2 * smatch/smatch_buf_size.c
4 * Copyright (C) 2010 Dan Carpenter.
6 * Licensed under the Open Software License version 1.1
14 #include "smatch_slist.h"
15 #include "smatch_extra.h"
18 * This check has two smatch IDs.
19 * my_size_id - used to store the size of arrays.
20 * my_strlen_id - track the strlen() of buffers.
23 static int my_size_id
;
24 static int my_strlen_id
;
30 static struct limiter b0_l2
= {0, 2};
32 static _Bool params_set
[32];
34 static void set_undefined(struct sm_state
*sm
)
36 if (sm
->state
!= &undefined
)
37 set_state(sm
->owner
, sm
->name
, sm
->sym
, &undefined
);
40 void set_param_buf_size(const char *name
, struct symbol
*sym
, char *key
, char *value
)
45 if (strncmp(key
, "$$", 2))
48 snprintf(fullname
, 256, "%s%s", name
, key
+ 2);
51 size
= strtoul(value
, NULL
, 10);
55 set_state(my_size_id
, fullname
, sym
, alloc_state_num(size
));
58 static int bytes_per_element(struct expression
*expr
)
63 if (expr
->type
== EXPR_STRING
)
65 type
= get_type(expr
);
69 if (type
->type
!= SYM_PTR
&& type
->type
!= SYM_ARRAY
)
72 type
= get_base_type(type
);
73 bpe
= bits_to_bytes(type
->bit_size
);
75 if (bpe
== -1) /* void pointer */
81 static int bytes_to_elements(struct expression
*expr
, int bytes
)
85 bpe
= bytes_per_element(expr
);
91 static int elements_to_bytes(struct expression
*expr
, int elements
)
95 bpe
= bytes_per_element(expr
);
96 return elements
* bpe
;
99 static int get_initializer_size(struct expression
*expr
)
101 switch (expr
->type
) {
103 return expr
->string
->length
;
104 case EXPR_INITIALIZER
: {
105 struct expression
*tmp
;
109 FOR_EACH_PTR(expr
->expr_list
, tmp
) {
110 if (tmp
->type
== EXPR_INDEX
&& tmp
->idx_to
> max
)
113 } END_FOR_EACH_PTR(tmp
);
119 return get_array_size(expr
);
125 static int db_size_callback(void *unused
, int argc
, char **argv
, char **azColName
)
128 db_size
= atoi(argv
[0]);
134 static int size_from_db(struct expression
*expr
)
141 name
= get_member_name(expr
);
146 run_sql(db_size_callback
, "select size from type_size where type = '%s' and file = '%s'",
147 name
, get_filename());
153 run_sql(db_size_callback
, "select size from type_size where type = '%s'",
162 static int get_real_array_size(struct expression
*expr
)
167 if (expr
->type
== EXPR_BINOP
) /* array elements foo[5] */
170 type
= get_type(expr
);
171 if (!type
|| type
->type
!= SYM_ARRAY
)
174 ret
= get_expression_value(type
->array_size
);
175 /* Dynamically sized array are -1 in sparse */
178 /* People put one element arrays on the end of structs */
185 static int get_size_from_initializer(struct expression
*expr
)
187 if (expr
->type
!= EXPR_SYMBOL
|| !expr
->symbol
->initializer
)
189 if (expr
->symbol
->initializer
== expr
) /* int a = a; */
191 return get_initializer_size(expr
->symbol
->initializer
);
194 static int get_stored_size_bytes(struct expression
*expr
)
196 struct smatch_state
*state
;
198 state
= get_state_expr(my_size_id
, expr
);
201 return PTR_INT(state
->data
);
204 static int get_bytes_from_address(struct expression
*expr
)
211 if (expr
->type
!= EXPR_PREOP
|| expr
->op
!= '&')
213 type
= get_type(expr
);
217 if (type
->type
== SYM_PTR
)
218 type
= get_base_type(type
);
220 ret
= bits_to_bytes(type
->bit_size
);
224 return 0; /* ignore char pointers */
229 static int get_size_from_strlen(struct expression
*expr
)
231 struct smatch_state
*state
;
234 state
= get_state_expr(my_strlen_id
, expr
);
235 if (!state
|| !state
->data
)
237 if (get_implied_max((struct expression
*)state
->data
, &len
))
238 return len
+ 1; /* add one because strlen doesn't include the NULL */
242 static struct expression
*remove_addr_fluff(struct expression
*expr
)
244 struct expression
*tmp
;
247 expr
= strip_expr(expr
);
249 /* remove '&' and '*' operations that cancel */
250 while (expr
->type
== EXPR_PREOP
&& expr
->op
== '&') {
251 tmp
= strip_expr(expr
->unop
);
252 if (tmp
->type
!= EXPR_PREOP
)
256 expr
= strip_expr(tmp
->unop
);
259 /* "foo + 0" is just "foo" */
260 if (expr
->type
== EXPR_BINOP
&& expr
->op
== '+' &&
261 get_value(expr
->right
, &val
) && val
== 0)
267 int get_array_size_bytes(struct expression
*expr
)
271 expr
= remove_addr_fluff(expr
);
275 /* strcpy(foo, "BAR"); */
276 if (expr
->type
== EXPR_STRING
)
277 return expr
->string
->length
;
280 size
= get_real_array_size(expr
);
282 return elements_to_bytes(expr
, size
);
284 /* buf = malloc(1024); */
285 size
= get_stored_size_bytes(expr
);
289 /* char *foo = "BAR" */
290 size
= get_size_from_initializer(expr
);
292 return elements_to_bytes(expr
, size
);
294 size
= get_bytes_from_address(expr
);
298 /* if (strlen(foo) > 4) */
299 size
= get_size_from_strlen(expr
);
303 return size_from_db(expr
);
306 int get_array_size(struct expression
*expr
)
310 bytes
= get_array_size_bytes(expr
);
311 return bytes_to_elements(expr
, bytes
);
314 static void match_strlen_condition(struct expression
*expr
)
316 struct expression
*left
;
317 struct expression
*right
;
318 struct expression
*str
= NULL
;
320 int strlen_right
= 0;
322 struct smatch_state
*true_state
= NULL
;
323 struct smatch_state
*false_state
= NULL
;
325 if (expr
->type
!= EXPR_COMPARE
)
327 left
= strip_expr(expr
->left
);
328 right
= strip_expr(expr
->right
);
330 if (left
->type
== EXPR_CALL
&& sym_name_is("strlen", left
->fn
)) {
331 str
= get_argument_from_call_expr(left
->args
, 0);
334 if (right
->type
== EXPR_CALL
&& sym_name_is("strlen", right
->fn
)) {
335 str
= get_argument_from_call_expr(right
->args
, 0);
339 if (!strlen_left
&& !strlen_right
)
341 if (strlen_left
&& strlen_right
)
345 if (!get_value(right
, &val
))
349 if (!get_value(left
, &val
))
353 if (expr
->op
== SPECIAL_EQUAL
) {
354 set_true_false_states_expr(my_size_id
, str
, alloc_state_num(val
+ 1), NULL
);
357 if (expr
->op
== SPECIAL_NOTEQUAL
) {
358 set_true_false_states_expr(my_size_id
, str
, NULL
, alloc_state_num(val
+ 1));
364 case SPECIAL_UNSIGNED_LT
:
366 true_state
= alloc_state_num(val
);
368 false_state
= alloc_state_num(val
+ 1);
371 case SPECIAL_UNSIGNED_LTE
:
373 true_state
= alloc_state_num(val
+ 1);
375 false_state
= alloc_state_num(val
);
378 case SPECIAL_UNSIGNED_GTE
:
380 false_state
= alloc_state_num(val
);
382 true_state
= alloc_state_num(val
+ 1);
385 case SPECIAL_UNSIGNED_GT
:
387 false_state
= alloc_state_num(val
+ 1);
389 true_state
= alloc_state_num(val
);
392 set_true_false_states_expr(my_size_id
, str
, true_state
, false_state
);
395 static struct expression
*strip_ampersands(struct expression
*expr
)
399 if (expr
->type
!= EXPR_PREOP
)
403 type
= get_type(expr
->unop
);
404 if (!type
|| type
->type
!= SYM_ARRAY
)
409 static void match_array_assignment(struct expression
*expr
)
411 struct expression
*left
;
412 struct expression
*right
;
417 left
= strip_expr(expr
->left
);
418 right
= strip_expr(expr
->right
);
419 right
= strip_ampersands(right
);
420 array_size
= get_array_size_bytes(right
);
422 set_state_expr(my_size_id
, left
, alloc_state_num(array_size
));
425 static void info_record_alloction(struct expression
*buffer
, struct expression
*size
)
432 member
= get_member_name(buffer
);
435 if (!get_implied_value(size
, &val
))
437 sm_msg("info: '%s' allocated_buf_size %lld", member
, val
);
441 static void match_alloc(const char *fn
, struct expression
*expr
, void *_size_arg
)
443 int size_arg
= PTR_INT(_size_arg
);
444 struct expression
*right
;
445 struct expression
*arg
;
448 right
= strip_expr(expr
->right
);
449 arg
= get_argument_from_call_expr(right
->args
, size_arg
);
451 info_record_alloction(expr
->left
, arg
);
453 if (!get_implied_value(arg
, &bytes
))
455 set_state_expr(my_size_id
, expr
->left
, alloc_state_num(bytes
));
458 static void match_calloc(const char *fn
, struct expression
*expr
, void *unused
)
460 struct expression
*right
;
461 struct expression
*arg
;
465 right
= strip_expr(expr
->right
);
466 arg
= get_argument_from_call_expr(right
->args
, 0);
467 if (!get_implied_value(arg
, &elements
))
469 arg
= get_argument_from_call_expr(right
->args
, 1);
470 if (!get_implied_value(arg
, &size
))
472 set_state_expr(my_size_id
, expr
->left
, alloc_state_num(elements
* size
));
475 static void match_strlen(const char *fn
, struct expression
*expr
, void *unused
)
477 struct expression
*right
;
478 struct expression
*str
;
479 struct expression
*len_expr
;
481 struct smatch_state
*state
;
483 right
= strip_expr(expr
->right
);
484 str
= get_argument_from_call_expr(right
->args
, 0);
485 len_expr
= strip_expr(expr
->left
);
487 len_name
= get_variable_from_expr(len_expr
, NULL
);
491 state
= __alloc_smatch_state(0);
492 state
->name
= len_name
;
493 state
->data
= len_expr
;
494 set_state_expr(my_strlen_id
, str
, state
);
497 static void match_limited(const char *fn
, struct expression
*expr
, void *_limiter
)
499 struct limiter
*limiter
= (struct limiter
*)_limiter
;
500 struct expression
*dest
;
501 struct expression
*size_expr
;
504 dest
= get_argument_from_call_expr(expr
->args
, limiter
->buf_arg
);
505 size_expr
= get_argument_from_call_expr(expr
->args
, limiter
->limit_arg
);
506 if (!get_implied_max(size_expr
, &size
))
508 set_state_expr(my_size_id
, dest
, alloc_state_num(size
));
511 static void match_strcpy(const char *fn
, struct expression
*expr
, void *unused
)
513 struct expression fake_assign
;
515 fake_assign
.op
= '=';
516 fake_assign
.left
= get_argument_from_call_expr(expr
->args
, 0);
517 fake_assign
.right
= get_argument_from_call_expr(expr
->args
, 1);
518 match_array_assignment(&fake_assign
);
521 static void match_strndup(const char *fn
, struct expression
*expr
, void *unused
)
523 struct expression
*fn_expr
;
524 struct expression
*size_expr
;
527 fn_expr
= strip_expr(expr
->right
);
528 size_expr
= get_argument_from_call_expr(fn_expr
->args
, 1);
529 if (!get_implied_max(size_expr
, &size
))
532 /* It's easy to forget space for the NUL char */
534 set_state_expr(my_size_id
, expr
->left
, alloc_state_num(size
));
537 static void match_call(struct expression
*expr
)
540 struct expression
*arg
;
544 name
= get_fnptr_name(expr
->fn
);
549 FOR_EACH_PTR(expr
->args
, arg
) {
550 bytes
= get_array_size_bytes(arg
);
552 sm_msg("info: passes_buffer '%s' %d '$$' %d %s",
554 is_static(expr
->fn
) ? "static" : "global");
556 } END_FOR_EACH_PTR(arg
);
561 static void struct_member_callback(char *fn
, char *global_static
, int param
, char *printed_name
, struct smatch_state
*state
)
563 if (state
== &merged
)
565 sm_msg("info: passes_buffer '%s' %d '%s' %s %s", fn
, param
, printed_name
, state
->name
, global_static
);
568 static void match_func_end(struct symbol
*sym
)
570 memset(params_set
, 0, sizeof(params_set
));
573 void register_buf_size(int id
)
577 add_definition_db_callback(set_param_buf_size
, BUF_SIZE
);
579 add_function_assign_hook("malloc", &match_alloc
, INT_PTR(0));
580 add_function_assign_hook("calloc", &match_calloc
, NULL
);
581 add_function_assign_hook("memdup", &match_alloc
, INT_PTR(1));
582 if (option_project
== PROJ_KERNEL
) {
583 add_function_assign_hook("kmalloc", &match_alloc
, INT_PTR(0));
584 add_function_assign_hook("kzalloc", &match_alloc
, INT_PTR(0));
585 add_function_assign_hook("vmalloc", &match_alloc
, INT_PTR(0));
586 add_function_assign_hook("__vmalloc", &match_alloc
, INT_PTR(0));
587 add_function_assign_hook("kcalloc", &match_calloc
, NULL
);
588 add_function_assign_hook("kmalloc_array", &match_calloc
, NULL
);
589 add_function_assign_hook("drm_malloc_ab", &match_calloc
, NULL
);
590 add_function_assign_hook("drm_calloc_large", &match_calloc
, NULL
);
591 add_function_assign_hook("sock_kmalloc", &match_alloc
, INT_PTR(1));
592 add_function_assign_hook("kmemdup", &match_alloc
, INT_PTR(1));
593 add_function_assign_hook("kmemdup_user", &match_alloc
, INT_PTR(1));
595 add_hook(&match_array_assignment
, ASSIGNMENT_HOOK
);
596 add_hook(&match_strlen_condition
, CONDITION_HOOK
);
597 add_function_assign_hook("strlen", &match_strlen
, NULL
);
599 add_function_assign_hook("strndup", match_strndup
, NULL
);
600 if (option_project
== PROJ_KERNEL
)
601 add_function_assign_hook("kstrndup", match_strndup
, NULL
);
603 add_hook(&match_func_end
, END_FUNC_HOOK
);
604 add_modification_hook(my_size_id
, &set_undefined
);
607 void register_strlen(int id
)
610 add_modification_hook(my_strlen_id
, &set_undefined
);
613 void register_buf_size_late(int id
)
615 add_function_hook("strlcpy", &match_limited
, &b0_l2
);
616 add_function_hook("strlcat", &match_limited
, &b0_l2
);
617 add_function_hook("memscan", &match_limited
, &b0_l2
);
619 add_function_hook("strcpy", &match_strcpy
, NULL
);
622 add_hook(&match_call
, FUNCTION_CALL_HOOK
);
623 add_member_info_callback(my_size_id
, struct_member_callback
);