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
)
127 db_size
= atoi(argv
[0]);
131 static int size_from_db(struct expression
*expr
)
138 name
= get_member_name(expr
);
143 run_sql(db_size_callback
, "select size from type_size where type = '%s'",
148 static int get_real_array_size(struct expression
*expr
)
153 if (expr
->type
== EXPR_BINOP
) /* array elements foo[5] */
156 type
= get_type(expr
);
157 if (!type
|| type
->type
!= SYM_ARRAY
)
160 ret
= get_expression_value(type
->array_size
);
161 /* Dynamically sized array are -1 in sparse */
164 /* People put one element arrays on the end of structs */
171 static int get_size_from_initializer(struct expression
*expr
)
173 if (expr
->type
!= EXPR_SYMBOL
|| !expr
->symbol
->initializer
)
175 if (expr
->symbol
->initializer
== expr
) /* int a = a; */
177 return get_initializer_size(expr
->symbol
->initializer
);
180 static int get_stored_size_bytes(struct expression
*expr
)
182 struct smatch_state
*state
;
184 state
= get_state_expr(my_size_id
, expr
);
187 return PTR_INT(state
->data
);
190 static int get_bytes_from_address(struct expression
*expr
)
197 if (expr
->type
!= EXPR_PREOP
|| expr
->op
!= '&')
199 type
= get_type(expr
);
203 if (type
->type
== SYM_PTR
)
204 type
= get_base_type(type
);
206 ret
= bits_to_bytes(type
->bit_size
);
210 return 0; /* ignore char pointers */
215 static int get_size_from_strlen(struct expression
*expr
)
217 struct smatch_state
*state
;
220 state
= get_state_expr(my_strlen_id
, expr
);
221 if (!state
|| !state
->data
)
223 if (get_implied_max((struct expression
*)state
->data
, &len
))
224 return len
+ 1; /* add one because strlen doesn't include the NULL */
228 static struct expression
*remove_addr_fluff(struct expression
*expr
)
230 struct expression
*tmp
;
233 expr
= strip_expr(expr
);
235 /* remove '&' and '*' operations that cancel */
236 while (expr
->type
== EXPR_PREOP
&& expr
->op
== '&') {
237 tmp
= strip_expr(expr
->unop
);
238 if (tmp
->type
!= EXPR_PREOP
)
242 expr
= strip_expr(tmp
->unop
);
245 /* "foo + 0" is just "foo" */
246 if (expr
->type
== EXPR_BINOP
&& expr
->op
== '+' &&
247 get_value(expr
->right
, &val
) && val
== 0)
253 int get_array_size_bytes(struct expression
*expr
)
257 expr
= remove_addr_fluff(expr
);
261 /* strcpy(foo, "BAR"); */
262 if (expr
->type
== EXPR_STRING
)
263 return expr
->string
->length
;
266 size
= get_real_array_size(expr
);
268 return elements_to_bytes(expr
, size
);
270 /* buf = malloc(1024); */
271 size
= get_stored_size_bytes(expr
);
275 /* char *foo = "BAR" */
276 size
= get_size_from_initializer(expr
);
278 return elements_to_bytes(expr
, size
);
280 size
= get_bytes_from_address(expr
);
284 /* if (strlen(foo) > 4) */
285 size
= get_size_from_strlen(expr
);
289 return size_from_db(expr
);
292 int get_array_size(struct expression
*expr
)
296 bytes
= get_array_size_bytes(expr
);
297 return bytes_to_elements(expr
, bytes
);
300 static void match_strlen_condition(struct expression
*expr
)
302 struct expression
*left
;
303 struct expression
*right
;
304 struct expression
*str
= NULL
;
306 int strlen_right
= 0;
308 struct smatch_state
*true_state
= NULL
;
309 struct smatch_state
*false_state
= NULL
;
311 if (expr
->type
!= EXPR_COMPARE
)
313 left
= strip_expr(expr
->left
);
314 right
= strip_expr(expr
->right
);
316 if (left
->type
== EXPR_CALL
&& sym_name_is("strlen", left
->fn
)) {
317 str
= get_argument_from_call_expr(left
->args
, 0);
320 if (right
->type
== EXPR_CALL
&& sym_name_is("strlen", right
->fn
)) {
321 str
= get_argument_from_call_expr(right
->args
, 0);
325 if (!strlen_left
&& !strlen_right
)
327 if (strlen_left
&& strlen_right
)
331 if (!get_value(right
, &val
))
335 if (!get_value(left
, &val
))
339 if (expr
->op
== SPECIAL_EQUAL
) {
340 set_true_false_states_expr(my_size_id
, str
, alloc_state_num(val
+ 1), NULL
);
343 if (expr
->op
== SPECIAL_NOTEQUAL
) {
344 set_true_false_states_expr(my_size_id
, str
, NULL
, alloc_state_num(val
+ 1));
350 case SPECIAL_UNSIGNED_LT
:
352 true_state
= alloc_state_num(val
);
354 false_state
= alloc_state_num(val
+ 1);
357 case SPECIAL_UNSIGNED_LTE
:
359 true_state
= alloc_state_num(val
+ 1);
361 false_state
= alloc_state_num(val
);
364 case SPECIAL_UNSIGNED_GTE
:
366 false_state
= alloc_state_num(val
);
368 true_state
= alloc_state_num(val
+ 1);
371 case SPECIAL_UNSIGNED_GT
:
373 false_state
= alloc_state_num(val
+ 1);
375 true_state
= alloc_state_num(val
);
378 set_true_false_states_expr(my_size_id
, str
, true_state
, false_state
);
381 static struct expression
*strip_ampersands(struct expression
*expr
)
385 if (expr
->type
!= EXPR_PREOP
)
389 type
= get_type(expr
->unop
);
390 if (!type
|| type
->type
!= SYM_ARRAY
)
395 static void match_array_assignment(struct expression
*expr
)
397 struct expression
*left
;
398 struct expression
*right
;
403 left
= strip_expr(expr
->left
);
404 right
= strip_expr(expr
->right
);
405 right
= strip_ampersands(right
);
406 array_size
= get_array_size_bytes(right
);
408 set_state_expr(my_size_id
, left
, alloc_state_num(array_size
));
411 static void info_record_alloction(struct expression
*buffer
, struct expression
*size
)
418 member
= get_member_name(buffer
);
421 if (!get_implied_value(size
, &val
))
423 sm_msg("info: '%s' allocated_buf_size %lld", member
, val
);
427 static void match_alloc(const char *fn
, struct expression
*expr
, void *_size_arg
)
429 int size_arg
= PTR_INT(_size_arg
);
430 struct expression
*right
;
431 struct expression
*arg
;
434 right
= strip_expr(expr
->right
);
435 arg
= get_argument_from_call_expr(right
->args
, size_arg
);
437 info_record_alloction(expr
->left
, arg
);
439 if (!get_implied_value(arg
, &bytes
))
441 set_state_expr(my_size_id
, expr
->left
, alloc_state_num(bytes
));
444 static void match_calloc(const char *fn
, struct expression
*expr
, void *unused
)
446 struct expression
*right
;
447 struct expression
*arg
;
451 right
= strip_expr(expr
->right
);
452 arg
= get_argument_from_call_expr(right
->args
, 0);
453 if (!get_implied_value(arg
, &elements
))
455 arg
= get_argument_from_call_expr(right
->args
, 1);
456 if (!get_implied_value(arg
, &size
))
458 set_state_expr(my_size_id
, expr
->left
, alloc_state_num(elements
* size
));
461 static void match_strlen(const char *fn
, struct expression
*expr
, void *unused
)
463 struct expression
*right
;
464 struct expression
*str
;
465 struct expression
*len_expr
;
467 struct smatch_state
*state
;
469 right
= strip_expr(expr
->right
);
470 str
= get_argument_from_call_expr(right
->args
, 0);
471 len_expr
= strip_expr(expr
->left
);
473 len_name
= get_variable_from_expr(len_expr
, NULL
);
477 state
= __alloc_smatch_state(0);
478 state
->name
= len_name
;
479 state
->data
= len_expr
;
480 set_state_expr(my_strlen_id
, str
, state
);
483 static void match_limited(const char *fn
, struct expression
*expr
, void *_limiter
)
485 struct limiter
*limiter
= (struct limiter
*)_limiter
;
486 struct expression
*dest
;
487 struct expression
*size_expr
;
490 dest
= get_argument_from_call_expr(expr
->args
, limiter
->buf_arg
);
491 size_expr
= get_argument_from_call_expr(expr
->args
, limiter
->limit_arg
);
492 if (!get_implied_max(size_expr
, &size
))
494 set_state_expr(my_size_id
, dest
, alloc_state_num(size
));
497 static void match_strcpy(const char *fn
, struct expression
*expr
, void *unused
)
499 struct expression fake_assign
;
501 fake_assign
.op
= '=';
502 fake_assign
.left
= get_argument_from_call_expr(expr
->args
, 0);
503 fake_assign
.right
= get_argument_from_call_expr(expr
->args
, 1);
504 match_array_assignment(&fake_assign
);
507 static void match_strndup(const char *fn
, struct expression
*expr
, void *unused
)
509 struct expression
*fn_expr
;
510 struct expression
*size_expr
;
513 fn_expr
= strip_expr(expr
->right
);
514 size_expr
= get_argument_from_call_expr(fn_expr
->args
, 1);
515 if (!get_implied_max(size_expr
, &size
))
518 /* It's easy to forget space for the NUL char */
520 set_state_expr(my_size_id
, expr
->left
, alloc_state_num(size
));
523 static void match_call(struct expression
*expr
)
526 struct expression
*arg
;
530 name
= get_fnptr_name(expr
->fn
);
535 FOR_EACH_PTR(expr
->args
, arg
) {
536 bytes
= get_array_size_bytes(arg
);
538 sm_msg("info: passes_buffer '%s' %d '$$' %d %s",
540 is_static(expr
->fn
) ? "static" : "global");
542 } END_FOR_EACH_PTR(arg
);
547 static void struct_member_callback(char *fn
, char *global_static
, int param
, char *printed_name
, struct smatch_state
*state
)
549 if (state
== &merged
)
551 sm_msg("info: passes_buffer '%s' %d '%s' %s %s", fn
, param
, printed_name
, state
->name
, global_static
);
554 static void match_func_end(struct symbol
*sym
)
556 memset(params_set
, 0, sizeof(params_set
));
559 void register_buf_size(int id
)
563 add_definition_db_callback(set_param_buf_size
, BUF_SIZE
);
565 add_function_assign_hook("malloc", &match_alloc
, INT_PTR(0));
566 add_function_assign_hook("calloc", &match_calloc
, NULL
);
567 add_function_assign_hook("memdup", &match_alloc
, INT_PTR(1));
568 if (option_project
== PROJ_KERNEL
) {
569 add_function_assign_hook("kmalloc", &match_alloc
, INT_PTR(0));
570 add_function_assign_hook("kzalloc", &match_alloc
, INT_PTR(0));
571 add_function_assign_hook("vmalloc", &match_alloc
, INT_PTR(0));
572 add_function_assign_hook("__vmalloc", &match_alloc
, INT_PTR(0));
573 add_function_assign_hook("kcalloc", &match_calloc
, NULL
);
574 add_function_assign_hook("kmalloc_array", &match_calloc
, NULL
);
575 add_function_assign_hook("drm_malloc_ab", &match_calloc
, NULL
);
576 add_function_assign_hook("drm_calloc_large", &match_calloc
, NULL
);
577 add_function_assign_hook("sock_kmalloc", &match_alloc
, INT_PTR(1));
578 add_function_assign_hook("kmemdup", &match_alloc
, INT_PTR(1));
579 add_function_assign_hook("kmemdup_user", &match_alloc
, INT_PTR(1));
581 add_hook(&match_array_assignment
, ASSIGNMENT_HOOK
);
582 add_hook(&match_strlen_condition
, CONDITION_HOOK
);
583 add_function_assign_hook("strlen", &match_strlen
, NULL
);
585 add_function_assign_hook("strndup", match_strndup
, NULL
);
586 if (option_project
== PROJ_KERNEL
)
587 add_function_assign_hook("kstrndup", match_strndup
, NULL
);
589 add_hook(&match_func_end
, END_FUNC_HOOK
);
590 add_modification_hook(my_size_id
, &set_undefined
);
593 void register_strlen(int id
)
596 add_modification_hook(my_strlen_id
, &set_undefined
);
599 void register_buf_size_late(int id
)
601 add_function_hook("strlcpy", &match_limited
, &b0_l2
);
602 add_function_hook("strlcat", &match_limited
, &b0_l2
);
603 add_function_hook("memscan", &match_limited
, &b0_l2
);
605 add_function_hook("strcpy", &match_strcpy
, NULL
);
608 add_hook(&match_call
, FUNCTION_CALL_HOOK
);
609 add_member_info_callback(my_size_id
, struct_member_callback
);