1 /* AddressSanitizer, a fast memory error detector.
2 Copyright (C) 2012-2014 Free Software Foundation, Inc.
3 Contributed by Kostya Serebryany <kcc@google.com>
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
24 #include "coretypes.h"
26 #include "hash-table.h"
33 #include "hard-reg-set.h"
36 #include "dominance.h"
39 #include "basic-block.h"
40 #include "tree-ssa-alias.h"
41 #include "internal-fn.h"
42 #include "gimple-expr.h"
47 #include "gimple-iterator.h"
50 #include "stor-layout.h"
51 #include "tree-iterator.h"
53 #include "plugin-api.h"
56 #include "stringpool.h"
57 #include "tree-ssanames.h"
58 #include "tree-pass.h"
60 #include "gimple-pretty-print.h"
63 #include "insn-codes.h"
67 #include "langhooks.h"
68 #include "alloc-pool.h"
70 #include "gimple-builder.h"
75 /* AddressSanitizer finds out-of-bounds and use-after-free bugs
76 with <2x slowdown on average.
78 The tool consists of two parts:
79 instrumentation module (this file) and a run-time library.
80 The instrumentation module adds a run-time check before every memory insn.
81 For a 8- or 16- byte load accessing address X:
82 ShadowAddr = (X >> 3) + Offset
83 ShadowValue = *(char*)ShadowAddr; // *(short*) for 16-byte access.
85 __asan_report_load8(X);
86 For a load of N bytes (N=1, 2 or 4) from address X:
87 ShadowAddr = (X >> 3) + Offset
88 ShadowValue = *(char*)ShadowAddr;
90 if ((X & 7) + N - 1 > ShadowValue)
91 __asan_report_loadN(X);
92 Stores are instrumented similarly, but using __asan_report_storeN functions.
93 A call too __asan_init_vN() is inserted to the list of module CTORs.
94 N is the version number of the AddressSanitizer API. The changes between the
95 API versions are listed in libsanitizer/asan/asan_interface_internal.h.
97 The run-time library redefines malloc (so that redzone are inserted around
98 the allocated memory) and free (so that reuse of free-ed memory is delayed),
99 provides __asan_report* and __asan_init_vN functions.
102 http://code.google.com/p/address-sanitizer/wiki/AddressSanitizerAlgorithm
104 The current implementation supports detection of out-of-bounds and
105 use-after-free in the heap, on the stack and for global variables.
107 [Protection of stack variables]
109 To understand how detection of out-of-bounds and use-after-free works
110 for stack variables, lets look at this example on x86_64 where the
111 stack grows downward:
125 For this function, the stack protected by asan will be organized as
126 follows, from the top of the stack to the bottom:
128 Slot 1/ [red zone of 32 bytes called 'RIGHT RedZone']
130 Slot 2/ [8 bytes of red zone, that adds up to the space of 'a' to make
131 the next slot be 32 bytes aligned; this one is called Partial
132 Redzone; this 32 bytes alignment is an asan constraint]
134 Slot 3/ [24 bytes for variable 'a']
136 Slot 4/ [red zone of 32 bytes called 'Middle RedZone']
138 Slot 5/ [24 bytes of Partial Red Zone (similar to slot 2]
140 Slot 6/ [8 bytes for variable 'b']
142 Slot 7/ [32 bytes of Red Zone at the bottom of the stack, called
145 The 32 bytes of LEFT red zone at the bottom of the stack can be
148 1/ The first 8 bytes contain a magical asan number that is always
151 2/ The following 8 bytes contains a pointer to a string (to be
152 parsed at runtime by the runtime asan library), which format is
155 "<function-name> <space> <num-of-variables-on-the-stack>
156 (<32-bytes-aligned-offset-in-bytes-of-variable> <space>
157 <length-of-var-in-bytes> ){n} "
159 where '(...){n}' means the content inside the parenthesis occurs 'n'
160 times, with 'n' being the number of variables on the stack.
162 3/ The following 8 bytes contain the PC of the current function which
163 will be used by the run-time library to print an error message.
165 4/ The following 8 bytes are reserved for internal use by the run-time.
167 The shadow memory for that stack layout is going to look like this:
169 - content of shadow memory 8 bytes for slot 7: 0xF1F1F1F1.
170 The F1 byte pattern is a magic number called
171 ASAN_STACK_MAGIC_LEFT and is a way for the runtime to know that
172 the memory for that shadow byte is part of a the LEFT red zone
173 intended to seat at the bottom of the variables on the stack.
175 - content of shadow memory 8 bytes for slots 6 and 5:
176 0xF4F4F400. The F4 byte pattern is a magic number
177 called ASAN_STACK_MAGIC_PARTIAL. It flags the fact that the
178 memory region for this shadow byte is a PARTIAL red zone
179 intended to pad a variable A, so that the slot following
180 {A,padding} is 32 bytes aligned.
182 Note that the fact that the least significant byte of this
183 shadow memory content is 00 means that 8 bytes of its
184 corresponding memory (which corresponds to the memory of
185 variable 'b') is addressable.
187 - content of shadow memory 8 bytes for slot 4: 0xF2F2F2F2.
188 The F2 byte pattern is a magic number called
189 ASAN_STACK_MAGIC_MIDDLE. It flags the fact that the memory
190 region for this shadow byte is a MIDDLE red zone intended to
191 seat between two 32 aligned slots of {variable,padding}.
193 - content of shadow memory 8 bytes for slot 3 and 2:
194 0xF4000000. This represents is the concatenation of
195 variable 'a' and the partial red zone following it, like what we
196 had for variable 'b'. The least significant 3 bytes being 00
197 means that the 3 bytes of variable 'a' are addressable.
199 - content of shadow memory 8 bytes for slot 1: 0xF3F3F3F3.
200 The F3 byte pattern is a magic number called
201 ASAN_STACK_MAGIC_RIGHT. It flags the fact that the memory
202 region for this shadow byte is a RIGHT red zone intended to seat
203 at the top of the variables of the stack.
205 Note that the real variable layout is done in expand_used_vars in
206 cfgexpand.c. As far as Address Sanitizer is concerned, it lays out
207 stack variables as well as the different red zones, emits some
208 prologue code to populate the shadow memory as to poison (mark as
209 non-accessible) the regions of the red zones and mark the regions of
210 stack variables as accessible, and emit some epilogue code to
211 un-poison (mark as accessible) the regions of red zones right before
214 [Protection of global variables]
216 The basic idea is to insert a red zone between two global variables
217 and install a constructor function that calls the asan runtime to do
218 the populating of the relevant shadow memory regions at load time.
220 So the global variables are laid out as to insert a red zone between
221 them. The size of the red zones is so that each variable starts on a
224 Then a constructor function is installed so that, for each global
225 variable, it calls the runtime asan library function
226 __asan_register_globals_with an instance of this type:
230 // Address of the beginning of the global variable.
233 // Initial size of the global variable.
236 // Size of the global variable + size of the red zone. This
237 // size is 32 bytes aligned.
238 uptr __size_with_redzone;
240 // Name of the global variable.
243 // Name of the module where the global variable is declared.
244 const void *__module_name;
246 // 1 if it has dynamic initialization, 0 otherwise.
247 uptr __has_dynamic_init;
249 // A pointer to struct that contains source location, could be NULL.
250 __asan_global_source_location *__location;
253 A destructor function that calls the runtime asan library function
254 _asan_unregister_globals is also installed. */
256 static unsigned HOST_WIDE_INT asan_shadow_offset_value
;
257 static bool asan_shadow_offset_computed
;
259 /* Sets shadow offset to value in string VAL. */
262 set_asan_shadow_offset (const char *val
)
267 #ifdef HAVE_LONG_LONG
268 asan_shadow_offset_value
= strtoull (val
, &endp
, 0);
270 asan_shadow_offset_value
= strtoul (val
, &endp
, 0);
272 if (!(*val
!= '\0' && *endp
== '\0' && errno
== 0))
275 asan_shadow_offset_computed
= true;
280 /* Returns Asan shadow offset. */
282 static unsigned HOST_WIDE_INT
283 asan_shadow_offset ()
285 if (!asan_shadow_offset_computed
)
287 asan_shadow_offset_computed
= true;
288 asan_shadow_offset_value
= targetm
.asan_shadow_offset ();
290 return asan_shadow_offset_value
;
293 alias_set_type asan_shadow_set
= -1;
295 /* Pointer types to 1 resp. 2 byte integers in shadow memory. A separate
296 alias set is used for all shadow memory accesses. */
297 static GTY(()) tree shadow_ptr_types
[2];
299 /* Decl for __asan_option_detect_stack_use_after_return. */
300 static GTY(()) tree asan_detect_stack_use_after_return
;
302 /* Various flags for Asan builtins. */
303 enum asan_check_flags
305 ASAN_CHECK_STORE
= 1 << 0,
306 ASAN_CHECK_SCALAR_ACCESS
= 1 << 1,
307 ASAN_CHECK_NON_ZERO_LEN
= 1 << 2,
308 ASAN_CHECK_LAST
= 1 << 3
311 /* Hashtable support for memory references used by gimple
314 /* This type represents a reference to a memory region. */
317 /* The expression of the beginning of the memory region. */
320 /* The size of the access. */
321 HOST_WIDE_INT access_size
;
324 static alloc_pool asan_mem_ref_alloc_pool
;
326 /* This creates the alloc pool used to store the instances of
327 asan_mem_ref that are stored in the hash table asan_mem_ref_ht. */
330 asan_mem_ref_get_alloc_pool ()
332 if (asan_mem_ref_alloc_pool
== NULL
)
333 asan_mem_ref_alloc_pool
= create_alloc_pool ("asan_mem_ref",
334 sizeof (asan_mem_ref
),
336 return asan_mem_ref_alloc_pool
;
340 /* Initializes an instance of asan_mem_ref. */
343 asan_mem_ref_init (asan_mem_ref
*ref
, tree start
, HOST_WIDE_INT access_size
)
346 ref
->access_size
= access_size
;
349 /* Allocates memory for an instance of asan_mem_ref into the memory
350 pool returned by asan_mem_ref_get_alloc_pool and initialize it.
351 START is the address of (or the expression pointing to) the
352 beginning of memory reference. ACCESS_SIZE is the size of the
353 access to the referenced memory. */
356 asan_mem_ref_new (tree start
, HOST_WIDE_INT access_size
)
359 (asan_mem_ref
*) pool_alloc (asan_mem_ref_get_alloc_pool ());
361 asan_mem_ref_init (ref
, start
, access_size
);
365 /* This builds and returns a pointer to the end of the memory region
366 that starts at START and of length LEN. */
369 asan_mem_ref_get_end (tree start
, tree len
)
371 if (len
== NULL_TREE
|| integer_zerop (len
))
374 if (!ptrofftype_p (len
))
375 len
= convert_to_ptrofftype (len
);
377 return fold_build2 (POINTER_PLUS_EXPR
, TREE_TYPE (start
), start
, len
);
380 /* Return a tree expression that represents the end of the referenced
381 memory region. Beware that this function can actually build a new
385 asan_mem_ref_get_end (const asan_mem_ref
*ref
, tree len
)
387 return asan_mem_ref_get_end (ref
->start
, len
);
390 struct asan_mem_ref_hasher
391 : typed_noop_remove
<asan_mem_ref
>
393 typedef asan_mem_ref value_type
;
394 typedef asan_mem_ref compare_type
;
396 static inline hashval_t
hash (const value_type
*);
397 static inline bool equal (const value_type
*, const compare_type
*);
400 /* Hash a memory reference. */
403 asan_mem_ref_hasher::hash (const asan_mem_ref
*mem_ref
)
405 return iterative_hash_expr (mem_ref
->start
, 0);
408 /* Compare two memory references. We accept the length of either
409 memory references to be NULL_TREE. */
412 asan_mem_ref_hasher::equal (const asan_mem_ref
*m1
,
413 const asan_mem_ref
*m2
)
415 return operand_equal_p (m1
->start
, m2
->start
, 0);
418 static hash_table
<asan_mem_ref_hasher
> *asan_mem_ref_ht
;
420 /* Returns a reference to the hash table containing memory references.
421 This function ensures that the hash table is created. Note that
422 this hash table is updated by the function
423 update_mem_ref_hash_table. */
425 static hash_table
<asan_mem_ref_hasher
> *
426 get_mem_ref_hash_table ()
428 if (!asan_mem_ref_ht
)
429 asan_mem_ref_ht
= new hash_table
<asan_mem_ref_hasher
> (10);
431 return asan_mem_ref_ht
;
434 /* Clear all entries from the memory references hash table. */
437 empty_mem_ref_hash_table ()
440 asan_mem_ref_ht
->empty ();
443 /* Free the memory references hash table. */
446 free_mem_ref_resources ()
448 delete asan_mem_ref_ht
;
449 asan_mem_ref_ht
= NULL
;
451 if (asan_mem_ref_alloc_pool
)
453 free_alloc_pool (asan_mem_ref_alloc_pool
);
454 asan_mem_ref_alloc_pool
= NULL
;
458 /* Return true iff the memory reference REF has been instrumented. */
461 has_mem_ref_been_instrumented (tree ref
, HOST_WIDE_INT access_size
)
464 asan_mem_ref_init (&r
, ref
, access_size
);
466 asan_mem_ref
*saved_ref
= get_mem_ref_hash_table ()->find (&r
);
467 return saved_ref
&& saved_ref
->access_size
>= access_size
;
470 /* Return true iff the memory reference REF has been instrumented. */
473 has_mem_ref_been_instrumented (const asan_mem_ref
*ref
)
475 return has_mem_ref_been_instrumented (ref
->start
, ref
->access_size
);
478 /* Return true iff access to memory region starting at REF and of
479 length LEN has been instrumented. */
482 has_mem_ref_been_instrumented (const asan_mem_ref
*ref
, tree len
)
484 HOST_WIDE_INT size_in_bytes
485 = tree_fits_shwi_p (len
) ? tree_to_shwi (len
) : -1;
487 return size_in_bytes
!= -1
488 && has_mem_ref_been_instrumented (ref
->start
, size_in_bytes
);
491 /* Set REF to the memory reference present in a gimple assignment
492 ASSIGNMENT. Return true upon successful completion, false
496 get_mem_ref_of_assignment (const gimple assignment
,
500 gcc_assert (gimple_assign_single_p (assignment
));
502 if (gimple_store_p (assignment
)
503 && !gimple_clobber_p (assignment
))
505 ref
->start
= gimple_assign_lhs (assignment
);
506 *ref_is_store
= true;
508 else if (gimple_assign_load_p (assignment
))
510 ref
->start
= gimple_assign_rhs1 (assignment
);
511 *ref_is_store
= false;
516 ref
->access_size
= int_size_in_bytes (TREE_TYPE (ref
->start
));
520 /* Return the memory references contained in a gimple statement
521 representing a builtin call that has to do with memory access. */
524 get_mem_refs_of_builtin_call (const gimple call
,
537 gcc_checking_assert (gimple_call_builtin_p (call
, BUILT_IN_NORMAL
));
539 tree callee
= gimple_call_fndecl (call
);
540 tree source0
= NULL_TREE
, source1
= NULL_TREE
,
541 dest
= NULL_TREE
, len
= NULL_TREE
;
542 bool is_store
= true, got_reference_p
= false;
543 HOST_WIDE_INT access_size
= 1;
545 *intercepted_p
= asan_intercepted_p ((DECL_FUNCTION_CODE (callee
)));
547 switch (DECL_FUNCTION_CODE (callee
))
549 /* (s, s, n) style memops. */
551 case BUILT_IN_MEMCMP
:
552 source0
= gimple_call_arg (call
, 0);
553 source1
= gimple_call_arg (call
, 1);
554 len
= gimple_call_arg (call
, 2);
557 /* (src, dest, n) style memops. */
559 source0
= gimple_call_arg (call
, 0);
560 dest
= gimple_call_arg (call
, 1);
561 len
= gimple_call_arg (call
, 2);
564 /* (dest, src, n) style memops. */
565 case BUILT_IN_MEMCPY
:
566 case BUILT_IN_MEMCPY_CHK
:
567 case BUILT_IN_MEMMOVE
:
568 case BUILT_IN_MEMMOVE_CHK
:
569 case BUILT_IN_MEMPCPY
:
570 case BUILT_IN_MEMPCPY_CHK
:
571 dest
= gimple_call_arg (call
, 0);
572 source0
= gimple_call_arg (call
, 1);
573 len
= gimple_call_arg (call
, 2);
576 /* (dest, n) style memops. */
578 dest
= gimple_call_arg (call
, 0);
579 len
= gimple_call_arg (call
, 1);
582 /* (dest, x, n) style memops*/
583 case BUILT_IN_MEMSET
:
584 case BUILT_IN_MEMSET_CHK
:
585 dest
= gimple_call_arg (call
, 0);
586 len
= gimple_call_arg (call
, 2);
589 case BUILT_IN_STRLEN
:
590 source0
= gimple_call_arg (call
, 0);
591 len
= gimple_call_lhs (call
);
594 /* And now the __atomic* and __sync builtins.
595 These are handled differently from the classical memory memory
596 access builtins above. */
598 case BUILT_IN_ATOMIC_LOAD_1
:
599 case BUILT_IN_ATOMIC_LOAD_2
:
600 case BUILT_IN_ATOMIC_LOAD_4
:
601 case BUILT_IN_ATOMIC_LOAD_8
:
602 case BUILT_IN_ATOMIC_LOAD_16
:
606 case BUILT_IN_SYNC_FETCH_AND_ADD_1
:
607 case BUILT_IN_SYNC_FETCH_AND_ADD_2
:
608 case BUILT_IN_SYNC_FETCH_AND_ADD_4
:
609 case BUILT_IN_SYNC_FETCH_AND_ADD_8
:
610 case BUILT_IN_SYNC_FETCH_AND_ADD_16
:
612 case BUILT_IN_SYNC_FETCH_AND_SUB_1
:
613 case BUILT_IN_SYNC_FETCH_AND_SUB_2
:
614 case BUILT_IN_SYNC_FETCH_AND_SUB_4
:
615 case BUILT_IN_SYNC_FETCH_AND_SUB_8
:
616 case BUILT_IN_SYNC_FETCH_AND_SUB_16
:
618 case BUILT_IN_SYNC_FETCH_AND_OR_1
:
619 case BUILT_IN_SYNC_FETCH_AND_OR_2
:
620 case BUILT_IN_SYNC_FETCH_AND_OR_4
:
621 case BUILT_IN_SYNC_FETCH_AND_OR_8
:
622 case BUILT_IN_SYNC_FETCH_AND_OR_16
:
624 case BUILT_IN_SYNC_FETCH_AND_AND_1
:
625 case BUILT_IN_SYNC_FETCH_AND_AND_2
:
626 case BUILT_IN_SYNC_FETCH_AND_AND_4
:
627 case BUILT_IN_SYNC_FETCH_AND_AND_8
:
628 case BUILT_IN_SYNC_FETCH_AND_AND_16
:
630 case BUILT_IN_SYNC_FETCH_AND_XOR_1
:
631 case BUILT_IN_SYNC_FETCH_AND_XOR_2
:
632 case BUILT_IN_SYNC_FETCH_AND_XOR_4
:
633 case BUILT_IN_SYNC_FETCH_AND_XOR_8
:
634 case BUILT_IN_SYNC_FETCH_AND_XOR_16
:
636 case BUILT_IN_SYNC_FETCH_AND_NAND_1
:
637 case BUILT_IN_SYNC_FETCH_AND_NAND_2
:
638 case BUILT_IN_SYNC_FETCH_AND_NAND_4
:
639 case BUILT_IN_SYNC_FETCH_AND_NAND_8
:
641 case BUILT_IN_SYNC_ADD_AND_FETCH_1
:
642 case BUILT_IN_SYNC_ADD_AND_FETCH_2
:
643 case BUILT_IN_SYNC_ADD_AND_FETCH_4
:
644 case BUILT_IN_SYNC_ADD_AND_FETCH_8
:
645 case BUILT_IN_SYNC_ADD_AND_FETCH_16
:
647 case BUILT_IN_SYNC_SUB_AND_FETCH_1
:
648 case BUILT_IN_SYNC_SUB_AND_FETCH_2
:
649 case BUILT_IN_SYNC_SUB_AND_FETCH_4
:
650 case BUILT_IN_SYNC_SUB_AND_FETCH_8
:
651 case BUILT_IN_SYNC_SUB_AND_FETCH_16
:
653 case BUILT_IN_SYNC_OR_AND_FETCH_1
:
654 case BUILT_IN_SYNC_OR_AND_FETCH_2
:
655 case BUILT_IN_SYNC_OR_AND_FETCH_4
:
656 case BUILT_IN_SYNC_OR_AND_FETCH_8
:
657 case BUILT_IN_SYNC_OR_AND_FETCH_16
:
659 case BUILT_IN_SYNC_AND_AND_FETCH_1
:
660 case BUILT_IN_SYNC_AND_AND_FETCH_2
:
661 case BUILT_IN_SYNC_AND_AND_FETCH_4
:
662 case BUILT_IN_SYNC_AND_AND_FETCH_8
:
663 case BUILT_IN_SYNC_AND_AND_FETCH_16
:
665 case BUILT_IN_SYNC_XOR_AND_FETCH_1
:
666 case BUILT_IN_SYNC_XOR_AND_FETCH_2
:
667 case BUILT_IN_SYNC_XOR_AND_FETCH_4
:
668 case BUILT_IN_SYNC_XOR_AND_FETCH_8
:
669 case BUILT_IN_SYNC_XOR_AND_FETCH_16
:
671 case BUILT_IN_SYNC_NAND_AND_FETCH_1
:
672 case BUILT_IN_SYNC_NAND_AND_FETCH_2
:
673 case BUILT_IN_SYNC_NAND_AND_FETCH_4
:
674 case BUILT_IN_SYNC_NAND_AND_FETCH_8
:
676 case BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_1
:
677 case BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_2
:
678 case BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_4
:
679 case BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_8
:
680 case BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_16
:
682 case BUILT_IN_SYNC_VAL_COMPARE_AND_SWAP_1
:
683 case BUILT_IN_SYNC_VAL_COMPARE_AND_SWAP_2
:
684 case BUILT_IN_SYNC_VAL_COMPARE_AND_SWAP_4
:
685 case BUILT_IN_SYNC_VAL_COMPARE_AND_SWAP_8
:
686 case BUILT_IN_SYNC_VAL_COMPARE_AND_SWAP_16
:
688 case BUILT_IN_SYNC_LOCK_TEST_AND_SET_1
:
689 case BUILT_IN_SYNC_LOCK_TEST_AND_SET_2
:
690 case BUILT_IN_SYNC_LOCK_TEST_AND_SET_4
:
691 case BUILT_IN_SYNC_LOCK_TEST_AND_SET_8
:
692 case BUILT_IN_SYNC_LOCK_TEST_AND_SET_16
:
694 case BUILT_IN_SYNC_LOCK_RELEASE_1
:
695 case BUILT_IN_SYNC_LOCK_RELEASE_2
:
696 case BUILT_IN_SYNC_LOCK_RELEASE_4
:
697 case BUILT_IN_SYNC_LOCK_RELEASE_8
:
698 case BUILT_IN_SYNC_LOCK_RELEASE_16
:
700 case BUILT_IN_ATOMIC_EXCHANGE_1
:
701 case BUILT_IN_ATOMIC_EXCHANGE_2
:
702 case BUILT_IN_ATOMIC_EXCHANGE_4
:
703 case BUILT_IN_ATOMIC_EXCHANGE_8
:
704 case BUILT_IN_ATOMIC_EXCHANGE_16
:
706 case BUILT_IN_ATOMIC_COMPARE_EXCHANGE_1
:
707 case BUILT_IN_ATOMIC_COMPARE_EXCHANGE_2
:
708 case BUILT_IN_ATOMIC_COMPARE_EXCHANGE_4
:
709 case BUILT_IN_ATOMIC_COMPARE_EXCHANGE_8
:
710 case BUILT_IN_ATOMIC_COMPARE_EXCHANGE_16
:
712 case BUILT_IN_ATOMIC_STORE_1
:
713 case BUILT_IN_ATOMIC_STORE_2
:
714 case BUILT_IN_ATOMIC_STORE_4
:
715 case BUILT_IN_ATOMIC_STORE_8
:
716 case BUILT_IN_ATOMIC_STORE_16
:
718 case BUILT_IN_ATOMIC_ADD_FETCH_1
:
719 case BUILT_IN_ATOMIC_ADD_FETCH_2
:
720 case BUILT_IN_ATOMIC_ADD_FETCH_4
:
721 case BUILT_IN_ATOMIC_ADD_FETCH_8
:
722 case BUILT_IN_ATOMIC_ADD_FETCH_16
:
724 case BUILT_IN_ATOMIC_SUB_FETCH_1
:
725 case BUILT_IN_ATOMIC_SUB_FETCH_2
:
726 case BUILT_IN_ATOMIC_SUB_FETCH_4
:
727 case BUILT_IN_ATOMIC_SUB_FETCH_8
:
728 case BUILT_IN_ATOMIC_SUB_FETCH_16
:
730 case BUILT_IN_ATOMIC_AND_FETCH_1
:
731 case BUILT_IN_ATOMIC_AND_FETCH_2
:
732 case BUILT_IN_ATOMIC_AND_FETCH_4
:
733 case BUILT_IN_ATOMIC_AND_FETCH_8
:
734 case BUILT_IN_ATOMIC_AND_FETCH_16
:
736 case BUILT_IN_ATOMIC_NAND_FETCH_1
:
737 case BUILT_IN_ATOMIC_NAND_FETCH_2
:
738 case BUILT_IN_ATOMIC_NAND_FETCH_4
:
739 case BUILT_IN_ATOMIC_NAND_FETCH_8
:
740 case BUILT_IN_ATOMIC_NAND_FETCH_16
:
742 case BUILT_IN_ATOMIC_XOR_FETCH_1
:
743 case BUILT_IN_ATOMIC_XOR_FETCH_2
:
744 case BUILT_IN_ATOMIC_XOR_FETCH_4
:
745 case BUILT_IN_ATOMIC_XOR_FETCH_8
:
746 case BUILT_IN_ATOMIC_XOR_FETCH_16
:
748 case BUILT_IN_ATOMIC_OR_FETCH_1
:
749 case BUILT_IN_ATOMIC_OR_FETCH_2
:
750 case BUILT_IN_ATOMIC_OR_FETCH_4
:
751 case BUILT_IN_ATOMIC_OR_FETCH_8
:
752 case BUILT_IN_ATOMIC_OR_FETCH_16
:
754 case BUILT_IN_ATOMIC_FETCH_ADD_1
:
755 case BUILT_IN_ATOMIC_FETCH_ADD_2
:
756 case BUILT_IN_ATOMIC_FETCH_ADD_4
:
757 case BUILT_IN_ATOMIC_FETCH_ADD_8
:
758 case BUILT_IN_ATOMIC_FETCH_ADD_16
:
760 case BUILT_IN_ATOMIC_FETCH_SUB_1
:
761 case BUILT_IN_ATOMIC_FETCH_SUB_2
:
762 case BUILT_IN_ATOMIC_FETCH_SUB_4
:
763 case BUILT_IN_ATOMIC_FETCH_SUB_8
:
764 case BUILT_IN_ATOMIC_FETCH_SUB_16
:
766 case BUILT_IN_ATOMIC_FETCH_AND_1
:
767 case BUILT_IN_ATOMIC_FETCH_AND_2
:
768 case BUILT_IN_ATOMIC_FETCH_AND_4
:
769 case BUILT_IN_ATOMIC_FETCH_AND_8
:
770 case BUILT_IN_ATOMIC_FETCH_AND_16
:
772 case BUILT_IN_ATOMIC_FETCH_NAND_1
:
773 case BUILT_IN_ATOMIC_FETCH_NAND_2
:
774 case BUILT_IN_ATOMIC_FETCH_NAND_4
:
775 case BUILT_IN_ATOMIC_FETCH_NAND_8
:
776 case BUILT_IN_ATOMIC_FETCH_NAND_16
:
778 case BUILT_IN_ATOMIC_FETCH_XOR_1
:
779 case BUILT_IN_ATOMIC_FETCH_XOR_2
:
780 case BUILT_IN_ATOMIC_FETCH_XOR_4
:
781 case BUILT_IN_ATOMIC_FETCH_XOR_8
:
782 case BUILT_IN_ATOMIC_FETCH_XOR_16
:
784 case BUILT_IN_ATOMIC_FETCH_OR_1
:
785 case BUILT_IN_ATOMIC_FETCH_OR_2
:
786 case BUILT_IN_ATOMIC_FETCH_OR_4
:
787 case BUILT_IN_ATOMIC_FETCH_OR_8
:
788 case BUILT_IN_ATOMIC_FETCH_OR_16
:
790 dest
= gimple_call_arg (call
, 0);
791 /* DEST represents the address of a memory location.
792 instrument_derefs wants the memory location, so lets
793 dereference the address DEST before handing it to
794 instrument_derefs. */
795 if (TREE_CODE (dest
) == ADDR_EXPR
)
796 dest
= TREE_OPERAND (dest
, 0);
797 else if (TREE_CODE (dest
) == SSA_NAME
|| TREE_CODE (dest
) == INTEGER_CST
)
798 dest
= build2 (MEM_REF
, TREE_TYPE (TREE_TYPE (dest
)),
799 dest
, build_int_cst (TREE_TYPE (dest
), 0));
803 access_size
= int_size_in_bytes (TREE_TYPE (dest
));
807 /* The other builtins memory access are not instrumented in this
808 function because they either don't have any length parameter,
809 or their length parameter is just a limit. */
813 if (len
!= NULL_TREE
)
815 if (source0
!= NULL_TREE
)
817 src0
->start
= source0
;
818 src0
->access_size
= access_size
;
820 *src0_is_store
= false;
823 if (source1
!= NULL_TREE
)
825 src1
->start
= source1
;
826 src1
->access_size
= access_size
;
828 *src1_is_store
= false;
831 if (dest
!= NULL_TREE
)
834 dst
->access_size
= access_size
;
836 *dst_is_store
= true;
839 got_reference_p
= true;
844 dst
->access_size
= access_size
;
845 *dst_len
= NULL_TREE
;
846 *dst_is_store
= is_store
;
847 *dest_is_deref
= true;
848 got_reference_p
= true;
851 return got_reference_p
;
854 /* Return true iff a given gimple statement has been instrumented.
855 Note that the statement is "defined" by the memory references it
859 has_stmt_been_instrumented_p (gimple stmt
)
861 if (gimple_assign_single_p (stmt
))
865 asan_mem_ref_init (&r
, NULL
, 1);
867 if (get_mem_ref_of_assignment (stmt
, &r
, &r_is_store
))
868 return has_mem_ref_been_instrumented (&r
);
870 else if (gimple_call_builtin_p (stmt
, BUILT_IN_NORMAL
))
872 asan_mem_ref src0
, src1
, dest
;
873 asan_mem_ref_init (&src0
, NULL
, 1);
874 asan_mem_ref_init (&src1
, NULL
, 1);
875 asan_mem_ref_init (&dest
, NULL
, 1);
877 tree src0_len
= NULL_TREE
, src1_len
= NULL_TREE
, dest_len
= NULL_TREE
;
878 bool src0_is_store
= false, src1_is_store
= false,
879 dest_is_store
= false, dest_is_deref
= false, intercepted_p
= true;
880 if (get_mem_refs_of_builtin_call (stmt
,
881 &src0
, &src0_len
, &src0_is_store
,
882 &src1
, &src1_len
, &src1_is_store
,
883 &dest
, &dest_len
, &dest_is_store
,
884 &dest_is_deref
, &intercepted_p
))
886 if (src0
.start
!= NULL_TREE
887 && !has_mem_ref_been_instrumented (&src0
, src0_len
))
890 if (src1
.start
!= NULL_TREE
891 && !has_mem_ref_been_instrumented (&src1
, src1_len
))
894 if (dest
.start
!= NULL_TREE
895 && !has_mem_ref_been_instrumented (&dest
, dest_len
))
904 /* Insert a memory reference into the hash table. */
907 update_mem_ref_hash_table (tree ref
, HOST_WIDE_INT access_size
)
909 hash_table
<asan_mem_ref_hasher
> *ht
= get_mem_ref_hash_table ();
912 asan_mem_ref_init (&r
, ref
, access_size
);
914 asan_mem_ref
**slot
= ht
->find_slot (&r
, INSERT
);
915 if (*slot
== NULL
|| (*slot
)->access_size
< access_size
)
916 *slot
= asan_mem_ref_new (ref
, access_size
);
919 /* Initialize shadow_ptr_types array. */
922 asan_init_shadow_ptr_types (void)
924 asan_shadow_set
= new_alias_set ();
925 shadow_ptr_types
[0] = build_distinct_type_copy (signed_char_type_node
);
926 TYPE_ALIAS_SET (shadow_ptr_types
[0]) = asan_shadow_set
;
927 shadow_ptr_types
[0] = build_pointer_type (shadow_ptr_types
[0]);
928 shadow_ptr_types
[1] = build_distinct_type_copy (short_integer_type_node
);
929 TYPE_ALIAS_SET (shadow_ptr_types
[1]) = asan_shadow_set
;
930 shadow_ptr_types
[1] = build_pointer_type (shadow_ptr_types
[1]);
931 initialize_sanitizer_builtins ();
934 /* Create ADDR_EXPR of STRING_CST with the PP pretty printer text. */
937 asan_pp_string (pretty_printer
*pp
)
939 const char *buf
= pp_formatted_text (pp
);
940 size_t len
= strlen (buf
);
941 tree ret
= build_string (len
+ 1, buf
);
943 = build_array_type (TREE_TYPE (shadow_ptr_types
[0]),
944 build_index_type (size_int (len
)));
945 TREE_READONLY (ret
) = 1;
946 TREE_STATIC (ret
) = 1;
947 return build1 (ADDR_EXPR
, shadow_ptr_types
[0], ret
);
950 /* Return a CONST_INT representing 4 subsequent shadow memory bytes. */
953 asan_shadow_cst (unsigned char shadow_bytes
[4])
956 unsigned HOST_WIDE_INT val
= 0;
957 gcc_assert (WORDS_BIG_ENDIAN
== BYTES_BIG_ENDIAN
);
958 for (i
= 0; i
< 4; i
++)
959 val
|= (unsigned HOST_WIDE_INT
) shadow_bytes
[BYTES_BIG_ENDIAN
? 3 - i
: i
]
960 << (BITS_PER_UNIT
* i
);
961 return gen_int_mode (val
, SImode
);
964 /* Clear shadow memory at SHADOW_MEM, LEN bytes. Can't call a library call here
968 asan_clear_shadow (rtx shadow_mem
, HOST_WIDE_INT len
)
970 rtx_insn
*insn
, *insns
, *jump
;
971 rtx_code_label
*top_label
;
975 clear_storage (shadow_mem
, GEN_INT (len
), BLOCK_OP_NORMAL
);
976 insns
= get_insns ();
978 for (insn
= insns
; insn
; insn
= NEXT_INSN (insn
))
981 if (insn
== NULL_RTX
)
987 gcc_assert ((len
& 3) == 0);
988 top_label
= gen_label_rtx ();
989 addr
= copy_to_mode_reg (Pmode
, XEXP (shadow_mem
, 0));
990 shadow_mem
= adjust_automodify_address (shadow_mem
, SImode
, addr
, 0);
991 end
= force_reg (Pmode
, plus_constant (Pmode
, addr
, len
));
992 emit_label (top_label
);
994 emit_move_insn (shadow_mem
, const0_rtx
);
995 tmp
= expand_simple_binop (Pmode
, PLUS
, addr
, gen_int_mode (4, Pmode
), addr
,
996 true, OPTAB_LIB_WIDEN
);
998 emit_move_insn (addr
, tmp
);
999 emit_cmp_and_jump_insns (addr
, end
, LT
, NULL_RTX
, Pmode
, true, top_label
);
1000 jump
= get_last_insn ();
1001 gcc_assert (JUMP_P (jump
));
1002 add_int_reg_note (jump
, REG_BR_PROB
, REG_BR_PROB_BASE
* 80 / 100);
1006 asan_function_start (void)
1008 section
*fnsec
= function_section (current_function_decl
);
1009 switch_to_section (fnsec
);
1010 ASM_OUTPUT_DEBUG_LABEL (asm_out_file
, "LASANPC",
1011 current_function_funcdef_no
);
1014 /* Insert code to protect stack vars. The prologue sequence should be emitted
1015 directly, epilogue sequence returned. BASE is the register holding the
1016 stack base, against which OFFSETS array offsets are relative to, OFFSETS
1017 array contains pairs of offsets in reverse order, always the end offset
1018 of some gap that needs protection followed by starting offset,
1019 and DECLS is an array of representative decls for each var partition.
1020 LENGTH is the length of the OFFSETS array, DECLS array is LENGTH / 2 - 1
1021 elements long (OFFSETS include gap before the first variable as well
1022 as gaps after each stack variable). PBASE is, if non-NULL, some pseudo
1023 register which stack vars DECL_RTLs are based on. Either BASE should be
1024 assigned to PBASE, when not doing use after return protection, or
1025 corresponding address based on __asan_stack_malloc* return value. */
1028 asan_emit_stack_protection (rtx base
, rtx pbase
, unsigned int alignb
,
1029 HOST_WIDE_INT
*offsets
, tree
*decls
, int length
)
1031 rtx shadow_base
, shadow_mem
, ret
, mem
, orig_base
;
1032 rtx_code_label
*lab
;
1035 unsigned char shadow_bytes
[4];
1036 HOST_WIDE_INT base_offset
= offsets
[length
- 1];
1037 HOST_WIDE_INT base_align_bias
= 0, offset
, prev_offset
;
1038 HOST_WIDE_INT asan_frame_size
= offsets
[0] - base_offset
;
1039 HOST_WIDE_INT last_offset
, last_size
;
1041 unsigned char cur_shadow_byte
= ASAN_STACK_MAGIC_LEFT
;
1042 tree str_cst
, decl
, id
;
1043 int use_after_return_class
= -1;
1045 if (shadow_ptr_types
[0] == NULL_TREE
)
1046 asan_init_shadow_ptr_types ();
1048 /* First of all, prepare the description string. */
1049 pretty_printer asan_pp
;
1051 pp_decimal_int (&asan_pp
, length
/ 2 - 1);
1052 pp_space (&asan_pp
);
1053 for (l
= length
- 2; l
; l
-= 2)
1055 tree decl
= decls
[l
/ 2 - 1];
1056 pp_wide_integer (&asan_pp
, offsets
[l
] - base_offset
);
1057 pp_space (&asan_pp
);
1058 pp_wide_integer (&asan_pp
, offsets
[l
- 1] - offsets
[l
]);
1059 pp_space (&asan_pp
);
1060 if (DECL_P (decl
) && DECL_NAME (decl
))
1062 pp_decimal_int (&asan_pp
, IDENTIFIER_LENGTH (DECL_NAME (decl
)));
1063 pp_space (&asan_pp
);
1064 pp_tree_identifier (&asan_pp
, DECL_NAME (decl
));
1067 pp_string (&asan_pp
, "9 <unknown>");
1068 pp_space (&asan_pp
);
1070 str_cst
= asan_pp_string (&asan_pp
);
1072 /* Emit the prologue sequence. */
1073 if (asan_frame_size
> 32 && asan_frame_size
<= 65536 && pbase
1074 && ASAN_USE_AFTER_RETURN
)
1076 use_after_return_class
= floor_log2 (asan_frame_size
- 1) - 5;
1077 /* __asan_stack_malloc_N guarantees alignment
1078 N < 6 ? (64 << N) : 4096 bytes. */
1079 if (alignb
> (use_after_return_class
< 6
1080 ? (64U << use_after_return_class
) : 4096U))
1081 use_after_return_class
= -1;
1082 else if (alignb
> ASAN_RED_ZONE_SIZE
&& (asan_frame_size
& (alignb
- 1)))
1083 base_align_bias
= ((asan_frame_size
+ alignb
- 1)
1084 & ~(alignb
- HOST_WIDE_INT_1
)) - asan_frame_size
;
1086 /* Align base if target is STRICT_ALIGNMENT. */
1087 if (STRICT_ALIGNMENT
)
1088 base
= expand_binop (Pmode
, and_optab
, base
,
1089 gen_int_mode (-((GET_MODE_ALIGNMENT (SImode
)
1090 << ASAN_SHADOW_SHIFT
)
1091 / BITS_PER_UNIT
), Pmode
), NULL_RTX
,
1094 if (use_after_return_class
== -1 && pbase
)
1095 emit_move_insn (pbase
, base
);
1097 base
= expand_binop (Pmode
, add_optab
, base
,
1098 gen_int_mode (base_offset
- base_align_bias
, Pmode
),
1099 NULL_RTX
, 1, OPTAB_DIRECT
);
1100 orig_base
= NULL_RTX
;
1101 if (use_after_return_class
!= -1)
1103 if (asan_detect_stack_use_after_return
== NULL_TREE
)
1105 id
= get_identifier ("__asan_option_detect_stack_use_after_return");
1106 decl
= build_decl (BUILTINS_LOCATION
, VAR_DECL
, id
,
1108 SET_DECL_ASSEMBLER_NAME (decl
, id
);
1109 TREE_ADDRESSABLE (decl
) = 1;
1110 DECL_ARTIFICIAL (decl
) = 1;
1111 DECL_IGNORED_P (decl
) = 1;
1112 DECL_EXTERNAL (decl
) = 1;
1113 TREE_STATIC (decl
) = 1;
1114 TREE_PUBLIC (decl
) = 1;
1115 TREE_USED (decl
) = 1;
1116 asan_detect_stack_use_after_return
= decl
;
1118 orig_base
= gen_reg_rtx (Pmode
);
1119 emit_move_insn (orig_base
, base
);
1120 ret
= expand_normal (asan_detect_stack_use_after_return
);
1121 lab
= gen_label_rtx ();
1122 int very_likely
= REG_BR_PROB_BASE
- (REG_BR_PROB_BASE
/ 2000 - 1);
1123 emit_cmp_and_jump_insns (ret
, const0_rtx
, EQ
, NULL_RTX
,
1124 VOIDmode
, 0, lab
, very_likely
);
1125 snprintf (buf
, sizeof buf
, "__asan_stack_malloc_%d",
1126 use_after_return_class
);
1127 ret
= init_one_libfunc (buf
);
1128 rtx addr
= convert_memory_address (ptr_mode
, base
);
1129 ret
= emit_library_call_value (ret
, NULL_RTX
, LCT_NORMAL
, ptr_mode
, 2,
1130 GEN_INT (asan_frame_size
1132 TYPE_MODE (pointer_sized_int_node
),
1134 ret
= convert_memory_address (Pmode
, ret
);
1135 emit_move_insn (base
, ret
);
1137 emit_move_insn (pbase
, expand_binop (Pmode
, add_optab
, base
,
1138 gen_int_mode (base_align_bias
1139 - base_offset
, Pmode
),
1140 NULL_RTX
, 1, OPTAB_DIRECT
));
1142 mem
= gen_rtx_MEM (ptr_mode
, base
);
1143 mem
= adjust_address (mem
, VOIDmode
, base_align_bias
);
1144 emit_move_insn (mem
, gen_int_mode (ASAN_STACK_FRAME_MAGIC
, ptr_mode
));
1145 mem
= adjust_address (mem
, VOIDmode
, GET_MODE_SIZE (ptr_mode
));
1146 emit_move_insn (mem
, expand_normal (str_cst
));
1147 mem
= adjust_address (mem
, VOIDmode
, GET_MODE_SIZE (ptr_mode
));
1148 ASM_GENERATE_INTERNAL_LABEL (buf
, "LASANPC", current_function_funcdef_no
);
1149 id
= get_identifier (buf
);
1150 decl
= build_decl (DECL_SOURCE_LOCATION (current_function_decl
),
1151 VAR_DECL
, id
, char_type_node
);
1152 SET_DECL_ASSEMBLER_NAME (decl
, id
);
1153 TREE_ADDRESSABLE (decl
) = 1;
1154 TREE_READONLY (decl
) = 1;
1155 DECL_ARTIFICIAL (decl
) = 1;
1156 DECL_IGNORED_P (decl
) = 1;
1157 TREE_STATIC (decl
) = 1;
1158 TREE_PUBLIC (decl
) = 0;
1159 TREE_USED (decl
) = 1;
1160 DECL_INITIAL (decl
) = decl
;
1161 TREE_ASM_WRITTEN (decl
) = 1;
1162 TREE_ASM_WRITTEN (id
) = 1;
1163 emit_move_insn (mem
, expand_normal (build_fold_addr_expr (decl
)));
1164 shadow_base
= expand_binop (Pmode
, lshr_optab
, base
,
1165 GEN_INT (ASAN_SHADOW_SHIFT
),
1166 NULL_RTX
, 1, OPTAB_DIRECT
);
1168 = plus_constant (Pmode
, shadow_base
,
1169 asan_shadow_offset ()
1170 + (base_align_bias
>> ASAN_SHADOW_SHIFT
));
1171 gcc_assert (asan_shadow_set
!= -1
1172 && (ASAN_RED_ZONE_SIZE
>> ASAN_SHADOW_SHIFT
) == 4);
1173 shadow_mem
= gen_rtx_MEM (SImode
, shadow_base
);
1174 set_mem_alias_set (shadow_mem
, asan_shadow_set
);
1175 if (STRICT_ALIGNMENT
)
1176 set_mem_align (shadow_mem
, (GET_MODE_ALIGNMENT (SImode
)));
1177 prev_offset
= base_offset
;
1178 for (l
= length
; l
; l
-= 2)
1181 cur_shadow_byte
= ASAN_STACK_MAGIC_RIGHT
;
1182 offset
= offsets
[l
- 1];
1183 if ((offset
- base_offset
) & (ASAN_RED_ZONE_SIZE
- 1))
1187 = base_offset
+ ((offset
- base_offset
)
1188 & ~(ASAN_RED_ZONE_SIZE
- HOST_WIDE_INT_1
));
1189 shadow_mem
= adjust_address (shadow_mem
, VOIDmode
,
1190 (aoff
- prev_offset
)
1191 >> ASAN_SHADOW_SHIFT
);
1193 for (i
= 0; i
< 4; i
++, aoff
+= (1 << ASAN_SHADOW_SHIFT
))
1196 if (aoff
< offset
- (1 << ASAN_SHADOW_SHIFT
) + 1)
1197 shadow_bytes
[i
] = 0;
1199 shadow_bytes
[i
] = offset
- aoff
;
1202 shadow_bytes
[i
] = ASAN_STACK_MAGIC_PARTIAL
;
1203 emit_move_insn (shadow_mem
, asan_shadow_cst (shadow_bytes
));
1206 while (offset
<= offsets
[l
- 2] - ASAN_RED_ZONE_SIZE
)
1208 shadow_mem
= adjust_address (shadow_mem
, VOIDmode
,
1209 (offset
- prev_offset
)
1210 >> ASAN_SHADOW_SHIFT
);
1211 prev_offset
= offset
;
1212 memset (shadow_bytes
, cur_shadow_byte
, 4);
1213 emit_move_insn (shadow_mem
, asan_shadow_cst (shadow_bytes
));
1214 offset
+= ASAN_RED_ZONE_SIZE
;
1216 cur_shadow_byte
= ASAN_STACK_MAGIC_MIDDLE
;
1218 do_pending_stack_adjust ();
1220 /* Construct epilogue sequence. */
1224 if (use_after_return_class
!= -1)
1226 rtx_code_label
*lab2
= gen_label_rtx ();
1227 char c
= (char) ASAN_STACK_MAGIC_USE_AFTER_RET
;
1228 int very_likely
= REG_BR_PROB_BASE
- (REG_BR_PROB_BASE
/ 2000 - 1);
1229 emit_cmp_and_jump_insns (orig_base
, base
, EQ
, NULL_RTX
,
1230 VOIDmode
, 0, lab2
, very_likely
);
1231 shadow_mem
= gen_rtx_MEM (BLKmode
, shadow_base
);
1232 set_mem_alias_set (shadow_mem
, asan_shadow_set
);
1233 mem
= gen_rtx_MEM (ptr_mode
, base
);
1234 mem
= adjust_address (mem
, VOIDmode
, base_align_bias
);
1235 emit_move_insn (mem
, gen_int_mode (ASAN_STACK_RETIRED_MAGIC
, ptr_mode
));
1236 unsigned HOST_WIDE_INT sz
= asan_frame_size
>> ASAN_SHADOW_SHIFT
;
1237 if (use_after_return_class
< 5
1238 && can_store_by_pieces (sz
, builtin_memset_read_str
, &c
,
1239 BITS_PER_UNIT
, true))
1240 store_by_pieces (shadow_mem
, sz
, builtin_memset_read_str
, &c
,
1241 BITS_PER_UNIT
, true, 0);
1242 else if (use_after_return_class
>= 5
1243 || !set_storage_via_setmem (shadow_mem
,
1245 gen_int_mode (c
, QImode
),
1246 BITS_PER_UNIT
, BITS_PER_UNIT
,
1249 snprintf (buf
, sizeof buf
, "__asan_stack_free_%d",
1250 use_after_return_class
);
1251 ret
= init_one_libfunc (buf
);
1252 rtx addr
= convert_memory_address (ptr_mode
, base
);
1253 rtx orig_addr
= convert_memory_address (ptr_mode
, orig_base
);
1254 emit_library_call (ret
, LCT_NORMAL
, ptr_mode
, 3, addr
, ptr_mode
,
1255 GEN_INT (asan_frame_size
+ base_align_bias
),
1256 TYPE_MODE (pointer_sized_int_node
),
1257 orig_addr
, ptr_mode
);
1259 lab
= gen_label_rtx ();
1264 shadow_mem
= gen_rtx_MEM (BLKmode
, shadow_base
);
1265 set_mem_alias_set (shadow_mem
, asan_shadow_set
);
1267 if (STRICT_ALIGNMENT
)
1268 set_mem_align (shadow_mem
, (GET_MODE_ALIGNMENT (SImode
)));
1270 prev_offset
= base_offset
;
1271 last_offset
= base_offset
;
1273 for (l
= length
; l
; l
-= 2)
1275 offset
= base_offset
+ ((offsets
[l
- 1] - base_offset
)
1276 & ~(ASAN_RED_ZONE_SIZE
- HOST_WIDE_INT_1
));
1277 if (last_offset
+ last_size
!= offset
)
1279 shadow_mem
= adjust_address (shadow_mem
, VOIDmode
,
1280 (last_offset
- prev_offset
)
1281 >> ASAN_SHADOW_SHIFT
);
1282 prev_offset
= last_offset
;
1283 asan_clear_shadow (shadow_mem
, last_size
>> ASAN_SHADOW_SHIFT
);
1284 last_offset
= offset
;
1287 last_size
+= base_offset
+ ((offsets
[l
- 2] - base_offset
)
1288 & ~(ASAN_RED_ZONE_SIZE
- HOST_WIDE_INT_1
))
1293 shadow_mem
= adjust_address (shadow_mem
, VOIDmode
,
1294 (last_offset
- prev_offset
)
1295 >> ASAN_SHADOW_SHIFT
);
1296 asan_clear_shadow (shadow_mem
, last_size
>> ASAN_SHADOW_SHIFT
);
1299 do_pending_stack_adjust ();
1303 insns
= get_insns ();
1308 /* Return true if DECL, a global var, might be overridden and needs
1309 therefore a local alias. */
1312 asan_needs_local_alias (tree decl
)
1314 return DECL_WEAK (decl
) || !targetm
.binds_local_p (decl
);
1317 /* Return true if DECL is a VAR_DECL that should be protected
1318 by Address Sanitizer, by appending a red zone with protected
1319 shadow memory after it and aligning it to at least
1320 ASAN_RED_ZONE_SIZE bytes. */
1323 asan_protect_global (tree decl
)
1330 if (TREE_CODE (decl
) == STRING_CST
)
1332 /* Instrument all STRING_CSTs except those created
1333 by asan_pp_string here. */
1334 if (shadow_ptr_types
[0] != NULL_TREE
1335 && TREE_CODE (TREE_TYPE (decl
)) == ARRAY_TYPE
1336 && TREE_TYPE (TREE_TYPE (decl
)) == TREE_TYPE (shadow_ptr_types
[0]))
1340 if (TREE_CODE (decl
) != VAR_DECL
1341 /* TLS vars aren't statically protectable. */
1342 || DECL_THREAD_LOCAL_P (decl
)
1343 /* Externs will be protected elsewhere. */
1344 || DECL_EXTERNAL (decl
)
1345 || !DECL_RTL_SET_P (decl
)
1346 /* Comdat vars pose an ABI problem, we can't know if
1347 the var that is selected by the linker will have
1349 || DECL_ONE_ONLY (decl
)
1350 /* Similarly for common vars. People can use -fno-common. */
1351 || (DECL_COMMON (decl
) && TREE_PUBLIC (decl
))
1352 /* Don't protect if using user section, often vars placed
1353 into user section from multiple TUs are then assumed
1354 to be an array of such vars, putting padding in there
1355 breaks this assumption. */
1356 || (DECL_SECTION_NAME (decl
) != NULL
1357 && !symtab_node::get (decl
)->implicit_section
)
1358 || DECL_SIZE (decl
) == 0
1359 || ASAN_RED_ZONE_SIZE
* BITS_PER_UNIT
> MAX_OFILE_ALIGNMENT
1360 || !valid_constant_size_p (DECL_SIZE_UNIT (decl
))
1361 || DECL_ALIGN_UNIT (decl
) > 2 * ASAN_RED_ZONE_SIZE
1362 || TREE_TYPE (decl
) == ubsan_get_source_location_type ())
1365 rtl
= DECL_RTL (decl
);
1366 if (!MEM_P (rtl
) || GET_CODE (XEXP (rtl
, 0)) != SYMBOL_REF
)
1368 symbol
= XEXP (rtl
, 0);
1370 if (CONSTANT_POOL_ADDRESS_P (symbol
)
1371 || TREE_CONSTANT_POOL_ADDRESS_P (symbol
))
1374 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl
)))
1377 #ifndef ASM_OUTPUT_DEF
1378 if (asan_needs_local_alias (decl
))
1385 /* Construct a function tree for __asan_report_{load,store}{1,2,4,8,16,_n}.
1386 IS_STORE is either 1 (for a store) or 0 (for a load). */
1389 report_error_func (bool is_store
, bool recover_p
, HOST_WIDE_INT size_in_bytes
,
1392 static enum built_in_function report
[2][2][6]
1393 = { { { BUILT_IN_ASAN_REPORT_LOAD1
, BUILT_IN_ASAN_REPORT_LOAD2
,
1394 BUILT_IN_ASAN_REPORT_LOAD4
, BUILT_IN_ASAN_REPORT_LOAD8
,
1395 BUILT_IN_ASAN_REPORT_LOAD16
, BUILT_IN_ASAN_REPORT_LOAD_N
},
1396 { BUILT_IN_ASAN_REPORT_STORE1
, BUILT_IN_ASAN_REPORT_STORE2
,
1397 BUILT_IN_ASAN_REPORT_STORE4
, BUILT_IN_ASAN_REPORT_STORE8
,
1398 BUILT_IN_ASAN_REPORT_STORE16
, BUILT_IN_ASAN_REPORT_STORE_N
} },
1399 { { BUILT_IN_ASAN_REPORT_LOAD1_NOABORT
,
1400 BUILT_IN_ASAN_REPORT_LOAD2_NOABORT
,
1401 BUILT_IN_ASAN_REPORT_LOAD4_NOABORT
,
1402 BUILT_IN_ASAN_REPORT_LOAD8_NOABORT
,
1403 BUILT_IN_ASAN_REPORT_LOAD16_NOABORT
,
1404 BUILT_IN_ASAN_REPORT_LOAD_N_NOABORT
},
1405 { BUILT_IN_ASAN_REPORT_STORE1_NOABORT
,
1406 BUILT_IN_ASAN_REPORT_STORE2_NOABORT
,
1407 BUILT_IN_ASAN_REPORT_STORE4_NOABORT
,
1408 BUILT_IN_ASAN_REPORT_STORE8_NOABORT
,
1409 BUILT_IN_ASAN_REPORT_STORE16_NOABORT
,
1410 BUILT_IN_ASAN_REPORT_STORE_N_NOABORT
} } };
1411 if (size_in_bytes
== -1)
1414 return builtin_decl_implicit (report
[recover_p
][is_store
][5]);
1417 int size_log2
= exact_log2 (size_in_bytes
);
1418 return builtin_decl_implicit (report
[recover_p
][is_store
][size_log2
]);
1421 /* Construct a function tree for __asan_{load,store}{1,2,4,8,16,_n}.
1422 IS_STORE is either 1 (for a store) or 0 (for a load). */
1425 check_func (bool is_store
, bool recover_p
, HOST_WIDE_INT size_in_bytes
,
1428 static enum built_in_function check
[2][2][6]
1429 = { { { BUILT_IN_ASAN_LOAD1
, BUILT_IN_ASAN_LOAD2
,
1430 BUILT_IN_ASAN_LOAD4
, BUILT_IN_ASAN_LOAD8
,
1431 BUILT_IN_ASAN_LOAD16
, BUILT_IN_ASAN_LOADN
},
1432 { BUILT_IN_ASAN_STORE1
, BUILT_IN_ASAN_STORE2
,
1433 BUILT_IN_ASAN_STORE4
, BUILT_IN_ASAN_STORE8
,
1434 BUILT_IN_ASAN_STORE16
, BUILT_IN_ASAN_STOREN
} },
1435 { { BUILT_IN_ASAN_LOAD1_NOABORT
,
1436 BUILT_IN_ASAN_LOAD2_NOABORT
,
1437 BUILT_IN_ASAN_LOAD4_NOABORT
,
1438 BUILT_IN_ASAN_LOAD8_NOABORT
,
1439 BUILT_IN_ASAN_LOAD16_NOABORT
,
1440 BUILT_IN_ASAN_LOADN_NOABORT
},
1441 { BUILT_IN_ASAN_STORE1_NOABORT
,
1442 BUILT_IN_ASAN_STORE2_NOABORT
,
1443 BUILT_IN_ASAN_STORE4_NOABORT
,
1444 BUILT_IN_ASAN_STORE8_NOABORT
,
1445 BUILT_IN_ASAN_STORE16_NOABORT
,
1446 BUILT_IN_ASAN_STOREN_NOABORT
} } };
1447 if (size_in_bytes
== -1)
1450 return builtin_decl_implicit (check
[recover_p
][is_store
][5]);
1453 int size_log2
= exact_log2 (size_in_bytes
);
1454 return builtin_decl_implicit (check
[recover_p
][is_store
][size_log2
]);
1457 /* Split the current basic block and create a condition statement
1458 insertion point right before or after the statement pointed to by
1459 ITER. Return an iterator to the point at which the caller might
1460 safely insert the condition statement.
1462 THEN_BLOCK must be set to the address of an uninitialized instance
1463 of basic_block. The function will then set *THEN_BLOCK to the
1464 'then block' of the condition statement to be inserted by the
1467 If CREATE_THEN_FALLTHRU_EDGE is false, no edge will be created from
1468 *THEN_BLOCK to *FALLTHROUGH_BLOCK.
1470 Similarly, the function will set *FALLTRHOUGH_BLOCK to the 'else
1471 block' of the condition statement to be inserted by the caller.
1473 Note that *FALLTHROUGH_BLOCK is a new block that contains the
1474 statements starting from *ITER, and *THEN_BLOCK is a new empty
1477 *ITER is adjusted to point to always point to the first statement
1478 of the basic block * FALLTHROUGH_BLOCK. That statement is the
1479 same as what ITER was pointing to prior to calling this function,
1480 if BEFORE_P is true; otherwise, it is its following statement. */
1482 gimple_stmt_iterator
1483 create_cond_insert_point (gimple_stmt_iterator
*iter
,
1485 bool then_more_likely_p
,
1486 bool create_then_fallthru_edge
,
1487 basic_block
*then_block
,
1488 basic_block
*fallthrough_block
)
1490 gimple_stmt_iterator gsi
= *iter
;
1492 if (!gsi_end_p (gsi
) && before_p
)
1495 basic_block cur_bb
= gsi_bb (*iter
);
1497 edge e
= split_block (cur_bb
, gsi_stmt (gsi
));
1499 /* Get a hold on the 'condition block', the 'then block' and the
1501 basic_block cond_bb
= e
->src
;
1502 basic_block fallthru_bb
= e
->dest
;
1503 basic_block then_bb
= create_empty_bb (cond_bb
);
1506 add_bb_to_loop (then_bb
, cond_bb
->loop_father
);
1507 loops_state_set (LOOPS_NEED_FIXUP
);
1510 /* Set up the newly created 'then block'. */
1511 e
= make_edge (cond_bb
, then_bb
, EDGE_TRUE_VALUE
);
1512 int fallthrough_probability
1513 = then_more_likely_p
1514 ? PROB_VERY_UNLIKELY
1515 : PROB_ALWAYS
- PROB_VERY_UNLIKELY
;
1516 e
->probability
= PROB_ALWAYS
- fallthrough_probability
;
1517 if (create_then_fallthru_edge
)
1518 make_single_succ_edge (then_bb
, fallthru_bb
, EDGE_FALLTHRU
);
1520 /* Set up the fallthrough basic block. */
1521 e
= find_edge (cond_bb
, fallthru_bb
);
1522 e
->flags
= EDGE_FALSE_VALUE
;
1523 e
->count
= cond_bb
->count
;
1524 e
->probability
= fallthrough_probability
;
1526 /* Update dominance info for the newly created then_bb; note that
1527 fallthru_bb's dominance info has already been updated by
1529 if (dom_info_available_p (CDI_DOMINATORS
))
1530 set_immediate_dominator (CDI_DOMINATORS
, then_bb
, cond_bb
);
1532 *then_block
= then_bb
;
1533 *fallthrough_block
= fallthru_bb
;
1534 *iter
= gsi_start_bb (fallthru_bb
);
1536 return gsi_last_bb (cond_bb
);
1539 /* Insert an if condition followed by a 'then block' right before the
1540 statement pointed to by ITER. The fallthrough block -- which is the
1541 else block of the condition as well as the destination of the
1542 outcoming edge of the 'then block' -- starts with the statement
1545 COND is the condition of the if.
1547 If THEN_MORE_LIKELY_P is true, the probability of the edge to the
1548 'then block' is higher than the probability of the edge to the
1551 Upon completion of the function, *THEN_BB is set to the newly
1552 inserted 'then block' and similarly, *FALLTHROUGH_BB is set to the
1555 *ITER is adjusted to still point to the same statement it was
1556 pointing to initially. */
1559 insert_if_then_before_iter (gimple cond
,
1560 gimple_stmt_iterator
*iter
,
1561 bool then_more_likely_p
,
1562 basic_block
*then_bb
,
1563 basic_block
*fallthrough_bb
)
1565 gimple_stmt_iterator cond_insert_point
=
1566 create_cond_insert_point (iter
,
1569 /*create_then_fallthru_edge=*/true,
1572 gsi_insert_after (&cond_insert_point
, cond
, GSI_NEW_STMT
);
1576 (base_addr >> ASAN_SHADOW_SHIFT) + asan_shadow_offset (). */
1579 build_shadow_mem_access (gimple_stmt_iterator
*gsi
, location_t location
,
1580 tree base_addr
, tree shadow_ptr_type
)
1582 tree t
, uintptr_type
= TREE_TYPE (base_addr
);
1583 tree shadow_type
= TREE_TYPE (shadow_ptr_type
);
1586 t
= build_int_cst (uintptr_type
, ASAN_SHADOW_SHIFT
);
1587 g
= gimple_build_assign_with_ops (RSHIFT_EXPR
,
1588 make_ssa_name (uintptr_type
, NULL
),
1590 gimple_set_location (g
, location
);
1591 gsi_insert_after (gsi
, g
, GSI_NEW_STMT
);
1593 t
= build_int_cst (uintptr_type
, asan_shadow_offset ());
1594 g
= gimple_build_assign_with_ops (PLUS_EXPR
,
1595 make_ssa_name (uintptr_type
, NULL
),
1596 gimple_assign_lhs (g
), t
);
1597 gimple_set_location (g
, location
);
1598 gsi_insert_after (gsi
, g
, GSI_NEW_STMT
);
1600 g
= gimple_build_assign_with_ops (NOP_EXPR
,
1601 make_ssa_name (shadow_ptr_type
, NULL
),
1602 gimple_assign_lhs (g
));
1603 gimple_set_location (g
, location
);
1604 gsi_insert_after (gsi
, g
, GSI_NEW_STMT
);
1606 t
= build2 (MEM_REF
, shadow_type
, gimple_assign_lhs (g
),
1607 build_int_cst (shadow_ptr_type
, 0));
1608 g
= gimple_build_assign_with_ops (MEM_REF
,
1609 make_ssa_name (shadow_type
, NULL
), t
);
1610 gimple_set_location (g
, location
);
1611 gsi_insert_after (gsi
, g
, GSI_NEW_STMT
);
1612 return gimple_assign_lhs (g
);
1615 /* BASE can already be an SSA_NAME; in that case, do not create a
1616 new SSA_NAME for it. */
1619 maybe_create_ssa_name (location_t loc
, tree base
, gimple_stmt_iterator
*iter
,
1622 if (TREE_CODE (base
) == SSA_NAME
)
1625 = gimple_build_assign_with_ops (TREE_CODE (base
),
1626 make_ssa_name (TREE_TYPE (base
), NULL
),
1628 gimple_set_location (g
, loc
);
1630 gsi_insert_before (iter
, g
, GSI_SAME_STMT
);
1632 gsi_insert_after (iter
, g
, GSI_NEW_STMT
);
1633 return gimple_assign_lhs (g
);
1636 /* LEN can already have necessary size and precision;
1637 in that case, do not create a new variable. */
1640 maybe_cast_to_ptrmode (location_t loc
, tree len
, gimple_stmt_iterator
*iter
,
1643 if (ptrofftype_p (len
))
1646 = gimple_build_assign_with_ops (NOP_EXPR
,
1647 make_ssa_name (pointer_sized_int_node
,
1649 gimple_set_location (g
, loc
);
1651 gsi_insert_before (iter
, g
, GSI_SAME_STMT
);
1653 gsi_insert_after (iter
, g
, GSI_NEW_STMT
);
1654 return gimple_assign_lhs (g
);
1657 /* Instrument the memory access instruction BASE. Insert new
1658 statements before or after ITER.
1660 Note that the memory access represented by BASE can be either an
1661 SSA_NAME, or a non-SSA expression. LOCATION is the source code
1662 location. IS_STORE is TRUE for a store, FALSE for a load.
1663 BEFORE_P is TRUE for inserting the instrumentation code before
1664 ITER, FALSE for inserting it after ITER. IS_SCALAR_ACCESS is TRUE
1665 for a scalar memory access and FALSE for memory region access.
1666 NON_ZERO_P is TRUE if memory region is guaranteed to have non-zero
1667 length. ALIGN tells alignment of accessed memory object.
1669 START_INSTRUMENTED and END_INSTRUMENTED are TRUE if start/end of
1670 memory region have already been instrumented.
1672 If BEFORE_P is TRUE, *ITER is arranged to still point to the
1673 statement it was pointing to prior to calling this function,
1674 otherwise, it points to the statement logically following it. */
1677 build_check_stmt (location_t loc
, tree base
, tree len
,
1678 HOST_WIDE_INT size_in_bytes
, gimple_stmt_iterator
*iter
,
1679 bool is_non_zero_len
, bool before_p
, bool is_store
,
1680 bool is_scalar_access
, unsigned int align
= 0)
1682 gimple_stmt_iterator gsi
= *iter
;
1685 gcc_assert (!(size_in_bytes
> 0 && !is_non_zero_len
));
1689 base
= unshare_expr (base
);
1690 base
= maybe_create_ssa_name (loc
, base
, &gsi
, before_p
);
1694 len
= unshare_expr (len
);
1695 len
= maybe_cast_to_ptrmode (loc
, len
, iter
, before_p
);
1699 gcc_assert (size_in_bytes
!= -1);
1700 len
= build_int_cst (pointer_sized_int_node
, size_in_bytes
);
1703 if (size_in_bytes
> 1)
1705 if ((size_in_bytes
& (size_in_bytes
- 1)) != 0
1706 || size_in_bytes
> 16)
1707 is_scalar_access
= false;
1708 else if (align
&& align
< size_in_bytes
* BITS_PER_UNIT
)
1710 /* On non-strict alignment targets, if
1711 16-byte access is just 8-byte aligned,
1712 this will result in misaligned shadow
1713 memory 2 byte load, but otherwise can
1714 be handled using one read. */
1715 if (size_in_bytes
!= 16
1717 || align
< 8 * BITS_PER_UNIT
)
1718 is_scalar_access
= false;
1722 HOST_WIDE_INT flags
= 0;
1724 flags
|= ASAN_CHECK_STORE
;
1725 if (is_non_zero_len
)
1726 flags
|= ASAN_CHECK_NON_ZERO_LEN
;
1727 if (is_scalar_access
)
1728 flags
|= ASAN_CHECK_SCALAR_ACCESS
;
1730 g
= gimple_build_call_internal (IFN_ASAN_CHECK
, 4,
1731 build_int_cst (integer_type_node
, flags
),
1733 build_int_cst (integer_type_node
,
1734 align
/ BITS_PER_UNIT
));
1735 gimple_set_location (g
, loc
);
1737 gsi_insert_before (&gsi
, g
, GSI_SAME_STMT
);
1740 gsi_insert_after (&gsi
, g
, GSI_NEW_STMT
);
1746 /* If T represents a memory access, add instrumentation code before ITER.
1747 LOCATION is source code location.
1748 IS_STORE is either TRUE (for a store) or FALSE (for a load). */
1751 instrument_derefs (gimple_stmt_iterator
*iter
, tree t
,
1752 location_t location
, bool is_store
)
1754 if (is_store
&& !ASAN_INSTRUMENT_WRITES
)
1756 if (!is_store
&& !ASAN_INSTRUMENT_READS
)
1760 HOST_WIDE_INT size_in_bytes
;
1762 type
= TREE_TYPE (t
);
1763 switch (TREE_CODE (t
))
1777 size_in_bytes
= int_size_in_bytes (type
);
1778 if (size_in_bytes
<= 0)
1781 HOST_WIDE_INT bitsize
, bitpos
;
1784 int volatilep
= 0, unsignedp
= 0;
1785 tree inner
= get_inner_reference (t
, &bitsize
, &bitpos
, &offset
,
1786 &mode
, &unsignedp
, &volatilep
, false);
1788 if (TREE_CODE (t
) == COMPONENT_REF
1789 && DECL_BIT_FIELD_REPRESENTATIVE (TREE_OPERAND (t
, 1)) != NULL_TREE
)
1791 tree repr
= DECL_BIT_FIELD_REPRESENTATIVE (TREE_OPERAND (t
, 1));
1792 instrument_derefs (iter
, build3 (COMPONENT_REF
, TREE_TYPE (repr
),
1793 TREE_OPERAND (t
, 0), repr
,
1794 NULL_TREE
), location
, is_store
);
1798 if (bitpos
% BITS_PER_UNIT
1799 || bitsize
!= size_in_bytes
* BITS_PER_UNIT
)
1802 if (TREE_CODE (inner
) == VAR_DECL
1803 && offset
== NULL_TREE
1805 && DECL_SIZE (inner
)
1806 && tree_fits_shwi_p (DECL_SIZE (inner
))
1807 && bitpos
+ bitsize
<= tree_to_shwi (DECL_SIZE (inner
)))
1809 if (DECL_THREAD_LOCAL_P (inner
))
1811 if (!TREE_STATIC (inner
))
1813 /* Automatic vars in the current function will be always
1815 if (decl_function_context (inner
) == current_function_decl
)
1818 /* Always instrument external vars, they might be dynamically
1820 else if (!DECL_EXTERNAL (inner
))
1822 /* For static vars if they are known not to be dynamically
1823 initialized, they will be always accessible. */
1824 varpool_node
*vnode
= varpool_node::get (inner
);
1825 if (vnode
&& !vnode
->dynamically_initialized
)
1830 base
= build_fold_addr_expr (t
);
1831 if (!has_mem_ref_been_instrumented (base
, size_in_bytes
))
1833 unsigned int align
= get_object_alignment (t
);
1834 build_check_stmt (location
, base
, NULL_TREE
, size_in_bytes
, iter
,
1835 /*is_non_zero_len*/size_in_bytes
> 0, /*before_p=*/true,
1836 is_store
, /*is_scalar_access*/true, align
);
1837 update_mem_ref_hash_table (base
, size_in_bytes
);
1838 update_mem_ref_hash_table (t
, size_in_bytes
);
1843 /* Insert a memory reference into the hash table if access length
1844 can be determined in compile time. */
1847 maybe_update_mem_ref_hash_table (tree base
, tree len
)
1849 if (!POINTER_TYPE_P (TREE_TYPE (base
))
1850 || !INTEGRAL_TYPE_P (TREE_TYPE (len
)))
1853 HOST_WIDE_INT size_in_bytes
= tree_fits_shwi_p (len
) ? tree_to_shwi (len
) : -1;
1855 if (size_in_bytes
!= -1)
1856 update_mem_ref_hash_table (base
, size_in_bytes
);
1859 /* Instrument an access to a contiguous memory region that starts at
1860 the address pointed to by BASE, over a length of LEN (expressed in
1861 the sizeof (*BASE) bytes). ITER points to the instruction before
1862 which the instrumentation instructions must be inserted. LOCATION
1863 is the source location that the instrumentation instructions must
1864 have. If IS_STORE is true, then the memory access is a store;
1865 otherwise, it's a load. */
1868 instrument_mem_region_access (tree base
, tree len
,
1869 gimple_stmt_iterator
*iter
,
1870 location_t location
, bool is_store
)
1872 if (!POINTER_TYPE_P (TREE_TYPE (base
))
1873 || !INTEGRAL_TYPE_P (TREE_TYPE (len
))
1874 || integer_zerop (len
))
1877 HOST_WIDE_INT size_in_bytes
= tree_fits_shwi_p (len
) ? tree_to_shwi (len
) : -1;
1879 if ((size_in_bytes
== -1)
1880 || !has_mem_ref_been_instrumented (base
, size_in_bytes
))
1882 build_check_stmt (location
, base
, len
, size_in_bytes
, iter
,
1883 /*is_non_zero_len*/size_in_bytes
> 0, /*before_p*/true,
1884 is_store
, /*is_scalar_access*/false, /*align*/0);
1887 maybe_update_mem_ref_hash_table (base
, len
);
1888 *iter
= gsi_for_stmt (gsi_stmt (*iter
));
1891 /* Instrument the call to a built-in memory access function that is
1892 pointed to by the iterator ITER.
1894 Upon completion, return TRUE iff *ITER has been advanced to the
1895 statement following the one it was originally pointing to. */
1898 instrument_builtin_call (gimple_stmt_iterator
*iter
)
1900 if (!ASAN_MEMINTRIN
)
1903 bool iter_advanced_p
= false;
1904 gimple call
= gsi_stmt (*iter
);
1906 gcc_checking_assert (gimple_call_builtin_p (call
, BUILT_IN_NORMAL
));
1908 location_t loc
= gimple_location (call
);
1910 asan_mem_ref src0
, src1
, dest
;
1911 asan_mem_ref_init (&src0
, NULL
, 1);
1912 asan_mem_ref_init (&src1
, NULL
, 1);
1913 asan_mem_ref_init (&dest
, NULL
, 1);
1915 tree src0_len
= NULL_TREE
, src1_len
= NULL_TREE
, dest_len
= NULL_TREE
;
1916 bool src0_is_store
= false, src1_is_store
= false, dest_is_store
= false,
1917 dest_is_deref
= false, intercepted_p
= true;
1919 if (get_mem_refs_of_builtin_call (call
,
1920 &src0
, &src0_len
, &src0_is_store
,
1921 &src1
, &src1_len
, &src1_is_store
,
1922 &dest
, &dest_len
, &dest_is_store
,
1923 &dest_is_deref
, &intercepted_p
))
1927 instrument_derefs (iter
, dest
.start
, loc
, dest_is_store
);
1929 iter_advanced_p
= true;
1931 else if (!intercepted_p
1932 && (src0_len
|| src1_len
|| dest_len
))
1934 if (src0
.start
!= NULL_TREE
)
1935 instrument_mem_region_access (src0
.start
, src0_len
,
1936 iter
, loc
, /*is_store=*/false);
1937 if (src1
.start
!= NULL_TREE
)
1938 instrument_mem_region_access (src1
.start
, src1_len
,
1939 iter
, loc
, /*is_store=*/false);
1940 if (dest
.start
!= NULL_TREE
)
1941 instrument_mem_region_access (dest
.start
, dest_len
,
1942 iter
, loc
, /*is_store=*/true);
1944 *iter
= gsi_for_stmt (call
);
1946 iter_advanced_p
= true;
1950 if (src0
.start
!= NULL_TREE
)
1951 maybe_update_mem_ref_hash_table (src0
.start
, src0_len
);
1952 if (src1
.start
!= NULL_TREE
)
1953 maybe_update_mem_ref_hash_table (src1
.start
, src1_len
);
1954 if (dest
.start
!= NULL_TREE
)
1955 maybe_update_mem_ref_hash_table (dest
.start
, dest_len
);
1958 return iter_advanced_p
;
1961 /* Instrument the assignment statement ITER if it is subject to
1962 instrumentation. Return TRUE iff instrumentation actually
1963 happened. In that case, the iterator ITER is advanced to the next
1964 logical expression following the one initially pointed to by ITER,
1965 and the relevant memory reference that which access has been
1966 instrumented is added to the memory references hash table. */
1969 maybe_instrument_assignment (gimple_stmt_iterator
*iter
)
1971 gimple s
= gsi_stmt (*iter
);
1973 gcc_assert (gimple_assign_single_p (s
));
1975 tree ref_expr
= NULL_TREE
;
1976 bool is_store
, is_instrumented
= false;
1978 if (gimple_store_p (s
))
1980 ref_expr
= gimple_assign_lhs (s
);
1982 instrument_derefs (iter
, ref_expr
,
1983 gimple_location (s
),
1985 is_instrumented
= true;
1988 if (gimple_assign_load_p (s
))
1990 ref_expr
= gimple_assign_rhs1 (s
);
1992 instrument_derefs (iter
, ref_expr
,
1993 gimple_location (s
),
1995 is_instrumented
= true;
1998 if (is_instrumented
)
2001 return is_instrumented
;
2004 /* Instrument the function call pointed to by the iterator ITER, if it
2005 is subject to instrumentation. At the moment, the only function
2006 calls that are instrumented are some built-in functions that access
2007 memory. Look at instrument_builtin_call to learn more.
2009 Upon completion return TRUE iff *ITER was advanced to the statement
2010 following the one it was originally pointing to. */
2013 maybe_instrument_call (gimple_stmt_iterator
*iter
)
2015 gimple stmt
= gsi_stmt (*iter
);
2016 bool is_builtin
= gimple_call_builtin_p (stmt
, BUILT_IN_NORMAL
);
2018 if (is_builtin
&& instrument_builtin_call (iter
))
2021 if (gimple_call_noreturn_p (stmt
))
2025 tree callee
= gimple_call_fndecl (stmt
);
2026 switch (DECL_FUNCTION_CODE (callee
))
2028 case BUILT_IN_UNREACHABLE
:
2030 /* Don't instrument these. */
2036 tree decl
= builtin_decl_implicit (BUILT_IN_ASAN_HANDLE_NO_RETURN
);
2037 gimple g
= gimple_build_call (decl
, 0);
2038 gimple_set_location (g
, gimple_location (stmt
));
2039 gsi_insert_before (iter
, g
, GSI_SAME_STMT
);
2044 /* Walk each instruction of all basic block and instrument those that
2045 represent memory references: loads, stores, or function calls.
2046 In a given basic block, this function avoids instrumenting memory
2047 references that have already been instrumented. */
2050 transform_statements (void)
2052 basic_block bb
, last_bb
= NULL
;
2053 gimple_stmt_iterator i
;
2054 int saved_last_basic_block
= last_basic_block_for_fn (cfun
);
2056 FOR_EACH_BB_FN (bb
, cfun
)
2058 basic_block prev_bb
= bb
;
2060 if (bb
->index
>= saved_last_basic_block
) continue;
2062 /* Flush the mem ref hash table, if current bb doesn't have
2063 exactly one predecessor, or if that predecessor (skipping
2064 over asan created basic blocks) isn't the last processed
2065 basic block. Thus we effectively flush on extended basic
2066 block boundaries. */
2067 while (single_pred_p (prev_bb
))
2069 prev_bb
= single_pred (prev_bb
);
2070 if (prev_bb
->index
< saved_last_basic_block
)
2073 if (prev_bb
!= last_bb
)
2074 empty_mem_ref_hash_table ();
2077 for (i
= gsi_start_bb (bb
); !gsi_end_p (i
);)
2079 gimple s
= gsi_stmt (i
);
2081 if (has_stmt_been_instrumented_p (s
))
2083 else if (gimple_assign_single_p (s
)
2084 && !gimple_clobber_p (s
)
2085 && maybe_instrument_assignment (&i
))
2086 /* Nothing to do as maybe_instrument_assignment advanced
2088 else if (is_gimple_call (s
) && maybe_instrument_call (&i
))
2089 /* Nothing to do as maybe_instrument_call
2090 advanced the iterator I. */;
2093 /* No instrumentation happened.
2095 If the current instruction is a function call that
2096 might free something, let's forget about the memory
2097 references that got instrumented. Otherwise we might
2098 miss some instrumentation opportunities. */
2099 if (is_gimple_call (s
) && !nonfreeing_call_p (s
))
2100 empty_mem_ref_hash_table ();
2106 free_mem_ref_resources ();
2110 __asan_before_dynamic_init (module_name)
2112 __asan_after_dynamic_init ()
2116 asan_dynamic_init_call (bool after_p
)
2118 tree fn
= builtin_decl_implicit (after_p
2119 ? BUILT_IN_ASAN_AFTER_DYNAMIC_INIT
2120 : BUILT_IN_ASAN_BEFORE_DYNAMIC_INIT
);
2121 tree module_name_cst
= NULL_TREE
;
2124 pretty_printer module_name_pp
;
2125 pp_string (&module_name_pp
, main_input_filename
);
2127 if (shadow_ptr_types
[0] == NULL_TREE
)
2128 asan_init_shadow_ptr_types ();
2129 module_name_cst
= asan_pp_string (&module_name_pp
);
2130 module_name_cst
= fold_convert (const_ptr_type_node
,
2134 return build_call_expr (fn
, after_p
? 0 : 1, module_name_cst
);
2138 struct __asan_global
2142 uptr __size_with_redzone;
2144 const void *__module_name;
2145 uptr __has_dynamic_init;
2146 __asan_global_source_location *__location;
2150 asan_global_struct (void)
2152 static const char *field_names
[7]
2153 = { "__beg", "__size", "__size_with_redzone",
2154 "__name", "__module_name", "__has_dynamic_init", "__location"};
2155 tree fields
[7], ret
;
2158 ret
= make_node (RECORD_TYPE
);
2159 for (i
= 0; i
< 7; i
++)
2162 = build_decl (UNKNOWN_LOCATION
, FIELD_DECL
,
2163 get_identifier (field_names
[i
]),
2164 (i
== 0 || i
== 3) ? const_ptr_type_node
2165 : pointer_sized_int_node
);
2166 DECL_CONTEXT (fields
[i
]) = ret
;
2168 DECL_CHAIN (fields
[i
- 1]) = fields
[i
];
2170 tree type_decl
= build_decl (input_location
, TYPE_DECL
,
2171 get_identifier ("__asan_global"), ret
);
2172 DECL_IGNORED_P (type_decl
) = 1;
2173 DECL_ARTIFICIAL (type_decl
) = 1;
2174 TYPE_FIELDS (ret
) = fields
[0];
2175 TYPE_NAME (ret
) = type_decl
;
2176 TYPE_STUB_DECL (ret
) = type_decl
;
2181 /* Append description of a single global DECL into vector V.
2182 TYPE is __asan_global struct type as returned by asan_global_struct. */
2185 asan_add_global (tree decl
, tree type
, vec
<constructor_elt
, va_gc
> *v
)
2187 tree init
, uptr
= TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (type
)));
2188 unsigned HOST_WIDE_INT size
;
2189 tree str_cst
, module_name_cst
, refdecl
= decl
;
2190 vec
<constructor_elt
, va_gc
> *vinner
= NULL
;
2192 pretty_printer asan_pp
, module_name_pp
;
2194 if (DECL_NAME (decl
))
2195 pp_tree_identifier (&asan_pp
, DECL_NAME (decl
));
2197 pp_string (&asan_pp
, "<unknown>");
2198 str_cst
= asan_pp_string (&asan_pp
);
2200 pp_string (&module_name_pp
, main_input_filename
);
2201 module_name_cst
= asan_pp_string (&module_name_pp
);
2203 if (asan_needs_local_alias (decl
))
2206 ASM_GENERATE_INTERNAL_LABEL (buf
, "LASAN", vec_safe_length (v
) + 1);
2207 refdecl
= build_decl (DECL_SOURCE_LOCATION (decl
),
2208 VAR_DECL
, get_identifier (buf
), TREE_TYPE (decl
));
2209 TREE_ADDRESSABLE (refdecl
) = TREE_ADDRESSABLE (decl
);
2210 TREE_READONLY (refdecl
) = TREE_READONLY (decl
);
2211 TREE_THIS_VOLATILE (refdecl
) = TREE_THIS_VOLATILE (decl
);
2212 DECL_GIMPLE_REG_P (refdecl
) = DECL_GIMPLE_REG_P (decl
);
2213 DECL_ARTIFICIAL (refdecl
) = DECL_ARTIFICIAL (decl
);
2214 DECL_IGNORED_P (refdecl
) = DECL_IGNORED_P (decl
);
2215 TREE_STATIC (refdecl
) = 1;
2216 TREE_PUBLIC (refdecl
) = 0;
2217 TREE_USED (refdecl
) = 1;
2218 assemble_alias (refdecl
, DECL_ASSEMBLER_NAME (decl
));
2221 CONSTRUCTOR_APPEND_ELT (vinner
, NULL_TREE
,
2222 fold_convert (const_ptr_type_node
,
2223 build_fold_addr_expr (refdecl
)));
2224 size
= tree_to_uhwi (DECL_SIZE_UNIT (decl
));
2225 CONSTRUCTOR_APPEND_ELT (vinner
, NULL_TREE
, build_int_cst (uptr
, size
));
2226 size
+= asan_red_zone_size (size
);
2227 CONSTRUCTOR_APPEND_ELT (vinner
, NULL_TREE
, build_int_cst (uptr
, size
));
2228 CONSTRUCTOR_APPEND_ELT (vinner
, NULL_TREE
,
2229 fold_convert (const_ptr_type_node
, str_cst
));
2230 CONSTRUCTOR_APPEND_ELT (vinner
, NULL_TREE
,
2231 fold_convert (const_ptr_type_node
, module_name_cst
));
2232 varpool_node
*vnode
= varpool_node::get (decl
);
2233 int has_dynamic_init
= vnode
? vnode
->dynamically_initialized
: 0;
2234 CONSTRUCTOR_APPEND_ELT (vinner
, NULL_TREE
,
2235 build_int_cst (uptr
, has_dynamic_init
));
2236 tree locptr
= NULL_TREE
;
2237 location_t loc
= DECL_SOURCE_LOCATION (decl
);
2238 expanded_location xloc
= expand_location (loc
);
2239 if (xloc
.file
!= NULL
)
2241 static int lasanloccnt
= 0;
2243 ASM_GENERATE_INTERNAL_LABEL (buf
, "LASANLOC", ++lasanloccnt
);
2244 tree var
= build_decl (UNKNOWN_LOCATION
, VAR_DECL
, get_identifier (buf
),
2245 ubsan_get_source_location_type ());
2246 TREE_STATIC (var
) = 1;
2247 TREE_PUBLIC (var
) = 0;
2248 DECL_ARTIFICIAL (var
) = 1;
2249 DECL_IGNORED_P (var
) = 1;
2250 pretty_printer filename_pp
;
2251 pp_string (&filename_pp
, xloc
.file
);
2252 tree str
= asan_pp_string (&filename_pp
);
2253 tree ctor
= build_constructor_va (TREE_TYPE (var
), 3,
2254 NULL_TREE
, str
, NULL_TREE
,
2255 build_int_cst (unsigned_type_node
,
2256 xloc
.line
), NULL_TREE
,
2257 build_int_cst (unsigned_type_node
,
2259 TREE_CONSTANT (ctor
) = 1;
2260 TREE_STATIC (ctor
) = 1;
2261 DECL_INITIAL (var
) = ctor
;
2262 varpool_node::finalize_decl (var
);
2263 locptr
= fold_convert (uptr
, build_fold_addr_expr (var
));
2266 locptr
= build_int_cst (uptr
, 0);
2267 CONSTRUCTOR_APPEND_ELT (vinner
, NULL_TREE
, locptr
);
2268 init
= build_constructor (type
, vinner
);
2269 CONSTRUCTOR_APPEND_ELT (v
, NULL_TREE
, init
);
2272 /* Initialize sanitizer.def builtins if the FE hasn't initialized them. */
2274 initialize_sanitizer_builtins (void)
2278 if (builtin_decl_implicit_p (BUILT_IN_ASAN_INIT
))
2281 tree BT_FN_VOID
= build_function_type_list (void_type_node
, NULL_TREE
);
2283 = build_function_type_list (void_type_node
, ptr_type_node
, NULL_TREE
);
2284 tree BT_FN_VOID_CONST_PTR
2285 = build_function_type_list (void_type_node
, const_ptr_type_node
, NULL_TREE
);
2286 tree BT_FN_VOID_PTR_PTR
2287 = build_function_type_list (void_type_node
, ptr_type_node
,
2288 ptr_type_node
, NULL_TREE
);
2289 tree BT_FN_VOID_PTR_PTR_PTR
2290 = build_function_type_list (void_type_node
, ptr_type_node
,
2291 ptr_type_node
, ptr_type_node
, NULL_TREE
);
2292 tree BT_FN_VOID_PTR_PTRMODE
2293 = build_function_type_list (void_type_node
, ptr_type_node
,
2294 pointer_sized_int_node
, NULL_TREE
);
2296 = build_function_type_list (void_type_node
, integer_type_node
, NULL_TREE
);
2297 tree BT_FN_BOOL_VPTR_PTR_IX_INT_INT
[5];
2298 tree BT_FN_IX_CONST_VPTR_INT
[5];
2299 tree BT_FN_IX_VPTR_IX_INT
[5];
2300 tree BT_FN_VOID_VPTR_IX_INT
[5];
2302 = build_pointer_type (build_qualified_type (void_type_node
,
2303 TYPE_QUAL_VOLATILE
));
2305 = build_pointer_type (build_qualified_type (void_type_node
,
2309 = lang_hooks
.types
.type_for_size (BOOL_TYPE_SIZE
, 1);
2311 for (i
= 0; i
< 5; i
++)
2313 tree ix
= build_nonstandard_integer_type (BITS_PER_UNIT
* (1 << i
), 1);
2314 BT_FN_BOOL_VPTR_PTR_IX_INT_INT
[i
]
2315 = build_function_type_list (boolt
, vptr
, ptr_type_node
, ix
,
2316 integer_type_node
, integer_type_node
,
2318 BT_FN_IX_CONST_VPTR_INT
[i
]
2319 = build_function_type_list (ix
, cvptr
, integer_type_node
, NULL_TREE
);
2320 BT_FN_IX_VPTR_IX_INT
[i
]
2321 = build_function_type_list (ix
, vptr
, ix
, integer_type_node
,
2323 BT_FN_VOID_VPTR_IX_INT
[i
]
2324 = build_function_type_list (void_type_node
, vptr
, ix
,
2325 integer_type_node
, NULL_TREE
);
2327 #define BT_FN_BOOL_VPTR_PTR_I1_INT_INT BT_FN_BOOL_VPTR_PTR_IX_INT_INT[0]
2328 #define BT_FN_I1_CONST_VPTR_INT BT_FN_IX_CONST_VPTR_INT[0]
2329 #define BT_FN_I1_VPTR_I1_INT BT_FN_IX_VPTR_IX_INT[0]
2330 #define BT_FN_VOID_VPTR_I1_INT BT_FN_VOID_VPTR_IX_INT[0]
2331 #define BT_FN_BOOL_VPTR_PTR_I2_INT_INT BT_FN_BOOL_VPTR_PTR_IX_INT_INT[1]
2332 #define BT_FN_I2_CONST_VPTR_INT BT_FN_IX_CONST_VPTR_INT[1]
2333 #define BT_FN_I2_VPTR_I2_INT BT_FN_IX_VPTR_IX_INT[1]
2334 #define BT_FN_VOID_VPTR_I2_INT BT_FN_VOID_VPTR_IX_INT[1]
2335 #define BT_FN_BOOL_VPTR_PTR_I4_INT_INT BT_FN_BOOL_VPTR_PTR_IX_INT_INT[2]
2336 #define BT_FN_I4_CONST_VPTR_INT BT_FN_IX_CONST_VPTR_INT[2]
2337 #define BT_FN_I4_VPTR_I4_INT BT_FN_IX_VPTR_IX_INT[2]
2338 #define BT_FN_VOID_VPTR_I4_INT BT_FN_VOID_VPTR_IX_INT[2]
2339 #define BT_FN_BOOL_VPTR_PTR_I8_INT_INT BT_FN_BOOL_VPTR_PTR_IX_INT_INT[3]
2340 #define BT_FN_I8_CONST_VPTR_INT BT_FN_IX_CONST_VPTR_INT[3]
2341 #define BT_FN_I8_VPTR_I8_INT BT_FN_IX_VPTR_IX_INT[3]
2342 #define BT_FN_VOID_VPTR_I8_INT BT_FN_VOID_VPTR_IX_INT[3]
2343 #define BT_FN_BOOL_VPTR_PTR_I16_INT_INT BT_FN_BOOL_VPTR_PTR_IX_INT_INT[4]
2344 #define BT_FN_I16_CONST_VPTR_INT BT_FN_IX_CONST_VPTR_INT[4]
2345 #define BT_FN_I16_VPTR_I16_INT BT_FN_IX_VPTR_IX_INT[4]
2346 #define BT_FN_VOID_VPTR_I16_INT BT_FN_VOID_VPTR_IX_INT[4]
2347 #undef ATTR_NOTHROW_LEAF_LIST
2348 #define ATTR_NOTHROW_LEAF_LIST ECF_NOTHROW | ECF_LEAF
2349 #undef ATTR_TMPURE_NOTHROW_LEAF_LIST
2350 #define ATTR_TMPURE_NOTHROW_LEAF_LIST ECF_TM_PURE | ATTR_NOTHROW_LEAF_LIST
2351 #undef ATTR_NORETURN_NOTHROW_LEAF_LIST
2352 #define ATTR_NORETURN_NOTHROW_LEAF_LIST ECF_NORETURN | ATTR_NOTHROW_LEAF_LIST
2353 #undef ATTR_CONST_NORETURN_NOTHROW_LEAF_LIST
2354 #define ATTR_CONST_NORETURN_NOTHROW_LEAF_LIST \
2355 ECF_CONST | ATTR_NORETURN_NOTHROW_LEAF_LIST
2356 #undef ATTR_TMPURE_NORETURN_NOTHROW_LEAF_LIST
2357 #define ATTR_TMPURE_NORETURN_NOTHROW_LEAF_LIST \
2358 ECF_TM_PURE | ATTR_NORETURN_NOTHROW_LEAF_LIST
2359 #undef ATTR_COLD_NOTHROW_LEAF_LIST
2360 #define ATTR_COLD_NOTHROW_LEAF_LIST \
2361 /* ECF_COLD missing */ ATTR_NOTHROW_LEAF_LIST
2362 #undef ATTR_COLD_NORETURN_NOTHROW_LEAF_LIST
2363 #define ATTR_COLD_NORETURN_NOTHROW_LEAF_LIST \
2364 /* ECF_COLD missing */ ATTR_NORETURN_NOTHROW_LEAF_LIST
2365 #undef ATTR_COLD_CONST_NORETURN_NOTHROW_LEAF_LIST
2366 #define ATTR_COLD_CONST_NORETURN_NOTHROW_LEAF_LIST \
2367 /* ECF_COLD missing */ ATTR_CONST_NORETURN_NOTHROW_LEAF_LIST
2368 #undef DEF_SANITIZER_BUILTIN
2369 #define DEF_SANITIZER_BUILTIN(ENUM, NAME, TYPE, ATTRS) \
2370 decl = add_builtin_function ("__builtin_" NAME, TYPE, ENUM, \
2371 BUILT_IN_NORMAL, NAME, NULL_TREE); \
2372 set_call_expr_flags (decl, ATTRS); \
2373 set_builtin_decl (ENUM, decl, true);
2375 #include "sanitizer.def"
2377 #undef DEF_SANITIZER_BUILTIN
2380 /* Called via htab_traverse. Count number of emitted
2381 STRING_CSTs in the constant hash table. */
2384 count_string_csts (constant_descriptor_tree
**slot
,
2385 unsigned HOST_WIDE_INT
*data
)
2387 struct constant_descriptor_tree
*desc
= *slot
;
2388 if (TREE_CODE (desc
->value
) == STRING_CST
2389 && TREE_ASM_WRITTEN (desc
->value
)
2390 && asan_protect_global (desc
->value
))
2395 /* Helper structure to pass two parameters to
2398 struct asan_add_string_csts_data
2401 vec
<constructor_elt
, va_gc
> *v
;
2404 /* Called via hash_table::traverse. Call asan_add_global
2405 on emitted STRING_CSTs from the constant hash table. */
2408 add_string_csts (constant_descriptor_tree
**slot
,
2409 asan_add_string_csts_data
*aascd
)
2411 struct constant_descriptor_tree
*desc
= *slot
;
2412 if (TREE_CODE (desc
->value
) == STRING_CST
2413 && TREE_ASM_WRITTEN (desc
->value
)
2414 && asan_protect_global (desc
->value
))
2416 asan_add_global (SYMBOL_REF_DECL (XEXP (desc
->rtl
, 0)),
2417 aascd
->type
, aascd
->v
);
2422 /* Needs to be GTY(()), because cgraph_build_static_cdtor may
2423 invoke ggc_collect. */
2424 static GTY(()) tree asan_ctor_statements
;
2426 /* Module-level instrumentation.
2427 - Insert __asan_init_vN() into the list of CTORs.
2428 - TODO: insert redzones around globals.
2432 asan_finish_file (void)
2434 varpool_node
*vnode
;
2435 unsigned HOST_WIDE_INT gcount
= 0;
2437 if (shadow_ptr_types
[0] == NULL_TREE
)
2438 asan_init_shadow_ptr_types ();
2439 /* Avoid instrumenting code in the asan ctors/dtors.
2440 We don't need to insert padding after the description strings,
2441 nor after .LASAN* array. */
2442 flag_sanitize
&= ~SANITIZE_ADDRESS
;
2444 if (flag_sanitize
& SANITIZE_USER_ADDRESS
)
2446 tree fn
= builtin_decl_implicit (BUILT_IN_ASAN_INIT
);
2447 append_to_statement_list (build_call_expr (fn
, 0), &asan_ctor_statements
);
2449 FOR_EACH_DEFINED_VARIABLE (vnode
)
2450 if (TREE_ASM_WRITTEN (vnode
->decl
)
2451 && asan_protect_global (vnode
->decl
))
2453 hash_table
<tree_descriptor_hasher
> *const_desc_htab
= constant_pool_htab ();
2454 const_desc_htab
->traverse
<unsigned HOST_WIDE_INT
*, count_string_csts
>
2458 tree type
= asan_global_struct (), var
, ctor
;
2459 tree dtor_statements
= NULL_TREE
;
2460 vec
<constructor_elt
, va_gc
> *v
;
2463 type
= build_array_type_nelts (type
, gcount
);
2464 ASM_GENERATE_INTERNAL_LABEL (buf
, "LASAN", 0);
2465 var
= build_decl (UNKNOWN_LOCATION
, VAR_DECL
, get_identifier (buf
),
2467 TREE_STATIC (var
) = 1;
2468 TREE_PUBLIC (var
) = 0;
2469 DECL_ARTIFICIAL (var
) = 1;
2470 DECL_IGNORED_P (var
) = 1;
2471 vec_alloc (v
, gcount
);
2472 FOR_EACH_DEFINED_VARIABLE (vnode
)
2473 if (TREE_ASM_WRITTEN (vnode
->decl
)
2474 && asan_protect_global (vnode
->decl
))
2475 asan_add_global (vnode
->decl
, TREE_TYPE (type
), v
);
2476 struct asan_add_string_csts_data aascd
;
2477 aascd
.type
= TREE_TYPE (type
);
2479 const_desc_htab
->traverse
<asan_add_string_csts_data
*, add_string_csts
>
2481 ctor
= build_constructor (type
, v
);
2482 TREE_CONSTANT (ctor
) = 1;
2483 TREE_STATIC (ctor
) = 1;
2484 DECL_INITIAL (var
) = ctor
;
2485 varpool_node::finalize_decl (var
);
2487 tree fn
= builtin_decl_implicit (BUILT_IN_ASAN_REGISTER_GLOBALS
);
2488 tree gcount_tree
= build_int_cst (pointer_sized_int_node
, gcount
);
2489 append_to_statement_list (build_call_expr (fn
, 2,
2490 build_fold_addr_expr (var
),
2492 &asan_ctor_statements
);
2494 fn
= builtin_decl_implicit (BUILT_IN_ASAN_UNREGISTER_GLOBALS
);
2495 append_to_statement_list (build_call_expr (fn
, 2,
2496 build_fold_addr_expr (var
),
2499 cgraph_build_static_cdtor ('D', dtor_statements
,
2500 MAX_RESERVED_INIT_PRIORITY
- 1);
2502 if (asan_ctor_statements
)
2503 cgraph_build_static_cdtor ('I', asan_ctor_statements
,
2504 MAX_RESERVED_INIT_PRIORITY
- 1);
2505 flag_sanitize
|= SANITIZE_ADDRESS
;
2508 /* Expand the ASAN_{LOAD,STORE} builtins. */
2511 asan_expand_check_ifn (gimple_stmt_iterator
*iter
, bool use_calls
)
2513 gimple g
= gsi_stmt (*iter
);
2514 location_t loc
= gimple_location (g
);
2517 = (flag_sanitize
& flag_sanitize_recover
& SANITIZE_KERNEL_ADDRESS
) != 0;
2519 HOST_WIDE_INT flags
= tree_to_shwi (gimple_call_arg (g
, 0));
2520 gcc_assert (flags
< ASAN_CHECK_LAST
);
2521 bool is_scalar_access
= (flags
& ASAN_CHECK_SCALAR_ACCESS
) != 0;
2522 bool is_store
= (flags
& ASAN_CHECK_STORE
) != 0;
2523 bool is_non_zero_len
= (flags
& ASAN_CHECK_NON_ZERO_LEN
) != 0;
2525 tree base
= gimple_call_arg (g
, 1);
2526 tree len
= gimple_call_arg (g
, 2);
2527 HOST_WIDE_INT align
= tree_to_shwi (gimple_call_arg (g
, 3));
2529 HOST_WIDE_INT size_in_bytes
2530 = is_scalar_access
&& tree_fits_shwi_p (len
) ? tree_to_shwi (len
) : -1;
2534 /* Instrument using callbacks. */
2536 = gimple_build_assign_with_ops (NOP_EXPR
,
2537 make_ssa_name (pointer_sized_int_node
,
2539 gimple_set_location (g
, loc
);
2540 gsi_insert_before (iter
, g
, GSI_SAME_STMT
);
2541 tree base_addr
= gimple_assign_lhs (g
);
2544 tree fun
= check_func (is_store
, recover_p
, size_in_bytes
, &nargs
);
2546 g
= gimple_build_call (fun
, 1, base_addr
);
2549 gcc_assert (nargs
== 2);
2550 g
= gimple_build_assign_with_ops (NOP_EXPR
,
2551 make_ssa_name (pointer_sized_int_node
,
2553 gimple_set_location (g
, loc
);
2554 gsi_insert_before (iter
, g
, GSI_SAME_STMT
);
2555 tree sz_arg
= gimple_assign_lhs (g
);
2556 g
= gimple_build_call (fun
, nargs
, base_addr
, sz_arg
);
2558 gimple_set_location (g
, loc
);
2559 gsi_replace (iter
, g
, false);
2563 HOST_WIDE_INT real_size_in_bytes
= size_in_bytes
== -1 ? 1 : size_in_bytes
;
2565 tree shadow_ptr_type
= shadow_ptr_types
[real_size_in_bytes
== 16 ? 1 : 0];
2566 tree shadow_type
= TREE_TYPE (shadow_ptr_type
);
2568 gimple_stmt_iterator gsi
= *iter
;
2570 if (!is_non_zero_len
)
2572 /* So, the length of the memory area to asan-protect is
2573 non-constant. Let's guard the generated instrumentation code
2578 //asan instrumentation code goes here.
2580 // falltrough instructions, starting with *ITER. */
2582 g
= gimple_build_cond (NE_EXPR
,
2584 build_int_cst (TREE_TYPE (len
), 0),
2585 NULL_TREE
, NULL_TREE
);
2586 gimple_set_location (g
, loc
);
2588 basic_block then_bb
, fallthrough_bb
;
2589 insert_if_then_before_iter (g
, iter
, /*then_more_likely_p=*/true,
2590 &then_bb
, &fallthrough_bb
);
2591 /* Note that fallthrough_bb starts with the statement that was
2592 pointed to by ITER. */
2594 /* The 'then block' of the 'if (len != 0) condition is where
2595 we'll generate the asan instrumentation code now. */
2596 gsi
= gsi_last_bb (then_bb
);
2599 /* Get an iterator on the point where we can add the condition
2600 statement for the instrumentation. */
2601 basic_block then_bb
, else_bb
;
2602 gsi
= create_cond_insert_point (&gsi
, /*before_p*/false,
2603 /*then_more_likely_p=*/false,
2604 /*create_then_fallthru_edge*/recover_p
,
2608 g
= gimple_build_assign_with_ops (NOP_EXPR
,
2609 make_ssa_name (pointer_sized_int_node
,
2611 gimple_set_location (g
, loc
);
2612 gsi_insert_before (&gsi
, g
, GSI_NEW_STMT
);
2613 tree base_addr
= gimple_assign_lhs (g
);
2616 if (real_size_in_bytes
>= 8)
2618 tree shadow
= build_shadow_mem_access (&gsi
, loc
, base_addr
,
2624 /* Slow path for 1, 2 and 4 byte accesses. */
2625 /* Test (shadow != 0)
2626 & ((base_addr & 7) + (real_size_in_bytes - 1)) >= shadow). */
2627 tree shadow
= build_shadow_mem_access (&gsi
, loc
, base_addr
,
2629 gimple shadow_test
= build_assign (NE_EXPR
, shadow
, 0);
2630 gimple_seq seq
= NULL
;
2631 gimple_seq_add_stmt (&seq
, shadow_test
);
2632 /* Aligned (>= 8 bytes) can test just
2633 (real_size_in_bytes - 1 >= shadow), as base_addr & 7 is known
2637 gimple_seq_add_stmt (&seq
, build_assign (BIT_AND_EXPR
,
2639 gimple_seq_add_stmt (&seq
,
2640 build_type_cast (shadow_type
,
2641 gimple_seq_last (seq
)));
2642 if (real_size_in_bytes
> 1)
2643 gimple_seq_add_stmt (&seq
,
2644 build_assign (PLUS_EXPR
,
2645 gimple_seq_last (seq
),
2646 real_size_in_bytes
- 1));
2647 t
= gimple_assign_lhs (gimple_seq_last_stmt (seq
));
2650 t
= build_int_cst (shadow_type
, real_size_in_bytes
- 1);
2651 gimple_seq_add_stmt (&seq
, build_assign (GE_EXPR
, t
, shadow
));
2652 gimple_seq_add_stmt (&seq
, build_assign (BIT_AND_EXPR
, shadow_test
,
2653 gimple_seq_last (seq
)));
2654 t
= gimple_assign_lhs (gimple_seq_last (seq
));
2655 gimple_seq_set_location (seq
, loc
);
2656 gsi_insert_seq_after (&gsi
, seq
, GSI_CONTINUE_LINKING
);
2658 /* For non-constant, misaligned or otherwise weird access sizes,
2659 check first and last byte. */
2660 if (size_in_bytes
== -1)
2662 g
= gimple_build_assign_with_ops (MINUS_EXPR
,
2663 make_ssa_name (pointer_sized_int_node
, NULL
),
2665 build_int_cst (pointer_sized_int_node
, 1));
2666 gimple_set_location (g
, loc
);
2667 gsi_insert_after (&gsi
, g
, GSI_NEW_STMT
);
2668 tree last
= gimple_assign_lhs (g
);
2669 g
= gimple_build_assign_with_ops (PLUS_EXPR
,
2670 make_ssa_name (pointer_sized_int_node
, NULL
),
2673 gimple_set_location (g
, loc
);
2674 gsi_insert_after (&gsi
, g
, GSI_NEW_STMT
);
2675 tree base_end_addr
= gimple_assign_lhs (g
);
2677 tree shadow
= build_shadow_mem_access (&gsi
, loc
, base_end_addr
,
2679 gimple shadow_test
= build_assign (NE_EXPR
, shadow
, 0);
2680 gimple_seq seq
= NULL
;
2681 gimple_seq_add_stmt (&seq
, shadow_test
);
2682 gimple_seq_add_stmt (&seq
, build_assign (BIT_AND_EXPR
,
2684 gimple_seq_add_stmt (&seq
, build_type_cast (shadow_type
,
2685 gimple_seq_last (seq
)));
2686 gimple_seq_add_stmt (&seq
, build_assign (GE_EXPR
,
2687 gimple_seq_last (seq
),
2689 gimple_seq_add_stmt (&seq
, build_assign (BIT_AND_EXPR
, shadow_test
,
2690 gimple_seq_last (seq
)));
2691 gimple_seq_add_stmt (&seq
, build_assign (BIT_IOR_EXPR
, t
,
2692 gimple_seq_last (seq
)));
2693 t
= gimple_assign_lhs (gimple_seq_last (seq
));
2694 gimple_seq_set_location (seq
, loc
);
2695 gsi_insert_seq_after (&gsi
, seq
, GSI_CONTINUE_LINKING
);
2699 g
= gimple_build_cond (NE_EXPR
, t
, build_int_cst (TREE_TYPE (t
), 0),
2700 NULL_TREE
, NULL_TREE
);
2701 gimple_set_location (g
, loc
);
2702 gsi_insert_after (&gsi
, g
, GSI_NEW_STMT
);
2704 /* Generate call to the run-time library (e.g. __asan_report_load8). */
2705 gsi
= gsi_start_bb (then_bb
);
2707 tree fun
= report_error_func (is_store
, recover_p
, size_in_bytes
, &nargs
);
2708 g
= gimple_build_call (fun
, nargs
, base_addr
, len
);
2709 gimple_set_location (g
, loc
);
2710 gsi_insert_after (&gsi
, g
, GSI_NEW_STMT
);
2712 gsi_remove (iter
, true);
2713 *iter
= gsi_start_bb (else_bb
);
2718 /* Instrument the current function. */
2721 asan_instrument (void)
2723 if (shadow_ptr_types
[0] == NULL_TREE
)
2724 asan_init_shadow_ptr_types ();
2725 transform_statements ();
2732 return (flag_sanitize
& SANITIZE_ADDRESS
) != 0
2733 && !lookup_attribute ("no_sanitize_address",
2734 DECL_ATTRIBUTES (current_function_decl
));
2739 const pass_data pass_data_asan
=
2741 GIMPLE_PASS
, /* type */
2743 OPTGROUP_NONE
, /* optinfo_flags */
2744 TV_NONE
, /* tv_id */
2745 ( PROP_ssa
| PROP_cfg
| PROP_gimple_leh
), /* properties_required */
2746 0, /* properties_provided */
2747 0, /* properties_destroyed */
2748 0, /* todo_flags_start */
2749 TODO_update_ssa
, /* todo_flags_finish */
2752 class pass_asan
: public gimple_opt_pass
2755 pass_asan (gcc::context
*ctxt
)
2756 : gimple_opt_pass (pass_data_asan
, ctxt
)
2759 /* opt_pass methods: */
2760 opt_pass
* clone () { return new pass_asan (m_ctxt
); }
2761 virtual bool gate (function
*) { return gate_asan (); }
2762 virtual unsigned int execute (function
*) { return asan_instrument (); }
2764 }; // class pass_asan
2769 make_pass_asan (gcc::context
*ctxt
)
2771 return new pass_asan (ctxt
);
2776 const pass_data pass_data_asan_O0
=
2778 GIMPLE_PASS
, /* type */
2780 OPTGROUP_NONE
, /* optinfo_flags */
2781 TV_NONE
, /* tv_id */
2782 ( PROP_ssa
| PROP_cfg
| PROP_gimple_leh
), /* properties_required */
2783 0, /* properties_provided */
2784 0, /* properties_destroyed */
2785 0, /* todo_flags_start */
2786 TODO_update_ssa
, /* todo_flags_finish */
2789 class pass_asan_O0
: public gimple_opt_pass
2792 pass_asan_O0 (gcc::context
*ctxt
)
2793 : gimple_opt_pass (pass_data_asan_O0
, ctxt
)
2796 /* opt_pass methods: */
2797 virtual bool gate (function
*) { return !optimize
&& gate_asan (); }
2798 virtual unsigned int execute (function
*) { return asan_instrument (); }
2800 }; // class pass_asan_O0
2805 make_pass_asan_O0 (gcc::context
*ctxt
)
2807 return new pass_asan_O0 (ctxt
);
2810 #include "gt-asan.h"