2 * Copyright (C) 2010 Dan Carpenter.
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.
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.
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
22 #include "smatch_slist.h"
23 #include "smatch_extra.h"
24 #include "smatch_function_hashtable.h"
26 #define UNKNOWN_SIZE (-1)
28 static int my_size_id
;
34 static struct limiter b0_l2
= {0, 2};
36 static DEFINE_HASHTABLE_INSERT(insert_func
, char, int);
37 static DEFINE_HASHTABLE_SEARCH(search_func
, char, int);
38 static struct hashtable
*allocation_funcs
;
40 static char *get_fn_name(struct expression
*expr
)
42 if (expr
->type
!= EXPR_CALL
)
44 if (expr
->fn
->type
!= EXPR_SYMBOL
)
46 return expr_to_var(expr
->fn
);
49 static int is_allocation_function(struct expression
*expr
)
54 func
= get_fn_name(expr
);
57 if (search_func(allocation_funcs
, func
))
63 static void add_allocation_function(const char *func
, void *call_back
, int param
)
65 insert_func(allocation_funcs
, (char *)func
, (int *)1);
66 add_function_assign_hook(func
, call_back
, INT_PTR(param
));
69 static int estate_to_size(struct smatch_state
*state
)
73 if (!state
|| !estate_rl(state
))
75 sval
= estate_max(state
);
79 static struct smatch_state
*size_to_estate(int size
)
83 sval
.type
= &int_ctype
;
86 return alloc_estate_sval(sval
);
89 static struct range_list
*size_to_rl(int size
)
93 sval
.type
= &int_ctype
;
96 return alloc_rl(sval
, sval
);
99 static struct smatch_state
*unmatched_size_state(struct sm_state
*sm
)
101 return size_to_estate(UNKNOWN_SIZE
);
104 static void set_size_undefined(struct sm_state
*sm
, struct expression
*mod_expr
)
106 set_state(sm
->owner
, sm
->name
, sm
->sym
, size_to_estate(UNKNOWN_SIZE
));
109 static struct smatch_state
*merge_size_func(struct smatch_state
*s1
, struct smatch_state
*s2
)
111 return merge_estates(s1
, s2
);
114 void set_param_buf_size(const char *name
, struct symbol
*sym
, char *key
, char *value
)
116 struct range_list
*rl
= NULL
;
117 struct smatch_state
*state
;
120 if (strncmp(key
, "$", 1) != 0)
123 snprintf(fullname
, 256, "%s%s", name
, key
+ 1);
125 str_to_rl(&int_ctype
, value
, &rl
);
126 if (!rl
|| is_whole_rl(rl
))
128 state
= alloc_estate_rl(rl
);
129 set_state(my_size_id
, fullname
, sym
, state
);
132 static int bytes_per_element(struct expression
*expr
)
138 if (expr
->type
== EXPR_STRING
)
140 type
= get_type(expr
);
144 if (type
->type
!= SYM_PTR
&& type
->type
!= SYM_ARRAY
)
147 type
= get_base_type(type
);
148 return type_bytes(type
);
151 static int bytes_to_elements(struct expression
*expr
, int bytes
)
155 bpe
= bytes_per_element(expr
);
161 static int elements_to_bytes(struct expression
*expr
, int elements
)
165 bpe
= bytes_per_element(expr
);
166 return elements
* bpe
;
169 static int get_initializer_size(struct expression
*expr
)
171 switch (expr
->type
) {
173 return expr
->string
->length
;
174 case EXPR_INITIALIZER
: {
175 struct expression
*tmp
;
178 FOR_EACH_PTR(expr
->expr_list
, tmp
) {
179 if (tmp
->type
== EXPR_INDEX
) {
180 if (tmp
->idx_to
>= i
)
187 } END_FOR_EACH_PTR(tmp
);
191 return get_array_size(expr
);
196 static struct range_list
*db_size_rl
;
197 static int db_size_callback(void *unused
, int argc
, char **argv
, char **azColName
)
199 struct range_list
*tmp
= NULL
;
202 str_to_rl(&int_ctype
, argv
[0], &db_size_rl
);
204 str_to_rl(&int_ctype
, argv
[0], &tmp
);
205 db_size_rl
= rl_union(db_size_rl
, tmp
);
210 static struct range_list
*size_from_db(struct expression
*expr
)
212 int this_file_only
= 0;
215 name
= get_member_name(expr
);
216 if (!name
&& is_static(expr
)) {
217 name
= expr_to_var(expr
);
223 if (this_file_only
) {
225 run_sql(db_size_callback
, NULL
,
226 "select size from function_type_size where type = '%s' and file = '%s';",
227 name
, get_filename());
234 run_sql(db_size_callback
, NULL
,
235 "select size from type_size where type = '%s';",
240 static void db_returns_buf_size(struct expression
*expr
, int param
, char *unused
, char *math
)
242 struct expression
*call
;
245 if (expr
->type
!= EXPR_ASSIGNMENT
)
247 call
= strip_expr(expr
->right
);
249 if (!parse_call_math(call
, math
, &sval
))
251 set_state_expr(my_size_id
, expr
->left
, size_to_estate(sval
.value
));
254 int get_real_array_size(struct expression
*expr
)
261 if (expr
->type
== EXPR_BINOP
) /* array elements foo[5] */
264 type
= get_type(expr
);
267 if (!type
|| type
->type
!= SYM_ARRAY
)
270 if (!get_implied_value(type
->array_size
, &sval
))
273 /* People put one element arrays on the end of structs */
280 static int get_size_from_initializer(struct expression
*expr
)
282 if (expr
->type
!= EXPR_SYMBOL
|| !expr
->symbol
|| !expr
->symbol
->initializer
)
284 if (expr
->symbol
->initializer
== expr
) /* int a = a; */
286 return get_initializer_size(expr
->symbol
->initializer
);
289 static struct range_list
*get_stored_size_bytes(struct expression
*expr
)
291 struct smatch_state
*state
;
293 state
= get_state_expr(my_size_id
, expr
);
296 return estate_rl(state
);
299 static int get_bytes_from_address(struct expression
*expr
)
306 if (expr
->type
!= EXPR_PREOP
|| expr
->op
!= '&')
308 type
= get_type(expr
);
312 if (type
->type
== SYM_PTR
)
313 type
= get_base_type(type
);
315 ret
= type_bytes(type
);
317 return 0; /* ignore char pointers */
322 static struct expression
*remove_addr_fluff(struct expression
*expr
)
324 struct expression
*tmp
;
327 expr
= strip_expr(expr
);
329 /* remove '&' and '*' operations that cancel */
330 while (expr
&& expr
->type
== EXPR_PREOP
&& expr
->op
== '&') {
331 tmp
= strip_expr(expr
->unop
);
332 if (tmp
->type
!= EXPR_PREOP
)
336 expr
= strip_expr(tmp
->unop
);
342 /* "foo + 0" is just "foo" */
343 if (expr
->type
== EXPR_BINOP
&& expr
->op
== '+' &&
344 get_value(expr
->right
, &sval
) && sval
.value
== 0)
350 static int is_last_member_of_struct(struct symbol
*sym
, struct ident
*member
)
356 FOR_EACH_PTR_REVERSE(sym
->symbol_list
, tmp
) {
357 if (i
++ || !tmp
->ident
)
359 if (tmp
->ident
== member
)
362 } END_FOR_EACH_PTR_REVERSE(tmp
);
367 static int last_member_is_resizable(struct symbol
*sym
)
369 struct symbol
*last_member
;
373 last_member
= last_ptr_list((struct ptr_list
*)sym
->symbol_list
);
374 if (!last_member
|| !last_member
->ident
)
377 type
= get_real_base_type(last_member
);
378 if (type
->type
== SYM_STRUCT
)
379 return last_member_is_resizable(type
);
380 if (type
->type
!= SYM_ARRAY
)
383 if (!get_implied_value(type
->array_size
, &sval
))
386 if (sval
.value
!= 0 && sval
.value
!= 1)
392 static int get_stored_size_end_struct_bytes(struct expression
*expr
)
395 struct symbol
*base_sym
;
396 struct smatch_state
*state
;
398 if (expr
->type
== EXPR_BINOP
) /* array elements foo[5] */
401 if (expr
->type
== EXPR_PREOP
&& expr
->op
== '&')
402 expr
= strip_parens(expr
->unop
);
404 sym
= expr_to_sym(expr
);
405 if (!sym
|| !sym
->ident
)
407 if (!type_bytes(sym
))
409 if (sym
->type
!= SYM_NODE
)
412 base_sym
= get_real_base_type(sym
);
413 if (!base_sym
|| base_sym
->type
!= SYM_PTR
)
415 base_sym
= get_real_base_type(base_sym
);
416 if (!base_sym
|| base_sym
->type
!= SYM_STRUCT
)
419 if (!is_last_member_of_struct(base_sym
, expr
->member
))
421 if (!last_member_is_resizable(base_sym
))
424 state
= get_state(my_size_id
, sym
->ident
->name
, sym
);
425 if (!estate_to_size(state
))
428 return estate_to_size(state
) - type_bytes(base_sym
) + type_bytes(get_type(expr
));
431 static struct range_list
*alloc_int_rl(int value
)
438 return alloc_rl(sval
, sval
);
441 struct range_list
*get_array_size_bytes_rl(struct expression
*expr
)
443 int declared_size
= 0;
444 struct range_list
*ret
= NULL
;
447 expr
= remove_addr_fluff(expr
);
452 if (expr
->type
== EXPR_STRING
)
453 return alloc_int_rl(expr
->string
->length
);
455 if (expr
->type
== EXPR_BINOP
&& expr
->op
== '+') {
458 if (!get_implied_value(expr
->right
, &offset
))
460 size
= get_array_size_bytes(expr
->left
);
463 return alloc_int_rl(size
- offset
.value
);
467 size
= get_real_array_size(expr
);
469 declared_size
= elements_to_bytes(expr
, size
);
471 /* buf = malloc(1024); */
472 ret
= get_stored_size_bytes(expr
);
475 return rl_union(ret
, alloc_int_rl(size
));
479 return alloc_int_rl(declared_size
);
481 size
= get_stored_size_end_struct_bytes(expr
);
483 return alloc_int_rl(size
);
485 /* char *foo = "BAR" */
486 size
= get_size_from_initializer(expr
);
488 return alloc_int_rl(elements_to_bytes(expr
, size
));
490 size
= get_bytes_from_address(expr
);
492 return alloc_int_rl(size
);
494 /* if (strlen(foo) > 4) */
495 size
= get_size_from_strlen(expr
);
497 return alloc_int_rl(size
);
499 ret
= size_from_db(expr
);
506 int get_array_size_bytes(struct expression
*expr
)
508 struct range_list
*rl
;
511 rl
= get_array_size_bytes_rl(expr
);
512 if (!rl_to_sval(rl
, &sval
))
514 if (sval
.uvalue
>= INT_MAX
)
519 int get_array_size_bytes_max(struct expression
*expr
)
521 struct range_list
*rl
;
524 rl
= get_array_size_bytes_rl(expr
);
531 if (bytes
.uvalue
>= INT_MAX
)
536 int get_array_size_bytes_min(struct expression
*expr
)
538 struct range_list
*rl
;
539 struct data_range
*range
;
541 rl
= get_array_size_bytes_rl(expr
);
545 FOR_EACH_PTR(rl
, range
) {
546 if (range
->min
.value
<= 0)
548 if (range
->max
.value
<= 0)
550 if (range
->min
.uvalue
>= INT_MAX
)
552 return range
->min
.value
;
553 } END_FOR_EACH_PTR(range
);
558 int get_array_size(struct expression
*expr
)
562 return bytes_to_elements(expr
, get_array_size_bytes_max(expr
));
565 static void match_strlen_condition(struct expression
*expr
)
567 struct expression
*left
;
568 struct expression
*right
;
569 struct expression
*str
= NULL
;
571 int strlen_right
= 0;
573 struct smatch_state
*true_state
= NULL
;
574 struct smatch_state
*false_state
= NULL
;
576 if (expr
->type
!= EXPR_COMPARE
)
578 left
= strip_expr(expr
->left
);
579 right
= strip_expr(expr
->right
);
581 if (left
->type
== EXPR_CALL
&& sym_name_is("strlen", left
->fn
)) {
582 str
= get_argument_from_call_expr(left
->args
, 0);
585 if (right
->type
== EXPR_CALL
&& sym_name_is("strlen", right
->fn
)) {
586 str
= get_argument_from_call_expr(right
->args
, 0);
590 if (!strlen_left
&& !strlen_right
)
592 if (strlen_left
&& strlen_right
)
596 if (!get_value(right
, &sval
))
600 if (!get_value(left
, &sval
))
604 /* FIXME: why are we using my_size_id here instead of my_strlen_id */
606 if (expr
->op
== SPECIAL_EQUAL
) {
607 set_true_false_states_expr(my_size_id
, str
, size_to_estate(sval
.value
+ 1), NULL
);
610 if (expr
->op
== SPECIAL_NOTEQUAL
) {
611 set_true_false_states_expr(my_size_id
, str
, NULL
, size_to_estate(sval
.value
+ 1));
617 case SPECIAL_UNSIGNED_LT
:
619 true_state
= size_to_estate(sval
.value
);
621 false_state
= size_to_estate(sval
.value
+ 1);
624 case SPECIAL_UNSIGNED_LTE
:
626 true_state
= size_to_estate(sval
.value
+ 1);
628 false_state
= size_to_estate(sval
.value
);
631 case SPECIAL_UNSIGNED_GTE
:
633 false_state
= size_to_estate(sval
.value
);
635 true_state
= size_to_estate(sval
.value
+ 1);
638 case SPECIAL_UNSIGNED_GT
:
640 true_state
= size_to_estate(-1);
641 false_state
= size_to_estate(sval
.value
+ 1);
643 true_state
= size_to_estate(sval
.value
);
646 set_true_false_states_expr(my_size_id
, str
, true_state
, false_state
);
649 static struct expression
*strip_ampersands(struct expression
*expr
)
653 if (expr
->type
!= EXPR_PREOP
)
657 type
= get_type(expr
->unop
);
658 if (!type
|| type
->type
!= SYM_ARRAY
)
663 static void info_record_alloction(struct expression
*buffer
, struct range_list
*rl
)
670 name
= get_member_name(buffer
);
671 if (!name
&& is_static(buffer
))
672 name
= expr_to_var(buffer
);
675 if (rl
&& !is_whole_rl(rl
))
676 sql_insert_function_type_size(name
, show_rl(rl
));
678 sql_insert_function_type_size(name
, "(-1)");
683 static void store_alloc(struct expression
*expr
, struct range_list
*rl
)
685 rl
= clone_rl(rl
); // FIXME!!!
686 info_record_alloction(expr
, rl
);
687 set_state_expr(my_size_id
, expr
, alloc_estate_rl(rl
));
690 static void match_array_assignment(struct expression
*expr
)
692 struct expression
*left
;
693 struct expression
*right
;
694 char *left_member
, *right_member
;
695 struct range_list
*rl
;
700 left
= strip_expr(expr
->left
);
701 right
= strip_expr(expr
->right
);
702 right
= strip_ampersands(right
);
704 if (!is_pointer(left
))
706 if (is_allocation_function(right
))
709 left_member
= get_member_name(left
);
710 right_member
= get_member_name(right
);
711 if (left_member
&& right_member
&& strcmp(left_member
, right_member
) == 0) {
712 free_string(left_member
);
713 free_string(right_member
);
716 free_string(left_member
);
717 free_string(right_member
);
719 if (get_implied_value(right
, &sval
) && sval
.value
== 0) {
720 rl
= alloc_int_rl(0);
724 rl
= get_array_size_bytes_rl(right
);
727 store_alloc(left
, rl
);
730 static void match_alloc(const char *fn
, struct expression
*expr
, void *_size_arg
)
732 int size_arg
= PTR_INT(_size_arg
);
733 struct expression
*right
;
734 struct expression
*arg
;
735 struct range_list
*rl
;
737 right
= strip_expr(expr
->right
);
738 arg
= get_argument_from_call_expr(right
->args
, size_arg
);
739 get_absolute_rl(arg
, &rl
);
740 rl
= cast_rl(&int_ctype
, rl
);
741 store_alloc(expr
->left
, rl
);
744 static void match_calloc(const char *fn
, struct expression
*expr
, void *unused
)
746 struct expression
*right
;
747 struct expression
*arg
;
751 right
= strip_expr(expr
->right
);
752 arg
= get_argument_from_call_expr(right
->args
, 0);
753 if (!get_implied_value(arg
, &elements
))
755 arg
= get_argument_from_call_expr(right
->args
, 1);
756 if (get_implied_value(arg
, &size
))
757 store_alloc(expr
->left
, size_to_rl(elements
.value
* size
.value
));
759 store_alloc(expr
->left
, size_to_rl(-1));
762 static void match_limited(const char *fn
, struct expression
*expr
, void *_limiter
)
764 struct limiter
*limiter
= (struct limiter
*)_limiter
;
765 struct expression
*dest
;
766 struct expression
*size_expr
;
769 dest
= get_argument_from_call_expr(expr
->args
, limiter
->buf_arg
);
770 size_expr
= get_argument_from_call_expr(expr
->args
, limiter
->limit_arg
);
771 if (!get_implied_max(size_expr
, &size
))
773 set_state_expr(my_size_id
, dest
, size_to_estate(size
.value
));
776 static void match_strcpy(const char *fn
, struct expression
*expr
, void *unused
)
778 struct expression fake_assign
;
780 fake_assign
.op
= '=';
781 fake_assign
.left
= get_argument_from_call_expr(expr
->args
, 0);
782 fake_assign
.right
= get_argument_from_call_expr(expr
->args
, 1);
783 match_array_assignment(&fake_assign
);
786 static void match_strndup(const char *fn
, struct expression
*expr
, void *unused
)
788 struct expression
*fn_expr
;
789 struct expression
*size_expr
;
792 fn_expr
= strip_expr(expr
->right
);
793 size_expr
= get_argument_from_call_expr(fn_expr
->args
, 1);
794 if (get_implied_max(size_expr
, &size
)) {
796 store_alloc(expr
->left
, size_to_rl(size
.value
));
798 store_alloc(expr
->left
, size_to_rl(-1));
803 static void match_call(struct expression
*expr
)
805 struct expression
*arg
;
807 struct range_list
*rl
;
811 FOR_EACH_PTR(expr
->args
, arg
) {
813 type
= get_type(arg
);
814 if (!type
|| (type
->type
!= SYM_PTR
&& type
->type
!= SYM_ARRAY
))
816 rl
= get_array_size_bytes_rl(arg
);
821 sql_insert_caller_info(expr
, BUF_SIZE
, i
, "$", show_rl(rl
));
822 } END_FOR_EACH_PTR(arg
);
825 static void struct_member_callback(struct expression
*call
, int param
, char *printed_name
, struct sm_state
*sm
)
827 if (sm
->state
== &merged
||
828 strcmp(sm
->state
->name
, "(-1)") == 0 ||
829 strcmp(sm
->state
->name
, "empty") == 0 ||
830 strcmp(sm
->state
->name
, "0") == 0)
832 sql_insert_caller_info(call
, BUF_SIZE
, param
, printed_name
, sm
->state
->name
);
835 void register_buf_size(int id
)
839 add_unmatched_state_hook(my_size_id
, &unmatched_size_state
);
841 select_caller_info_hook(set_param_buf_size
, BUF_SIZE
);
842 select_return_states_hook(BUF_SIZE
, &db_returns_buf_size
);
844 allocation_funcs
= create_function_hashtable(100);
845 add_allocation_function("malloc", &match_alloc
, 0);
846 add_allocation_function("calloc", &match_calloc
, 0);
847 add_allocation_function("memdup", &match_alloc
, 1);
848 add_allocation_function("realloc", &match_alloc
, 1);
849 if (option_project
== PROJ_KERNEL
) {
850 add_allocation_function("kmalloc", &match_alloc
, 0);
851 add_allocation_function("kzalloc", &match_alloc
, 0);
852 add_allocation_function("vmalloc", &match_alloc
, 0);
853 add_allocation_function("__vmalloc", &match_alloc
, 0);
854 add_allocation_function("kcalloc", &match_calloc
, 0);
855 add_allocation_function("kmalloc_array", &match_calloc
, 0);
856 add_allocation_function("drm_malloc_ab", &match_calloc
, 0);
857 add_allocation_function("drm_calloc_large", &match_calloc
, 0);
858 add_allocation_function("sock_kmalloc", &match_alloc
, 1);
859 add_allocation_function("kmemdup", &match_alloc
, 1);
860 add_allocation_function("kmemdup_user", &match_alloc
, 1);
861 add_allocation_function("dma_alloc_attrs", &match_alloc
, 1);
862 add_allocation_function("pci_alloc_consistent", &match_alloc
, 1);
863 add_allocation_function("pci_alloc_coherent", &match_alloc
, 1);
864 add_allocation_function("devm_kmalloc", &match_alloc
, 1);
865 add_allocation_function("devm_kzalloc", &match_alloc
, 1);
866 add_allocation_function("krealloc", &match_alloc
, 1);
868 add_hook(&match_strlen_condition
, CONDITION_HOOK
);
870 add_allocation_function("strndup", match_strndup
, 0);
871 if (option_project
== PROJ_KERNEL
)
872 add_allocation_function("kstrndup", match_strndup
, 0);
874 add_modification_hook(my_size_id
, &set_size_undefined
);
876 add_merge_hook(my_size_id
, &merge_size_func
);
879 void register_buf_size_late(int id
)
881 /* has to happen after match_alloc() */
882 add_hook(&match_array_assignment
, ASSIGNMENT_HOOK
);
884 add_function_hook("strlcpy", &match_limited
, &b0_l2
);
885 add_function_hook("strlcat", &match_limited
, &b0_l2
);
886 add_function_hook("memscan", &match_limited
, &b0_l2
);
888 add_function_hook("strcpy", &match_strcpy
, NULL
);
890 add_hook(&match_call
, FUNCTION_CALL_HOOK
);
891 add_member_info_callback(my_size_id
, struct_member_callback
);