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user_data: kstrtoul() and friends should taint data as untrusted
[smatch.git] / smatch_extra.c
blob08dcb5da1991014b4a1d39c573bae4674f88d875
1 /*
2 * Copyright (C) 2008 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 * smatch_extra.c is supposed to track the value of every variable.
20 *
21 */
22
23 #include <stdlib.h>
24 #include <errno.h>
25 #ifndef __USE_ISOC99
26 #define __USE_ISOC99
27 #endif
28 #include <limits.h>
29 #include "parse.h"
30 #include "smatch.h"
31 #include "smatch_slist.h"
32 #include "smatch_extra.h"
33
34 static int my_id;
35
36 struct string_list *__ignored_macros = NULL;
37 static int in_warn_on_macro()
38 {
39 struct statement *stmt;
40 char *tmp;
41 char *macro;
42
43 stmt = get_current_statement();
44 if (!stmt)
45 return 0;
46 macro = get_macro_name(stmt->pos);
47 if (!macro)
48 return 0;
49
50 FOR_EACH_PTR(__ignored_macros, tmp) {
51 if (!strcmp(tmp, macro))
52 return 1;
53 } END_FOR_EACH_PTR(tmp);
54 return 0;
55 }
56
57 typedef void (mod_hook)(const char *name, struct symbol *sym, struct smatch_state *state);
58 DECLARE_PTR_LIST(void_fn_list, mod_hook *);
59 static struct void_fn_list *extra_mod_hooks;
60 void add_extra_mod_hook(mod_hook *fn)
61 {
62 mod_hook **p = malloc(sizeof(mod_hook *));
63 *p = fn;
64 add_ptr_list(&extra_mod_hooks, p);
65 }
66
67 void call_extra_mod_hooks(const char *name, struct symbol *sym, struct smatch_state *state)
68 {
69 mod_hook **fn;
70
71 FOR_EACH_PTR(extra_mod_hooks, fn) {
72 (*fn)(name, sym, state);
73 } END_FOR_EACH_PTR(fn);
74 }
75
76 struct sm_state *set_extra_mod(const char *name, struct symbol *sym, struct smatch_state *state)
77 {
78 if (in_warn_on_macro())
79 return NULL;
80 remove_from_equiv(name, sym);
81 call_extra_mod_hooks(name, sym, state);
82 return set_state(SMATCH_EXTRA, name, sym, state);
83 }
84
85 struct sm_state *set_extra_expr_mod(struct expression *expr, struct smatch_state *state)
86 {
87 struct symbol *sym;
88 char *name;
89 struct sm_state *ret = NULL;
90
91 expr = strip_expr(expr);
92 name = expr_to_var_sym(expr, &sym);
93 if (!name || !sym)
94 goto free;
95 ret = set_extra_mod(name, sym, state);
96 free:
97 free_string(name);
98 return ret;
99 }
100
101 void set_extra_nomod(const char *name, struct symbol *sym, struct smatch_state *state)
102 {
103 struct relation *rel;
104 struct smatch_state *orig_state;
105
106 orig_state = get_state(SMATCH_EXTRA, name, sym);
107
108 if (!estate_related(orig_state)) {
109 set_state(SMATCH_EXTRA, name, sym, state);
110 return;
111 }
112
113 set_related(state, estate_related(orig_state));
114 FOR_EACH_PTR(estate_related(orig_state), rel) {
115 if (option_debug_related)
116 sm_msg("updating related %s to %s", rel->name, state->name);
117 set_state(SMATCH_EXTRA, rel->name, rel->sym, state);
118 } END_FOR_EACH_PTR(rel);
119 }
120
121 /*
122 * This is for return_implies_state() hooks which modify a SMATCH_EXTRA state
123 */
124 void set_extra_expr_nomod(struct expression *expr, struct smatch_state *state)
125 {
126 char *name;
127 struct symbol *sym;
128
129 name = expr_to_var_sym(expr, &sym);
130 if (!name || !sym)
131 goto free;
132 set_extra_nomod(name, sym, state);
133 free:
134 free_string(name);
135
136 }
137
138 static void set_extra_true_false(const char *name, struct symbol *sym,
139 struct smatch_state *true_state,
140 struct smatch_state *false_state)
141 {
142 struct relation *rel;
143 struct smatch_state *orig_state;
144
145 if (in_warn_on_macro())
146 return;
147
148 orig_state = get_state(SMATCH_EXTRA, name, sym);
149
150 if (!estate_related(orig_state)) {
151 set_true_false_states(SMATCH_EXTRA, name, sym, true_state, false_state);
152 return;
153 }
154
155 if (true_state)
156 set_related(true_state, estate_related(orig_state));
157 if (false_state)
158 set_related(false_state, estate_related(orig_state));
159
160 FOR_EACH_PTR(estate_related(orig_state), rel) {
161 set_true_false_states(SMATCH_EXTRA, rel->name, rel->sym,
162 true_state, false_state);
163 } END_FOR_EACH_PTR(rel);
164 }
165
166 static void set_extra_expr_true_false(struct expression *expr,
167 struct smatch_state *true_state,
168 struct smatch_state *false_state)
169 {
170 char *name;
171 struct symbol *sym;
172
173 expr = strip_expr(expr);
174 name = expr_to_var_sym(expr, &sym);
175 if (!name || !sym)
176 goto free;
177 set_extra_true_false(name, sym, true_state, false_state);
178 free:
179 free_string(name);
180 }
181
182 static struct sm_state *handle_canonical_while_count_down(struct statement *loop)
183 {
184 struct expression *iter_var;
185 struct expression *condition;
186 struct sm_state *sm;
187 struct smatch_state *estate;
188 sval_t start;
189
190 condition = strip_expr(loop->iterator_pre_condition);
191 if (!condition)
192 return NULL;
193 if (condition->type != EXPR_PREOP && condition->type != EXPR_POSTOP)
194 return NULL;
195 if (condition->op != SPECIAL_DECREMENT)
196 return NULL;
197
198 iter_var = condition->unop;
199 sm = get_sm_state_expr(SMATCH_EXTRA, iter_var);
200 if (!sm)
201 return NULL;
202 if (sval_cmp_val(estate_min(sm->state), 0) < 0)
203 return NULL;
204 start = estate_max(sm->state);
205 if (sval_cmp_val(start, 0) <= 0)
206 return NULL;
207 if (!sval_is_max(start))
208 start.value--;
209
210 if (condition->type == EXPR_PREOP) {
211 estate = alloc_estate_range(sval_type_val(start.type, 1), start);
212 if (estate_has_hard_max(sm->state))
213 estate_set_hard_max(estate);
214 estate_copy_fuzzy_max(estate, sm->state);
215 set_extra_expr_mod(iter_var, estate);
216 }
217 if (condition->type == EXPR_POSTOP) {
218 estate = alloc_estate_range(sval_type_val(start.type, 0), start);
219 if (estate_has_hard_max(sm->state))
220 estate_set_hard_max(estate);
221 estate_copy_fuzzy_max(estate, sm->state);
222 set_extra_expr_mod(iter_var, estate);
223 }
224 return get_sm_state_expr(SMATCH_EXTRA, iter_var);
225 }
226
227 static struct sm_state *handle_canonical_for_inc(struct expression *iter_expr,
228 struct expression *condition)
229 {
230 struct expression *iter_var;
231 struct sm_state *sm;
232 struct smatch_state *estate;
233 sval_t start, end, max;
234
235 iter_var = iter_expr->unop;
236 sm = get_sm_state_expr(SMATCH_EXTRA, iter_var);
237 if (!sm)
238 return NULL;
239 if (!estate_get_single_value(sm->state, &start))
240 return NULL;
241 if (get_implied_max(condition->right, &end))
242 end = sval_cast(get_type(iter_var), end);
243 else
244 end = sval_type_max(get_type(iter_var));
245
246 if (get_sm_state_expr(SMATCH_EXTRA, condition->left) != sm)
247 return NULL;
248
249 switch (condition->op) {
250 case SPECIAL_UNSIGNED_LT:
251 case SPECIAL_NOTEQUAL:
252 case '<':
253 if (!sval_is_min(end))
254 end.value--;
255 break;
256 case SPECIAL_UNSIGNED_LTE:
257 case SPECIAL_LTE:
258 break;
259 default:
260 return NULL;
261 }
262 if (sval_cmp(end, start) < 0)
263 return NULL;
264 estate = alloc_estate_range(start, end);
265 if (get_hard_max(condition->right, &max)) {
266 estate_set_hard_max(estate);
267 if (condition->op == '<' ||
268 condition->op == SPECIAL_UNSIGNED_LT ||
269 condition->op == SPECIAL_NOTEQUAL)
270 max.value--;
271 estate_set_fuzzy_max(estate, max);
272 }
273 set_extra_expr_mod(iter_var, estate);
274 return get_sm_state_expr(SMATCH_EXTRA, iter_var);
275 }
276
277 static struct sm_state *handle_canonical_for_dec(struct expression *iter_expr,
278 struct expression *condition)
279 {
280 struct expression *iter_var;
281 struct sm_state *sm;
282 struct smatch_state *estate;
283 sval_t start, end;
284
285 iter_var = iter_expr->unop;
286 sm = get_sm_state_expr(SMATCH_EXTRA, iter_var);
287 if (!sm)
288 return NULL;
289 if (!estate_get_single_value(sm->state, &start))
290 return NULL;
291 if (!get_implied_min(condition->right, &end))
292 end = sval_type_min(get_type(iter_var));
293 if (get_sm_state_expr(SMATCH_EXTRA, condition->left) != sm)
294 return NULL;
295
296 switch (condition->op) {
297 case SPECIAL_NOTEQUAL:
298 case '>':
299 if (!sval_is_min(end) && !sval_is_max(end))
300 end.value++;
301 break;
302 case SPECIAL_GTE:
303 break;
304 default:
305 return NULL;
306 }
307 if (sval_cmp(end, start) > 0)
308 return NULL;
309 estate = alloc_estate_range(end, start);
310 estate_set_hard_max(estate);
311 estate_set_fuzzy_max(estate, estate_get_fuzzy_max(estate));
312 set_extra_expr_mod(iter_var, estate);
313 return get_sm_state_expr(SMATCH_EXTRA, iter_var);
314 }
315
316 static struct sm_state *handle_canonical_for_loops(struct statement *loop)
317 {
318 struct expression *iter_expr;
319 struct expression *condition;
320
321 if (!loop->iterator_post_statement)
322 return NULL;
323 if (loop->iterator_post_statement->type != STMT_EXPRESSION)
324 return NULL;
325 iter_expr = loop->iterator_post_statement->expression;
326 if (!loop->iterator_pre_condition)
327 return NULL;
328 if (loop->iterator_pre_condition->type != EXPR_COMPARE)
329 return NULL;
330 condition = loop->iterator_pre_condition;
331
332 if (iter_expr->op == SPECIAL_INCREMENT)
333 return handle_canonical_for_inc(iter_expr, condition);
334 if (iter_expr->op == SPECIAL_DECREMENT)
335 return handle_canonical_for_dec(iter_expr, condition);
336 return NULL;
337 }
338
339 struct sm_state *__extra_handle_canonical_loops(struct statement *loop, struct stree **stree)
340 {
341 struct sm_state *ret;
342
343 __push_fake_cur_stree();
344 if (!loop->iterator_post_statement)
345 ret = handle_canonical_while_count_down(loop);
346 else
347 ret = handle_canonical_for_loops(loop);
348 *stree = __pop_fake_cur_stree();
349 return ret;
350 }
351
352 int __iterator_unchanged(struct sm_state *sm)
353 {
354 if (!sm)
355 return 0;
356 if (get_sm_state(my_id, sm->name, sm->sym) == sm)
357 return 1;
358 return 0;
359 }
360
361 static void while_count_down_after(struct sm_state *sm, struct expression *condition)
362 {
363 sval_t after_value;
364
365 /* paranoid checking. prolly not needed */
366 condition = strip_expr(condition);
367 if (!condition)
368 return;
369 if (condition->type != EXPR_PREOP && condition->type != EXPR_POSTOP)
370 return;
371 if (condition->op != SPECIAL_DECREMENT)
372 return;
373 after_value = estate_min(sm->state);
374 after_value.value--;
375 set_extra_mod(sm->name, sm->sym, alloc_estate_sval(after_value));
376 }
377
378 void __extra_pre_loop_hook_after(struct sm_state *sm,
379 struct statement *iterator,
380 struct expression *condition)
381 {
382 struct expression *iter_expr;
383 sval_t limit;
384 struct smatch_state *state;
385
386 if (!iterator) {
387 while_count_down_after(sm, condition);
388 return;
389 }
390
391 iter_expr = iterator->expression;
392
393 if (condition->type != EXPR_COMPARE)
394 return;
395 if (iter_expr->op == SPECIAL_INCREMENT) {
396 limit = sval_binop(estate_max(sm->state), '+',
397 sval_type_val(estate_type(sm->state), 1));
398 } else {
399 limit = sval_binop(estate_min(sm->state), '-',
400 sval_type_val(estate_type(sm->state), 1));
401 }
402 if (!estate_has_hard_max(sm->state) && !__has_breaks()) {
403 if (iter_expr->op == SPECIAL_INCREMENT)
404 state = alloc_estate_range(estate_min(sm->state), limit);
405 else
406 state = alloc_estate_range(limit, estate_max(sm->state));
407 } else {
408 state = alloc_estate_sval(limit);
409 }
410 if (!estate_has_hard_max(sm->state)) {
411 estate_clear_hard_max(state);
412 }
413 if (estate_has_fuzzy_max(sm->state)) {
414 sval_t hmax = estate_get_fuzzy_max(sm->state);
415 sval_t max = estate_max(sm->state);
416
417 if (sval_cmp(hmax, max) != 0)
418 estate_clear_fuzzy_max(state);
419 } else if (!estate_has_fuzzy_max(sm->state)) {
420 estate_clear_fuzzy_max(state);
421 }
422
423 set_extra_mod(sm->name, sm->sym, state);
424 }
425
426 static struct stree *unmatched_stree;
427 static struct smatch_state *unmatched_state(struct sm_state *sm)
428 {
429 struct smatch_state *state;
430
431 if (unmatched_stree) {
432 state = get_state_stree(unmatched_stree, SMATCH_EXTRA, sm->name, sm->sym);
433 if (state)
434 return state;
435 }
436 return alloc_estate_whole(estate_type(sm->state));
437 }
438
439 static void clear_the_pointed_at(struct expression *expr)
440 {
441 struct stree *stree;
442 char *name;
443 struct symbol *sym;
444 struct sm_state *tmp;
445
446 name = expr_to_var_sym(expr, &sym);
447 if (!name || !sym)
448 goto free;
449
450 stree = __get_cur_stree();
451 FOR_EACH_MY_SM(SMATCH_EXTRA, stree, tmp) {
452 if (tmp->name[0] != '*')
453 continue;
454 if (tmp->sym != sym)
455 continue;
456 if (strcmp(tmp->name + 1, name) != 0)
457 continue;
458 set_extra_mod(tmp->name, tmp->sym, alloc_estate_whole(estate_type(tmp->state)));
459 } END_FOR_EACH_SM(tmp);
460
461 free:
462 free_string(name);
463 }
464
465 static void match_function_call(struct expression *expr)
466 {
467 struct expression *arg;
468 struct expression *tmp;
469
470 /* if we have the db this is handled in smatch_function_hooks.c */
471 if (!option_no_db)
472 return;
473 if (inlinable(expr->fn))
474 return;
475
476 FOR_EACH_PTR(expr->args, arg) {
477 tmp = strip_expr(arg);
478 if (tmp->type == EXPR_PREOP && tmp->op == '&')
479 set_extra_expr_mod(tmp->unop, alloc_estate_whole(get_type(tmp->unop)));
480 else
481 clear_the_pointed_at(tmp);
482 } END_FOR_EACH_PTR(arg);
483 }
484
485 static int types_equiv_or_pointer(struct symbol *one, struct symbol *two)
486 {
487 if (!one || !two)
488 return 0;
489 if (one->type == SYM_PTR && two->type == SYM_PTR)
490 return 1;
491 return types_equiv(one, two);
492 }
493
494 static void match_vanilla_assign(struct expression *left, struct expression *right)
495 {
496 struct range_list *rl = NULL;
497 struct symbol *right_sym;
498 struct symbol *left_type;
499 struct symbol *right_type;
500 char *right_name = NULL;
501 struct symbol *sym;
502 char *name;
503 sval_t max;
504 struct smatch_state *state;
505
506 if (is_struct(left))
507 return;
508
509 name = expr_to_var_sym(left, &sym);
510 if (!name)
511 return;
512
513 left_type = get_type(left);
514 right_type = get_type(right);
515
516 right_name = expr_to_var_sym(right, &right_sym);
517
518 if (!(right->type == EXPR_PREOP && right->op == '&') &&
519 right_name && right_sym &&
520 types_equiv_or_pointer(left_type, right_type) &&
521 !has_symbol(right, sym)) {
522 set_equiv(left, right);
523 goto free;
524 }
525
526 if (get_implied_rl(right, &rl)) {
527 rl = cast_rl(left_type, rl);
528 state = alloc_estate_rl(rl);
529 if (get_hard_max(right, &max)) {
530 estate_set_hard_max(state);
531 estate_set_fuzzy_max(state, max);
532 }
533 } else {
534 rl = alloc_whole_rl(right_type);
535 rl = cast_rl(left_type, rl);
536 state = alloc_estate_rl(rl);
537 }
538 set_extra_mod(name, sym, state);
539 free:
540 free_string(right_name);
541 }
542
543 static int op_remove_assign(int op)
544 {
545 switch (op) {
546 case SPECIAL_ADD_ASSIGN:
547 return '+';
548 case SPECIAL_SUB_ASSIGN:
549 return '-';
550 case SPECIAL_MUL_ASSIGN:
551 return '*';
552 case SPECIAL_DIV_ASSIGN:
553 return '/';
554 case SPECIAL_MOD_ASSIGN:
555 return '%';
556 case SPECIAL_AND_ASSIGN:
557 return '&';
558 case SPECIAL_OR_ASSIGN:
559 return '|';
560 case SPECIAL_XOR_ASSIGN:
561 return '^';
562 case SPECIAL_SHL_ASSIGN:
563 return SPECIAL_LEFTSHIFT;
564 case SPECIAL_SHR_ASSIGN:
565 return SPECIAL_RIGHTSHIFT;
566 default:
567 return op;
568 }
569 }
570
571 static void match_assign(struct expression *expr)
572 {
573 struct range_list *rl = NULL;
574 struct expression *left;
575 struct expression *right;
576 struct expression *binop_expr;
577 struct symbol *left_type;
578 struct symbol *right_type;
579 struct symbol *sym;
580 char *name;
581 sval_t left_min, left_max;
582 sval_t right_min, right_max;
583 sval_t res_min, res_max;
584
585 left = strip_expr(expr->left);
586
587 right = strip_expr(expr->right);
588 while (right->type == EXPR_ASSIGNMENT && right->op == '=')
589 right = strip_expr(right->left);
590
591 if (is_condition(expr->right))
592 return; /* handled in smatch_condition.c */
593 if (expr->op == '=' && right->type == EXPR_CALL)
594 return; /* handled in smatch_function_hooks.c */
595 if (expr->op == '=') {
596 match_vanilla_assign(left, right);
597 return;
598 }
599
600 name = expr_to_var_sym(left, &sym);
601 if (!name)
602 return;
603
604 left_type = get_type(left);
605 right_type = get_type(right);
606
607 res_min = sval_type_min(left_type);
608 res_max = sval_type_max(left_type);
609
610 switch (expr->op) {
611 case SPECIAL_ADD_ASSIGN:
612 get_absolute_max(left, &left_max);
613 get_absolute_max(right, &right_max);
614 if (sval_binop_overflows(left_max, '+', right_max))
615 break;
616 if (get_implied_min(left, &left_min) &&
617 !sval_is_negative_min(left_min) &&
618 get_implied_min(right, &right_min) &&
619 !sval_is_negative_min(right_min)) {
620 res_min = sval_binop(left_min, '+', right_min);
621 res_min = sval_cast(right_type, res_min);
622 }
623 if (inside_loop()) /* we are assuming loops don't lead to wrapping */
624 break;
625 res_max = sval_binop(left_max, '+', right_max);
626 res_max = sval_cast(right_type, res_max);
627 break;
628 case SPECIAL_SUB_ASSIGN:
629 if (get_implied_max(left, &left_max) &&
630 !sval_is_max(left_max) &&
631 get_implied_min(right, &right_min) &&
632 !sval_is_min(right_min)) {
633 res_max = sval_binop(left_max, '-', right_min);
634 res_max = sval_cast(right_type, res_max);
635 }
636 if (inside_loop())
637 break;
638 if (get_implied_min(left, &left_min) &&
639 !sval_is_min(left_min) &&
640 get_implied_max(right, &right_max) &&
641 !sval_is_max(right_max)) {
642 res_min = sval_binop(left_min, '-', right_max);
643 res_min = sval_cast(right_type, res_min);
644 }
645 break;
646 case SPECIAL_AND_ASSIGN:
647 case SPECIAL_MOD_ASSIGN:
648 case SPECIAL_SHL_ASSIGN:
649 case SPECIAL_SHR_ASSIGN:
650 case SPECIAL_OR_ASSIGN:
651 case SPECIAL_XOR_ASSIGN:
652 case SPECIAL_MUL_ASSIGN:
653 case SPECIAL_DIV_ASSIGN:
654 binop_expr = binop_expression(expr->left,
655 op_remove_assign(expr->op),
656 expr->right);
657 if (get_absolute_rl(binop_expr, &rl)) {
658 rl = cast_rl(left_type, rl);
659 set_extra_mod(name, sym, alloc_estate_rl(rl));
660 goto free;
661 }
662 break;
663 }
664 rl = cast_rl(left_type, alloc_rl(res_min, res_max));
665 set_extra_mod(name, sym, alloc_estate_rl(rl));
666 free:
667 free_string(name);
668 }
669
670 static struct smatch_state *increment_state(struct smatch_state *state)
671 {
672 sval_t min = estate_min(state);
673 sval_t max = estate_max(state);
674
675 if (!estate_rl(state))
676 return NULL;
677
678 if (inside_loop())
679 max = sval_type_max(max.type);
680
681 if (!sval_is_min(min) && !sval_is_max(min))
682 min.value++;
683 if (!sval_is_min(max) && !sval_is_max(max))
684 max.value++;
685 return alloc_estate_range(min, max);
686 }
687
688 static struct smatch_state *decrement_state(struct smatch_state *state)
689 {
690 sval_t min = estate_min(state);
691 sval_t max = estate_max(state);
692
693 if (!estate_rl(state))
694 return NULL;
695
696 if (inside_loop())
697 min = sval_type_min(min.type);
698
699 if (!sval_is_min(min) && !sval_is_max(min))
700 min.value--;
701 if (!sval_is_min(max) && !sval_is_max(max))
702 max.value--;
703 return alloc_estate_range(min, max);
704 }
705
706 static void unop_expr(struct expression *expr)
707 {
708 struct smatch_state *state;
709
710 if (expr->smatch_flags & Handled)
711 return;
712
713 switch (expr->op) {
714 case SPECIAL_INCREMENT:
715 state = get_state_expr(SMATCH_EXTRA, expr->unop);
716 state = increment_state(state);
717 if (!state)
718 state = alloc_estate_whole(get_type(expr));
719 set_extra_expr_mod(expr->unop, state);
720 break;
721 case SPECIAL_DECREMENT:
722 state = get_state_expr(SMATCH_EXTRA, expr->unop);
723 state = decrement_state(state);
724 if (!state)
725 state = alloc_estate_whole(get_type(expr));
726 set_extra_expr_mod(expr->unop, state);
727 break;
728 default:
729 return;
730 }
731 }
732
733 static void asm_expr(struct statement *stmt)
734 {
735
736 struct expression *expr;
737 struct symbol *type;
738 int state = 0;
739
740 FOR_EACH_PTR(stmt->asm_outputs, expr) {
741 switch (state) {
742 case 0: /* identifier */
743 case 1: /* constraint */
744 state++;
745 continue;
746 case 2: /* expression */
747 state = 0;
748 type = get_type(strip_expr(expr));
749 set_extra_expr_mod(expr, alloc_estate_whole(type));
750 continue;
751 }
752 } END_FOR_EACH_PTR(expr);
753 }
754
755 static void delete_state_tracker(struct tracker *t)
756 {
757 remove_from_equiv(t->name, t->sym);
758 delete_state(t->owner, t->name, t->sym);
759 }
760
761 static void scoped_state_extra(const char *name, struct symbol *sym)
762 {
763 struct tracker *t;
764
765 t = alloc_tracker(SMATCH_EXTRA, name, sym);
766 add_scope_hook((scope_hook *)&delete_state_tracker, t);
767 }
768
769 static void match_declarations(struct symbol *sym)
770 {
771 const char *name;
772
773 if (sym->ident) {
774 name = sym->ident->name;
775 if (!sym->initializer) {
776 set_state(SMATCH_EXTRA, name, sym, alloc_estate_whole(get_real_base_type(sym)));
777 scoped_state_extra(name, sym);
778 }
779 }
780 }
781
782 static void check_dereference(struct expression *expr)
783 {
784 if (outside_of_function())
785 return;
786 set_extra_expr_nomod(expr, alloc_estate_range(valid_ptr_min_sval, valid_ptr_max_sval));
787 }
788
789 static void match_dereferences(struct expression *expr)
790 {
791 if (expr->type != EXPR_PREOP)
792 return;
793 check_dereference(expr->unop);
794 }
795
796 static void match_pointer_as_array(struct expression *expr)
797 {
798 if (!is_array(expr))
799 return;
800 check_dereference(expr->unop->left);
801 }
802
803 static void set_param_dereferenced(struct expression *arg, char *unused)
804 {
805 check_dereference(arg);
806 }
807
808 static void match_function_def(struct symbol *sym)
809 {
810 struct symbol *arg;
811
812 FOR_EACH_PTR(sym->ctype.base_type->arguments, arg) {
813 if (!arg->ident)
814 continue;
815 set_state(my_id, arg->ident->name, arg, alloc_estate_whole(get_real_base_type(arg)));
816 } END_FOR_EACH_PTR(arg);
817 }
818
819 static sval_t add_one(sval_t sval)
820 {
821 sval.value++;
822 return sval;
823 }
824
825 static sval_t sub_one(sval_t sval)
826 {
827 sval.value--;
828 return sval;
829 }
830
831 static void handle_comparison(struct symbol *type, struct expression *left, int op, struct expression *right)
832 {
833 struct range_list *left_orig;
834 struct range_list *left_true;
835 struct range_list *left_false;
836 struct range_list *right_orig;
837 struct range_list *right_true;
838 struct range_list *right_false;
839 struct smatch_state *left_true_state;
840 struct smatch_state *left_false_state;
841 struct smatch_state *right_true_state;
842 struct smatch_state *right_false_state;
843 sval_t min, max, dummy, hard_max;
844 int left_postop = 0;
845 int right_postop = 0;
846
847 if (left->op == SPECIAL_INCREMENT || left->op == SPECIAL_DECREMENT) {
848 if (left->type == EXPR_POSTOP) {
849 left->smatch_flags |= Handled;
850 left_postop = left->op;
851 }
852 left = strip_expr(left->unop);
853 }
854 while (left->type == EXPR_ASSIGNMENT)
855 left = strip_expr(left->left);
856
857 if (right->op == SPECIAL_INCREMENT || right->op == SPECIAL_DECREMENT) {
858 if (right->type == EXPR_POSTOP) {
859 right->smatch_flags |= Handled;
860 right_postop = right->op;
861 }
862 right = strip_expr(right->unop);
863 }
864
865 if (get_implied_rl(left, &left_orig)) {
866 left_orig = cast_rl(type, left_orig);
867 } else {
868 min = sval_type_min(get_type(left));
869 max = sval_type_max(get_type(left));
870 left_orig = cast_rl(type, alloc_rl(min, max));
871 }
872
873 if (get_implied_rl(right, &right_orig)) {
874 right_orig = cast_rl(type, right_orig);
875 } else {
876 min = sval_type_min(get_type(right));
877 max = sval_type_max(get_type(right));
878 right_orig = cast_rl(type, alloc_rl(min, max));
879 }
880 min = sval_type_min(type);
881 max = sval_type_max(type);
882
883 left_true = clone_rl(left_orig);
884 left_false = clone_rl(left_orig);
885 right_true = clone_rl(right_orig);
886 right_false = clone_rl(right_orig);
887
888 switch (op) {
889 case '<':
890 case SPECIAL_UNSIGNED_LT:
891 left_true = remove_range(left_orig, rl_max(right_orig), max);
892 if (!sval_is_min(rl_min(right_orig))) {
893 left_false = remove_range(left_orig, min, sub_one(rl_min(right_orig)));
894 }
895
896 right_true = remove_range(right_orig, min, rl_min(left_orig));
897 if (!sval_is_max(rl_max(left_orig)))
898 right_false = remove_range(right_orig, add_one(rl_max(left_orig)), max);
899 break;
900 case SPECIAL_UNSIGNED_LTE:
901 case SPECIAL_LTE:
902 if (!sval_is_max(rl_max(right_orig)))
903 left_true = remove_range(left_orig, add_one(rl_max(right_orig)), max);
904 left_false = remove_range(left_orig, min, rl_min(right_orig));
905
906 if (!sval_is_min(rl_min(left_orig)))
907 right_true = remove_range(right_orig, min, sub_one(rl_min(left_orig)));
908 right_false = remove_range(right_orig, rl_max(left_orig), max);
909
910 if (sval_cmp(rl_min(left_orig), rl_min(right_orig)) == 0)
911 left_false = remove_range(left_false, rl_min(left_orig), rl_min(left_orig));
912 if (sval_cmp(rl_max(left_orig), rl_max(right_orig)) == 0)
913 right_false = remove_range(right_false, rl_max(left_orig), rl_max(left_orig));
914 break;
915 case SPECIAL_EQUAL:
916 if (!sval_is_max(rl_max(right_orig))) {
917 left_true = remove_range(left_true, add_one(rl_max(right_orig)), max);
918 }
919 if (!sval_is_min(rl_min(right_orig))) {
920 left_true = remove_range(left_true, min, sub_one(rl_min(right_orig)));
921 }
922 if (sval_cmp(rl_min(right_orig), rl_max(right_orig)) == 0)
923 left_false = remove_range(left_orig, rl_min(right_orig), rl_min(right_orig));
924
925 if (!sval_is_max(rl_max(left_orig)))
926 right_true = remove_range(right_true, add_one(rl_max(left_orig)), max);
927 if (!sval_is_min(rl_min(left_orig)))
928 right_true = remove_range(right_true, min, sub_one(rl_min(left_orig)));
929 if (sval_cmp(rl_min(left_orig), rl_max(left_orig)) == 0)
930 right_false = remove_range(right_orig, rl_min(left_orig), rl_min(left_orig));
931 break;
932 case SPECIAL_UNSIGNED_GTE:
933 case SPECIAL_GTE:
934 if (!sval_is_min(rl_min(right_orig)))
935 left_true = remove_range(left_orig, min, sub_one(rl_min(right_orig)));
936 left_false = remove_range(left_orig, rl_max(right_orig), max);
937
938 if (!sval_is_max(rl_max(left_orig)))
939 right_true = remove_range(right_orig, add_one(rl_max(left_orig)), max);
940 right_false = remove_range(right_orig, min, rl_min(left_orig));
941
942 if (sval_cmp(rl_min(left_orig), rl_min(right_orig)) == 0)
943 right_false = remove_range(right_false, rl_min(left_orig), rl_min(left_orig));
944 if (sval_cmp(rl_max(left_orig), rl_max(right_orig)) == 0)
945 left_false = remove_range(left_false, rl_max(left_orig), rl_max(left_orig));
946 break;
947 case '>':
948 case SPECIAL_UNSIGNED_GT:
949 left_true = remove_range(left_orig, min, rl_min(right_orig));
950 if (!sval_is_max(rl_max(right_orig)))
951 left_false = remove_range(left_orig, add_one(rl_max(right_orig)), max);
952
953 right_true = remove_range(right_orig, rl_max(left_orig), max);
954 if (!sval_is_min(rl_min(left_orig)))
955 right_false = remove_range(right_orig, min, sub_one(rl_min(left_orig)));
956 break;
957 case SPECIAL_NOTEQUAL:
958 if (!sval_is_max(rl_max(right_orig)))
959 left_false = remove_range(left_false, add_one(rl_max(right_orig)), max);
960 if (!sval_is_min(rl_min(right_orig)))
961 left_false = remove_range(left_false, min, sub_one(rl_min(right_orig)));
962 if (sval_cmp(rl_min(right_orig), rl_max(right_orig)) == 0)
963 left_true = remove_range(left_orig, rl_min(right_orig), rl_min(right_orig));
964
965 if (!sval_is_max(rl_max(left_orig)))
966 right_false = remove_range(right_false, add_one(rl_max(left_orig)), max);
967 if (!sval_is_min(rl_min(left_orig)))
968 right_false = remove_range(right_false, min, sub_one(rl_min(left_orig)));
969 if (sval_cmp(rl_min(left_orig), rl_max(left_orig)) == 0)
970 right_true = remove_range(right_orig, rl_min(left_orig), rl_min(left_orig));
971 break;
972 default:
973 return;
974 }
975
976 left_true = rl_truncate_cast(get_type(left), left_true);
977 left_false = rl_truncate_cast(get_type(left), left_false);
978 right_true = rl_truncate_cast(get_type(right), right_true);
979 right_false = rl_truncate_cast(get_type(right), right_false);
980
981 left_true_state = alloc_estate_rl(left_true);
982 left_false_state = alloc_estate_rl(left_false);
983 right_true_state = alloc_estate_rl(right_true);
984 right_false_state = alloc_estate_rl(right_false);
985
986 switch (op) {
987 case '<':
988 case SPECIAL_UNSIGNED_LT:
989 case SPECIAL_UNSIGNED_LTE:
990 case SPECIAL_LTE:
991 if (get_hard_max(right, &dummy))
992 estate_set_hard_max(left_true_state);
993 if (get_hard_max(left, &dummy))
994 estate_set_hard_max(right_false_state);
995 break;
996 case '>':
997 case SPECIAL_UNSIGNED_GT:
998 case SPECIAL_UNSIGNED_GTE:
999 case SPECIAL_GTE:
1000 if (get_hard_max(left, &dummy))
1001 estate_set_hard_max(right_true_state);
1002 if (get_hard_max(right, &dummy))
1003 estate_set_hard_max(left_false_state);
1004 break;
1005 }
1006
1007 switch (op) {
1008 case '<':
1009 case SPECIAL_UNSIGNED_LT:
1010 case SPECIAL_UNSIGNED_LTE:
1011 case SPECIAL_LTE:
1012 if (get_hard_max(right, &hard_max)) {
1013 if (op == '<' || op == SPECIAL_UNSIGNED_LT)
1014 hard_max.value--;
1015 estate_set_fuzzy_max(left_true_state, hard_max);
1016 }
1017 if (get_implied_value(right, &hard_max)) {
1018 if (op == SPECIAL_UNSIGNED_LTE ||
1019 op == SPECIAL_LTE)
1020 hard_max.value++;
1021 estate_set_fuzzy_max(left_false_state, hard_max);
1022 }
1023 if (get_hard_max(left, &hard_max)) {
1024 if (op == SPECIAL_UNSIGNED_LTE ||
1025 op == SPECIAL_LTE)
1026 hard_max.value--;
1027 estate_set_fuzzy_max(right_false_state, hard_max);
1028 }
1029 if (get_implied_value(left, &hard_max)) {
1030 if (op == '<' || op == SPECIAL_UNSIGNED_LT)
1031 hard_max.value++;
1032 estate_set_fuzzy_max(right_true_state, hard_max);
1033 }
1034 break;
1035 case '>':
1036 case SPECIAL_UNSIGNED_GT:
1037 case SPECIAL_UNSIGNED_GTE:
1038 case SPECIAL_GTE:
1039 if (get_hard_max(left, &hard_max)) {
1040 if (op == '>' || op == SPECIAL_UNSIGNED_GT)
1041 hard_max.value--;
1042 estate_set_fuzzy_max(right_true_state, hard_max);
1043 }
1044 if (get_implied_value(left, &hard_max)) {
1045 if (op == SPECIAL_UNSIGNED_GTE ||
1046 op == SPECIAL_GTE)
1047 hard_max.value++;
1048 estate_set_fuzzy_max(right_false_state, hard_max);
1049 }
1050 if (get_hard_max(right, &hard_max)) {
1051 if (op == SPECIAL_UNSIGNED_LTE ||
1052 op == SPECIAL_LTE)
1053 hard_max.value--;
1054 estate_set_fuzzy_max(left_false_state, hard_max);
1055 }
1056 if (get_implied_value(right, &hard_max)) {
1057 if (op == '>' ||
1058 op == SPECIAL_UNSIGNED_GT)
1059 hard_max.value++;
1060 estate_set_fuzzy_max(left_true_state, hard_max);
1061 }
1062 break;
1063 case SPECIAL_EQUAL:
1064 if (get_hard_max(left, &hard_max))
1065 estate_set_fuzzy_max(right_true_state, hard_max);
1066 if (get_hard_max(right, &hard_max))
1067 estate_set_fuzzy_max(left_true_state, hard_max);
1068 break;
1069 }
1070
1071 if (get_hard_max(left, &hard_max)) {
1072 estate_set_hard_max(left_true_state);
1073 estate_set_hard_max(left_false_state);
1074 }
1075 if (get_hard_max(right, &hard_max)) {
1076 estate_set_hard_max(right_true_state);
1077 estate_set_hard_max(right_false_state);
1078 }
1079
1080 if (left_postop == SPECIAL_INCREMENT) {
1081 left_true_state = increment_state(left_true_state);
1082 left_false_state = increment_state(left_false_state);
1083 }
1084 if (left_postop == SPECIAL_DECREMENT) {
1085 left_true_state = decrement_state(left_true_state);
1086 left_false_state = decrement_state(left_false_state);
1087 }
1088 if (right_postop == SPECIAL_INCREMENT) {
1089 right_true_state = increment_state(right_true_state);
1090 right_false_state = increment_state(right_false_state);
1091 }
1092 if (right_postop == SPECIAL_DECREMENT) {
1093 right_true_state = decrement_state(right_true_state);
1094 right_false_state = decrement_state(right_false_state);
1095 }
1096
1097 set_extra_expr_true_false(left, left_true_state, left_false_state);
1098 set_extra_expr_true_false(right, right_true_state, right_false_state);
1099 }
1100
1101 static int opposite_op(int op)
1102 {
1103 switch (op) {
1104 case '+':
1105 return '-';
1106 case '-':
1107 return '+';
1108 }
1109 return 0;
1110 }
1111
1112 static int is_simple_math(struct expression *expr)
1113 {
1114 if (!expr)
1115 return 0;
1116 if (expr->type != EXPR_BINOP)
1117 return 0;
1118 if (!opposite_op(expr->op))
1119 return 0;
1120 return 1;
1121 }
1122
1123 static void move_known_values(struct expression **left_p, struct expression **right_p)
1124 {
1125 struct expression *left = *left_p;
1126 struct expression *right = *right_p;
1127 sval_t sval;
1128
1129 if (get_implied_value(left, &sval)) {
1130 if (!is_simple_math(right))
1131 return;
1132 if (right->op == '+' && get_value(right->left, &sval)) {
1133 *left_p = binop_expression(left, opposite_op(right->op), right->left);
1134 *right_p = right->right;
1135 return;
1136 }
1137 if (get_value(right->right, &sval)) {
1138 *left_p = binop_expression(left, opposite_op(right->op), right->right);
1139 *right_p = right->left;
1140 return;
1141 }
1142 return;
1143 }
1144 if (get_implied_value(right, &sval)) {
1145 if (!is_simple_math(left))
1146 return;
1147 if (left->op == '+' && get_value(left->left, &sval)) {
1148 *right_p = binop_expression(right, opposite_op(left->op), left->left);
1149 *left_p = left->right;
1150 return;
1151 }
1152
1153 if (get_value(left->right, &sval)) {
1154 *right_p = binop_expression(right, opposite_op(left->op), left->right);
1155 *left_p = left->left;
1156 return;
1157 }
1158 return;
1159 }
1160 }
1161
1162 static int match_func_comparison(struct expression *expr)
1163 {
1164 struct expression *left = strip_expr(expr->left);
1165 struct expression *right = strip_expr(expr->right);
1166 sval_t sval;
1167
1168 /*
1169 * fixme: think about this harder. We should always be trying to limit
1170 * the non-call side as well. If we can't determine the limitter does
1171 * that mean we aren't querying the database and are missing important
1172 * information?
1173 */
1174
1175 if (left->type == EXPR_CALL) {
1176 if (get_implied_value(left, &sval)) {
1177 handle_comparison(get_type(expr), left, expr->op, right);
1178 return 1;
1179 }
1180 if (!get_implied_value(right, &sval))
1181 return 1;
1182 function_comparison(expr->op, left, sval, 1);
1183 return 1;
1184 }
1185
1186 if (right->type == EXPR_CALL) {
1187 if (get_implied_value(right, &sval)) {
1188 handle_comparison(get_type(expr), left, expr->op, right);
1189 return 1;
1190 }
1191 if (!get_implied_value(left, &sval))
1192 return 1;
1193 function_comparison(expr->op, right, sval, 0);
1194 return 1;
1195 }
1196
1197 return 0;
1198 }
1199
1200 static void match_comparison(struct expression *expr)
1201 {
1202 struct expression *left_orig = strip_expr(expr->left);
1203 struct expression *right_orig = strip_expr(expr->right);
1204 struct expression *left, *right;
1205 struct expression *prev;
1206 struct symbol *type;
1207
1208 if (match_func_comparison(expr))
1209 return;
1210
1211 type = get_type(expr);
1212 if (!type)
1213 type = &llong_ctype;
1214
1215 left = left_orig;
1216 right = right_orig;
1217 move_known_values(&left, &right);
1218 handle_comparison(type, left, expr->op, right);
1219
1220 prev = get_assigned_expr(left_orig);
1221 if (is_simple_math(prev) && has_variable(prev, left_orig) == 0) {
1222 left = prev;
1223 right = right_orig;
1224 move_known_values(&left, &right);
1225 handle_comparison(type, left, expr->op, right);
1226 }
1227
1228 prev = get_assigned_expr(right_orig);
1229 if (is_simple_math(prev) && has_variable(prev, right_orig) == 0) {
1230 left = left_orig;
1231 right = prev;
1232 move_known_values(&left, &right);
1233 handle_comparison(type, left, expr->op, right);
1234 }
1235 }
1236
1237 static void handle_AND_condition(struct expression *expr)
1238 {
1239 struct range_list *rl = NULL;
1240 sval_t known;
1241
1242 if (get_implied_value(expr->left, &known) && known.value > 0) {
1243 known.value--;
1244 get_absolute_rl(expr->right, &rl);
1245 rl = remove_range(rl, sval_type_val(known.type, 0), known);
1246 set_extra_expr_true_false(expr->right, alloc_estate_rl(rl), NULL);
1247 return;
1248 }
1249
1250 if (get_implied_value(expr->right, &known) && known.value > 0) {
1251 known.value--;
1252 get_absolute_rl(expr->left, &rl);
1253 rl = remove_range(rl, sval_type_val(known.type, 0), known);
1254 set_extra_expr_true_false(expr->left, alloc_estate_rl(rl), NULL);
1255 return;
1256 }
1257 }
1258
1259 /* this is actually hooked from smatch_implied.c... it's hacky, yes */
1260 void __extra_match_condition(struct expression *expr)
1261 {
1262 struct symbol *sym;
1263 char *name;
1264 struct smatch_state *pre_state;
1265 struct smatch_state *true_state;
1266 struct smatch_state *false_state;
1267
1268 expr = strip_expr(expr);
1269 switch (expr->type) {
1270 case EXPR_CALL:
1271 function_comparison(SPECIAL_NOTEQUAL, expr, ll_to_sval(0), 1);
1272 return;
1273 case EXPR_PREOP:
1274 case EXPR_SYMBOL:
1275 case EXPR_DEREF: {
1276 sval_t zero;
1277
1278 zero = sval_blank(expr);
1279 zero.value = 0;
1280
1281 name = expr_to_var_sym(expr, &sym);
1282 if (!name)
1283 return;
1284 pre_state = get_state(my_id, name, sym);
1285 true_state = estate_filter_sval(pre_state, zero);
1286 if (possibly_true(expr, SPECIAL_EQUAL, zero_expr()))
1287 false_state = alloc_estate_sval(zero);
1288 else
1289 false_state = alloc_estate_empty();
1290 set_extra_true_false(name, sym, true_state, false_state);
1291 free_string(name);
1292 return;
1293 }
1294 case EXPR_COMPARE:
1295 match_comparison(expr);
1296 return;
1297 case EXPR_ASSIGNMENT:
1298 __extra_match_condition(expr->left);
1299 return;
1300 case EXPR_BINOP:
1301 if (expr->op == '&')
1302 handle_AND_condition(expr);
1303 return;
1304 }
1305 }
1306
1307 static void assume_indexes_are_valid(struct expression *expr)
1308 {
1309 struct expression *array_expr;
1310 int array_size;
1311 struct expression *offset;
1312 struct symbol *offset_type;
1313 struct range_list *rl_before;
1314 struct range_list *rl_after;
1315 struct range_list *filter = NULL;
1316 sval_t size;
1317
1318 expr = strip_expr(expr);
1319 if (!is_array(expr))
1320 return;
1321
1322 offset = get_array_offset(expr);
1323 offset_type = get_type(offset);
1324 if (offset_type && type_signed(offset_type)) {
1325 filter = alloc_rl(sval_type_min(offset_type),
1326 sval_type_val(offset_type, -1));
1327 }
1328
1329 array_expr = strip_parens(expr->unop->left);
1330 array_size = get_real_array_size(array_expr);
1331 if (array_size > 1) {
1332 size = sval_type_val(offset_type, array_size);
1333 add_range(&filter, size, sval_type_max(offset_type));
1334 }
1335
1336 if (!filter)
1337 return;
1338 get_absolute_rl(offset, &rl_before);
1339 rl_after = rl_filter(rl_before, filter);
1340 if (rl_equiv(rl_before, rl_after))
1341 return;
1342 set_extra_expr_nomod(offset, alloc_estate_rl(rl_after));
1343 }
1344
1345 /* returns 1 if it is not possible for expr to be value, otherwise returns 0 */
1346 int implied_not_equal(struct expression *expr, long long val)
1347 {
1348 return !possibly_false(expr, SPECIAL_NOTEQUAL, value_expr(val));
1349 }
1350
1351 static void struct_member_callback(struct expression *call, int param, char *printed_name, struct smatch_state *state)
1352 {
1353 if (estate_is_whole(state))
1354 return;
1355 sql_insert_caller_info(call, PARAM_VALUE, param, printed_name, state->name);
1356 if (estate_has_fuzzy_max(state))
1357 sql_insert_caller_info(call, FUZZY_MAX, param, printed_name,
1358 sval_to_str(estate_get_fuzzy_max(state)));
1359 }
1360
1361 static void db_limited_before(void)
1362 {
1363 unmatched_stree = clone_stree(__get_cur_stree());
1364 }
1365
1366 static void db_limited_after(void)
1367 {
1368 free_stree(&unmatched_stree);
1369 }
1370
1371 static void db_param_limit_filter(struct expression *expr, int param, char *key, char *value, int mod)
1372 {
1373 struct expression *arg;
1374 char *name;
1375 struct symbol *sym;
1376 struct sm_state *sm;
1377 struct symbol *type;
1378 struct range_list *rl;
1379 struct range_list *limit;
1380 struct range_list *new;
1381
1382 while (expr->type == EXPR_ASSIGNMENT)
1383 expr = strip_expr(expr->right);
1384 if (expr->type != EXPR_CALL)
1385 return;
1386
1387 arg = get_argument_from_call_expr(expr->args, param);
1388 if (!arg)
1389 return;
1390
1391 name = get_variable_from_key(arg, key, &sym);
1392 if (!name || !sym)
1393 goto free;
1394
1395 sm = get_sm_state(SMATCH_EXTRA, name, sym);
1396 type = get_member_type_from_key(arg, key);
1397 if (sm)
1398 rl = estate_rl(sm->state);
1399 else
1400 rl = alloc_whole_rl(type);
1401
1402 call_results_to_rl(expr, type, value, &limit);
1403 new = rl_intersection(rl, limit);
1404
1405 /* We want to preserve the implications here */
1406 if (sm && rl_equiv(estate_rl(sm->state), new)) {
1407 __set_sm(sm);
1408 } else {
1409 if (mod)
1410 set_extra_mod(name, sym, alloc_estate_rl(new));
1411 else
1412 set_extra_nomod(name, sym, alloc_estate_rl(new));
1413 }
1414
1415 free:
1416 free_string(name);
1417 }
1418
1419 static void db_param_limit(struct expression *expr, int param, char *key, char *value)
1420 {
1421 db_param_limit_filter(expr, param, key, value, 0);
1422 }
1423
1424 static void db_param_filter(struct expression *expr, int param, char *key, char *value)
1425 {
1426 db_param_limit_filter(expr, param, key, value, 1);
1427 }
1428
1429 static void db_param_add(struct expression *expr, int param, char *key, char *value)
1430 {
1431 struct expression *arg;
1432 char *name;
1433 struct symbol *sym;
1434 struct symbol *type;
1435 struct smatch_state *state;
1436 struct range_list *added = NULL;
1437 struct range_list *new;
1438
1439 while (expr->type == EXPR_ASSIGNMENT)
1440 expr = strip_expr(expr->right);
1441 if (expr->type != EXPR_CALL)
1442 return;
1443
1444 arg = get_argument_from_call_expr(expr->args, param);
1445 if (!arg)
1446 return;
1447 name = get_variable_from_key(arg, key, &sym);
1448 if (!name || !sym)
1449 goto free;
1450
1451 type = get_member_type_from_key(arg, key);
1452 state = get_state(SMATCH_EXTRA, name, sym);
1453 if (state) {
1454 call_results_to_rl(expr, type, value, &added);
1455 new = rl_union(estate_rl(state), added);
1456 } else {
1457 new = alloc_whole_rl(type);
1458 }
1459
1460 set_extra_mod(name, sym, alloc_estate_rl(new));
1461 free:
1462 free_string(name);
1463 }
1464
1465 static void db_returned_member_info(struct expression *expr, int param, char *key, char *value)
1466 {
1467 struct symbol *type;
1468 struct symbol *sym;
1469 char *name;
1470 struct range_list *rl;
1471
1472 if (expr->type != EXPR_ASSIGNMENT)
1473 return;
1474
1475 name = return_state_to_var_sym(expr, param, key, &sym);
1476 if (!name || !sym)
1477 goto free;
1478 type = get_member_type_from_key(expr->left, key);
1479 if (!type)
1480 return;
1481 call_results_to_rl(expr->right, type, value, &rl);
1482 set_extra_mod(name, sym, alloc_estate_rl(rl));
1483
1484 free:
1485 free_string(name);
1486 }
1487
1488 static void returned_member_callback(int return_id, char *return_ranges, char *printed_name, struct smatch_state *state)
1489 {
1490 if (estate_is_whole(state))
1491 return;
1492
1493 /* these are handled in smatch_param_filter/set/limit.c */
1494 if (printed_name[0] != '*' &&
1495 !strchr(printed_name, '.') && !strchr(printed_name, '-'))
1496 return;
1497
1498 sql_insert_return_states(return_id, return_ranges, RETURN_VALUE, -1,
1499 printed_name, state->name);
1500 }
1501
1502 static void match_call_info(struct expression *expr)
1503 {
1504 struct smatch_state *state;
1505 struct range_list *rl = NULL;
1506 struct expression *arg;
1507 struct symbol *type;
1508 int i = 0;
1509
1510 FOR_EACH_PTR(expr->args, arg) {
1511 type = get_arg_type(expr->fn, i);
1512
1513 if (get_implied_rl(arg, &rl))
1514 rl = cast_rl(type, rl);
1515 else
1516 rl = cast_rl(type, alloc_whole_rl(get_type(arg)));
1517
1518 if (!is_whole_rl(rl))
1519 sql_insert_caller_info(expr, PARAM_VALUE, i, "$$", show_rl(rl));
1520 state = get_state_expr(SMATCH_EXTRA, arg);
1521 if (estate_has_fuzzy_max(state)) {
1522 sql_insert_caller_info(expr, FUZZY_MAX, i, "$$",
1523 sval_to_str(estate_get_fuzzy_max(state)));
1524 }
1525 i++;
1526 } END_FOR_EACH_PTR(arg);
1527 }
1528
1529 static void set_param_value(const char *name, struct symbol *sym, char *key, char *value)
1530 {
1531 struct range_list *rl = NULL;
1532 struct smatch_state *state;
1533 struct symbol *type;
1534 char fullname[256];
1535
1536 if (strcmp(key, "*$$") == 0)
1537 snprintf(fullname, sizeof(fullname), "*%s", name);
1538 else if (strncmp(key, "$$", 2) == 0)
1539 snprintf(fullname, 256, "%s%s", name, key + 2);
1540 else
1541 return;
1542
1543 type = get_member_type_from_key(symbol_expression(sym), key);
1544 str_to_rl(type, value, &rl);
1545 state = alloc_estate_rl(rl);
1546 set_state(SMATCH_EXTRA, fullname, sym, state);
1547 }
1548
1549 static void set_param_hard_max(const char *name, struct symbol *sym, char *key, char *value)
1550 {
1551 struct range_list *rl = NULL;
1552 struct smatch_state *state;
1553 struct symbol *type;
1554 char fullname[256];
1555 sval_t max;
1556
1557 if (strcmp(key, "*$$") == 0)
1558 snprintf(fullname, sizeof(fullname), "*%s", name);
1559 else if (strncmp(key, "$$", 2) == 0)
1560 snprintf(fullname, 256, "%s%s", name, key + 2);
1561 else
1562 return;
1563
1564 state = get_state(SMATCH_EXTRA, fullname, sym);
1565 if (!state)
1566 return;
1567 type = get_member_type_from_key(symbol_expression(sym), key);
1568 str_to_rl(type, value, &rl);
1569 if (!rl_to_sval(rl, &max))
1570 return;
1571 estate_set_fuzzy_max(state, max);
1572 }
1573
1574 void register_smatch_extra(int id)
1575 {
1576 my_id = id;
1577
1578 add_merge_hook(my_id, &merge_estates);
1579 add_unmatched_state_hook(my_id, &unmatched_state);
1580 add_hook(&match_function_def, FUNC_DEF_HOOK);
1581 add_hook(&match_declarations, DECLARATION_HOOK);
1582 select_caller_info_hook(set_param_value, PARAM_VALUE);
1583 select_caller_info_hook(set_param_hard_max, FUZZY_MAX);
1584 select_return_states_hook(RETURN_VALUE, &db_returned_member_info);
1585 select_return_states_before(&db_limited_before);
1586 select_return_states_hook(LIMITED_VALUE, &db_param_limit);
1587 select_return_states_hook(FILTER_VALUE, &db_param_filter);
1588 select_return_states_hook(ADDED_VALUE, &db_param_add);
1589 select_return_states_after(&db_limited_after);
1590 }
1591
1592 void register_smatch_extra_late(int id)
1593 {
1594 add_hook(&match_dereferences, DEREF_HOOK);
1595 add_hook(&match_pointer_as_array, OP_HOOK);
1596 select_call_implies_hook(DEREFERENCE, &set_param_dereferenced);
1597 add_hook(&match_function_call, FUNCTION_CALL_HOOK);
1598 add_hook(&match_assign, ASSIGNMENT_HOOK);
1599 add_hook(&unop_expr, OP_HOOK);
1600 add_hook(&asm_expr, ASM_HOOK);
1601
1602 add_hook(&match_call_info, FUNCTION_CALL_HOOK);
1603 add_member_info_callback(my_id, struct_member_callback);
1604 add_returned_member_callback(my_id, returned_member_callback);
1605
1606 add_hook(&assume_indexes_are_valid, OP_HOOK);
1607 }
Static analysis for C