr_to_sym(arg);
 899                 if (!sym)
 900                         continue;
 901                 if (has_user_data(sym))
 902                         return true;
 903         } END_FOR_EACH_PTR(arg);
 904
 905         return false;
 906 }
 907
 908 // TODO: faked_assign this should already be handled
 909 static int db_returned_user_rl(struct expression *call, struct range_list **rl)
 910 {
 911         struct smatch_state *state;
 912         char buf[48];
 913
 914         if (is_fake_call(call))
 915                 return 0;
 916         snprintf(buf, sizeof(buf), "return %p", call);
 917         state = get_state(my_id, buf, NULL);
 918         if (!state || !estate_rl(state))
 919                 return 0;
 920         *rl = estate_rl(state);
 921         return 1;
 922 }
 923
 924 struct stree *get_user_stree(void)
 925 {
 926         return get_all_states_stree(my_id);
 927 }
 928
 929 static int user_data_flag;
 930 static int no_user_data_flag;
 931 struct range_list *var_user_rl(struct expression *expr)
 932 {
 933         struct smatch_state *state;
 934         struct range_list *rl;
 935         struct range_list *absolute_rl;
 936
 937         if (expr->type == EXPR_PREOP && expr->op == '&') {
 938                 no_user_data_flag = 1;
 939                 return NULL;
 940         }
 941
 942         if (expr->type == EXPR_BINOP && expr->op == '%') {
 943                 struct range_list *left, *right;
 944
 945                 if (!get_user_rl(expr->right, &right))
 946                         return NULL;
 947                 get_absolute_rl(expr->left, &left);
 948                 rl = rl_binop(left, '%', right);
 949                 goto found;
 950         }
 951
 952         if (expr->type == EXPR_BINOP && expr->op == '/') {
 953                 struct range_list *left = NULL;
 954                 struct range_list *right = NULL;
 955                 struct range_list *abs_right;
 956
 957                 /*
 958                  * The specific bug I'm dealing with is:
 959                  *
 960                  * foo = capped_user / unknown;
 961                  *
 962                  * Instead of just saying foo is now entirely user_rl we should
 963                  * probably say instead that it is not at all user data.
 964                  *
 965                  */
 966
 967                 get_user_rl(expr->left, &left);
 968                 get_user_rl(expr->right, &right);
 969                 get_absolute_rl(expr->right, &abs_right);
 970
 971                 if (left && !right) {
 972                         rl = rl_binop(left, '/', abs_right);
 973                         if (sval_cmp(rl_max(left), rl_max(rl)) < 0)
 974                                 no_user_data_flag = 1;
 975                 }
 976
 977                 return NULL;
 978         }
 979
 980         if (get_rl_from_function(expr, &rl))
 981                 goto found;
 982
 983         if (get_user_macro_rl(expr, &rl))
 984                 goto found;
 985
 986         if (comes_from_skb_data(expr)) {
 987                 rl = alloc_whole_rl(get_type(expr));
 988                 goto found;
 989         }
 990
 991         state = get_state_expr(my_id, expr);
 992         if (state && estate_rl(state)) {
 993                 rl = estate_rl(state);
 994                 goto found;
 995         }
 996
 997         if (expr->type == EXPR_CALL && db_returned_user_rl(expr, &rl))
 998                 goto found;
 999
1000         if (expr->type == EXPR_PREOP && expr->op == '*' &&
1001             points_to_user_data(expr->unop)) {
1002                 rl = var_to_absolute_rl(expr);
1003                 goto found;
1004         }
1005
1006         if (is_array(expr)) {
1007                 struct expression *array = get_array_base(expr);
1008
1009                 if (!get_state_expr(my_id, array)) {
1010                         no_user_data_flag = 1;
1011                         return NULL;
1012                 }
1013         }
1014
1015         return NULL;
1016 found:
1017         user_data_flag = 1;
1018         absolute_rl = var_to_absolute_rl(expr);
1019         return rl_intersection(rl, absolute_rl);
1020 }
1021
1022 static bool is_ptr_subtract(struct expression *expr)
1023 {
1024         expr = strip_expr(expr);
1025         if (!expr)
1026                 return false;
1027         if (expr->type == EXPR_BINOP && expr->op == '-' &&
1028             type_is_ptr(get_type(expr->left))) {
1029                 return true;
1030         }
1031         return false;
1032 }
1033
1034 int get_user_rl(struct expression *expr, struct range_list **rl)
1035 {
1036         if (is_ptr_subtract(expr))
1037                 return 0;
1038
1039         user_data_flag = 0;
1040         no_user_data_flag = 0;
1041         custom_get_absolute_rl(expr, &var_user_rl, rl);
1042         if (!user_data_flag || no_user_data_flag)
1043                 *rl = NULL;
1044
1045         return !!*rl;
1046 }
1047
1048 int is_user_rl(struct expression *expr)
1049 {
1050         struct range_list *tmp;
1051
1052         return get_user_rl(expr, &tmp) && tmp;
1053 }
1054
1055 int get_user_rl_var_sym(const char *name, struct symbol *sym, struct range_list **rl)
1056 {
1057         struct smatch_state *state, *extra;
1058
1059         state = get_state(my_id, name, sym);
1060         if (!estate_rl(state))
1061                 return 0;
1062         *rl = estate_rl(state);
1063
1064         extra = get_state(SMATCH_EXTRA, name, sym);
1065         if (estate_rl(extra))
1066                 *rl = rl_intersection(estate_rl(state), estate_rl(extra));
1067
1068         return 1;
1069 }
1070
1071 bool is_socket_stuff(struct symbol *sym)
1072 {
1073         struct symbol *type;
1074
1075         /* This is a hack.
1076          * Basically I never want to consider an skb or sk as user pointer.
1077          * The skb->data is already marked as a source of user data, and if
1078          * anything else is marked as user data it's almost certainly wrong.
1079          *
1080          * Ideally, I would figure out where this bogus data is coming from,
1081          * but possibly it just was stuck in the database from previous updates
1082          * and can't get cleared out without deleting all user data.  Things
1083          * like this gets stuck in the DB because of recursion.
1084          *
1085          * I could make this a temporary hack, but I keep wanting to do it so
1086          * I'm just going to make it permanent.  It either doesn't change
1087          * anything or it makes life better.
1088          */
1089
1090         type = get_real_base_type(sym);
1091         if (!type || type->type != SYM_PTR)
1092                 return false;
1093         type = get_real_base_type(type);
1094         if (!type || type->type != SYM_STRUCT || !type->ident)
1095                 return false;
1096
1097         if (strcmp(type->ident->name, "sk_buff") == 0)
1098                 return true;
1099         if (strcmp(type->ident->name, "sock") == 0)
1100                 return true;
1101         if (strcmp(type->ident->name, "socket") == 0)
1102                 return true;
1103
1104         return false;
1105 }
1106
1107 static void return_info_callback(int return_id, char *return_ranges,
1108                                  struct expression *returned_expr,
1109                                  int param,
1110                                  const char *printed_name,
1111                                  struct sm_state *sm)
1112 {
1113         struct smatch_state *extra;
1114         struct range_list *rl;
1115         char buf[64];
1116
1117         if (is_socket_stuff(sm->sym))
1118                 return;
1119
1120         if (param >= 0) {
1121                 if (strcmp(printed_name, "$") == 0)
1122                         return;
1123                 if (!estate_assigned(sm->state) &&
1124                     !estate_new(sm->state))
1125                         return;
1126         }
1127         rl = estate_rl(sm->state);
1128         if (!rl)
1129                 return;
1130         extra = get_state(SMATCH_EXTRA, sm->name, sm->sym);
1131         if (estate_rl(extra))
1132                 rl = rl_intersection(estate_rl(sm->state), estate_rl(extra));
1133         if (!rl)
1134                 return;
1135
1136         snprintf(buf, sizeof(buf), "%s%s%s",
1137                  show_rl(rl),
1138                  estate_capped(sm->state) ? "[c]" : "",
1139                  estate_treat_untagged(sm->state) ? "[u]" : "");
1140         sql_insert_return_states(return_id, return_ranges,
1141                                  estate_new(sm->state) ? USER_DATA_SET : USER_DATA,
1142                                  param, printed_name, buf);
1143 }
1144
1145 static bool is_ignored_macro(struct position pos)
1146 {
1147         const char *macro;
1148
1149         macro = get_macro_name(pos);
1150         if (!macro)
1151                 return false;
1152         if (strcmp(macro, "v4l2_subdev_call") == 0)
1153                 return true;
1154         return false;
1155 }
1156
1157 static void caller_info_callback(struct expression *call, int param, char *printed_name, struct sm_state *sm)
1158 {
1159         struct smatch_state *state;
1160         struct range_list *rl;
1161         struct symbol *type;
1162         char buf[64];
1163
1164         if (is_ignored_macro(call->pos))
1165                 return;
1166
1167         if (is_socket_stuff(sm->sym))
1168                 return;
1169
1170         /*
1171          * Smatch uses a hack where if we get an unsigned long we say it's
1172          * both user data and it points to user data.  But if we pass it to a
1173          * function which takes an int, then it's just user data.  There's not
1174          * enough bytes for it to be a pointer.
1175          *
1176          */
1177         type = get_arg_type(call->fn, param);
1178         if (strcmp(printed_name, "$") != 0 && type && type_bits(type) < type_bits(&ptr_ctype))
1179                 return;
1180
1181         if (strcmp(sm->state->name, "") == 0)
1182                 return;
1183
1184         state = __get_state(SMATCH_EXTRA, sm->name, sm->sym);
1185         if (!state || !estate_rl(state))
1186                 rl = estate_rl(sm->state);
1187         else
1188                 rl = rl_intersection(estate_rl(sm->state), estate_rl(state));
1189
1190         if (!rl)
1191                 return;
1192
1193         snprintf(buf, sizeof(buf), "%s%s%s", show_rl(rl),
1194                  estate_capped(sm->state) ? "[c]" : "",
1195                  estate_treat_untagged(sm->state) ? "[u]" : "");
1196         sql_insert_caller_info(call, USER_DATA, param, printed_name, buf);
1197 }
1198
1199 static void db_param_set(struct expression *expr, int param, char *key, char *value)
1200 {
1201         struct expression *arg;
1202         char *name;
1203         struct symbol *sym;
1204         struct smatch_state *state;
1205
1206         while (expr->type == EXPR_ASSIGNMENT)
1207                 expr = strip_expr(expr->right);
1208         if (expr->type != EXPR_CALL)
1209                 return;
1210         if (expr == ignore_param_set)
1211                 return;
1212
1213         arg = get_argument_from_call_expr(expr->args, param);
1214         if (!arg)
1215                 return;
1216         name = get_variable_from_key(arg, key, &sym);
1217         if (!name || !sym)
1218                 goto free;
1219
1220         state = get_state(my_id, name, sym);
1221         if (!state)
1222                 goto free;
1223
1224         set_state(my_id, name, sym, alloc_estate_empty());
1225 free:
1226         free_string(name);
1227 }
1228
1229 static bool param_data_capped(const char *value)
1230 {
1231         if (strstr(value, ",c") || strstr(value, "[c"))
1232                 return true;
1233         return false;
1234 }
1235
1236 static bool param_data_treat_untagged(const char *value)
1237 {
1238         if (strstr(value, ",u") || strstr(value, "[u"))
1239                 return true;
1240         return false;
1241 }
1242
1243 static void set_param_user_data(const char *name, struct symbol *sym, char *key, char *value)
1244 {
1245         struct expression *expr;
1246         struct range_list *rl = NULL;
1247         struct smatch_state *state;
1248         struct symbol *type;
1249         char *fullname;
1250
1251         expr = symbol_expression(sym);
1252         fullname = get_variable_from_key(expr, key, NULL);
1253         if (!fullname)
1254                 return;
1255
1256         type = get_member_type_from_key(expr, key);
1257         if (type && type->type == SYM_STRUCT)
1258                 return;
1259
1260         if (!type)
1261                 return;
1262
1263         str_to_rl(type, value, &rl);
1264         rl = swap_mtag_seed(expr, rl);
1265         state = alloc_estate_rl(rl);
1266         if (param_data_capped(value) || is_capped(expr))
1267                 estate_set_capped(state);
1268         if (param_data_treat_untagged(value) || sym->ctype.as == 5)
1269                 estate_set_treat_untagged(state);
1270         set_state(my_id, fullname, sym, state);
1271 }
1272
1273 static void set_called(const char *name, struct symbol *sym, char *key, char *value)
1274 {
1275         set_state(my_call_id, "this_function", NULL, &called);
1276 }
1277
1278 static void match_syscall_definition(struct symbol *sym)
1279 {
1280         struct symbol *arg;
1281         char *macro;
1282         char *name;
1283         int is_syscall = 0;
1284
1285         macro = get_macro_name(sym->pos);
1286         if (macro &&
1287             (strncmp("SYSCALL_DEFINE", macro, strlen("SYSCALL_DEFINE")) == 0 ||
1288              strncmp("COMPAT_SYSCALL_DEFINE", macro, strlen("COMPAT_SYSCALL_DEFINE")) == 0))
1289                 is_syscall = 1;
1290
1291         name = get_function();
1292         if (!option_no_db && get_state(my_call_id, "this_function", NULL) != &called) {
1293                 if (name && strncmp(name, "sys_", 4) == 0)
1294                         is_syscall = 1;
1295         }
1296
1297         if (name && strncmp(name, "compat_sys_", 11) == 0)
1298                 is_syscall = 1;
1299
1300         if (!is_syscall)
1301                 return;
1302
1303         FOR_EACH_PTR(sym->ctype.base_type->arguments, arg) {
1304                 set_state(my_id, arg->ident->name, arg, alloc_estate_whole(get_real_base_type(arg)));
1305         } END_FOR_EACH_PTR(arg);
1306 }
1307
1308 #define OLD 0
1309 #define NEW 1
1310
1311 static void store_user_data_return(struct expression *expr, char *key, char *value, bool is_new)
1312 {
1313         struct smatch_state *state;
1314         struct range_list *rl;
1315         struct symbol *type;
1316         char buf[48];
1317
1318         if (key[0] != '$')
1319                 return;
1320
1321         type = get_type(expr);
1322         snprintf(buf, sizeof(buf), "return %p%s", expr, key + 1);
1323         call_results_to_rl(expr, type, value, &rl);
1324
1325         state = alloc_estate_rl(rl);
1326         if (is_new)
1327                 estate_set_new(state);
1328
1329         set_state(my_id, buf, NULL, state);
1330 }
1331
1332 static void set_to_user_data(struct expression *expr, char *key, char *value, bool is_new)
1333 {
1334         struct smatch_state *state;
1335         char *name;
1336         struct symbol *sym;
1337         struct symbol *type;
1338         struct range_list *rl = NULL;
1339
1340         type = get_member_type_from_key(expr, key);
1341         name = get_variable_from_key(expr, key, &sym);
1342         if (!name || !sym)
1343                 goto free;
1344
1345         call_results_to_rl(expr, type, value, &rl);
1346
1347         state = alloc_estate_rl(rl);
1348         if (param_data_capped(value))
1349                 estate_set_capped(state);
1350         if (param_data_treat_untagged(value))
1351                 estate_set_treat_untagged(state);
1352         if (is_new)
1353                 estate_set_new(state);
1354         estate_set_assigned(state);
1355         set_state(my_id, name, sym, state);
1356 free:
1357         free_string(name);
1358 }
1359
1360 static void returns_param_user_data(struct expression *expr, int param, char *key, char *value)
1361 {
1362         struct expression *arg;
1363         struct expression *call;
1364
1365         call = expr;
1366         while (call->type == EXPR_ASSIGNMENT)
1367                 call = strip_expr(call->right);
1368         if (call->type != EXPR_CALL)
1369                 return;
1370
1371         if (!we_pass_user_data(call))
1372                 return;
1373
1374         if (param == -1) {
1375                 if (expr->type != EXPR_ASSIGNMENT) {
1376                         // TODO: faked_assign this should all be handled as a fake assignment
1377                         store_user_data_return(expr, key, value, OLD);
1378                         return;
1379                 }
1380                 set_to_user_data(expr->left, key, value, OLD);
1381                 return;
1382         }
1383
1384         arg = get_argument_from_call_expr(call->args, param);
1385         if (!arg)
1386                 return;
1387         set_to_user_data(arg, key, value, OLD);
1388 }
1389
1390 static void returns_param_user_data_set(struct expression *expr, int param, char *key, char *value)
1391 {
1392         struct expression *arg;
1393
1394         func_gets_user_data = true;
1395
1396         if (param == -1) {
1397                 if (expr->type != EXPR_ASSIGNMENT) {
1398                         store_user_data_return(expr, key, value, NEW);
1399                         return;
1400                 }
1401                 set_to_user_data(expr->left, key, value, NEW);
1402                 return;
1403         }
1404
1405         while (expr->type == EXPR_ASSIGNMENT)
1406                 expr = strip_expr(expr->right);
1407         if (expr->type != EXPR_CALL)
1408                 return;
1409
1410         arg = get_argument_from_call_expr(expr->args, param);
1411         if (!arg)
1412                 return;
1413         set_to_user_data(arg, key, value, NEW);
1414 }
1415
1416 static void match_capped(struct expression *expr, const char *name, struct symbol *sym, void *info)
1417 {
1418         struct smatch_state *state, *new;
1419
1420         state = get_state(my_id, name, sym);
1421         if (!state || estate_capped(state))
1422                 return;
1423
1424         new = clone_estate(state);
1425         estate_set_capped(new);
1426
1427         set_state(my_id, name, sym, new);
1428 }
1429
1430 static void match_function_def(struct symbol *sym)
1431 {
1432         if (is_user_data_fn(sym))
1433                 func_gets_user_data = true;
1434 }
1435
1436 void register_kernel_user_data(int id)
1437 {
1438         int i;
1439
1440         my_id = id;
1441
1442         if (option_project != PROJ_KERNEL)
1443                 return;
1444
1445         set_dynamic_states(my_id);
1446
1447         add_function_data(&func_gets_user_data);
1448         add_hook(&match_function_def, FUNC_DEF_HOOK);
1449
1450         add_unmatched_state_hook(my_id, &empty_state);
1451         add_extra_nomod_hook(&extra_nomod_hook);
1452         add_pre_merge_hook(my_id, &pre_merge_hook);
1453         add_merge_hook(my_id, &merge_estates);
1454
1455         add_function_hook("copy_from_user", &match_user_copy, INT_PTR(0));
1456         add_function_hook("__copy_from_user", &match_user_copy, INT_PTR(0));
1457         add_function_hook("memcpy_fromiovec", &match_user_copy, INT_PTR(0));
1458         for (i = 0; i < ARRAY_SIZE(kstr_funcs); i++)
1459                 add_function_hook_late(kstr_funcs[i], &match_user_copy, INT_PTR(2));
1460         add_function_hook("usb_control_msg", &match_user_copy, INT_PTR(6));
1461         add_function_hook("kvm_read_guest_virt", &match_user_copy, INT_PTR(2));
1462         add_function_hook("vpu_iface_receive_msg", &match_user_copy, INT_PTR(1));
1463         add_function_hook("xdr_stream_decode_u32", &match_user_copy, INT_PTR(1));
1464
1465         for (i = 0; i < ARRAY_SIZE(returns_user_data); i++)
1466                 add_function_hook(returns_user_data[i], &match_returns_user_rl, NULL);
1467
1468         add_function_hook("sscanf", &match_sscanf, NULL);
1469
1470         add_hook(&match_syscall_definition, AFTER_DEF_HOOK);
1471
1472         add_hook(&match_assign, ASSIGNMENT_HOOK);
1473         select_return_states_hook(PARAM_SET, &db_param_set);
1474         add_hook(&match_condition, CONDITION_HOOK);
1475
1476         add_caller_info_callback(my_id, caller_info_callback);
1477         add_return_info_callback(my_id, return_info_callback);
1478         select_caller_info_hook(set_param_user_data, USER_DATA);
1479         select_return_states_hook(USER_DATA, &returns_param_user_data);
1480         select_return_states_hook(USER_DATA_SET, &returns_param_user_data_set);
1481
1482         select_return_param_key(CAPPED_DATA, &match_capped);
1483         add_function_param_key_hook_late("memcpy", &match_capped, 2, "$", NULL);
1484         add_function_param_key_hook_late("_memcpy", &match_capped, 2, "$", NULL);
1485         add_function_param_key_hook_late("__memcpy", &match_capped, 2, "$", NULL);
1486         add_function_param_key_hook_late("memset", &match_capped, 2, "$", NULL);
1487         add_function_param_key_hook_late("_memset", &match_capped, 2, "$", NULL);
1488         add_function_param_key_hook_late("__memset", &match_capped, 2, "$", NULL);
1489 }
1490
1491 void register_kernel_user_data2(int id)
1492 {
1493         my_call_id = id;
1494
1495         if (option_project != PROJ_KERNEL)
1496                 return;
1497         select_caller_info_hook(set_called, INTERNAL);
1498 }