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 type
= get_type(expr
);
66 if (type
->type
== SYM_PTR
) {
67 type
= get_base_type(type
);
68 bpe
= bits_to_bytes(type
->bit_size
);
69 } else if (type
->type
== SYM_ARRAY
) {
70 bpe
= type
->ctype
.alignment
;
77 if (bpe
== -1) /* void pointer */
83 static int bytes_to_elements(struct expression
*expr
, int bytes
)
87 bpe
= bytes_per_element(expr
);
93 static int elements_to_bytes(struct expression
*expr
, int elements
)
97 bpe
= bytes_per_element(expr
);
98 return elements
* bpe
;
101 static int get_initializer_size(struct expression
*expr
)
103 switch (expr
->type
) {
105 return expr
->string
->length
;
106 case EXPR_INITIALIZER
: {
107 struct expression
*tmp
;
111 FOR_EACH_PTR(expr
->expr_list
, tmp
) {
112 if (tmp
->type
== EXPR_INDEX
&& tmp
->idx_to
> max
)
115 } END_FOR_EACH_PTR(tmp
);
121 return get_array_size(expr
);
126 static float get_cast_ratio(struct expression
*unstripped
)
128 struct expression
*start_expr
;
129 struct symbol
*start_type
;
130 struct symbol
*end_type
;
134 start_expr
= strip_expr(unstripped
);
135 start_type
= get_type(start_expr
);
136 end_type
= get_type(unstripped
);
137 if (!start_type
|| !end_type
)
140 if (start_type
->type
== SYM_PTR
)
141 start_bytes
= (get_base_type(start_type
))->ctype
.alignment
;
142 if (start_type
->type
== SYM_ARRAY
)
143 start_bytes
= (get_base_type(start_type
))->bit_size
/ 8;
144 if (end_type
->type
== SYM_PTR
)
145 end_bytes
= (get_base_type(end_type
))->ctype
.alignment
;
146 if (end_type
->type
== SYM_ARRAY
)
147 end_bytes
= (get_base_type(end_type
))->bit_size
/ 8;
149 if (!start_bytes
|| !end_bytes
)
151 return start_bytes
/ end_bytes
;
155 static int db_size_callback(void *unused
, int argc
, char **argv
, char **azColName
)
157 db_size
= atoi(argv
[0]);
161 static int size_from_db(struct expression
*expr
)
168 name
= get_member_name(expr
);
173 run_sql(db_size_callback
, "select size from type_size where type = '%s'",
178 static int get_real_array_size(struct expression
*expr
)
184 type
= get_type(expr
);
185 if (!type
|| type
->type
!= SYM_ARRAY
)
188 cast_ratio
= get_cast_ratio(expr
);
190 ret
= get_expression_value(type
->array_size
);
191 /* Dynamically sized array are -1 in sparse */
194 /* People put one element arrays on the end of structs */
198 return ret
* cast_ratio
;
201 static int get_size_from_initializer(struct expression
*expr
)
205 if (expr
->type
!= EXPR_SYMBOL
|| !expr
->symbol
->initializer
)
207 if (expr
->symbol
->initializer
== expr
) /* int a = a; */
209 cast_ratio
= get_cast_ratio(expr
);
210 return get_initializer_size(expr
->symbol
->initializer
) * cast_ratio
;
213 static int get_stored_size_bytes(struct expression
*expr
)
215 struct sm_state
*sm
, *tmp
;
218 sm
= get_sm_state_expr(my_size_id
, expr
);
222 FOR_EACH_PTR(sm
->possible
, tmp
) {
223 if (PTR_INT(tmp
->state
->data
) > max
)
224 max
= PTR_INT(tmp
->state
->data
);
225 } END_FOR_EACH_PTR(tmp
);
230 static int get_stored_size(struct expression
*expr
)
235 cast_ratio
= get_cast_ratio(expr
);
237 size
= get_stored_size_bytes(expr
);
238 size
= bytes_to_elements(expr
, size
);
239 return size
* cast_ratio
;
242 static int get_size_from_strlen(struct expression
*expr
)
244 struct smatch_state
*state
;
247 state
= get_state_expr(my_strlen_id
, expr
);
248 if (!state
|| !state
->data
)
250 if (get_implied_max((struct expression
*)state
->data
, &len
))
251 return len
+ 1; /* add one because strlen doesn't include the NULL */
255 int get_array_size(struct expression
*expr
)
259 expr
= strip_expr(expr
);
263 /* strcpy(foo, "BAR"); */
264 if (expr
->type
== EXPR_STRING
)
265 return expr
->string
->length
;
268 ret
= get_real_array_size(expr
);
272 /* buf = malloc(1024); */
273 ret
= get_stored_size(expr
);
277 /* char *foo = "BAR" */
278 ret
= get_size_from_initializer(expr
);
282 /* if (strlen(foo) > 4) */
283 ret
= get_size_from_strlen(expr
);
289 int get_array_size_bytes(struct expression
*expr
)
296 size
= get_stored_size_bytes(expr
);
300 if (expr
->type
== EXPR_STRING
)
301 return expr
->string
->length
;
303 size
= get_array_size(expr
);
305 return elements_to_bytes(expr
, size
);
307 return size_from_db(expr
);
310 static void match_strlen_condition(struct expression
*expr
)
312 struct expression
*left
;
313 struct expression
*right
;
314 struct expression
*str
= NULL
;
316 int strlen_right
= 0;
318 struct smatch_state
*true_state
= NULL
;
319 struct smatch_state
*false_state
= NULL
;
321 if (expr
->type
!= EXPR_COMPARE
)
323 left
= strip_expr(expr
->left
);
324 right
= strip_expr(expr
->right
);
326 if (left
->type
== EXPR_CALL
&& sym_name_is("strlen", left
->fn
)) {
327 str
= get_argument_from_call_expr(left
->args
, 0);
330 if (right
->type
== EXPR_CALL
&& sym_name_is("strlen", right
->fn
)) {
331 str
= get_argument_from_call_expr(right
->args
, 0);
335 if (!strlen_left
&& !strlen_right
)
337 if (strlen_left
&& strlen_right
)
341 if (!get_value(right
, &val
))
345 if (!get_value(left
, &val
))
349 if (expr
->op
== SPECIAL_EQUAL
) {
350 set_true_false_states_expr(my_size_id
, str
, alloc_state_num(val
+ 1), NULL
);
353 if (expr
->op
== SPECIAL_NOTEQUAL
) {
354 set_true_false_states_expr(my_size_id
, str
, NULL
, alloc_state_num(val
+ 1));
360 case SPECIAL_UNSIGNED_LT
:
362 true_state
= alloc_state_num(val
);
364 false_state
= alloc_state_num(val
+ 1);
367 case SPECIAL_UNSIGNED_LTE
:
369 true_state
= alloc_state_num(val
+ 1);
371 false_state
= alloc_state_num(val
);
374 case SPECIAL_UNSIGNED_GTE
:
376 false_state
= alloc_state_num(val
);
378 true_state
= alloc_state_num(val
+ 1);
381 case SPECIAL_UNSIGNED_GT
:
383 false_state
= alloc_state_num(val
+ 1);
385 true_state
= alloc_state_num(val
);
388 set_true_false_states_expr(my_size_id
, str
, true_state
, false_state
);
391 static struct expression
*strip_ampersands(struct expression
*expr
)
395 if (expr
->type
!= EXPR_PREOP
)
399 type
= get_type(expr
->unop
);
400 if (!type
|| type
->type
!= SYM_ARRAY
)
405 static void match_array_assignment(struct expression
*expr
)
407 struct expression
*left
;
408 struct expression
*right
;
413 left
= strip_expr(expr
->left
);
414 right
= strip_expr(expr
->right
);
415 right
= strip_ampersands(right
);
416 array_size
= get_array_size_bytes(right
);
418 set_state_expr(my_size_id
, left
, alloc_state_num(array_size
));
421 static void match_alloc(const char *fn
, struct expression
*expr
, void *_size_arg
)
423 int size_arg
= PTR_INT(_size_arg
);
424 struct expression
*right
;
425 struct expression
*arg
;
428 right
= strip_expr(expr
->right
);
429 arg
= get_argument_from_call_expr(right
->args
, size_arg
);
430 if (!get_implied_value(arg
, &bytes
))
433 set_state_expr(my_size_id
, expr
->left
, alloc_state_num(bytes
));
436 char *member
= get_member_name(expr
->left
);
439 sm_msg("info: '%s' allocated_buf_size %lld",
445 static void match_calloc(const char *fn
, struct expression
*expr
, void *unused
)
447 struct expression
*right
;
448 struct expression
*arg
;
452 right
= strip_expr(expr
->right
);
453 arg
= get_argument_from_call_expr(right
->args
, 0);
454 if (!get_implied_value(arg
, &elements
))
456 arg
= get_argument_from_call_expr(right
->args
, 1);
457 if (!get_implied_value(arg
, &size
))
459 set_state_expr(my_size_id
, expr
->left
, alloc_state_num(elements
* size
));
462 static void match_strlen(const char *fn
, struct expression
*expr
, void *unused
)
464 struct expression
*right
;
465 struct expression
*str
;
466 struct expression
*len_expr
;
468 struct smatch_state
*state
;
470 right
= strip_expr(expr
->right
);
471 str
= get_argument_from_call_expr(right
->args
, 0);
472 len_expr
= strip_expr(expr
->left
);
474 len_name
= get_variable_from_expr(len_expr
, NULL
);
478 state
= __alloc_smatch_state(0);
479 state
->name
= len_name
;
480 state
->data
= len_expr
;
481 set_state_expr(my_strlen_id
, str
, state
);
484 static void match_limited(const char *fn
, struct expression
*expr
, void *_limiter
)
486 struct limiter
*limiter
= (struct limiter
*)_limiter
;
487 struct expression
*dest
;
488 struct expression
*size_expr
;
491 dest
= get_argument_from_call_expr(expr
->args
, limiter
->buf_arg
);
492 size_expr
= get_argument_from_call_expr(expr
->args
, limiter
->limit_arg
);
493 if (!get_implied_max(size_expr
, &size
))
495 set_state_expr(my_size_id
, dest
, alloc_state_num(size
));
498 static void match_strcpy(const char *fn
, struct expression
*expr
, void *unused
)
500 struct expression fake_assign
;
502 fake_assign
.op
= '=';
503 fake_assign
.left
= get_argument_from_call_expr(expr
->args
, 0);
504 fake_assign
.right
= get_argument_from_call_expr(expr
->args
, 1);
505 match_array_assignment(&fake_assign
);
508 static void match_strndup(const char *fn
, struct expression
*expr
, void *unused
)
510 struct expression
*fn_expr
;
511 struct expression
*size_expr
;
514 fn_expr
= strip_expr(expr
->right
);
515 size_expr
= get_argument_from_call_expr(fn_expr
->args
, 1);
516 if (!get_implied_max(size_expr
, &size
))
519 /* It's easy to forget space for the NUL char */
521 set_state_expr(my_size_id
, expr
->left
, alloc_state_num(size
));
524 static void match_call(struct expression
*expr
)
527 struct expression
*arg
;
531 name
= get_fnptr_name(expr
->fn
);
536 FOR_EACH_PTR(expr
->args
, arg
) {
537 bytes
= get_array_size_bytes(arg
);
539 sm_msg("info: passes_buffer '%s' %d '$$' %d %s",
541 is_static(expr
->fn
) ? "static" : "global");
543 } END_FOR_EACH_PTR(arg
);
548 static void struct_member_callback(char *fn
, char *global_static
, int param
, char *printed_name
, struct smatch_state
*state
)
550 if (state
== &merged
)
552 sm_msg("info: passes_buffer '%s' %d '%s' %s %s", fn
, param
, printed_name
, state
->name
, global_static
);
555 static void match_func_end(struct symbol
*sym
)
557 memset(params_set
, 0, sizeof(params_set
));
560 void register_buf_size(int id
)
564 add_definition_db_callback(set_param_buf_size
, BUF_SIZE
);
566 add_function_assign_hook("malloc", &match_alloc
, INT_PTR(0));
567 add_function_assign_hook("calloc", &match_calloc
, NULL
);
568 add_function_assign_hook("memdup", &match_alloc
, INT_PTR(1));
569 if (option_project
== PROJ_KERNEL
) {
570 add_function_assign_hook("kmalloc", &match_alloc
, INT_PTR(0));
571 add_function_assign_hook("kzalloc", &match_alloc
, INT_PTR(0));
572 add_function_assign_hook("vmalloc", &match_alloc
, INT_PTR(0));
573 add_function_assign_hook("__vmalloc", &match_alloc
, INT_PTR(0));
574 add_function_assign_hook("kcalloc", &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("kmemdup", &match_alloc
, INT_PTR(1));
578 add_function_assign_hook("kmemdup_user", &match_alloc
, INT_PTR(1));
580 add_hook(&match_array_assignment
, ASSIGNMENT_HOOK
);
581 add_hook(&match_strlen_condition
, CONDITION_HOOK
);
582 add_function_assign_hook("strlen", &match_strlen
, NULL
);
584 add_function_hook("strlcpy", &match_limited
, &b0_l2
);
585 add_function_hook("strlcat", &match_limited
, &b0_l2
);
586 add_function_hook("memscan", &match_limited
, &b0_l2
);
588 add_function_hook("strcpy", &match_strcpy
, NULL
);
590 add_function_assign_hook("strndup", match_strndup
, NULL
);
591 if (option_project
== PROJ_KERNEL
)
592 add_function_assign_hook("kstrndup", match_strndup
, NULL
);
595 add_hook(&match_call
, FUNCTION_CALL_HOOK
);
596 add_member_info_callback(my_size_id
, struct_member_callback
);
599 add_hook(&match_func_end
, END_FUNC_HOOK
);
600 add_modification_hook(my_size_id
, &set_undefined
);
603 void register_strlen(int id
)
606 add_modification_hook(my_strlen_id
, &set_undefined
);