[AArch64] Improve scheduling model for X-Gene
[official-gcc.git] / gcc / asan.c
blobca5fceed9fcafcb4d11fb7196f999750f03da7af
1 /* AddressSanitizer, a fast memory error detector.
2 Copyright (C) 2012-2017 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
10 version.
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
15 for more details.
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/>. */
22 #include "config.h"
23 #include "system.h"
24 #include "coretypes.h"
25 #include "backend.h"
26 #include "target.h"
27 #include "rtl.h"
28 #include "tree.h"
29 #include "gimple.h"
30 #include "cfghooks.h"
31 #include "alloc-pool.h"
32 #include "tree-pass.h"
33 #include "memmodel.h"
34 #include "tm_p.h"
35 #include "ssa.h"
36 #include "stringpool.h"
37 #include "tree-ssanames.h"
38 #include "optabs.h"
39 #include "emit-rtl.h"
40 #include "cgraph.h"
41 #include "gimple-pretty-print.h"
42 #include "alias.h"
43 #include "fold-const.h"
44 #include "cfganal.h"
45 #include "gimplify.h"
46 #include "gimple-iterator.h"
47 #include "varasm.h"
48 #include "stor-layout.h"
49 #include "tree-iterator.h"
50 #include "stringpool.h"
51 #include "attribs.h"
52 #include "asan.h"
53 #include "dojump.h"
54 #include "explow.h"
55 #include "expr.h"
56 #include "output.h"
57 #include "langhooks.h"
58 #include "cfgloop.h"
59 #include "gimple-builder.h"
60 #include "gimple-fold.h"
61 #include "ubsan.h"
62 #include "params.h"
63 #include "builtins.h"
64 #include "fnmatch.h"
65 #include "tree-inline.h"
67 /* AddressSanitizer finds out-of-bounds and use-after-free bugs
68 with <2x slowdown on average.
70 The tool consists of two parts:
71 instrumentation module (this file) and a run-time library.
72 The instrumentation module adds a run-time check before every memory insn.
73 For a 8- or 16- byte load accessing address X:
74 ShadowAddr = (X >> 3) + Offset
75 ShadowValue = *(char*)ShadowAddr; // *(short*) for 16-byte access.
76 if (ShadowValue)
77 __asan_report_load8(X);
78 For a load of N bytes (N=1, 2 or 4) from address X:
79 ShadowAddr = (X >> 3) + Offset
80 ShadowValue = *(char*)ShadowAddr;
81 if (ShadowValue)
82 if ((X & 7) + N - 1 > ShadowValue)
83 __asan_report_loadN(X);
84 Stores are instrumented similarly, but using __asan_report_storeN functions.
85 A call too __asan_init_vN() is inserted to the list of module CTORs.
86 N is the version number of the AddressSanitizer API. The changes between the
87 API versions are listed in libsanitizer/asan/asan_interface_internal.h.
89 The run-time library redefines malloc (so that redzone are inserted around
90 the allocated memory) and free (so that reuse of free-ed memory is delayed),
91 provides __asan_report* and __asan_init_vN functions.
93 Read more:
94 http://code.google.com/p/address-sanitizer/wiki/AddressSanitizerAlgorithm
96 The current implementation supports detection of out-of-bounds and
97 use-after-free in the heap, on the stack and for global variables.
99 [Protection of stack variables]
101 To understand how detection of out-of-bounds and use-after-free works
102 for stack variables, lets look at this example on x86_64 where the
103 stack grows downward:
106 foo ()
108 char a[23] = {0};
109 int b[2] = {0};
111 a[5] = 1;
112 b[1] = 2;
114 return a[5] + b[1];
117 For this function, the stack protected by asan will be organized as
118 follows, from the top of the stack to the bottom:
120 Slot 1/ [red zone of 32 bytes called 'RIGHT RedZone']
122 Slot 2/ [8 bytes of red zone, that adds up to the space of 'a' to make
123 the next slot be 32 bytes aligned; this one is called Partial
124 Redzone; this 32 bytes alignment is an asan constraint]
126 Slot 3/ [24 bytes for variable 'a']
128 Slot 4/ [red zone of 32 bytes called 'Middle RedZone']
130 Slot 5/ [24 bytes of Partial Red Zone (similar to slot 2]
132 Slot 6/ [8 bytes for variable 'b']
134 Slot 7/ [32 bytes of Red Zone at the bottom of the stack, called
135 'LEFT RedZone']
137 The 32 bytes of LEFT red zone at the bottom of the stack can be
138 decomposed as such:
140 1/ The first 8 bytes contain a magical asan number that is always
141 0x41B58AB3.
143 2/ The following 8 bytes contains a pointer to a string (to be
144 parsed at runtime by the runtime asan library), which format is
145 the following:
147 "<function-name> <space> <num-of-variables-on-the-stack>
148 (<32-bytes-aligned-offset-in-bytes-of-variable> <space>
149 <length-of-var-in-bytes> ){n} "
151 where '(...){n}' means the content inside the parenthesis occurs 'n'
152 times, with 'n' being the number of variables on the stack.
154 3/ The following 8 bytes contain the PC of the current function which
155 will be used by the run-time library to print an error message.
157 4/ The following 8 bytes are reserved for internal use by the run-time.
159 The shadow memory for that stack layout is going to look like this:
161 - content of shadow memory 8 bytes for slot 7: 0xF1F1F1F1.
162 The F1 byte pattern is a magic number called
163 ASAN_STACK_MAGIC_LEFT and is a way for the runtime to know that
164 the memory for that shadow byte is part of a the LEFT red zone
165 intended to seat at the bottom of the variables on the stack.
167 - content of shadow memory 8 bytes for slots 6 and 5:
168 0xF4F4F400. The F4 byte pattern is a magic number
169 called ASAN_STACK_MAGIC_PARTIAL. It flags the fact that the
170 memory region for this shadow byte is a PARTIAL red zone
171 intended to pad a variable A, so that the slot following
172 {A,padding} is 32 bytes aligned.
174 Note that the fact that the least significant byte of this
175 shadow memory content is 00 means that 8 bytes of its
176 corresponding memory (which corresponds to the memory of
177 variable 'b') is addressable.
179 - content of shadow memory 8 bytes for slot 4: 0xF2F2F2F2.
180 The F2 byte pattern is a magic number called
181 ASAN_STACK_MAGIC_MIDDLE. It flags the fact that the memory
182 region for this shadow byte is a MIDDLE red zone intended to
183 seat between two 32 aligned slots of {variable,padding}.
185 - content of shadow memory 8 bytes for slot 3 and 2:
186 0xF4000000. This represents is the concatenation of
187 variable 'a' and the partial red zone following it, like what we
188 had for variable 'b'. The least significant 3 bytes being 00
189 means that the 3 bytes of variable 'a' are addressable.
191 - content of shadow memory 8 bytes for slot 1: 0xF3F3F3F3.
192 The F3 byte pattern is a magic number called
193 ASAN_STACK_MAGIC_RIGHT. It flags the fact that the memory
194 region for this shadow byte is a RIGHT red zone intended to seat
195 at the top of the variables of the stack.
197 Note that the real variable layout is done in expand_used_vars in
198 cfgexpand.c. As far as Address Sanitizer is concerned, it lays out
199 stack variables as well as the different red zones, emits some
200 prologue code to populate the shadow memory as to poison (mark as
201 non-accessible) the regions of the red zones and mark the regions of
202 stack variables as accessible, and emit some epilogue code to
203 un-poison (mark as accessible) the regions of red zones right before
204 the function exits.
206 [Protection of global variables]
208 The basic idea is to insert a red zone between two global variables
209 and install a constructor function that calls the asan runtime to do
210 the populating of the relevant shadow memory regions at load time.
212 So the global variables are laid out as to insert a red zone between
213 them. The size of the red zones is so that each variable starts on a
214 32 bytes boundary.
216 Then a constructor function is installed so that, for each global
217 variable, it calls the runtime asan library function
218 __asan_register_globals_with an instance of this type:
220 struct __asan_global
222 // Address of the beginning of the global variable.
223 const void *__beg;
225 // Initial size of the global variable.
226 uptr __size;
228 // Size of the global variable + size of the red zone. This
229 // size is 32 bytes aligned.
230 uptr __size_with_redzone;
232 // Name of the global variable.
233 const void *__name;
235 // Name of the module where the global variable is declared.
236 const void *__module_name;
238 // 1 if it has dynamic initialization, 0 otherwise.
239 uptr __has_dynamic_init;
241 // A pointer to struct that contains source location, could be NULL.
242 __asan_global_source_location *__location;
245 A destructor function that calls the runtime asan library function
246 _asan_unregister_globals is also installed. */
248 static unsigned HOST_WIDE_INT asan_shadow_offset_value;
249 static bool asan_shadow_offset_computed;
250 static vec<char *> sanitized_sections;
251 static tree last_alloca_addr;
253 /* Set of variable declarations that are going to be guarded by
254 use-after-scope sanitizer. */
256 static hash_set<tree> *asan_handled_variables = NULL;
258 hash_set <tree> *asan_used_labels = NULL;
260 /* Sets shadow offset to value in string VAL. */
262 bool
263 set_asan_shadow_offset (const char *val)
265 char *endp;
267 errno = 0;
268 #ifdef HAVE_LONG_LONG
269 asan_shadow_offset_value = strtoull (val, &endp, 0);
270 #else
271 asan_shadow_offset_value = strtoul (val, &endp, 0);
272 #endif
273 if (!(*val != '\0' && *endp == '\0' && errno == 0))
274 return false;
276 asan_shadow_offset_computed = true;
278 return true;
281 /* Set list of user-defined sections that need to be sanitized. */
283 void
284 set_sanitized_sections (const char *sections)
286 char *pat;
287 unsigned i;
288 FOR_EACH_VEC_ELT (sanitized_sections, i, pat)
289 free (pat);
290 sanitized_sections.truncate (0);
292 for (const char *s = sections; *s; )
294 const char *end;
295 for (end = s; *end && *end != ','; ++end);
296 size_t len = end - s;
297 sanitized_sections.safe_push (xstrndup (s, len));
298 s = *end ? end + 1 : end;
302 bool
303 asan_mark_p (gimple *stmt, enum asan_mark_flags flag)
305 return (gimple_call_internal_p (stmt, IFN_ASAN_MARK)
306 && tree_to_uhwi (gimple_call_arg (stmt, 0)) == flag);
309 bool
310 asan_sanitize_stack_p (void)
312 return (sanitize_flags_p (SANITIZE_ADDRESS) && ASAN_STACK);
315 bool
316 asan_sanitize_allocas_p (void)
318 return (asan_sanitize_stack_p () && ASAN_PROTECT_ALLOCAS);
321 /* Checks whether section SEC should be sanitized. */
323 static bool
324 section_sanitized_p (const char *sec)
326 char *pat;
327 unsigned i;
328 FOR_EACH_VEC_ELT (sanitized_sections, i, pat)
329 if (fnmatch (pat, sec, FNM_PERIOD) == 0)
330 return true;
331 return false;
334 /* Returns Asan shadow offset. */
336 static unsigned HOST_WIDE_INT
337 asan_shadow_offset ()
339 if (!asan_shadow_offset_computed)
341 asan_shadow_offset_computed = true;
342 asan_shadow_offset_value = targetm.asan_shadow_offset ();
344 return asan_shadow_offset_value;
347 alias_set_type asan_shadow_set = -1;
349 /* Pointer types to 1, 2 or 4 byte integers in shadow memory. A separate
350 alias set is used for all shadow memory accesses. */
351 static GTY(()) tree shadow_ptr_types[3];
353 /* Decl for __asan_option_detect_stack_use_after_return. */
354 static GTY(()) tree asan_detect_stack_use_after_return;
356 /* Hashtable support for memory references used by gimple
357 statements. */
359 /* This type represents a reference to a memory region. */
360 struct asan_mem_ref
362 /* The expression of the beginning of the memory region. */
363 tree start;
365 /* The size of the access. */
366 HOST_WIDE_INT access_size;
369 object_allocator <asan_mem_ref> asan_mem_ref_pool ("asan_mem_ref");
371 /* Initializes an instance of asan_mem_ref. */
373 static void
374 asan_mem_ref_init (asan_mem_ref *ref, tree start, HOST_WIDE_INT access_size)
376 ref->start = start;
377 ref->access_size = access_size;
380 /* Allocates memory for an instance of asan_mem_ref into the memory
381 pool returned by asan_mem_ref_get_alloc_pool and initialize it.
382 START is the address of (or the expression pointing to) the
383 beginning of memory reference. ACCESS_SIZE is the size of the
384 access to the referenced memory. */
386 static asan_mem_ref*
387 asan_mem_ref_new (tree start, HOST_WIDE_INT access_size)
389 asan_mem_ref *ref = asan_mem_ref_pool.allocate ();
391 asan_mem_ref_init (ref, start, access_size);
392 return ref;
395 /* This builds and returns a pointer to the end of the memory region
396 that starts at START and of length LEN. */
398 tree
399 asan_mem_ref_get_end (tree start, tree len)
401 if (len == NULL_TREE || integer_zerop (len))
402 return start;
404 if (!ptrofftype_p (len))
405 len = convert_to_ptrofftype (len);
407 return fold_build2 (POINTER_PLUS_EXPR, TREE_TYPE (start), start, len);
410 /* Return a tree expression that represents the end of the referenced
411 memory region. Beware that this function can actually build a new
412 tree expression. */
414 tree
415 asan_mem_ref_get_end (const asan_mem_ref *ref, tree len)
417 return asan_mem_ref_get_end (ref->start, len);
420 struct asan_mem_ref_hasher : nofree_ptr_hash <asan_mem_ref>
422 static inline hashval_t hash (const asan_mem_ref *);
423 static inline bool equal (const asan_mem_ref *, const asan_mem_ref *);
426 /* Hash a memory reference. */
428 inline hashval_t
429 asan_mem_ref_hasher::hash (const asan_mem_ref *mem_ref)
431 return iterative_hash_expr (mem_ref->start, 0);
434 /* Compare two memory references. We accept the length of either
435 memory references to be NULL_TREE. */
437 inline bool
438 asan_mem_ref_hasher::equal (const asan_mem_ref *m1,
439 const asan_mem_ref *m2)
441 return operand_equal_p (m1->start, m2->start, 0);
444 static hash_table<asan_mem_ref_hasher> *asan_mem_ref_ht;
446 /* Returns a reference to the hash table containing memory references.
447 This function ensures that the hash table is created. Note that
448 this hash table is updated by the function
449 update_mem_ref_hash_table. */
451 static hash_table<asan_mem_ref_hasher> *
452 get_mem_ref_hash_table ()
454 if (!asan_mem_ref_ht)
455 asan_mem_ref_ht = new hash_table<asan_mem_ref_hasher> (10);
457 return asan_mem_ref_ht;
460 /* Clear all entries from the memory references hash table. */
462 static void
463 empty_mem_ref_hash_table ()
465 if (asan_mem_ref_ht)
466 asan_mem_ref_ht->empty ();
469 /* Free the memory references hash table. */
471 static void
472 free_mem_ref_resources ()
474 delete asan_mem_ref_ht;
475 asan_mem_ref_ht = NULL;
477 asan_mem_ref_pool.release ();
480 /* Return true iff the memory reference REF has been instrumented. */
482 static bool
483 has_mem_ref_been_instrumented (tree ref, HOST_WIDE_INT access_size)
485 asan_mem_ref r;
486 asan_mem_ref_init (&r, ref, access_size);
488 asan_mem_ref *saved_ref = get_mem_ref_hash_table ()->find (&r);
489 return saved_ref && saved_ref->access_size >= access_size;
492 /* Return true iff the memory reference REF has been instrumented. */
494 static bool
495 has_mem_ref_been_instrumented (const asan_mem_ref *ref)
497 return has_mem_ref_been_instrumented (ref->start, ref->access_size);
500 /* Return true iff access to memory region starting at REF and of
501 length LEN has been instrumented. */
503 static bool
504 has_mem_ref_been_instrumented (const asan_mem_ref *ref, tree len)
506 HOST_WIDE_INT size_in_bytes
507 = tree_fits_shwi_p (len) ? tree_to_shwi (len) : -1;
509 return size_in_bytes != -1
510 && has_mem_ref_been_instrumented (ref->start, size_in_bytes);
513 /* Set REF to the memory reference present in a gimple assignment
514 ASSIGNMENT. Return true upon successful completion, false
515 otherwise. */
517 static bool
518 get_mem_ref_of_assignment (const gassign *assignment,
519 asan_mem_ref *ref,
520 bool *ref_is_store)
522 gcc_assert (gimple_assign_single_p (assignment));
524 if (gimple_store_p (assignment)
525 && !gimple_clobber_p (assignment))
527 ref->start = gimple_assign_lhs (assignment);
528 *ref_is_store = true;
530 else if (gimple_assign_load_p (assignment))
532 ref->start = gimple_assign_rhs1 (assignment);
533 *ref_is_store = false;
535 else
536 return false;
538 ref->access_size = int_size_in_bytes (TREE_TYPE (ref->start));
539 return true;
542 /* Return address of last allocated dynamic alloca. */
544 static tree
545 get_last_alloca_addr ()
547 if (last_alloca_addr)
548 return last_alloca_addr;
550 last_alloca_addr = create_tmp_reg (ptr_type_node, "last_alloca_addr");
551 gassign *g = gimple_build_assign (last_alloca_addr, null_pointer_node);
552 edge e = single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun));
553 gsi_insert_on_edge_immediate (e, g);
554 return last_alloca_addr;
557 /* Insert __asan_allocas_unpoison (top, bottom) call after
558 __builtin_stack_restore (new_sp) call.
559 The pseudocode of this routine should look like this:
560 __builtin_stack_restore (new_sp);
561 top = last_alloca_addr;
562 bot = new_sp;
563 __asan_allocas_unpoison (top, bot);
564 last_alloca_addr = new_sp;
565 In general, we can't use new_sp as bot parameter because on some
566 architectures SP has non zero offset from dynamic stack area. Moreover, on
567 some architectures this offset (STACK_DYNAMIC_OFFSET) becomes known for each
568 particular function only after all callees were expanded to rtl.
569 The most noticeable example is PowerPC{,64}, see
570 http://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi.html#DYNAM-STACK.
571 To overcome the issue we use following trick: pass new_sp as a second
572 parameter to __asan_allocas_unpoison and rewrite it during expansion with
573 virtual_dynamic_stack_rtx later in expand_asan_emit_allocas_unpoison
574 function.
577 static void
578 handle_builtin_stack_restore (gcall *call, gimple_stmt_iterator *iter)
580 if (!iter || !asan_sanitize_allocas_p ())
581 return;
583 tree last_alloca = get_last_alloca_addr ();
584 tree restored_stack = gimple_call_arg (call, 0);
585 tree fn = builtin_decl_implicit (BUILT_IN_ASAN_ALLOCAS_UNPOISON);
586 gimple *g = gimple_build_call (fn, 2, last_alloca, restored_stack);
587 gsi_insert_after (iter, g, GSI_NEW_STMT);
588 g = gimple_build_assign (last_alloca, restored_stack);
589 gsi_insert_after (iter, g, GSI_NEW_STMT);
592 /* Deploy and poison redzones around __builtin_alloca call. To do this, we
593 should replace this call with another one with changed parameters and
594 replace all its uses with new address, so
595 addr = __builtin_alloca (old_size, align);
596 is replaced by
597 left_redzone_size = max (align, ASAN_RED_ZONE_SIZE);
598 Following two statements are optimized out if we know that
599 old_size & (ASAN_RED_ZONE_SIZE - 1) == 0, i.e. alloca doesn't need partial
600 redzone.
601 misalign = old_size & (ASAN_RED_ZONE_SIZE - 1);
602 partial_redzone_size = ASAN_RED_ZONE_SIZE - misalign;
603 right_redzone_size = ASAN_RED_ZONE_SIZE;
604 additional_size = left_redzone_size + partial_redzone_size +
605 right_redzone_size;
606 new_size = old_size + additional_size;
607 new_alloca = __builtin_alloca (new_size, max (align, 32))
608 __asan_alloca_poison (new_alloca, old_size)
609 addr = new_alloca + max (align, ASAN_RED_ZONE_SIZE);
610 last_alloca_addr = new_alloca;
611 ADDITIONAL_SIZE is added to make new memory allocation contain not only
612 requested memory, but also left, partial and right redzones as well as some
613 additional space, required by alignment. */
615 static void
616 handle_builtin_alloca (gcall *call, gimple_stmt_iterator *iter)
618 if (!iter || !asan_sanitize_allocas_p ())
619 return;
621 gassign *g;
622 gcall *gg;
623 const HOST_WIDE_INT redzone_mask = ASAN_RED_ZONE_SIZE - 1;
625 tree last_alloca = get_last_alloca_addr ();
626 tree callee = gimple_call_fndecl (call);
627 tree old_size = gimple_call_arg (call, 0);
628 tree ptr_type = gimple_call_lhs (call) ? TREE_TYPE (gimple_call_lhs (call))
629 : ptr_type_node;
630 tree partial_size = NULL_TREE;
631 unsigned int align
632 = DECL_FUNCTION_CODE (callee) == BUILT_IN_ALLOCA
633 ? 0 : tree_to_uhwi (gimple_call_arg (call, 1));
635 /* If ALIGN > ASAN_RED_ZONE_SIZE, we embed left redzone into first ALIGN
636 bytes of allocated space. Otherwise, align alloca to ASAN_RED_ZONE_SIZE
637 manually. */
638 align = MAX (align, ASAN_RED_ZONE_SIZE * BITS_PER_UNIT);
640 tree alloca_rz_mask = build_int_cst (size_type_node, redzone_mask);
641 tree redzone_size = build_int_cst (size_type_node, ASAN_RED_ZONE_SIZE);
643 /* Extract lower bits from old_size. */
644 wide_int size_nonzero_bits = get_nonzero_bits (old_size);
645 wide_int rz_mask
646 = wi::uhwi (redzone_mask, wi::get_precision (size_nonzero_bits));
647 wide_int old_size_lower_bits = wi::bit_and (size_nonzero_bits, rz_mask);
649 /* If alloca size is aligned to ASAN_RED_ZONE_SIZE, we don't need partial
650 redzone. Otherwise, compute its size here. */
651 if (wi::ne_p (old_size_lower_bits, 0))
653 /* misalign = size & (ASAN_RED_ZONE_SIZE - 1)
654 partial_size = ASAN_RED_ZONE_SIZE - misalign. */
655 g = gimple_build_assign (make_ssa_name (size_type_node, NULL),
656 BIT_AND_EXPR, old_size, alloca_rz_mask);
657 gsi_insert_before (iter, g, GSI_SAME_STMT);
658 tree misalign = gimple_assign_lhs (g);
659 g = gimple_build_assign (make_ssa_name (size_type_node, NULL), MINUS_EXPR,
660 redzone_size, misalign);
661 gsi_insert_before (iter, g, GSI_SAME_STMT);
662 partial_size = gimple_assign_lhs (g);
665 /* additional_size = align + ASAN_RED_ZONE_SIZE. */
666 tree additional_size = build_int_cst (size_type_node, align / BITS_PER_UNIT
667 + ASAN_RED_ZONE_SIZE);
668 /* If alloca has partial redzone, include it to additional_size too. */
669 if (partial_size)
671 /* additional_size += partial_size. */
672 g = gimple_build_assign (make_ssa_name (size_type_node), PLUS_EXPR,
673 partial_size, additional_size);
674 gsi_insert_before (iter, g, GSI_SAME_STMT);
675 additional_size = gimple_assign_lhs (g);
678 /* new_size = old_size + additional_size. */
679 g = gimple_build_assign (make_ssa_name (size_type_node), PLUS_EXPR, old_size,
680 additional_size);
681 gsi_insert_before (iter, g, GSI_SAME_STMT);
682 tree new_size = gimple_assign_lhs (g);
684 /* Build new __builtin_alloca call:
685 new_alloca_with_rz = __builtin_alloca (new_size, align). */
686 tree fn = builtin_decl_implicit (BUILT_IN_ALLOCA_WITH_ALIGN);
687 gg = gimple_build_call (fn, 2, new_size,
688 build_int_cst (size_type_node, align));
689 tree new_alloca_with_rz = make_ssa_name (ptr_type, gg);
690 gimple_call_set_lhs (gg, new_alloca_with_rz);
691 gsi_insert_before (iter, gg, GSI_SAME_STMT);
693 /* new_alloca = new_alloca_with_rz + align. */
694 g = gimple_build_assign (make_ssa_name (ptr_type), POINTER_PLUS_EXPR,
695 new_alloca_with_rz,
696 build_int_cst (size_type_node,
697 align / BITS_PER_UNIT));
698 gsi_insert_before (iter, g, GSI_SAME_STMT);
699 tree new_alloca = gimple_assign_lhs (g);
701 /* Poison newly created alloca redzones:
702 __asan_alloca_poison (new_alloca, old_size). */
703 fn = builtin_decl_implicit (BUILT_IN_ASAN_ALLOCA_POISON);
704 gg = gimple_build_call (fn, 2, new_alloca, old_size);
705 gsi_insert_before (iter, gg, GSI_SAME_STMT);
707 /* Save new_alloca_with_rz value into last_alloca to use it during
708 allocas unpoisoning. */
709 g = gimple_build_assign (last_alloca, new_alloca_with_rz);
710 gsi_insert_before (iter, g, GSI_SAME_STMT);
712 /* Finally, replace old alloca ptr with NEW_ALLOCA. */
713 replace_call_with_value (iter, new_alloca);
716 /* Return the memory references contained in a gimple statement
717 representing a builtin call that has to do with memory access. */
719 static bool
720 get_mem_refs_of_builtin_call (gcall *call,
721 asan_mem_ref *src0,
722 tree *src0_len,
723 bool *src0_is_store,
724 asan_mem_ref *src1,
725 tree *src1_len,
726 bool *src1_is_store,
727 asan_mem_ref *dst,
728 tree *dst_len,
729 bool *dst_is_store,
730 bool *dest_is_deref,
731 bool *intercepted_p,
732 gimple_stmt_iterator *iter = NULL)
734 gcc_checking_assert (gimple_call_builtin_p (call, BUILT_IN_NORMAL));
736 tree callee = gimple_call_fndecl (call);
737 tree source0 = NULL_TREE, source1 = NULL_TREE,
738 dest = NULL_TREE, len = NULL_TREE;
739 bool is_store = true, got_reference_p = false;
740 HOST_WIDE_INT access_size = 1;
742 *intercepted_p = asan_intercepted_p ((DECL_FUNCTION_CODE (callee)));
744 switch (DECL_FUNCTION_CODE (callee))
746 /* (s, s, n) style memops. */
747 case BUILT_IN_BCMP:
748 case BUILT_IN_MEMCMP:
749 source0 = gimple_call_arg (call, 0);
750 source1 = gimple_call_arg (call, 1);
751 len = gimple_call_arg (call, 2);
752 break;
754 /* (src, dest, n) style memops. */
755 case BUILT_IN_BCOPY:
756 source0 = gimple_call_arg (call, 0);
757 dest = gimple_call_arg (call, 1);
758 len = gimple_call_arg (call, 2);
759 break;
761 /* (dest, src, n) style memops. */
762 case BUILT_IN_MEMCPY:
763 case BUILT_IN_MEMCPY_CHK:
764 case BUILT_IN_MEMMOVE:
765 case BUILT_IN_MEMMOVE_CHK:
766 case BUILT_IN_MEMPCPY:
767 case BUILT_IN_MEMPCPY_CHK:
768 dest = gimple_call_arg (call, 0);
769 source0 = gimple_call_arg (call, 1);
770 len = gimple_call_arg (call, 2);
771 break;
773 /* (dest, n) style memops. */
774 case BUILT_IN_BZERO:
775 dest = gimple_call_arg (call, 0);
776 len = gimple_call_arg (call, 1);
777 break;
779 /* (dest, x, n) style memops*/
780 case BUILT_IN_MEMSET:
781 case BUILT_IN_MEMSET_CHK:
782 dest = gimple_call_arg (call, 0);
783 len = gimple_call_arg (call, 2);
784 break;
786 case BUILT_IN_STRLEN:
787 source0 = gimple_call_arg (call, 0);
788 len = gimple_call_lhs (call);
789 break;
791 case BUILT_IN_STACK_RESTORE:
792 handle_builtin_stack_restore (call, iter);
793 break;
795 CASE_BUILT_IN_ALLOCA:
796 handle_builtin_alloca (call, iter);
797 break;
798 /* And now the __atomic* and __sync builtins.
799 These are handled differently from the classical memory memory
800 access builtins above. */
802 case BUILT_IN_ATOMIC_LOAD_1:
803 is_store = false;
804 /* FALLTHRU */
805 case BUILT_IN_SYNC_FETCH_AND_ADD_1:
806 case BUILT_IN_SYNC_FETCH_AND_SUB_1:
807 case BUILT_IN_SYNC_FETCH_AND_OR_1:
808 case BUILT_IN_SYNC_FETCH_AND_AND_1:
809 case BUILT_IN_SYNC_FETCH_AND_XOR_1:
810 case BUILT_IN_SYNC_FETCH_AND_NAND_1:
811 case BUILT_IN_SYNC_ADD_AND_FETCH_1:
812 case BUILT_IN_SYNC_SUB_AND_FETCH_1:
813 case BUILT_IN_SYNC_OR_AND_FETCH_1:
814 case BUILT_IN_SYNC_AND_AND_FETCH_1:
815 case BUILT_IN_SYNC_XOR_AND_FETCH_1:
816 case BUILT_IN_SYNC_NAND_AND_FETCH_1:
817 case BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_1:
818 case BUILT_IN_SYNC_VAL_COMPARE_AND_SWAP_1:
819 case BUILT_IN_SYNC_LOCK_TEST_AND_SET_1:
820 case BUILT_IN_SYNC_LOCK_RELEASE_1:
821 case BUILT_IN_ATOMIC_EXCHANGE_1:
822 case BUILT_IN_ATOMIC_COMPARE_EXCHANGE_1:
823 case BUILT_IN_ATOMIC_STORE_1:
824 case BUILT_IN_ATOMIC_ADD_FETCH_1:
825 case BUILT_IN_ATOMIC_SUB_FETCH_1:
826 case BUILT_IN_ATOMIC_AND_FETCH_1:
827 case BUILT_IN_ATOMIC_NAND_FETCH_1:
828 case BUILT_IN_ATOMIC_XOR_FETCH_1:
829 case BUILT_IN_ATOMIC_OR_FETCH_1:
830 case BUILT_IN_ATOMIC_FETCH_ADD_1:
831 case BUILT_IN_ATOMIC_FETCH_SUB_1:
832 case BUILT_IN_ATOMIC_FETCH_AND_1:
833 case BUILT_IN_ATOMIC_FETCH_NAND_1:
834 case BUILT_IN_ATOMIC_FETCH_XOR_1:
835 case BUILT_IN_ATOMIC_FETCH_OR_1:
836 access_size = 1;
837 goto do_atomic;
839 case BUILT_IN_ATOMIC_LOAD_2:
840 is_store = false;
841 /* FALLTHRU */
842 case BUILT_IN_SYNC_FETCH_AND_ADD_2:
843 case BUILT_IN_SYNC_FETCH_AND_SUB_2:
844 case BUILT_IN_SYNC_FETCH_AND_OR_2:
845 case BUILT_IN_SYNC_FETCH_AND_AND_2:
846 case BUILT_IN_SYNC_FETCH_AND_XOR_2:
847 case BUILT_IN_SYNC_FETCH_AND_NAND_2:
848 case BUILT_IN_SYNC_ADD_AND_FETCH_2:
849 case BUILT_IN_SYNC_SUB_AND_FETCH_2:
850 case BUILT_IN_SYNC_OR_AND_FETCH_2:
851 case BUILT_IN_SYNC_AND_AND_FETCH_2:
852 case BUILT_IN_SYNC_XOR_AND_FETCH_2:
853 case BUILT_IN_SYNC_NAND_AND_FETCH_2:
854 case BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_2:
855 case BUILT_IN_SYNC_VAL_COMPARE_AND_SWAP_2:
856 case BUILT_IN_SYNC_LOCK_TEST_AND_SET_2:
857 case BUILT_IN_SYNC_LOCK_RELEASE_2:
858 case BUILT_IN_ATOMIC_EXCHANGE_2:
859 case BUILT_IN_ATOMIC_COMPARE_EXCHANGE_2:
860 case BUILT_IN_ATOMIC_STORE_2:
861 case BUILT_IN_ATOMIC_ADD_FETCH_2:
862 case BUILT_IN_ATOMIC_SUB_FETCH_2:
863 case BUILT_IN_ATOMIC_AND_FETCH_2:
864 case BUILT_IN_ATOMIC_NAND_FETCH_2:
865 case BUILT_IN_ATOMIC_XOR_FETCH_2:
866 case BUILT_IN_ATOMIC_OR_FETCH_2:
867 case BUILT_IN_ATOMIC_FETCH_ADD_2:
868 case BUILT_IN_ATOMIC_FETCH_SUB_2:
869 case BUILT_IN_ATOMIC_FETCH_AND_2:
870 case BUILT_IN_ATOMIC_FETCH_NAND_2:
871 case BUILT_IN_ATOMIC_FETCH_XOR_2:
872 case BUILT_IN_ATOMIC_FETCH_OR_2:
873 access_size = 2;
874 goto do_atomic;
876 case BUILT_IN_ATOMIC_LOAD_4:
877 is_store = false;
878 /* FALLTHRU */
879 case BUILT_IN_SYNC_FETCH_AND_ADD_4:
880 case BUILT_IN_SYNC_FETCH_AND_SUB_4:
881 case BUILT_IN_SYNC_FETCH_AND_OR_4:
882 case BUILT_IN_SYNC_FETCH_AND_AND_4:
883 case BUILT_IN_SYNC_FETCH_AND_XOR_4:
884 case BUILT_IN_SYNC_FETCH_AND_NAND_4:
885 case BUILT_IN_SYNC_ADD_AND_FETCH_4:
886 case BUILT_IN_SYNC_SUB_AND_FETCH_4:
887 case BUILT_IN_SYNC_OR_AND_FETCH_4:
888 case BUILT_IN_SYNC_AND_AND_FETCH_4:
889 case BUILT_IN_SYNC_XOR_AND_FETCH_4:
890 case BUILT_IN_SYNC_NAND_AND_FETCH_4:
891 case BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_4:
892 case BUILT_IN_SYNC_VAL_COMPARE_AND_SWAP_4:
893 case BUILT_IN_SYNC_LOCK_TEST_AND_SET_4:
894 case BUILT_IN_SYNC_LOCK_RELEASE_4:
895 case BUILT_IN_ATOMIC_EXCHANGE_4:
896 case BUILT_IN_ATOMIC_COMPARE_EXCHANGE_4:
897 case BUILT_IN_ATOMIC_STORE_4:
898 case BUILT_IN_ATOMIC_ADD_FETCH_4:
899 case BUILT_IN_ATOMIC_SUB_FETCH_4:
900 case BUILT_IN_ATOMIC_AND_FETCH_4:
901 case BUILT_IN_ATOMIC_NAND_FETCH_4:
902 case BUILT_IN_ATOMIC_XOR_FETCH_4:
903 case BUILT_IN_ATOMIC_OR_FETCH_4:
904 case BUILT_IN_ATOMIC_FETCH_ADD_4:
905 case BUILT_IN_ATOMIC_FETCH_SUB_4:
906 case BUILT_IN_ATOMIC_FETCH_AND_4:
907 case BUILT_IN_ATOMIC_FETCH_NAND_4:
908 case BUILT_IN_ATOMIC_FETCH_XOR_4:
909 case BUILT_IN_ATOMIC_FETCH_OR_4:
910 access_size = 4;
911 goto do_atomic;
913 case BUILT_IN_ATOMIC_LOAD_8:
914 is_store = false;
915 /* FALLTHRU */
916 case BUILT_IN_SYNC_FETCH_AND_ADD_8:
917 case BUILT_IN_SYNC_FETCH_AND_SUB_8:
918 case BUILT_IN_SYNC_FETCH_AND_OR_8:
919 case BUILT_IN_SYNC_FETCH_AND_AND_8:
920 case BUILT_IN_SYNC_FETCH_AND_XOR_8:
921 case BUILT_IN_SYNC_FETCH_AND_NAND_8:
922 case BUILT_IN_SYNC_ADD_AND_FETCH_8:
923 case BUILT_IN_SYNC_SUB_AND_FETCH_8:
924 case BUILT_IN_SYNC_OR_AND_FETCH_8:
925 case BUILT_IN_SYNC_AND_AND_FETCH_8:
926 case BUILT_IN_SYNC_XOR_AND_FETCH_8:
927 case BUILT_IN_SYNC_NAND_AND_FETCH_8:
928 case BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_8:
929 case BUILT_IN_SYNC_VAL_COMPARE_AND_SWAP_8:
930 case BUILT_IN_SYNC_LOCK_TEST_AND_SET_8:
931 case BUILT_IN_SYNC_LOCK_RELEASE_8:
932 case BUILT_IN_ATOMIC_EXCHANGE_8:
933 case BUILT_IN_ATOMIC_COMPARE_EXCHANGE_8:
934 case BUILT_IN_ATOMIC_STORE_8:
935 case BUILT_IN_ATOMIC_ADD_FETCH_8:
936 case BUILT_IN_ATOMIC_SUB_FETCH_8:
937 case BUILT_IN_ATOMIC_AND_FETCH_8:
938 case BUILT_IN_ATOMIC_NAND_FETCH_8:
939 case BUILT_IN_ATOMIC_XOR_FETCH_8:
940 case BUILT_IN_ATOMIC_OR_FETCH_8:
941 case BUILT_IN_ATOMIC_FETCH_ADD_8:
942 case BUILT_IN_ATOMIC_FETCH_SUB_8:
943 case BUILT_IN_ATOMIC_FETCH_AND_8:
944 case BUILT_IN_ATOMIC_FETCH_NAND_8:
945 case BUILT_IN_ATOMIC_FETCH_XOR_8:
946 case BUILT_IN_ATOMIC_FETCH_OR_8:
947 access_size = 8;
948 goto do_atomic;
950 case BUILT_IN_ATOMIC_LOAD_16:
951 is_store = false;
952 /* FALLTHRU */
953 case BUILT_IN_SYNC_FETCH_AND_ADD_16:
954 case BUILT_IN_SYNC_FETCH_AND_SUB_16:
955 case BUILT_IN_SYNC_FETCH_AND_OR_16:
956 case BUILT_IN_SYNC_FETCH_AND_AND_16:
957 case BUILT_IN_SYNC_FETCH_AND_XOR_16:
958 case BUILT_IN_SYNC_FETCH_AND_NAND_16:
959 case BUILT_IN_SYNC_ADD_AND_FETCH_16:
960 case BUILT_IN_SYNC_SUB_AND_FETCH_16:
961 case BUILT_IN_SYNC_OR_AND_FETCH_16:
962 case BUILT_IN_SYNC_AND_AND_FETCH_16:
963 case BUILT_IN_SYNC_XOR_AND_FETCH_16:
964 case BUILT_IN_SYNC_NAND_AND_FETCH_16:
965 case BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_16:
966 case BUILT_IN_SYNC_VAL_COMPARE_AND_SWAP_16:
967 case BUILT_IN_SYNC_LOCK_TEST_AND_SET_16:
968 case BUILT_IN_SYNC_LOCK_RELEASE_16:
969 case BUILT_IN_ATOMIC_EXCHANGE_16:
970 case BUILT_IN_ATOMIC_COMPARE_EXCHANGE_16:
971 case BUILT_IN_ATOMIC_STORE_16:
972 case BUILT_IN_ATOMIC_ADD_FETCH_16:
973 case BUILT_IN_ATOMIC_SUB_FETCH_16:
974 case BUILT_IN_ATOMIC_AND_FETCH_16:
975 case BUILT_IN_ATOMIC_NAND_FETCH_16:
976 case BUILT_IN_ATOMIC_XOR_FETCH_16:
977 case BUILT_IN_ATOMIC_OR_FETCH_16:
978 case BUILT_IN_ATOMIC_FETCH_ADD_16:
979 case BUILT_IN_ATOMIC_FETCH_SUB_16:
980 case BUILT_IN_ATOMIC_FETCH_AND_16:
981 case BUILT_IN_ATOMIC_FETCH_NAND_16:
982 case BUILT_IN_ATOMIC_FETCH_XOR_16:
983 case BUILT_IN_ATOMIC_FETCH_OR_16:
984 access_size = 16;
985 /* FALLTHRU */
986 do_atomic:
988 dest = gimple_call_arg (call, 0);
989 /* DEST represents the address of a memory location.
990 instrument_derefs wants the memory location, so lets
991 dereference the address DEST before handing it to
992 instrument_derefs. */
993 tree type = build_nonstandard_integer_type (access_size
994 * BITS_PER_UNIT, 1);
995 dest = build2 (MEM_REF, type, dest,
996 build_int_cst (build_pointer_type (char_type_node), 0));
997 break;
1000 default:
1001 /* The other builtins memory access are not instrumented in this
1002 function because they either don't have any length parameter,
1003 or their length parameter is just a limit. */
1004 break;
1007 if (len != NULL_TREE)
1009 if (source0 != NULL_TREE)
1011 src0->start = source0;
1012 src0->access_size = access_size;
1013 *src0_len = len;
1014 *src0_is_store = false;
1017 if (source1 != NULL_TREE)
1019 src1->start = source1;
1020 src1->access_size = access_size;
1021 *src1_len = len;
1022 *src1_is_store = false;
1025 if (dest != NULL_TREE)
1027 dst->start = dest;
1028 dst->access_size = access_size;
1029 *dst_len = len;
1030 *dst_is_store = true;
1033 got_reference_p = true;
1035 else if (dest)
1037 dst->start = dest;
1038 dst->access_size = access_size;
1039 *dst_len = NULL_TREE;
1040 *dst_is_store = is_store;
1041 *dest_is_deref = true;
1042 got_reference_p = true;
1045 return got_reference_p;
1048 /* Return true iff a given gimple statement has been instrumented.
1049 Note that the statement is "defined" by the memory references it
1050 contains. */
1052 static bool
1053 has_stmt_been_instrumented_p (gimple *stmt)
1055 if (gimple_assign_single_p (stmt))
1057 bool r_is_store;
1058 asan_mem_ref r;
1059 asan_mem_ref_init (&r, NULL, 1);
1061 if (get_mem_ref_of_assignment (as_a <gassign *> (stmt), &r,
1062 &r_is_store))
1063 return has_mem_ref_been_instrumented (&r);
1065 else if (gimple_call_builtin_p (stmt, BUILT_IN_NORMAL))
1067 asan_mem_ref src0, src1, dest;
1068 asan_mem_ref_init (&src0, NULL, 1);
1069 asan_mem_ref_init (&src1, NULL, 1);
1070 asan_mem_ref_init (&dest, NULL, 1);
1072 tree src0_len = NULL_TREE, src1_len = NULL_TREE, dest_len = NULL_TREE;
1073 bool src0_is_store = false, src1_is_store = false,
1074 dest_is_store = false, dest_is_deref = false, intercepted_p = true;
1075 if (get_mem_refs_of_builtin_call (as_a <gcall *> (stmt),
1076 &src0, &src0_len, &src0_is_store,
1077 &src1, &src1_len, &src1_is_store,
1078 &dest, &dest_len, &dest_is_store,
1079 &dest_is_deref, &intercepted_p))
1081 if (src0.start != NULL_TREE
1082 && !has_mem_ref_been_instrumented (&src0, src0_len))
1083 return false;
1085 if (src1.start != NULL_TREE
1086 && !has_mem_ref_been_instrumented (&src1, src1_len))
1087 return false;
1089 if (dest.start != NULL_TREE
1090 && !has_mem_ref_been_instrumented (&dest, dest_len))
1091 return false;
1093 return true;
1096 else if (is_gimple_call (stmt) && gimple_store_p (stmt))
1098 asan_mem_ref r;
1099 asan_mem_ref_init (&r, NULL, 1);
1101 r.start = gimple_call_lhs (stmt);
1102 r.access_size = int_size_in_bytes (TREE_TYPE (r.start));
1103 return has_mem_ref_been_instrumented (&r);
1106 return false;
1109 /* Insert a memory reference into the hash table. */
1111 static void
1112 update_mem_ref_hash_table (tree ref, HOST_WIDE_INT access_size)
1114 hash_table<asan_mem_ref_hasher> *ht = get_mem_ref_hash_table ();
1116 asan_mem_ref r;
1117 asan_mem_ref_init (&r, ref, access_size);
1119 asan_mem_ref **slot = ht->find_slot (&r, INSERT);
1120 if (*slot == NULL || (*slot)->access_size < access_size)
1121 *slot = asan_mem_ref_new (ref, access_size);
1124 /* Initialize shadow_ptr_types array. */
1126 static void
1127 asan_init_shadow_ptr_types (void)
1129 asan_shadow_set = new_alias_set ();
1130 tree types[3] = { signed_char_type_node, short_integer_type_node,
1131 integer_type_node };
1133 for (unsigned i = 0; i < 3; i++)
1135 shadow_ptr_types[i] = build_distinct_type_copy (types[i]);
1136 TYPE_ALIAS_SET (shadow_ptr_types[i]) = asan_shadow_set;
1137 shadow_ptr_types[i] = build_pointer_type (shadow_ptr_types[i]);
1140 initialize_sanitizer_builtins ();
1143 /* Create ADDR_EXPR of STRING_CST with the PP pretty printer text. */
1145 static tree
1146 asan_pp_string (pretty_printer *pp)
1148 const char *buf = pp_formatted_text (pp);
1149 size_t len = strlen (buf);
1150 tree ret = build_string (len + 1, buf);
1151 TREE_TYPE (ret)
1152 = build_array_type (TREE_TYPE (shadow_ptr_types[0]),
1153 build_index_type (size_int (len)));
1154 TREE_READONLY (ret) = 1;
1155 TREE_STATIC (ret) = 1;
1156 return build1 (ADDR_EXPR, shadow_ptr_types[0], ret);
1159 /* Return a CONST_INT representing 4 subsequent shadow memory bytes. */
1161 static rtx
1162 asan_shadow_cst (unsigned char shadow_bytes[4])
1164 int i;
1165 unsigned HOST_WIDE_INT val = 0;
1166 gcc_assert (WORDS_BIG_ENDIAN == BYTES_BIG_ENDIAN);
1167 for (i = 0; i < 4; i++)
1168 val |= (unsigned HOST_WIDE_INT) shadow_bytes[BYTES_BIG_ENDIAN ? 3 - i : i]
1169 << (BITS_PER_UNIT * i);
1170 return gen_int_mode (val, SImode);
1173 /* Clear shadow memory at SHADOW_MEM, LEN bytes. Can't call a library call here
1174 though. */
1176 static void
1177 asan_clear_shadow (rtx shadow_mem, HOST_WIDE_INT len)
1179 rtx_insn *insn, *insns, *jump;
1180 rtx_code_label *top_label;
1181 rtx end, addr, tmp;
1183 start_sequence ();
1184 clear_storage (shadow_mem, GEN_INT (len), BLOCK_OP_NORMAL);
1185 insns = get_insns ();
1186 end_sequence ();
1187 for (insn = insns; insn; insn = NEXT_INSN (insn))
1188 if (CALL_P (insn))
1189 break;
1190 if (insn == NULL_RTX)
1192 emit_insn (insns);
1193 return;
1196 gcc_assert ((len & 3) == 0);
1197 top_label = gen_label_rtx ();
1198 addr = copy_to_mode_reg (Pmode, XEXP (shadow_mem, 0));
1199 shadow_mem = adjust_automodify_address (shadow_mem, SImode, addr, 0);
1200 end = force_reg (Pmode, plus_constant (Pmode, addr, len));
1201 emit_label (top_label);
1203 emit_move_insn (shadow_mem, const0_rtx);
1204 tmp = expand_simple_binop (Pmode, PLUS, addr, gen_int_mode (4, Pmode), addr,
1205 true, OPTAB_LIB_WIDEN);
1206 if (tmp != addr)
1207 emit_move_insn (addr, tmp);
1208 emit_cmp_and_jump_insns (addr, end, LT, NULL_RTX, Pmode, true, top_label);
1209 jump = get_last_insn ();
1210 gcc_assert (JUMP_P (jump));
1211 add_reg_br_prob_note (jump,
1212 profile_probability::guessed_always ()
1213 .apply_scale (80, 100));
1216 void
1217 asan_function_start (void)
1219 section *fnsec = function_section (current_function_decl);
1220 switch_to_section (fnsec);
1221 ASM_OUTPUT_DEBUG_LABEL (asm_out_file, "LASANPC",
1222 current_function_funcdef_no);
1225 /* Return number of shadow bytes that are occupied by a local variable
1226 of SIZE bytes. */
1228 static unsigned HOST_WIDE_INT
1229 shadow_mem_size (unsigned HOST_WIDE_INT size)
1231 return ROUND_UP (size, ASAN_SHADOW_GRANULARITY) / ASAN_SHADOW_GRANULARITY;
1234 /* Insert code to protect stack vars. The prologue sequence should be emitted
1235 directly, epilogue sequence returned. BASE is the register holding the
1236 stack base, against which OFFSETS array offsets are relative to, OFFSETS
1237 array contains pairs of offsets in reverse order, always the end offset
1238 of some gap that needs protection followed by starting offset,
1239 and DECLS is an array of representative decls for each var partition.
1240 LENGTH is the length of the OFFSETS array, DECLS array is LENGTH / 2 - 1
1241 elements long (OFFSETS include gap before the first variable as well
1242 as gaps after each stack variable). PBASE is, if non-NULL, some pseudo
1243 register which stack vars DECL_RTLs are based on. Either BASE should be
1244 assigned to PBASE, when not doing use after return protection, or
1245 corresponding address based on __asan_stack_malloc* return value. */
1247 rtx_insn *
1248 asan_emit_stack_protection (rtx base, rtx pbase, unsigned int alignb,
1249 HOST_WIDE_INT *offsets, tree *decls, int length)
1251 rtx shadow_base, shadow_mem, ret, mem, orig_base;
1252 rtx_code_label *lab;
1253 rtx_insn *insns;
1254 char buf[32];
1255 unsigned char shadow_bytes[4];
1256 HOST_WIDE_INT base_offset = offsets[length - 1];
1257 HOST_WIDE_INT base_align_bias = 0, offset, prev_offset;
1258 HOST_WIDE_INT asan_frame_size = offsets[0] - base_offset;
1259 HOST_WIDE_INT last_offset, last_size;
1260 int l;
1261 unsigned char cur_shadow_byte = ASAN_STACK_MAGIC_LEFT;
1262 tree str_cst, decl, id;
1263 int use_after_return_class = -1;
1265 if (shadow_ptr_types[0] == NULL_TREE)
1266 asan_init_shadow_ptr_types ();
1268 /* First of all, prepare the description string. */
1269 pretty_printer asan_pp;
1271 pp_decimal_int (&asan_pp, length / 2 - 1);
1272 pp_space (&asan_pp);
1273 for (l = length - 2; l; l -= 2)
1275 tree decl = decls[l / 2 - 1];
1276 pp_wide_integer (&asan_pp, offsets[l] - base_offset);
1277 pp_space (&asan_pp);
1278 pp_wide_integer (&asan_pp, offsets[l - 1] - offsets[l]);
1279 pp_space (&asan_pp);
1280 if (DECL_P (decl) && DECL_NAME (decl))
1282 pp_decimal_int (&asan_pp, IDENTIFIER_LENGTH (DECL_NAME (decl)));
1283 pp_space (&asan_pp);
1284 pp_tree_identifier (&asan_pp, DECL_NAME (decl));
1286 else
1287 pp_string (&asan_pp, "9 <unknown>");
1288 pp_space (&asan_pp);
1290 str_cst = asan_pp_string (&asan_pp);
1292 /* Emit the prologue sequence. */
1293 if (asan_frame_size > 32 && asan_frame_size <= 65536 && pbase
1294 && ASAN_USE_AFTER_RETURN)
1296 use_after_return_class = floor_log2 (asan_frame_size - 1) - 5;
1297 /* __asan_stack_malloc_N guarantees alignment
1298 N < 6 ? (64 << N) : 4096 bytes. */
1299 if (alignb > (use_after_return_class < 6
1300 ? (64U << use_after_return_class) : 4096U))
1301 use_after_return_class = -1;
1302 else if (alignb > ASAN_RED_ZONE_SIZE && (asan_frame_size & (alignb - 1)))
1303 base_align_bias = ((asan_frame_size + alignb - 1)
1304 & ~(alignb - HOST_WIDE_INT_1)) - asan_frame_size;
1306 /* Align base if target is STRICT_ALIGNMENT. */
1307 if (STRICT_ALIGNMENT)
1308 base = expand_binop (Pmode, and_optab, base,
1309 gen_int_mode (-((GET_MODE_ALIGNMENT (SImode)
1310 << ASAN_SHADOW_SHIFT)
1311 / BITS_PER_UNIT), Pmode), NULL_RTX,
1312 1, OPTAB_DIRECT);
1314 if (use_after_return_class == -1 && pbase)
1315 emit_move_insn (pbase, base);
1317 base = expand_binop (Pmode, add_optab, base,
1318 gen_int_mode (base_offset - base_align_bias, Pmode),
1319 NULL_RTX, 1, OPTAB_DIRECT);
1320 orig_base = NULL_RTX;
1321 if (use_after_return_class != -1)
1323 if (asan_detect_stack_use_after_return == NULL_TREE)
1325 id = get_identifier ("__asan_option_detect_stack_use_after_return");
1326 decl = build_decl (BUILTINS_LOCATION, VAR_DECL, id,
1327 integer_type_node);
1328 SET_DECL_ASSEMBLER_NAME (decl, id);
1329 TREE_ADDRESSABLE (decl) = 1;
1330 DECL_ARTIFICIAL (decl) = 1;
1331 DECL_IGNORED_P (decl) = 1;
1332 DECL_EXTERNAL (decl) = 1;
1333 TREE_STATIC (decl) = 1;
1334 TREE_PUBLIC (decl) = 1;
1335 TREE_USED (decl) = 1;
1336 asan_detect_stack_use_after_return = decl;
1338 orig_base = gen_reg_rtx (Pmode);
1339 emit_move_insn (orig_base, base);
1340 ret = expand_normal (asan_detect_stack_use_after_return);
1341 lab = gen_label_rtx ();
1342 emit_cmp_and_jump_insns (ret, const0_rtx, EQ, NULL_RTX,
1343 VOIDmode, 0, lab,
1344 profile_probability::very_likely ());
1345 snprintf (buf, sizeof buf, "__asan_stack_malloc_%d",
1346 use_after_return_class);
1347 ret = init_one_libfunc (buf);
1348 ret = emit_library_call_value (ret, NULL_RTX, LCT_NORMAL, ptr_mode,
1349 GEN_INT (asan_frame_size
1350 + base_align_bias),
1351 TYPE_MODE (pointer_sized_int_node));
1352 /* __asan_stack_malloc_[n] returns a pointer to fake stack if succeeded
1353 and NULL otherwise. Check RET value is NULL here and jump over the
1354 BASE reassignment in this case. Otherwise, reassign BASE to RET. */
1355 emit_cmp_and_jump_insns (ret, const0_rtx, EQ, NULL_RTX,
1356 VOIDmode, 0, lab,
1357 profile_probability:: very_unlikely ());
1358 ret = convert_memory_address (Pmode, ret);
1359 emit_move_insn (base, ret);
1360 emit_label (lab);
1361 emit_move_insn (pbase, expand_binop (Pmode, add_optab, base,
1362 gen_int_mode (base_align_bias
1363 - base_offset, Pmode),
1364 NULL_RTX, 1, OPTAB_DIRECT));
1366 mem = gen_rtx_MEM (ptr_mode, base);
1367 mem = adjust_address (mem, VOIDmode, base_align_bias);
1368 emit_move_insn (mem, gen_int_mode (ASAN_STACK_FRAME_MAGIC, ptr_mode));
1369 mem = adjust_address (mem, VOIDmode, GET_MODE_SIZE (ptr_mode));
1370 emit_move_insn (mem, expand_normal (str_cst));
1371 mem = adjust_address (mem, VOIDmode, GET_MODE_SIZE (ptr_mode));
1372 ASM_GENERATE_INTERNAL_LABEL (buf, "LASANPC", current_function_funcdef_no);
1373 id = get_identifier (buf);
1374 decl = build_decl (DECL_SOURCE_LOCATION (current_function_decl),
1375 VAR_DECL, id, char_type_node);
1376 SET_DECL_ASSEMBLER_NAME (decl, id);
1377 TREE_ADDRESSABLE (decl) = 1;
1378 TREE_READONLY (decl) = 1;
1379 DECL_ARTIFICIAL (decl) = 1;
1380 DECL_IGNORED_P (decl) = 1;
1381 TREE_STATIC (decl) = 1;
1382 TREE_PUBLIC (decl) = 0;
1383 TREE_USED (decl) = 1;
1384 DECL_INITIAL (decl) = decl;
1385 TREE_ASM_WRITTEN (decl) = 1;
1386 TREE_ASM_WRITTEN (id) = 1;
1387 emit_move_insn (mem, expand_normal (build_fold_addr_expr (decl)));
1388 shadow_base = expand_binop (Pmode, lshr_optab, base,
1389 GEN_INT (ASAN_SHADOW_SHIFT),
1390 NULL_RTX, 1, OPTAB_DIRECT);
1391 shadow_base
1392 = plus_constant (Pmode, shadow_base,
1393 asan_shadow_offset ()
1394 + (base_align_bias >> ASAN_SHADOW_SHIFT));
1395 gcc_assert (asan_shadow_set != -1
1396 && (ASAN_RED_ZONE_SIZE >> ASAN_SHADOW_SHIFT) == 4);
1397 shadow_mem = gen_rtx_MEM (SImode, shadow_base);
1398 set_mem_alias_set (shadow_mem, asan_shadow_set);
1399 if (STRICT_ALIGNMENT)
1400 set_mem_align (shadow_mem, (GET_MODE_ALIGNMENT (SImode)));
1401 prev_offset = base_offset;
1402 for (l = length; l; l -= 2)
1404 if (l == 2)
1405 cur_shadow_byte = ASAN_STACK_MAGIC_RIGHT;
1406 offset = offsets[l - 1];
1407 if ((offset - base_offset) & (ASAN_RED_ZONE_SIZE - 1))
1409 int i;
1410 HOST_WIDE_INT aoff
1411 = base_offset + ((offset - base_offset)
1412 & ~(ASAN_RED_ZONE_SIZE - HOST_WIDE_INT_1));
1413 shadow_mem = adjust_address (shadow_mem, VOIDmode,
1414 (aoff - prev_offset)
1415 >> ASAN_SHADOW_SHIFT);
1416 prev_offset = aoff;
1417 for (i = 0; i < 4; i++, aoff += ASAN_SHADOW_GRANULARITY)
1418 if (aoff < offset)
1420 if (aoff < offset - (HOST_WIDE_INT)ASAN_SHADOW_GRANULARITY + 1)
1421 shadow_bytes[i] = 0;
1422 else
1423 shadow_bytes[i] = offset - aoff;
1425 else
1426 shadow_bytes[i] = ASAN_STACK_MAGIC_MIDDLE;
1427 emit_move_insn (shadow_mem, asan_shadow_cst (shadow_bytes));
1428 offset = aoff;
1430 while (offset <= offsets[l - 2] - ASAN_RED_ZONE_SIZE)
1432 shadow_mem = adjust_address (shadow_mem, VOIDmode,
1433 (offset - prev_offset)
1434 >> ASAN_SHADOW_SHIFT);
1435 prev_offset = offset;
1436 memset (shadow_bytes, cur_shadow_byte, 4);
1437 emit_move_insn (shadow_mem, asan_shadow_cst (shadow_bytes));
1438 offset += ASAN_RED_ZONE_SIZE;
1440 cur_shadow_byte = ASAN_STACK_MAGIC_MIDDLE;
1442 do_pending_stack_adjust ();
1444 /* Construct epilogue sequence. */
1445 start_sequence ();
1447 lab = NULL;
1448 if (use_after_return_class != -1)
1450 rtx_code_label *lab2 = gen_label_rtx ();
1451 char c = (char) ASAN_STACK_MAGIC_USE_AFTER_RET;
1452 emit_cmp_and_jump_insns (orig_base, base, EQ, NULL_RTX,
1453 VOIDmode, 0, lab2,
1454 profile_probability::very_likely ());
1455 shadow_mem = gen_rtx_MEM (BLKmode, shadow_base);
1456 set_mem_alias_set (shadow_mem, asan_shadow_set);
1457 mem = gen_rtx_MEM (ptr_mode, base);
1458 mem = adjust_address (mem, VOIDmode, base_align_bias);
1459 emit_move_insn (mem, gen_int_mode (ASAN_STACK_RETIRED_MAGIC, ptr_mode));
1460 unsigned HOST_WIDE_INT sz = asan_frame_size >> ASAN_SHADOW_SHIFT;
1461 if (use_after_return_class < 5
1462 && can_store_by_pieces (sz, builtin_memset_read_str, &c,
1463 BITS_PER_UNIT, true))
1464 store_by_pieces (shadow_mem, sz, builtin_memset_read_str, &c,
1465 BITS_PER_UNIT, true, 0);
1466 else if (use_after_return_class >= 5
1467 || !set_storage_via_setmem (shadow_mem,
1468 GEN_INT (sz),
1469 gen_int_mode (c, QImode),
1470 BITS_PER_UNIT, BITS_PER_UNIT,
1471 -1, sz, sz, sz))
1473 snprintf (buf, sizeof buf, "__asan_stack_free_%d",
1474 use_after_return_class);
1475 ret = init_one_libfunc (buf);
1476 rtx addr = convert_memory_address (ptr_mode, base);
1477 rtx orig_addr = convert_memory_address (ptr_mode, orig_base);
1478 emit_library_call (ret, LCT_NORMAL, ptr_mode, addr, ptr_mode,
1479 GEN_INT (asan_frame_size + base_align_bias),
1480 TYPE_MODE (pointer_sized_int_node),
1481 orig_addr, ptr_mode);
1483 lab = gen_label_rtx ();
1484 emit_jump (lab);
1485 emit_label (lab2);
1488 shadow_mem = gen_rtx_MEM (BLKmode, shadow_base);
1489 set_mem_alias_set (shadow_mem, asan_shadow_set);
1491 if (STRICT_ALIGNMENT)
1492 set_mem_align (shadow_mem, (GET_MODE_ALIGNMENT (SImode)));
1494 prev_offset = base_offset;
1495 last_offset = base_offset;
1496 last_size = 0;
1497 for (l = length; l; l -= 2)
1499 offset = base_offset + ((offsets[l - 1] - base_offset)
1500 & ~(ASAN_RED_ZONE_SIZE - HOST_WIDE_INT_1));
1501 if (last_offset + last_size != offset)
1503 shadow_mem = adjust_address (shadow_mem, VOIDmode,
1504 (last_offset - prev_offset)
1505 >> ASAN_SHADOW_SHIFT);
1506 prev_offset = last_offset;
1507 asan_clear_shadow (shadow_mem, last_size >> ASAN_SHADOW_SHIFT);
1508 last_offset = offset;
1509 last_size = 0;
1511 last_size += base_offset + ((offsets[l - 2] - base_offset)
1512 & ~(ASAN_RED_ZONE_SIZE - HOST_WIDE_INT_1))
1513 - offset;
1515 /* Unpoison shadow memory that corresponds to a variable that is
1516 is subject of use-after-return sanitization. */
1517 if (l > 2)
1519 decl = decls[l / 2 - 2];
1520 if (asan_handled_variables != NULL
1521 && asan_handled_variables->contains (decl))
1523 HOST_WIDE_INT size = offsets[l - 3] - offsets[l - 2];
1524 if (dump_file && (dump_flags & TDF_DETAILS))
1526 const char *n = (DECL_NAME (decl)
1527 ? IDENTIFIER_POINTER (DECL_NAME (decl))
1528 : "<unknown>");
1529 fprintf (dump_file, "Unpoisoning shadow stack for variable: "
1530 "%s (%" PRId64 " B)\n", n, size);
1533 last_size += size & ~(ASAN_RED_ZONE_SIZE - HOST_WIDE_INT_1);
1537 if (last_size)
1539 shadow_mem = adjust_address (shadow_mem, VOIDmode,
1540 (last_offset - prev_offset)
1541 >> ASAN_SHADOW_SHIFT);
1542 asan_clear_shadow (shadow_mem, last_size >> ASAN_SHADOW_SHIFT);
1545 /* Clean-up set with instrumented stack variables. */
1546 delete asan_handled_variables;
1547 asan_handled_variables = NULL;
1548 delete asan_used_labels;
1549 asan_used_labels = NULL;
1551 do_pending_stack_adjust ();
1552 if (lab)
1553 emit_label (lab);
1555 insns = get_insns ();
1556 end_sequence ();
1557 return insns;
1560 /* Emit __asan_allocas_unpoison (top, bot) call. The BASE parameter corresponds
1561 to BOT argument, for TOP virtual_stack_dynamic_rtx is used. NEW_SEQUENCE
1562 indicates whether we're emitting new instructions sequence or not. */
1564 rtx_insn *
1565 asan_emit_allocas_unpoison (rtx top, rtx bot, rtx_insn *before)
1567 if (before)
1568 push_to_sequence (before);
1569 else
1570 start_sequence ();
1571 rtx ret = init_one_libfunc ("__asan_allocas_unpoison");
1572 top = convert_memory_address (ptr_mode, top);
1573 bot = convert_memory_address (ptr_mode, bot);
1574 ret = emit_library_call_value (ret, NULL_RTX, LCT_NORMAL, ptr_mode,
1575 top, ptr_mode, bot, ptr_mode);
1577 do_pending_stack_adjust ();
1578 rtx_insn *insns = get_insns ();
1579 end_sequence ();
1580 return insns;
1583 /* Return true if DECL, a global var, might be overridden and needs
1584 therefore a local alias. */
1586 static bool
1587 asan_needs_local_alias (tree decl)
1589 return DECL_WEAK (decl) || !targetm.binds_local_p (decl);
1592 /* Return true if DECL, a global var, is an artificial ODR indicator symbol
1593 therefore doesn't need protection. */
1595 static bool
1596 is_odr_indicator (tree decl)
1598 return (DECL_ARTIFICIAL (decl)
1599 && lookup_attribute ("asan odr indicator", DECL_ATTRIBUTES (decl)));
1602 /* Return true if DECL is a VAR_DECL that should be protected
1603 by Address Sanitizer, by appending a red zone with protected
1604 shadow memory after it and aligning it to at least
1605 ASAN_RED_ZONE_SIZE bytes. */
1607 bool
1608 asan_protect_global (tree decl)
1610 if (!ASAN_GLOBALS)
1611 return false;
1613 rtx rtl, symbol;
1615 if (TREE_CODE (decl) == STRING_CST)
1617 /* Instrument all STRING_CSTs except those created
1618 by asan_pp_string here. */
1619 if (shadow_ptr_types[0] != NULL_TREE
1620 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
1621 && TREE_TYPE (TREE_TYPE (decl)) == TREE_TYPE (shadow_ptr_types[0]))
1622 return false;
1623 return true;
1625 if (!VAR_P (decl)
1626 /* TLS vars aren't statically protectable. */
1627 || DECL_THREAD_LOCAL_P (decl)
1628 /* Externs will be protected elsewhere. */
1629 || DECL_EXTERNAL (decl)
1630 || !DECL_RTL_SET_P (decl)
1631 /* Comdat vars pose an ABI problem, we can't know if
1632 the var that is selected by the linker will have
1633 padding or not. */
1634 || DECL_ONE_ONLY (decl)
1635 /* Similarly for common vars. People can use -fno-common.
1636 Note: Linux kernel is built with -fno-common, so we do instrument
1637 globals there even if it is C. */
1638 || (DECL_COMMON (decl) && TREE_PUBLIC (decl))
1639 /* Don't protect if using user section, often vars placed
1640 into user section from multiple TUs are then assumed
1641 to be an array of such vars, putting padding in there
1642 breaks this assumption. */
1643 || (DECL_SECTION_NAME (decl) != NULL
1644 && !symtab_node::get (decl)->implicit_section
1645 && !section_sanitized_p (DECL_SECTION_NAME (decl)))
1646 || DECL_SIZE (decl) == 0
1647 || ASAN_RED_ZONE_SIZE * BITS_PER_UNIT > MAX_OFILE_ALIGNMENT
1648 || !valid_constant_size_p (DECL_SIZE_UNIT (decl))
1649 || DECL_ALIGN_UNIT (decl) > 2 * ASAN_RED_ZONE_SIZE
1650 || TREE_TYPE (decl) == ubsan_get_source_location_type ()
1651 || is_odr_indicator (decl))
1652 return false;
1654 rtl = DECL_RTL (decl);
1655 if (!MEM_P (rtl) || GET_CODE (XEXP (rtl, 0)) != SYMBOL_REF)
1656 return false;
1657 symbol = XEXP (rtl, 0);
1659 if (CONSTANT_POOL_ADDRESS_P (symbol)
1660 || TREE_CONSTANT_POOL_ADDRESS_P (symbol))
1661 return false;
1663 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
1664 return false;
1666 if (!TARGET_SUPPORTS_ALIASES && asan_needs_local_alias (decl))
1667 return false;
1669 return true;
1672 /* Construct a function tree for __asan_report_{load,store}{1,2,4,8,16,_n}.
1673 IS_STORE is either 1 (for a store) or 0 (for a load). */
1675 static tree
1676 report_error_func (bool is_store, bool recover_p, HOST_WIDE_INT size_in_bytes,
1677 int *nargs)
1679 static enum built_in_function report[2][2][6]
1680 = { { { BUILT_IN_ASAN_REPORT_LOAD1, BUILT_IN_ASAN_REPORT_LOAD2,
1681 BUILT_IN_ASAN_REPORT_LOAD4, BUILT_IN_ASAN_REPORT_LOAD8,
1682 BUILT_IN_ASAN_REPORT_LOAD16, BUILT_IN_ASAN_REPORT_LOAD_N },
1683 { BUILT_IN_ASAN_REPORT_STORE1, BUILT_IN_ASAN_REPORT_STORE2,
1684 BUILT_IN_ASAN_REPORT_STORE4, BUILT_IN_ASAN_REPORT_STORE8,
1685 BUILT_IN_ASAN_REPORT_STORE16, BUILT_IN_ASAN_REPORT_STORE_N } },
1686 { { BUILT_IN_ASAN_REPORT_LOAD1_NOABORT,
1687 BUILT_IN_ASAN_REPORT_LOAD2_NOABORT,
1688 BUILT_IN_ASAN_REPORT_LOAD4_NOABORT,
1689 BUILT_IN_ASAN_REPORT_LOAD8_NOABORT,
1690 BUILT_IN_ASAN_REPORT_LOAD16_NOABORT,
1691 BUILT_IN_ASAN_REPORT_LOAD_N_NOABORT },
1692 { BUILT_IN_ASAN_REPORT_STORE1_NOABORT,
1693 BUILT_IN_ASAN_REPORT_STORE2_NOABORT,
1694 BUILT_IN_ASAN_REPORT_STORE4_NOABORT,
1695 BUILT_IN_ASAN_REPORT_STORE8_NOABORT,
1696 BUILT_IN_ASAN_REPORT_STORE16_NOABORT,
1697 BUILT_IN_ASAN_REPORT_STORE_N_NOABORT } } };
1698 if (size_in_bytes == -1)
1700 *nargs = 2;
1701 return builtin_decl_implicit (report[recover_p][is_store][5]);
1703 *nargs = 1;
1704 int size_log2 = exact_log2 (size_in_bytes);
1705 return builtin_decl_implicit (report[recover_p][is_store][size_log2]);
1708 /* Construct a function tree for __asan_{load,store}{1,2,4,8,16,_n}.
1709 IS_STORE is either 1 (for a store) or 0 (for a load). */
1711 static tree
1712 check_func (bool is_store, bool recover_p, HOST_WIDE_INT size_in_bytes,
1713 int *nargs)
1715 static enum built_in_function check[2][2][6]
1716 = { { { BUILT_IN_ASAN_LOAD1, BUILT_IN_ASAN_LOAD2,
1717 BUILT_IN_ASAN_LOAD4, BUILT_IN_ASAN_LOAD8,
1718 BUILT_IN_ASAN_LOAD16, BUILT_IN_ASAN_LOADN },
1719 { BUILT_IN_ASAN_STORE1, BUILT_IN_ASAN_STORE2,
1720 BUILT_IN_ASAN_STORE4, BUILT_IN_ASAN_STORE8,
1721 BUILT_IN_ASAN_STORE16, BUILT_IN_ASAN_STOREN } },
1722 { { BUILT_IN_ASAN_LOAD1_NOABORT,
1723 BUILT_IN_ASAN_LOAD2_NOABORT,
1724 BUILT_IN_ASAN_LOAD4_NOABORT,
1725 BUILT_IN_ASAN_LOAD8_NOABORT,
1726 BUILT_IN_ASAN_LOAD16_NOABORT,
1727 BUILT_IN_ASAN_LOADN_NOABORT },
1728 { BUILT_IN_ASAN_STORE1_NOABORT,
1729 BUILT_IN_ASAN_STORE2_NOABORT,
1730 BUILT_IN_ASAN_STORE4_NOABORT,
1731 BUILT_IN_ASAN_STORE8_NOABORT,
1732 BUILT_IN_ASAN_STORE16_NOABORT,
1733 BUILT_IN_ASAN_STOREN_NOABORT } } };
1734 if (size_in_bytes == -1)
1736 *nargs = 2;
1737 return builtin_decl_implicit (check[recover_p][is_store][5]);
1739 *nargs = 1;
1740 int size_log2 = exact_log2 (size_in_bytes);
1741 return builtin_decl_implicit (check[recover_p][is_store][size_log2]);
1744 /* Split the current basic block and create a condition statement
1745 insertion point right before or after the statement pointed to by
1746 ITER. Return an iterator to the point at which the caller might
1747 safely insert the condition statement.
1749 THEN_BLOCK must be set to the address of an uninitialized instance
1750 of basic_block. The function will then set *THEN_BLOCK to the
1751 'then block' of the condition statement to be inserted by the
1752 caller.
1754 If CREATE_THEN_FALLTHRU_EDGE is false, no edge will be created from
1755 *THEN_BLOCK to *FALLTHROUGH_BLOCK.
1757 Similarly, the function will set *FALLTRHOUGH_BLOCK to the 'else
1758 block' of the condition statement to be inserted by the caller.
1760 Note that *FALLTHROUGH_BLOCK is a new block that contains the
1761 statements starting from *ITER, and *THEN_BLOCK is a new empty
1762 block.
1764 *ITER is adjusted to point to always point to the first statement
1765 of the basic block * FALLTHROUGH_BLOCK. That statement is the
1766 same as what ITER was pointing to prior to calling this function,
1767 if BEFORE_P is true; otherwise, it is its following statement. */
1769 gimple_stmt_iterator
1770 create_cond_insert_point (gimple_stmt_iterator *iter,
1771 bool before_p,
1772 bool then_more_likely_p,
1773 bool create_then_fallthru_edge,
1774 basic_block *then_block,
1775 basic_block *fallthrough_block)
1777 gimple_stmt_iterator gsi = *iter;
1779 if (!gsi_end_p (gsi) && before_p)
1780 gsi_prev (&gsi);
1782 basic_block cur_bb = gsi_bb (*iter);
1784 edge e = split_block (cur_bb, gsi_stmt (gsi));
1786 /* Get a hold on the 'condition block', the 'then block' and the
1787 'else block'. */
1788 basic_block cond_bb = e->src;
1789 basic_block fallthru_bb = e->dest;
1790 basic_block then_bb = create_empty_bb (cond_bb);
1791 if (current_loops)
1793 add_bb_to_loop (then_bb, cond_bb->loop_father);
1794 loops_state_set (LOOPS_NEED_FIXUP);
1797 /* Set up the newly created 'then block'. */
1798 e = make_edge (cond_bb, then_bb, EDGE_TRUE_VALUE);
1799 profile_probability fallthrough_probability
1800 = then_more_likely_p
1801 ? profile_probability::very_unlikely ()
1802 : profile_probability::very_likely ();
1803 e->probability = fallthrough_probability.invert ();
1804 then_bb->count = e->count ();
1805 if (create_then_fallthru_edge)
1806 make_single_succ_edge (then_bb, fallthru_bb, EDGE_FALLTHRU);
1808 /* Set up the fallthrough basic block. */
1809 e = find_edge (cond_bb, fallthru_bb);
1810 e->flags = EDGE_FALSE_VALUE;
1811 e->probability = fallthrough_probability;
1813 /* Update dominance info for the newly created then_bb; note that
1814 fallthru_bb's dominance info has already been updated by
1815 split_bock. */
1816 if (dom_info_available_p (CDI_DOMINATORS))
1817 set_immediate_dominator (CDI_DOMINATORS, then_bb, cond_bb);
1819 *then_block = then_bb;
1820 *fallthrough_block = fallthru_bb;
1821 *iter = gsi_start_bb (fallthru_bb);
1823 return gsi_last_bb (cond_bb);
1826 /* Insert an if condition followed by a 'then block' right before the
1827 statement pointed to by ITER. The fallthrough block -- which is the
1828 else block of the condition as well as the destination of the
1829 outcoming edge of the 'then block' -- starts with the statement
1830 pointed to by ITER.
1832 COND is the condition of the if.
1834 If THEN_MORE_LIKELY_P is true, the probability of the edge to the
1835 'then block' is higher than the probability of the edge to the
1836 fallthrough block.
1838 Upon completion of the function, *THEN_BB is set to the newly
1839 inserted 'then block' and similarly, *FALLTHROUGH_BB is set to the
1840 fallthrough block.
1842 *ITER is adjusted to still point to the same statement it was
1843 pointing to initially. */
1845 static void
1846 insert_if_then_before_iter (gcond *cond,
1847 gimple_stmt_iterator *iter,
1848 bool then_more_likely_p,
1849 basic_block *then_bb,
1850 basic_block *fallthrough_bb)
1852 gimple_stmt_iterator cond_insert_point =
1853 create_cond_insert_point (iter,
1854 /*before_p=*/true,
1855 then_more_likely_p,
1856 /*create_then_fallthru_edge=*/true,
1857 then_bb,
1858 fallthrough_bb);
1859 gsi_insert_after (&cond_insert_point, cond, GSI_NEW_STMT);
1862 /* Build (base_addr >> ASAN_SHADOW_SHIFT) + asan_shadow_offset ().
1863 If RETURN_ADDRESS is set to true, return memory location instread
1864 of a value in the shadow memory. */
1866 static tree
1867 build_shadow_mem_access (gimple_stmt_iterator *gsi, location_t location,
1868 tree base_addr, tree shadow_ptr_type,
1869 bool return_address = false)
1871 tree t, uintptr_type = TREE_TYPE (base_addr);
1872 tree shadow_type = TREE_TYPE (shadow_ptr_type);
1873 gimple *g;
1875 t = build_int_cst (uintptr_type, ASAN_SHADOW_SHIFT);
1876 g = gimple_build_assign (make_ssa_name (uintptr_type), RSHIFT_EXPR,
1877 base_addr, t);
1878 gimple_set_location (g, location);
1879 gsi_insert_after (gsi, g, GSI_NEW_STMT);
1881 t = build_int_cst (uintptr_type, asan_shadow_offset ());
1882 g = gimple_build_assign (make_ssa_name (uintptr_type), PLUS_EXPR,
1883 gimple_assign_lhs (g), t);
1884 gimple_set_location (g, location);
1885 gsi_insert_after (gsi, g, GSI_NEW_STMT);
1887 g = gimple_build_assign (make_ssa_name (shadow_ptr_type), NOP_EXPR,
1888 gimple_assign_lhs (g));
1889 gimple_set_location (g, location);
1890 gsi_insert_after (gsi, g, GSI_NEW_STMT);
1892 if (!return_address)
1894 t = build2 (MEM_REF, shadow_type, gimple_assign_lhs (g),
1895 build_int_cst (shadow_ptr_type, 0));
1896 g = gimple_build_assign (make_ssa_name (shadow_type), MEM_REF, t);
1897 gimple_set_location (g, location);
1898 gsi_insert_after (gsi, g, GSI_NEW_STMT);
1901 return gimple_assign_lhs (g);
1904 /* BASE can already be an SSA_NAME; in that case, do not create a
1905 new SSA_NAME for it. */
1907 static tree
1908 maybe_create_ssa_name (location_t loc, tree base, gimple_stmt_iterator *iter,
1909 bool before_p)
1911 if (TREE_CODE (base) == SSA_NAME)
1912 return base;
1913 gimple *g = gimple_build_assign (make_ssa_name (TREE_TYPE (base)),
1914 TREE_CODE (base), base);
1915 gimple_set_location (g, loc);
1916 if (before_p)
1917 gsi_insert_before (iter, g, GSI_SAME_STMT);
1918 else
1919 gsi_insert_after (iter, g, GSI_NEW_STMT);
1920 return gimple_assign_lhs (g);
1923 /* LEN can already have necessary size and precision;
1924 in that case, do not create a new variable. */
1926 tree
1927 maybe_cast_to_ptrmode (location_t loc, tree len, gimple_stmt_iterator *iter,
1928 bool before_p)
1930 if (ptrofftype_p (len))
1931 return len;
1932 gimple *g = gimple_build_assign (make_ssa_name (pointer_sized_int_node),
1933 NOP_EXPR, len);
1934 gimple_set_location (g, loc);
1935 if (before_p)
1936 gsi_insert_before (iter, g, GSI_SAME_STMT);
1937 else
1938 gsi_insert_after (iter, g, GSI_NEW_STMT);
1939 return gimple_assign_lhs (g);
1942 /* Instrument the memory access instruction BASE. Insert new
1943 statements before or after ITER.
1945 Note that the memory access represented by BASE can be either an
1946 SSA_NAME, or a non-SSA expression. LOCATION is the source code
1947 location. IS_STORE is TRUE for a store, FALSE for a load.
1948 BEFORE_P is TRUE for inserting the instrumentation code before
1949 ITER, FALSE for inserting it after ITER. IS_SCALAR_ACCESS is TRUE
1950 for a scalar memory access and FALSE for memory region access.
1951 NON_ZERO_P is TRUE if memory region is guaranteed to have non-zero
1952 length. ALIGN tells alignment of accessed memory object.
1954 START_INSTRUMENTED and END_INSTRUMENTED are TRUE if start/end of
1955 memory region have already been instrumented.
1957 If BEFORE_P is TRUE, *ITER is arranged to still point to the
1958 statement it was pointing to prior to calling this function,
1959 otherwise, it points to the statement logically following it. */
1961 static void
1962 build_check_stmt (location_t loc, tree base, tree len,
1963 HOST_WIDE_INT size_in_bytes, gimple_stmt_iterator *iter,
1964 bool is_non_zero_len, bool before_p, bool is_store,
1965 bool is_scalar_access, unsigned int align = 0)
1967 gimple_stmt_iterator gsi = *iter;
1968 gimple *g;
1970 gcc_assert (!(size_in_bytes > 0 && !is_non_zero_len));
1972 gsi = *iter;
1974 base = unshare_expr (base);
1975 base = maybe_create_ssa_name (loc, base, &gsi, before_p);
1977 if (len)
1979 len = unshare_expr (len);
1980 len = maybe_cast_to_ptrmode (loc, len, iter, before_p);
1982 else
1984 gcc_assert (size_in_bytes != -1);
1985 len = build_int_cst (pointer_sized_int_node, size_in_bytes);
1988 if (size_in_bytes > 1)
1990 if ((size_in_bytes & (size_in_bytes - 1)) != 0
1991 || size_in_bytes > 16)
1992 is_scalar_access = false;
1993 else if (align && align < size_in_bytes * BITS_PER_UNIT)
1995 /* On non-strict alignment targets, if
1996 16-byte access is just 8-byte aligned,
1997 this will result in misaligned shadow
1998 memory 2 byte load, but otherwise can
1999 be handled using one read. */
2000 if (size_in_bytes != 16
2001 || STRICT_ALIGNMENT
2002 || align < 8 * BITS_PER_UNIT)
2003 is_scalar_access = false;
2007 HOST_WIDE_INT flags = 0;
2008 if (is_store)
2009 flags |= ASAN_CHECK_STORE;
2010 if (is_non_zero_len)
2011 flags |= ASAN_CHECK_NON_ZERO_LEN;
2012 if (is_scalar_access)
2013 flags |= ASAN_CHECK_SCALAR_ACCESS;
2015 g = gimple_build_call_internal (IFN_ASAN_CHECK, 4,
2016 build_int_cst (integer_type_node, flags),
2017 base, len,
2018 build_int_cst (integer_type_node,
2019 align / BITS_PER_UNIT));
2020 gimple_set_location (g, loc);
2021 if (before_p)
2022 gsi_insert_before (&gsi, g, GSI_SAME_STMT);
2023 else
2025 gsi_insert_after (&gsi, g, GSI_NEW_STMT);
2026 gsi_next (&gsi);
2027 *iter = gsi;
2031 /* If T represents a memory access, add instrumentation code before ITER.
2032 LOCATION is source code location.
2033 IS_STORE is either TRUE (for a store) or FALSE (for a load). */
2035 static void
2036 instrument_derefs (gimple_stmt_iterator *iter, tree t,
2037 location_t location, bool is_store)
2039 if (is_store && !ASAN_INSTRUMENT_WRITES)
2040 return;
2041 if (!is_store && !ASAN_INSTRUMENT_READS)
2042 return;
2044 tree type, base;
2045 HOST_WIDE_INT size_in_bytes;
2046 if (location == UNKNOWN_LOCATION)
2047 location = EXPR_LOCATION (t);
2049 type = TREE_TYPE (t);
2050 switch (TREE_CODE (t))
2052 case ARRAY_REF:
2053 case COMPONENT_REF:
2054 case INDIRECT_REF:
2055 case MEM_REF:
2056 case VAR_DECL:
2057 case BIT_FIELD_REF:
2058 break;
2059 /* FALLTHRU */
2060 default:
2061 return;
2064 size_in_bytes = int_size_in_bytes (type);
2065 if (size_in_bytes <= 0)
2066 return;
2068 HOST_WIDE_INT bitsize, bitpos;
2069 tree offset;
2070 machine_mode mode;
2071 int unsignedp, reversep, volatilep = 0;
2072 tree inner = get_inner_reference (t, &bitsize, &bitpos, &offset, &mode,
2073 &unsignedp, &reversep, &volatilep);
2075 if (TREE_CODE (t) == COMPONENT_REF
2076 && DECL_BIT_FIELD_REPRESENTATIVE (TREE_OPERAND (t, 1)) != NULL_TREE)
2078 tree repr = DECL_BIT_FIELD_REPRESENTATIVE (TREE_OPERAND (t, 1));
2079 instrument_derefs (iter, build3 (COMPONENT_REF, TREE_TYPE (repr),
2080 TREE_OPERAND (t, 0), repr,
2081 TREE_OPERAND (t, 2)),
2082 location, is_store);
2083 return;
2086 if (bitpos % BITS_PER_UNIT
2087 || bitsize != size_in_bytes * BITS_PER_UNIT)
2088 return;
2090 if (VAR_P (inner) && DECL_HARD_REGISTER (inner))
2091 return;
2093 if (VAR_P (inner)
2094 && offset == NULL_TREE
2095 && bitpos >= 0
2096 && DECL_SIZE (inner)
2097 && tree_fits_shwi_p (DECL_SIZE (inner))
2098 && bitpos + bitsize <= tree_to_shwi (DECL_SIZE (inner)))
2100 if (DECL_THREAD_LOCAL_P (inner))
2101 return;
2102 if (!ASAN_GLOBALS && is_global_var (inner))
2103 return;
2104 if (!TREE_STATIC (inner))
2106 /* Automatic vars in the current function will be always
2107 accessible. */
2108 if (decl_function_context (inner) == current_function_decl
2109 && (!asan_sanitize_use_after_scope ()
2110 || !TREE_ADDRESSABLE (inner)))
2111 return;
2113 /* Always instrument external vars, they might be dynamically
2114 initialized. */
2115 else if (!DECL_EXTERNAL (inner))
2117 /* For static vars if they are known not to be dynamically
2118 initialized, they will be always accessible. */
2119 varpool_node *vnode = varpool_node::get (inner);
2120 if (vnode && !vnode->dynamically_initialized)
2121 return;
2125 base = build_fold_addr_expr (t);
2126 if (!has_mem_ref_been_instrumented (base, size_in_bytes))
2128 unsigned int align = get_object_alignment (t);
2129 build_check_stmt (location, base, NULL_TREE, size_in_bytes, iter,
2130 /*is_non_zero_len*/size_in_bytes > 0, /*before_p=*/true,
2131 is_store, /*is_scalar_access*/true, align);
2132 update_mem_ref_hash_table (base, size_in_bytes);
2133 update_mem_ref_hash_table (t, size_in_bytes);
2138 /* Insert a memory reference into the hash table if access length
2139 can be determined in compile time. */
2141 static void
2142 maybe_update_mem_ref_hash_table (tree base, tree len)
2144 if (!POINTER_TYPE_P (TREE_TYPE (base))
2145 || !INTEGRAL_TYPE_P (TREE_TYPE (len)))
2146 return;
2148 HOST_WIDE_INT size_in_bytes = tree_fits_shwi_p (len) ? tree_to_shwi (len) : -1;
2150 if (size_in_bytes != -1)
2151 update_mem_ref_hash_table (base, size_in_bytes);
2154 /* Instrument an access to a contiguous memory region that starts at
2155 the address pointed to by BASE, over a length of LEN (expressed in
2156 the sizeof (*BASE) bytes). ITER points to the instruction before
2157 which the instrumentation instructions must be inserted. LOCATION
2158 is the source location that the instrumentation instructions must
2159 have. If IS_STORE is true, then the memory access is a store;
2160 otherwise, it's a load. */
2162 static void
2163 instrument_mem_region_access (tree base, tree len,
2164 gimple_stmt_iterator *iter,
2165 location_t location, bool is_store)
2167 if (!POINTER_TYPE_P (TREE_TYPE (base))
2168 || !INTEGRAL_TYPE_P (TREE_TYPE (len))
2169 || integer_zerop (len))
2170 return;
2172 HOST_WIDE_INT size_in_bytes = tree_fits_shwi_p (len) ? tree_to_shwi (len) : -1;
2174 if ((size_in_bytes == -1)
2175 || !has_mem_ref_been_instrumented (base, size_in_bytes))
2177 build_check_stmt (location, base, len, size_in_bytes, iter,
2178 /*is_non_zero_len*/size_in_bytes > 0, /*before_p*/true,
2179 is_store, /*is_scalar_access*/false, /*align*/0);
2182 maybe_update_mem_ref_hash_table (base, len);
2183 *iter = gsi_for_stmt (gsi_stmt (*iter));
2186 /* Instrument the call to a built-in memory access function that is
2187 pointed to by the iterator ITER.
2189 Upon completion, return TRUE iff *ITER has been advanced to the
2190 statement following the one it was originally pointing to. */
2192 static bool
2193 instrument_builtin_call (gimple_stmt_iterator *iter)
2195 if (!ASAN_MEMINTRIN)
2196 return false;
2198 bool iter_advanced_p = false;
2199 gcall *call = as_a <gcall *> (gsi_stmt (*iter));
2201 gcc_checking_assert (gimple_call_builtin_p (call, BUILT_IN_NORMAL));
2203 location_t loc = gimple_location (call);
2205 asan_mem_ref src0, src1, dest;
2206 asan_mem_ref_init (&src0, NULL, 1);
2207 asan_mem_ref_init (&src1, NULL, 1);
2208 asan_mem_ref_init (&dest, NULL, 1);
2210 tree src0_len = NULL_TREE, src1_len = NULL_TREE, dest_len = NULL_TREE;
2211 bool src0_is_store = false, src1_is_store = false, dest_is_store = false,
2212 dest_is_deref = false, intercepted_p = true;
2214 if (get_mem_refs_of_builtin_call (call,
2215 &src0, &src0_len, &src0_is_store,
2216 &src1, &src1_len, &src1_is_store,
2217 &dest, &dest_len, &dest_is_store,
2218 &dest_is_deref, &intercepted_p, iter))
2220 if (dest_is_deref)
2222 instrument_derefs (iter, dest.start, loc, dest_is_store);
2223 gsi_next (iter);
2224 iter_advanced_p = true;
2226 else if (!intercepted_p
2227 && (src0_len || src1_len || dest_len))
2229 if (src0.start != NULL_TREE)
2230 instrument_mem_region_access (src0.start, src0_len,
2231 iter, loc, /*is_store=*/false);
2232 if (src1.start != NULL_TREE)
2233 instrument_mem_region_access (src1.start, src1_len,
2234 iter, loc, /*is_store=*/false);
2235 if (dest.start != NULL_TREE)
2236 instrument_mem_region_access (dest.start, dest_len,
2237 iter, loc, /*is_store=*/true);
2239 *iter = gsi_for_stmt (call);
2240 gsi_next (iter);
2241 iter_advanced_p = true;
2243 else
2245 if (src0.start != NULL_TREE)
2246 maybe_update_mem_ref_hash_table (src0.start, src0_len);
2247 if (src1.start != NULL_TREE)
2248 maybe_update_mem_ref_hash_table (src1.start, src1_len);
2249 if (dest.start != NULL_TREE)
2250 maybe_update_mem_ref_hash_table (dest.start, dest_len);
2253 return iter_advanced_p;
2256 /* Instrument the assignment statement ITER if it is subject to
2257 instrumentation. Return TRUE iff instrumentation actually
2258 happened. In that case, the iterator ITER is advanced to the next
2259 logical expression following the one initially pointed to by ITER,
2260 and the relevant memory reference that which access has been
2261 instrumented is added to the memory references hash table. */
2263 static bool
2264 maybe_instrument_assignment (gimple_stmt_iterator *iter)
2266 gimple *s = gsi_stmt (*iter);
2268 gcc_assert (gimple_assign_single_p (s));
2270 tree ref_expr = NULL_TREE;
2271 bool is_store, is_instrumented = false;
2273 if (gimple_store_p (s))
2275 ref_expr = gimple_assign_lhs (s);
2276 is_store = true;
2277 instrument_derefs (iter, ref_expr,
2278 gimple_location (s),
2279 is_store);
2280 is_instrumented = true;
2283 if (gimple_assign_load_p (s))
2285 ref_expr = gimple_assign_rhs1 (s);
2286 is_store = false;
2287 instrument_derefs (iter, ref_expr,
2288 gimple_location (s),
2289 is_store);
2290 is_instrumented = true;
2293 if (is_instrumented)
2294 gsi_next (iter);
2296 return is_instrumented;
2299 /* Instrument the function call pointed to by the iterator ITER, if it
2300 is subject to instrumentation. At the moment, the only function
2301 calls that are instrumented are some built-in functions that access
2302 memory. Look at instrument_builtin_call to learn more.
2304 Upon completion return TRUE iff *ITER was advanced to the statement
2305 following the one it was originally pointing to. */
2307 static bool
2308 maybe_instrument_call (gimple_stmt_iterator *iter)
2310 gimple *stmt = gsi_stmt (*iter);
2311 bool is_builtin = gimple_call_builtin_p (stmt, BUILT_IN_NORMAL);
2313 if (is_builtin && instrument_builtin_call (iter))
2314 return true;
2316 if (gimple_call_noreturn_p (stmt))
2318 if (is_builtin)
2320 tree callee = gimple_call_fndecl (stmt);
2321 switch (DECL_FUNCTION_CODE (callee))
2323 case BUILT_IN_UNREACHABLE:
2324 case BUILT_IN_TRAP:
2325 /* Don't instrument these. */
2326 return false;
2327 default:
2328 break;
2331 tree decl = builtin_decl_implicit (BUILT_IN_ASAN_HANDLE_NO_RETURN);
2332 gimple *g = gimple_build_call (decl, 0);
2333 gimple_set_location (g, gimple_location (stmt));
2334 gsi_insert_before (iter, g, GSI_SAME_STMT);
2337 bool instrumented = false;
2338 if (gimple_store_p (stmt))
2340 tree ref_expr = gimple_call_lhs (stmt);
2341 instrument_derefs (iter, ref_expr,
2342 gimple_location (stmt),
2343 /*is_store=*/true);
2345 instrumented = true;
2348 /* Walk through gimple_call arguments and check them id needed. */
2349 unsigned args_num = gimple_call_num_args (stmt);
2350 for (unsigned i = 0; i < args_num; ++i)
2352 tree arg = gimple_call_arg (stmt, i);
2353 /* If ARG is not a non-aggregate register variable, compiler in general
2354 creates temporary for it and pass it as argument to gimple call.
2355 But in some cases, e.g. when we pass by value a small structure that
2356 fits to register, compiler can avoid extra overhead by pulling out
2357 these temporaries. In this case, we should check the argument. */
2358 if (!is_gimple_reg (arg) && !is_gimple_min_invariant (arg))
2360 instrument_derefs (iter, arg,
2361 gimple_location (stmt),
2362 /*is_store=*/false);
2363 instrumented = true;
2366 if (instrumented)
2367 gsi_next (iter);
2368 return instrumented;
2371 /* Walk each instruction of all basic block and instrument those that
2372 represent memory references: loads, stores, or function calls.
2373 In a given basic block, this function avoids instrumenting memory
2374 references that have already been instrumented. */
2376 static void
2377 transform_statements (void)
2379 basic_block bb, last_bb = NULL;
2380 gimple_stmt_iterator i;
2381 int saved_last_basic_block = last_basic_block_for_fn (cfun);
2383 FOR_EACH_BB_FN (bb, cfun)
2385 basic_block prev_bb = bb;
2387 if (bb->index >= saved_last_basic_block) continue;
2389 /* Flush the mem ref hash table, if current bb doesn't have
2390 exactly one predecessor, or if that predecessor (skipping
2391 over asan created basic blocks) isn't the last processed
2392 basic block. Thus we effectively flush on extended basic
2393 block boundaries. */
2394 while (single_pred_p (prev_bb))
2396 prev_bb = single_pred (prev_bb);
2397 if (prev_bb->index < saved_last_basic_block)
2398 break;
2400 if (prev_bb != last_bb)
2401 empty_mem_ref_hash_table ();
2402 last_bb = bb;
2404 for (i = gsi_start_bb (bb); !gsi_end_p (i);)
2406 gimple *s = gsi_stmt (i);
2408 if (has_stmt_been_instrumented_p (s))
2409 gsi_next (&i);
2410 else if (gimple_assign_single_p (s)
2411 && !gimple_clobber_p (s)
2412 && maybe_instrument_assignment (&i))
2413 /* Nothing to do as maybe_instrument_assignment advanced
2414 the iterator I. */;
2415 else if (is_gimple_call (s) && maybe_instrument_call (&i))
2416 /* Nothing to do as maybe_instrument_call
2417 advanced the iterator I. */;
2418 else
2420 /* No instrumentation happened.
2422 If the current instruction is a function call that
2423 might free something, let's forget about the memory
2424 references that got instrumented. Otherwise we might
2425 miss some instrumentation opportunities. Do the same
2426 for a ASAN_MARK poisoning internal function. */
2427 if (is_gimple_call (s)
2428 && (!nonfreeing_call_p (s)
2429 || asan_mark_p (s, ASAN_MARK_POISON)))
2430 empty_mem_ref_hash_table ();
2432 gsi_next (&i);
2436 free_mem_ref_resources ();
2439 /* Build
2440 __asan_before_dynamic_init (module_name)
2442 __asan_after_dynamic_init ()
2443 call. */
2445 tree
2446 asan_dynamic_init_call (bool after_p)
2448 if (shadow_ptr_types[0] == NULL_TREE)
2449 asan_init_shadow_ptr_types ();
2451 tree fn = builtin_decl_implicit (after_p
2452 ? BUILT_IN_ASAN_AFTER_DYNAMIC_INIT
2453 : BUILT_IN_ASAN_BEFORE_DYNAMIC_INIT);
2454 tree module_name_cst = NULL_TREE;
2455 if (!after_p)
2457 pretty_printer module_name_pp;
2458 pp_string (&module_name_pp, main_input_filename);
2460 module_name_cst = asan_pp_string (&module_name_pp);
2461 module_name_cst = fold_convert (const_ptr_type_node,
2462 module_name_cst);
2465 return build_call_expr (fn, after_p ? 0 : 1, module_name_cst);
2468 /* Build
2469 struct __asan_global
2471 const void *__beg;
2472 uptr __size;
2473 uptr __size_with_redzone;
2474 const void *__name;
2475 const void *__module_name;
2476 uptr __has_dynamic_init;
2477 __asan_global_source_location *__location;
2478 char *__odr_indicator;
2479 } type. */
2481 static tree
2482 asan_global_struct (void)
2484 static const char *field_names[]
2485 = { "__beg", "__size", "__size_with_redzone",
2486 "__name", "__module_name", "__has_dynamic_init", "__location",
2487 "__odr_indicator" };
2488 tree fields[ARRAY_SIZE (field_names)], ret;
2489 unsigned i;
2491 ret = make_node (RECORD_TYPE);
2492 for (i = 0; i < ARRAY_SIZE (field_names); i++)
2494 fields[i]
2495 = build_decl (UNKNOWN_LOCATION, FIELD_DECL,
2496 get_identifier (field_names[i]),
2497 (i == 0 || i == 3) ? const_ptr_type_node
2498 : pointer_sized_int_node);
2499 DECL_CONTEXT (fields[i]) = ret;
2500 if (i)
2501 DECL_CHAIN (fields[i - 1]) = fields[i];
2503 tree type_decl = build_decl (input_location, TYPE_DECL,
2504 get_identifier ("__asan_global"), ret);
2505 DECL_IGNORED_P (type_decl) = 1;
2506 DECL_ARTIFICIAL (type_decl) = 1;
2507 TYPE_FIELDS (ret) = fields[0];
2508 TYPE_NAME (ret) = type_decl;
2509 TYPE_STUB_DECL (ret) = type_decl;
2510 layout_type (ret);
2511 return ret;
2514 /* Create and return odr indicator symbol for DECL.
2515 TYPE is __asan_global struct type as returned by asan_global_struct. */
2517 static tree
2518 create_odr_indicator (tree decl, tree type)
2520 char *name;
2521 tree uptr = TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (type)));
2522 tree decl_name
2523 = (HAS_DECL_ASSEMBLER_NAME_P (decl) ? DECL_ASSEMBLER_NAME (decl)
2524 : DECL_NAME (decl));
2525 /* DECL_NAME theoretically might be NULL. Bail out with 0 in this case. */
2526 if (decl_name == NULL_TREE)
2527 return build_int_cst (uptr, 0);
2528 const char *dname = IDENTIFIER_POINTER (decl_name);
2529 if (HAS_DECL_ASSEMBLER_NAME_P (decl))
2530 dname = targetm.strip_name_encoding (dname);
2531 size_t len = strlen (dname) + sizeof ("__odr_asan_");
2532 name = XALLOCAVEC (char, len);
2533 snprintf (name, len, "__odr_asan_%s", dname);
2534 #ifndef NO_DOT_IN_LABEL
2535 name[sizeof ("__odr_asan") - 1] = '.';
2536 #elif !defined(NO_DOLLAR_IN_LABEL)
2537 name[sizeof ("__odr_asan") - 1] = '$';
2538 #endif
2539 tree var = build_decl (UNKNOWN_LOCATION, VAR_DECL, get_identifier (name),
2540 char_type_node);
2541 TREE_ADDRESSABLE (var) = 1;
2542 TREE_READONLY (var) = 0;
2543 TREE_THIS_VOLATILE (var) = 1;
2544 DECL_GIMPLE_REG_P (var) = 0;
2545 DECL_ARTIFICIAL (var) = 1;
2546 DECL_IGNORED_P (var) = 1;
2547 TREE_STATIC (var) = 1;
2548 TREE_PUBLIC (var) = 1;
2549 DECL_VISIBILITY (var) = DECL_VISIBILITY (decl);
2550 DECL_VISIBILITY_SPECIFIED (var) = DECL_VISIBILITY_SPECIFIED (decl);
2552 TREE_USED (var) = 1;
2553 tree ctor = build_constructor_va (TREE_TYPE (var), 1, NULL_TREE,
2554 build_int_cst (unsigned_type_node, 0));
2555 TREE_CONSTANT (ctor) = 1;
2556 TREE_STATIC (ctor) = 1;
2557 DECL_INITIAL (var) = ctor;
2558 DECL_ATTRIBUTES (var) = tree_cons (get_identifier ("asan odr indicator"),
2559 NULL, DECL_ATTRIBUTES (var));
2560 make_decl_rtl (var);
2561 varpool_node::finalize_decl (var);
2562 return fold_convert (uptr, build_fold_addr_expr (var));
2565 /* Return true if DECL, a global var, might be overridden and needs
2566 an additional odr indicator symbol. */
2568 static bool
2569 asan_needs_odr_indicator_p (tree decl)
2571 /* Don't emit ODR indicators for kernel because:
2572 a) Kernel is written in C thus doesn't need ODR indicators.
2573 b) Some kernel code may have assumptions about symbols containing specific
2574 patterns in their names. Since ODR indicators contain original names
2575 of symbols they are emitted for, these assumptions would be broken for
2576 ODR indicator symbols. */
2577 return (!(flag_sanitize & SANITIZE_KERNEL_ADDRESS)
2578 && !DECL_ARTIFICIAL (decl)
2579 && !DECL_WEAK (decl)
2580 && TREE_PUBLIC (decl));
2583 /* Append description of a single global DECL into vector V.
2584 TYPE is __asan_global struct type as returned by asan_global_struct. */
2586 static void
2587 asan_add_global (tree decl, tree type, vec<constructor_elt, va_gc> *v)
2589 tree init, uptr = TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (type)));
2590 unsigned HOST_WIDE_INT size;
2591 tree str_cst, module_name_cst, refdecl = decl;
2592 vec<constructor_elt, va_gc> *vinner = NULL;
2594 pretty_printer asan_pp, module_name_pp;
2596 if (DECL_NAME (decl))
2597 pp_tree_identifier (&asan_pp, DECL_NAME (decl));
2598 else
2599 pp_string (&asan_pp, "<unknown>");
2600 str_cst = asan_pp_string (&asan_pp);
2602 pp_string (&module_name_pp, main_input_filename);
2603 module_name_cst = asan_pp_string (&module_name_pp);
2605 if (asan_needs_local_alias (decl))
2607 char buf[20];
2608 ASM_GENERATE_INTERNAL_LABEL (buf, "LASAN", vec_safe_length (v) + 1);
2609 refdecl = build_decl (DECL_SOURCE_LOCATION (decl),
2610 VAR_DECL, get_identifier (buf), TREE_TYPE (decl));
2611 TREE_ADDRESSABLE (refdecl) = TREE_ADDRESSABLE (decl);
2612 TREE_READONLY (refdecl) = TREE_READONLY (decl);
2613 TREE_THIS_VOLATILE (refdecl) = TREE_THIS_VOLATILE (decl);
2614 DECL_GIMPLE_REG_P (refdecl) = DECL_GIMPLE_REG_P (decl);
2615 DECL_ARTIFICIAL (refdecl) = DECL_ARTIFICIAL (decl);
2616 DECL_IGNORED_P (refdecl) = DECL_IGNORED_P (decl);
2617 TREE_STATIC (refdecl) = 1;
2618 TREE_PUBLIC (refdecl) = 0;
2619 TREE_USED (refdecl) = 1;
2620 assemble_alias (refdecl, DECL_ASSEMBLER_NAME (decl));
2623 tree odr_indicator_ptr
2624 = (asan_needs_odr_indicator_p (decl) ? create_odr_indicator (decl, type)
2625 : build_int_cst (uptr, 0));
2626 CONSTRUCTOR_APPEND_ELT (vinner, NULL_TREE,
2627 fold_convert (const_ptr_type_node,
2628 build_fold_addr_expr (refdecl)));
2629 size = tree_to_uhwi (DECL_SIZE_UNIT (decl));
2630 CONSTRUCTOR_APPEND_ELT (vinner, NULL_TREE, build_int_cst (uptr, size));
2631 size += asan_red_zone_size (size);
2632 CONSTRUCTOR_APPEND_ELT (vinner, NULL_TREE, build_int_cst (uptr, size));
2633 CONSTRUCTOR_APPEND_ELT (vinner, NULL_TREE,
2634 fold_convert (const_ptr_type_node, str_cst));
2635 CONSTRUCTOR_APPEND_ELT (vinner, NULL_TREE,
2636 fold_convert (const_ptr_type_node, module_name_cst));
2637 varpool_node *vnode = varpool_node::get (decl);
2638 int has_dynamic_init = 0;
2639 /* FIXME: Enable initialization order fiasco detection in LTO mode once
2640 proper fix for PR 79061 will be applied. */
2641 if (!in_lto_p)
2642 has_dynamic_init = vnode ? vnode->dynamically_initialized : 0;
2643 CONSTRUCTOR_APPEND_ELT (vinner, NULL_TREE,
2644 build_int_cst (uptr, has_dynamic_init));
2645 tree locptr = NULL_TREE;
2646 location_t loc = DECL_SOURCE_LOCATION (decl);
2647 expanded_location xloc = expand_location (loc);
2648 if (xloc.file != NULL)
2650 static int lasanloccnt = 0;
2651 char buf[25];
2652 ASM_GENERATE_INTERNAL_LABEL (buf, "LASANLOC", ++lasanloccnt);
2653 tree var = build_decl (UNKNOWN_LOCATION, VAR_DECL, get_identifier (buf),
2654 ubsan_get_source_location_type ());
2655 TREE_STATIC (var) = 1;
2656 TREE_PUBLIC (var) = 0;
2657 DECL_ARTIFICIAL (var) = 1;
2658 DECL_IGNORED_P (var) = 1;
2659 pretty_printer filename_pp;
2660 pp_string (&filename_pp, xloc.file);
2661 tree str = asan_pp_string (&filename_pp);
2662 tree ctor = build_constructor_va (TREE_TYPE (var), 3,
2663 NULL_TREE, str, NULL_TREE,
2664 build_int_cst (unsigned_type_node,
2665 xloc.line), NULL_TREE,
2666 build_int_cst (unsigned_type_node,
2667 xloc.column));
2668 TREE_CONSTANT (ctor) = 1;
2669 TREE_STATIC (ctor) = 1;
2670 DECL_INITIAL (var) = ctor;
2671 varpool_node::finalize_decl (var);
2672 locptr = fold_convert (uptr, build_fold_addr_expr (var));
2674 else
2675 locptr = build_int_cst (uptr, 0);
2676 CONSTRUCTOR_APPEND_ELT (vinner, NULL_TREE, locptr);
2677 CONSTRUCTOR_APPEND_ELT (vinner, NULL_TREE, odr_indicator_ptr);
2678 init = build_constructor (type, vinner);
2679 CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, init);
2682 /* Initialize sanitizer.def builtins if the FE hasn't initialized them. */
2683 void
2684 initialize_sanitizer_builtins (void)
2686 tree decl;
2688 if (builtin_decl_implicit_p (BUILT_IN_ASAN_INIT))
2689 return;
2691 tree BT_FN_VOID = build_function_type_list (void_type_node, NULL_TREE);
2692 tree BT_FN_VOID_PTR
2693 = build_function_type_list (void_type_node, ptr_type_node, NULL_TREE);
2694 tree BT_FN_VOID_CONST_PTR
2695 = build_function_type_list (void_type_node, const_ptr_type_node, NULL_TREE);
2696 tree BT_FN_VOID_PTR_PTR
2697 = build_function_type_list (void_type_node, ptr_type_node,
2698 ptr_type_node, NULL_TREE);
2699 tree BT_FN_VOID_PTR_PTR_PTR
2700 = build_function_type_list (void_type_node, ptr_type_node,
2701 ptr_type_node, ptr_type_node, NULL_TREE);
2702 tree BT_FN_VOID_PTR_PTRMODE
2703 = build_function_type_list (void_type_node, ptr_type_node,
2704 pointer_sized_int_node, NULL_TREE);
2705 tree BT_FN_VOID_INT
2706 = build_function_type_list (void_type_node, integer_type_node, NULL_TREE);
2707 tree BT_FN_SIZE_CONST_PTR_INT
2708 = build_function_type_list (size_type_node, const_ptr_type_node,
2709 integer_type_node, NULL_TREE);
2711 tree BT_FN_VOID_UINT8_UINT8
2712 = build_function_type_list (void_type_node, unsigned_char_type_node,
2713 unsigned_char_type_node, NULL_TREE);
2714 tree BT_FN_VOID_UINT16_UINT16
2715 = build_function_type_list (void_type_node, uint16_type_node,
2716 uint16_type_node, NULL_TREE);
2717 tree BT_FN_VOID_UINT32_UINT32
2718 = build_function_type_list (void_type_node, uint32_type_node,
2719 uint32_type_node, NULL_TREE);
2720 tree BT_FN_VOID_UINT64_UINT64
2721 = build_function_type_list (void_type_node, uint64_type_node,
2722 uint64_type_node, NULL_TREE);
2723 tree BT_FN_VOID_FLOAT_FLOAT
2724 = build_function_type_list (void_type_node, float_type_node,
2725 float_type_node, NULL_TREE);
2726 tree BT_FN_VOID_DOUBLE_DOUBLE
2727 = build_function_type_list (void_type_node, double_type_node,
2728 double_type_node, NULL_TREE);
2729 tree BT_FN_VOID_UINT64_PTR
2730 = build_function_type_list (void_type_node, uint64_type_node,
2731 ptr_type_node, NULL_TREE);
2733 tree BT_FN_BOOL_VPTR_PTR_IX_INT_INT[5];
2734 tree BT_FN_IX_CONST_VPTR_INT[5];
2735 tree BT_FN_IX_VPTR_IX_INT[5];
2736 tree BT_FN_VOID_VPTR_IX_INT[5];
2737 tree vptr
2738 = build_pointer_type (build_qualified_type (void_type_node,
2739 TYPE_QUAL_VOLATILE));
2740 tree cvptr
2741 = build_pointer_type (build_qualified_type (void_type_node,
2742 TYPE_QUAL_VOLATILE
2743 |TYPE_QUAL_CONST));
2744 tree boolt
2745 = lang_hooks.types.type_for_size (BOOL_TYPE_SIZE, 1);
2746 int i;
2747 for (i = 0; i < 5; i++)
2749 tree ix = build_nonstandard_integer_type (BITS_PER_UNIT * (1 << i), 1);
2750 BT_FN_BOOL_VPTR_PTR_IX_INT_INT[i]
2751 = build_function_type_list (boolt, vptr, ptr_type_node, ix,
2752 integer_type_node, integer_type_node,
2753 NULL_TREE);
2754 BT_FN_IX_CONST_VPTR_INT[i]
2755 = build_function_type_list (ix, cvptr, integer_type_node, NULL_TREE);
2756 BT_FN_IX_VPTR_IX_INT[i]
2757 = build_function_type_list (ix, vptr, ix, integer_type_node,
2758 NULL_TREE);
2759 BT_FN_VOID_VPTR_IX_INT[i]
2760 = build_function_type_list (void_type_node, vptr, ix,
2761 integer_type_node, NULL_TREE);
2763 #define BT_FN_BOOL_VPTR_PTR_I1_INT_INT BT_FN_BOOL_VPTR_PTR_IX_INT_INT[0]
2764 #define BT_FN_I1_CONST_VPTR_INT BT_FN_IX_CONST_VPTR_INT[0]
2765 #define BT_FN_I1_VPTR_I1_INT BT_FN_IX_VPTR_IX_INT[0]
2766 #define BT_FN_VOID_VPTR_I1_INT BT_FN_VOID_VPTR_IX_INT[0]
2767 #define BT_FN_BOOL_VPTR_PTR_I2_INT_INT BT_FN_BOOL_VPTR_PTR_IX_INT_INT[1]
2768 #define BT_FN_I2_CONST_VPTR_INT BT_FN_IX_CONST_VPTR_INT[1]
2769 #define BT_FN_I2_VPTR_I2_INT BT_FN_IX_VPTR_IX_INT[1]
2770 #define BT_FN_VOID_VPTR_I2_INT BT_FN_VOID_VPTR_IX_INT[1]
2771 #define BT_FN_BOOL_VPTR_PTR_I4_INT_INT BT_FN_BOOL_VPTR_PTR_IX_INT_INT[2]
2772 #define BT_FN_I4_CONST_VPTR_INT BT_FN_IX_CONST_VPTR_INT[2]
2773 #define BT_FN_I4_VPTR_I4_INT BT_FN_IX_VPTR_IX_INT[2]
2774 #define BT_FN_VOID_VPTR_I4_INT BT_FN_VOID_VPTR_IX_INT[2]
2775 #define BT_FN_BOOL_VPTR_PTR_I8_INT_INT BT_FN_BOOL_VPTR_PTR_IX_INT_INT[3]
2776 #define BT_FN_I8_CONST_VPTR_INT BT_FN_IX_CONST_VPTR_INT[3]
2777 #define BT_FN_I8_VPTR_I8_INT BT_FN_IX_VPTR_IX_INT[3]
2778 #define BT_FN_VOID_VPTR_I8_INT BT_FN_VOID_VPTR_IX_INT[3]
2779 #define BT_FN_BOOL_VPTR_PTR_I16_INT_INT BT_FN_BOOL_VPTR_PTR_IX_INT_INT[4]
2780 #define BT_FN_I16_CONST_VPTR_INT BT_FN_IX_CONST_VPTR_INT[4]
2781 #define BT_FN_I16_VPTR_I16_INT BT_FN_IX_VPTR_IX_INT[4]
2782 #define BT_FN_VOID_VPTR_I16_INT BT_FN_VOID_VPTR_IX_INT[4]
2783 #undef ATTR_NOTHROW_LEAF_LIST
2784 #define ATTR_NOTHROW_LEAF_LIST ECF_NOTHROW | ECF_LEAF
2785 #undef ATTR_TMPURE_NOTHROW_LEAF_LIST
2786 #define ATTR_TMPURE_NOTHROW_LEAF_LIST ECF_TM_PURE | ATTR_NOTHROW_LEAF_LIST
2787 #undef ATTR_NORETURN_NOTHROW_LEAF_LIST
2788 #define ATTR_NORETURN_NOTHROW_LEAF_LIST ECF_NORETURN | ATTR_NOTHROW_LEAF_LIST
2789 #undef ATTR_CONST_NORETURN_NOTHROW_LEAF_LIST
2790 #define ATTR_CONST_NORETURN_NOTHROW_LEAF_LIST \
2791 ECF_CONST | ATTR_NORETURN_NOTHROW_LEAF_LIST
2792 #undef ATTR_TMPURE_NORETURN_NOTHROW_LEAF_LIST
2793 #define ATTR_TMPURE_NORETURN_NOTHROW_LEAF_LIST \
2794 ECF_TM_PURE | ATTR_NORETURN_NOTHROW_LEAF_LIST
2795 #undef ATTR_COLD_NOTHROW_LEAF_LIST
2796 #define ATTR_COLD_NOTHROW_LEAF_LIST \
2797 /* ECF_COLD missing */ ATTR_NOTHROW_LEAF_LIST
2798 #undef ATTR_COLD_NORETURN_NOTHROW_LEAF_LIST
2799 #define ATTR_COLD_NORETURN_NOTHROW_LEAF_LIST \
2800 /* ECF_COLD missing */ ATTR_NORETURN_NOTHROW_LEAF_LIST
2801 #undef ATTR_COLD_CONST_NORETURN_NOTHROW_LEAF_LIST
2802 #define ATTR_COLD_CONST_NORETURN_NOTHROW_LEAF_LIST \
2803 /* ECF_COLD missing */ ATTR_CONST_NORETURN_NOTHROW_LEAF_LIST
2804 #undef ATTR_PURE_NOTHROW_LEAF_LIST
2805 #define ATTR_PURE_NOTHROW_LEAF_LIST ECF_PURE | ATTR_NOTHROW_LEAF_LIST
2806 #undef DEF_BUILTIN_STUB
2807 #define DEF_BUILTIN_STUB(ENUM, NAME)
2808 #undef DEF_SANITIZER_BUILTIN_1
2809 #define DEF_SANITIZER_BUILTIN_1(ENUM, NAME, TYPE, ATTRS) \
2810 do { \
2811 decl = add_builtin_function ("__builtin_" NAME, TYPE, ENUM, \
2812 BUILT_IN_NORMAL, NAME, NULL_TREE); \
2813 set_call_expr_flags (decl, ATTRS); \
2814 set_builtin_decl (ENUM, decl, true); \
2815 } while (0)
2816 #undef DEF_SANITIZER_BUILTIN
2817 #define DEF_SANITIZER_BUILTIN(ENUM, NAME, TYPE, ATTRS) \
2818 DEF_SANITIZER_BUILTIN_1 (ENUM, NAME, TYPE, ATTRS);
2820 #include "sanitizer.def"
2822 /* -fsanitize=object-size uses __builtin_object_size, but that might
2823 not be available for e.g. Fortran at this point. We use
2824 DEF_SANITIZER_BUILTIN here only as a convenience macro. */
2825 if ((flag_sanitize & SANITIZE_OBJECT_SIZE)
2826 && !builtin_decl_implicit_p (BUILT_IN_OBJECT_SIZE))
2827 DEF_SANITIZER_BUILTIN_1 (BUILT_IN_OBJECT_SIZE, "object_size",
2828 BT_FN_SIZE_CONST_PTR_INT,
2829 ATTR_PURE_NOTHROW_LEAF_LIST);
2831 #undef DEF_SANITIZER_BUILTIN_1
2832 #undef DEF_SANITIZER_BUILTIN
2833 #undef DEF_BUILTIN_STUB
2836 /* Called via htab_traverse. Count number of emitted
2837 STRING_CSTs in the constant hash table. */
2840 count_string_csts (constant_descriptor_tree **slot,
2841 unsigned HOST_WIDE_INT *data)
2843 struct constant_descriptor_tree *desc = *slot;
2844 if (TREE_CODE (desc->value) == STRING_CST
2845 && TREE_ASM_WRITTEN (desc->value)
2846 && asan_protect_global (desc->value))
2847 ++*data;
2848 return 1;
2851 /* Helper structure to pass two parameters to
2852 add_string_csts. */
2854 struct asan_add_string_csts_data
2856 tree type;
2857 vec<constructor_elt, va_gc> *v;
2860 /* Called via hash_table::traverse. Call asan_add_global
2861 on emitted STRING_CSTs from the constant hash table. */
2864 add_string_csts (constant_descriptor_tree **slot,
2865 asan_add_string_csts_data *aascd)
2867 struct constant_descriptor_tree *desc = *slot;
2868 if (TREE_CODE (desc->value) == STRING_CST
2869 && TREE_ASM_WRITTEN (desc->value)
2870 && asan_protect_global (desc->value))
2872 asan_add_global (SYMBOL_REF_DECL (XEXP (desc->rtl, 0)),
2873 aascd->type, aascd->v);
2875 return 1;
2878 /* Needs to be GTY(()), because cgraph_build_static_cdtor may
2879 invoke ggc_collect. */
2880 static GTY(()) tree asan_ctor_statements;
2882 /* Module-level instrumentation.
2883 - Insert __asan_init_vN() into the list of CTORs.
2884 - TODO: insert redzones around globals.
2887 void
2888 asan_finish_file (void)
2890 varpool_node *vnode;
2891 unsigned HOST_WIDE_INT gcount = 0;
2893 if (shadow_ptr_types[0] == NULL_TREE)
2894 asan_init_shadow_ptr_types ();
2895 /* Avoid instrumenting code in the asan ctors/dtors.
2896 We don't need to insert padding after the description strings,
2897 nor after .LASAN* array. */
2898 flag_sanitize &= ~SANITIZE_ADDRESS;
2900 /* For user-space we want asan constructors to run first.
2901 Linux kernel does not support priorities other than default, and the only
2902 other user of constructors is coverage. So we run with the default
2903 priority. */
2904 int priority = flag_sanitize & SANITIZE_USER_ADDRESS
2905 ? MAX_RESERVED_INIT_PRIORITY - 1 : DEFAULT_INIT_PRIORITY;
2907 if (flag_sanitize & SANITIZE_USER_ADDRESS)
2909 tree fn = builtin_decl_implicit (BUILT_IN_ASAN_INIT);
2910 append_to_statement_list (build_call_expr (fn, 0), &asan_ctor_statements);
2911 fn = builtin_decl_implicit (BUILT_IN_ASAN_VERSION_MISMATCH_CHECK);
2912 append_to_statement_list (build_call_expr (fn, 0), &asan_ctor_statements);
2914 FOR_EACH_DEFINED_VARIABLE (vnode)
2915 if (TREE_ASM_WRITTEN (vnode->decl)
2916 && asan_protect_global (vnode->decl))
2917 ++gcount;
2918 hash_table<tree_descriptor_hasher> *const_desc_htab = constant_pool_htab ();
2919 const_desc_htab->traverse<unsigned HOST_WIDE_INT *, count_string_csts>
2920 (&gcount);
2921 if (gcount)
2923 tree type = asan_global_struct (), var, ctor;
2924 tree dtor_statements = NULL_TREE;
2925 vec<constructor_elt, va_gc> *v;
2926 char buf[20];
2928 type = build_array_type_nelts (type, gcount);
2929 ASM_GENERATE_INTERNAL_LABEL (buf, "LASAN", 0);
2930 var = build_decl (UNKNOWN_LOCATION, VAR_DECL, get_identifier (buf),
2931 type);
2932 TREE_STATIC (var) = 1;
2933 TREE_PUBLIC (var) = 0;
2934 DECL_ARTIFICIAL (var) = 1;
2935 DECL_IGNORED_P (var) = 1;
2936 vec_alloc (v, gcount);
2937 FOR_EACH_DEFINED_VARIABLE (vnode)
2938 if (TREE_ASM_WRITTEN (vnode->decl)
2939 && asan_protect_global (vnode->decl))
2940 asan_add_global (vnode->decl, TREE_TYPE (type), v);
2941 struct asan_add_string_csts_data aascd;
2942 aascd.type = TREE_TYPE (type);
2943 aascd.v = v;
2944 const_desc_htab->traverse<asan_add_string_csts_data *, add_string_csts>
2945 (&aascd);
2946 ctor = build_constructor (type, v);
2947 TREE_CONSTANT (ctor) = 1;
2948 TREE_STATIC (ctor) = 1;
2949 DECL_INITIAL (var) = ctor;
2950 SET_DECL_ALIGN (var, MAX (DECL_ALIGN (var),
2951 ASAN_SHADOW_GRANULARITY * BITS_PER_UNIT));
2953 varpool_node::finalize_decl (var);
2955 tree fn = builtin_decl_implicit (BUILT_IN_ASAN_REGISTER_GLOBALS);
2956 tree gcount_tree = build_int_cst (pointer_sized_int_node, gcount);
2957 append_to_statement_list (build_call_expr (fn, 2,
2958 build_fold_addr_expr (var),
2959 gcount_tree),
2960 &asan_ctor_statements);
2962 fn = builtin_decl_implicit (BUILT_IN_ASAN_UNREGISTER_GLOBALS);
2963 append_to_statement_list (build_call_expr (fn, 2,
2964 build_fold_addr_expr (var),
2965 gcount_tree),
2966 &dtor_statements);
2967 cgraph_build_static_cdtor ('D', dtor_statements, priority);
2969 if (asan_ctor_statements)
2970 cgraph_build_static_cdtor ('I', asan_ctor_statements, priority);
2971 flag_sanitize |= SANITIZE_ADDRESS;
2974 /* Poison or unpoison (depending on IS_CLOBBER variable) shadow memory based
2975 on SHADOW address. Newly added statements will be added to ITER with
2976 given location LOC. We mark SIZE bytes in shadow memory, where
2977 LAST_CHUNK_SIZE is greater than zero in situation where we are at the
2978 end of a variable. */
2980 static void
2981 asan_store_shadow_bytes (gimple_stmt_iterator *iter, location_t loc,
2982 tree shadow,
2983 unsigned HOST_WIDE_INT base_addr_offset,
2984 bool is_clobber, unsigned size,
2985 unsigned last_chunk_size)
2987 tree shadow_ptr_type;
2989 switch (size)
2991 case 1:
2992 shadow_ptr_type = shadow_ptr_types[0];
2993 break;
2994 case 2:
2995 shadow_ptr_type = shadow_ptr_types[1];
2996 break;
2997 case 4:
2998 shadow_ptr_type = shadow_ptr_types[2];
2999 break;
3000 default:
3001 gcc_unreachable ();
3004 unsigned char c = (char) is_clobber ? ASAN_STACK_MAGIC_USE_AFTER_SCOPE : 0;
3005 unsigned HOST_WIDE_INT val = 0;
3006 unsigned last_pos = size;
3007 if (last_chunk_size && !is_clobber)
3008 last_pos = BYTES_BIG_ENDIAN ? 0 : size - 1;
3009 for (unsigned i = 0; i < size; ++i)
3011 unsigned char shadow_c = c;
3012 if (i == last_pos)
3013 shadow_c = last_chunk_size;
3014 val |= (unsigned HOST_WIDE_INT) shadow_c << (BITS_PER_UNIT * i);
3017 /* Handle last chunk in unpoisoning. */
3018 tree magic = build_int_cst (TREE_TYPE (shadow_ptr_type), val);
3020 tree dest = build2 (MEM_REF, TREE_TYPE (shadow_ptr_type), shadow,
3021 build_int_cst (shadow_ptr_type, base_addr_offset));
3023 gimple *g = gimple_build_assign (dest, magic);
3024 gimple_set_location (g, loc);
3025 gsi_insert_after (iter, g, GSI_NEW_STMT);
3028 /* Expand the ASAN_MARK builtins. */
3030 bool
3031 asan_expand_mark_ifn (gimple_stmt_iterator *iter)
3033 gimple *g = gsi_stmt (*iter);
3034 location_t loc = gimple_location (g);
3035 HOST_WIDE_INT flag = tree_to_shwi (gimple_call_arg (g, 0));
3036 bool is_poison = ((asan_mark_flags)flag) == ASAN_MARK_POISON;
3038 tree base = gimple_call_arg (g, 1);
3039 gcc_checking_assert (TREE_CODE (base) == ADDR_EXPR);
3040 tree decl = TREE_OPERAND (base, 0);
3042 /* For a nested function, we can have: ASAN_MARK (2, &FRAME.2.fp_input, 4) */
3043 if (TREE_CODE (decl) == COMPONENT_REF
3044 && DECL_NONLOCAL_FRAME (TREE_OPERAND (decl, 0)))
3045 decl = TREE_OPERAND (decl, 0);
3047 gcc_checking_assert (TREE_CODE (decl) == VAR_DECL);
3049 if (is_poison)
3051 if (asan_handled_variables == NULL)
3052 asan_handled_variables = new hash_set<tree> (16);
3053 asan_handled_variables->add (decl);
3055 tree len = gimple_call_arg (g, 2);
3057 gcc_assert (tree_fits_shwi_p (len));
3058 unsigned HOST_WIDE_INT size_in_bytes = tree_to_shwi (len);
3059 gcc_assert (size_in_bytes);
3061 g = gimple_build_assign (make_ssa_name (pointer_sized_int_node),
3062 NOP_EXPR, base);
3063 gimple_set_location (g, loc);
3064 gsi_replace (iter, g, false);
3065 tree base_addr = gimple_assign_lhs (g);
3067 /* Generate direct emission if size_in_bytes is small. */
3068 if (size_in_bytes <= ASAN_PARAM_USE_AFTER_SCOPE_DIRECT_EMISSION_THRESHOLD)
3070 unsigned HOST_WIDE_INT shadow_size = shadow_mem_size (size_in_bytes);
3072 tree shadow = build_shadow_mem_access (iter, loc, base_addr,
3073 shadow_ptr_types[0], true);
3075 for (unsigned HOST_WIDE_INT offset = 0; offset < shadow_size;)
3077 unsigned size = 1;
3078 if (shadow_size - offset >= 4)
3079 size = 4;
3080 else if (shadow_size - offset >= 2)
3081 size = 2;
3083 unsigned HOST_WIDE_INT last_chunk_size = 0;
3084 unsigned HOST_WIDE_INT s = (offset + size) * ASAN_SHADOW_GRANULARITY;
3085 if (s > size_in_bytes)
3086 last_chunk_size = ASAN_SHADOW_GRANULARITY - (s - size_in_bytes);
3088 asan_store_shadow_bytes (iter, loc, shadow, offset, is_poison,
3089 size, last_chunk_size);
3090 offset += size;
3093 else
3095 g = gimple_build_assign (make_ssa_name (pointer_sized_int_node),
3096 NOP_EXPR, len);
3097 gimple_set_location (g, loc);
3098 gsi_insert_before (iter, g, GSI_SAME_STMT);
3099 tree sz_arg = gimple_assign_lhs (g);
3101 tree fun
3102 = builtin_decl_implicit (is_poison ? BUILT_IN_ASAN_POISON_STACK_MEMORY
3103 : BUILT_IN_ASAN_UNPOISON_STACK_MEMORY);
3104 g = gimple_build_call (fun, 2, base_addr, sz_arg);
3105 gimple_set_location (g, loc);
3106 gsi_insert_after (iter, g, GSI_NEW_STMT);
3109 return false;
3112 /* Expand the ASAN_{LOAD,STORE} builtins. */
3114 bool
3115 asan_expand_check_ifn (gimple_stmt_iterator *iter, bool use_calls)
3117 gimple *g = gsi_stmt (*iter);
3118 location_t loc = gimple_location (g);
3119 bool recover_p;
3120 if (flag_sanitize & SANITIZE_USER_ADDRESS)
3121 recover_p = (flag_sanitize_recover & SANITIZE_USER_ADDRESS) != 0;
3122 else
3123 recover_p = (flag_sanitize_recover & SANITIZE_KERNEL_ADDRESS) != 0;
3125 HOST_WIDE_INT flags = tree_to_shwi (gimple_call_arg (g, 0));
3126 gcc_assert (flags < ASAN_CHECK_LAST);
3127 bool is_scalar_access = (flags & ASAN_CHECK_SCALAR_ACCESS) != 0;
3128 bool is_store = (flags & ASAN_CHECK_STORE) != 0;
3129 bool is_non_zero_len = (flags & ASAN_CHECK_NON_ZERO_LEN) != 0;
3131 tree base = gimple_call_arg (g, 1);
3132 tree len = gimple_call_arg (g, 2);
3133 HOST_WIDE_INT align = tree_to_shwi (gimple_call_arg (g, 3));
3135 HOST_WIDE_INT size_in_bytes
3136 = is_scalar_access && tree_fits_shwi_p (len) ? tree_to_shwi (len) : -1;
3138 if (use_calls)
3140 /* Instrument using callbacks. */
3141 gimple *g = gimple_build_assign (make_ssa_name (pointer_sized_int_node),
3142 NOP_EXPR, base);
3143 gimple_set_location (g, loc);
3144 gsi_insert_before (iter, g, GSI_SAME_STMT);
3145 tree base_addr = gimple_assign_lhs (g);
3147 int nargs;
3148 tree fun = check_func (is_store, recover_p, size_in_bytes, &nargs);
3149 if (nargs == 1)
3150 g = gimple_build_call (fun, 1, base_addr);
3151 else
3153 gcc_assert (nargs == 2);
3154 g = gimple_build_assign (make_ssa_name (pointer_sized_int_node),
3155 NOP_EXPR, len);
3156 gimple_set_location (g, loc);
3157 gsi_insert_before (iter, g, GSI_SAME_STMT);
3158 tree sz_arg = gimple_assign_lhs (g);
3159 g = gimple_build_call (fun, nargs, base_addr, sz_arg);
3161 gimple_set_location (g, loc);
3162 gsi_replace (iter, g, false);
3163 return false;
3166 HOST_WIDE_INT real_size_in_bytes = size_in_bytes == -1 ? 1 : size_in_bytes;
3168 tree shadow_ptr_type = shadow_ptr_types[real_size_in_bytes == 16 ? 1 : 0];
3169 tree shadow_type = TREE_TYPE (shadow_ptr_type);
3171 gimple_stmt_iterator gsi = *iter;
3173 if (!is_non_zero_len)
3175 /* So, the length of the memory area to asan-protect is
3176 non-constant. Let's guard the generated instrumentation code
3177 like:
3179 if (len != 0)
3181 //asan instrumentation code goes here.
3183 // falltrough instructions, starting with *ITER. */
3185 g = gimple_build_cond (NE_EXPR,
3186 len,
3187 build_int_cst (TREE_TYPE (len), 0),
3188 NULL_TREE, NULL_TREE);
3189 gimple_set_location (g, loc);
3191 basic_block then_bb, fallthrough_bb;
3192 insert_if_then_before_iter (as_a <gcond *> (g), iter,
3193 /*then_more_likely_p=*/true,
3194 &then_bb, &fallthrough_bb);
3195 /* Note that fallthrough_bb starts with the statement that was
3196 pointed to by ITER. */
3198 /* The 'then block' of the 'if (len != 0) condition is where
3199 we'll generate the asan instrumentation code now. */
3200 gsi = gsi_last_bb (then_bb);
3203 /* Get an iterator on the point where we can add the condition
3204 statement for the instrumentation. */
3205 basic_block then_bb, else_bb;
3206 gsi = create_cond_insert_point (&gsi, /*before_p*/false,
3207 /*then_more_likely_p=*/false,
3208 /*create_then_fallthru_edge*/recover_p,
3209 &then_bb,
3210 &else_bb);
3212 g = gimple_build_assign (make_ssa_name (pointer_sized_int_node),
3213 NOP_EXPR, base);
3214 gimple_set_location (g, loc);
3215 gsi_insert_before (&gsi, g, GSI_NEW_STMT);
3216 tree base_addr = gimple_assign_lhs (g);
3218 tree t = NULL_TREE;
3219 if (real_size_in_bytes >= 8)
3221 tree shadow = build_shadow_mem_access (&gsi, loc, base_addr,
3222 shadow_ptr_type);
3223 t = shadow;
3225 else
3227 /* Slow path for 1, 2 and 4 byte accesses. */
3228 /* Test (shadow != 0)
3229 & ((base_addr & 7) + (real_size_in_bytes - 1)) >= shadow). */
3230 tree shadow = build_shadow_mem_access (&gsi, loc, base_addr,
3231 shadow_ptr_type);
3232 gimple *shadow_test = build_assign (NE_EXPR, shadow, 0);
3233 gimple_seq seq = NULL;
3234 gimple_seq_add_stmt (&seq, shadow_test);
3235 /* Aligned (>= 8 bytes) can test just
3236 (real_size_in_bytes - 1 >= shadow), as base_addr & 7 is known
3237 to be 0. */
3238 if (align < 8)
3240 gimple_seq_add_stmt (&seq, build_assign (BIT_AND_EXPR,
3241 base_addr, 7));
3242 gimple_seq_add_stmt (&seq,
3243 build_type_cast (shadow_type,
3244 gimple_seq_last (seq)));
3245 if (real_size_in_bytes > 1)
3246 gimple_seq_add_stmt (&seq,
3247 build_assign (PLUS_EXPR,
3248 gimple_seq_last (seq),
3249 real_size_in_bytes - 1));
3250 t = gimple_assign_lhs (gimple_seq_last_stmt (seq));
3252 else
3253 t = build_int_cst (shadow_type, real_size_in_bytes - 1);
3254 gimple_seq_add_stmt (&seq, build_assign (GE_EXPR, t, shadow));
3255 gimple_seq_add_stmt (&seq, build_assign (BIT_AND_EXPR, shadow_test,
3256 gimple_seq_last (seq)));
3257 t = gimple_assign_lhs (gimple_seq_last (seq));
3258 gimple_seq_set_location (seq, loc);
3259 gsi_insert_seq_after (&gsi, seq, GSI_CONTINUE_LINKING);
3261 /* For non-constant, misaligned or otherwise weird access sizes,
3262 check first and last byte. */
3263 if (size_in_bytes == -1)
3265 g = gimple_build_assign (make_ssa_name (pointer_sized_int_node),
3266 MINUS_EXPR, len,
3267 build_int_cst (pointer_sized_int_node, 1));
3268 gimple_set_location (g, loc);
3269 gsi_insert_after (&gsi, g, GSI_NEW_STMT);
3270 tree last = gimple_assign_lhs (g);
3271 g = gimple_build_assign (make_ssa_name (pointer_sized_int_node),
3272 PLUS_EXPR, base_addr, last);
3273 gimple_set_location (g, loc);
3274 gsi_insert_after (&gsi, g, GSI_NEW_STMT);
3275 tree base_end_addr = gimple_assign_lhs (g);
3277 tree shadow = build_shadow_mem_access (&gsi, loc, base_end_addr,
3278 shadow_ptr_type);
3279 gimple *shadow_test = build_assign (NE_EXPR, shadow, 0);
3280 gimple_seq seq = NULL;
3281 gimple_seq_add_stmt (&seq, shadow_test);
3282 gimple_seq_add_stmt (&seq, build_assign (BIT_AND_EXPR,
3283 base_end_addr, 7));
3284 gimple_seq_add_stmt (&seq, build_type_cast (shadow_type,
3285 gimple_seq_last (seq)));
3286 gimple_seq_add_stmt (&seq, build_assign (GE_EXPR,
3287 gimple_seq_last (seq),
3288 shadow));
3289 gimple_seq_add_stmt (&seq, build_assign (BIT_AND_EXPR, shadow_test,
3290 gimple_seq_last (seq)));
3291 gimple_seq_add_stmt (&seq, build_assign (BIT_IOR_EXPR, t,
3292 gimple_seq_last (seq)));
3293 t = gimple_assign_lhs (gimple_seq_last (seq));
3294 gimple_seq_set_location (seq, loc);
3295 gsi_insert_seq_after (&gsi, seq, GSI_CONTINUE_LINKING);
3299 g = gimple_build_cond (NE_EXPR, t, build_int_cst (TREE_TYPE (t), 0),
3300 NULL_TREE, NULL_TREE);
3301 gimple_set_location (g, loc);
3302 gsi_insert_after (&gsi, g, GSI_NEW_STMT);
3304 /* Generate call to the run-time library (e.g. __asan_report_load8). */
3305 gsi = gsi_start_bb (then_bb);
3306 int nargs;
3307 tree fun = report_error_func (is_store, recover_p, size_in_bytes, &nargs);
3308 g = gimple_build_call (fun, nargs, base_addr, len);
3309 gimple_set_location (g, loc);
3310 gsi_insert_after (&gsi, g, GSI_NEW_STMT);
3312 gsi_remove (iter, true);
3313 *iter = gsi_start_bb (else_bb);
3315 return true;
3318 /* Create ASAN shadow variable for a VAR_DECL which has been rewritten
3319 into SSA. Already seen VAR_DECLs are stored in SHADOW_VARS_MAPPING. */
3321 static tree
3322 create_asan_shadow_var (tree var_decl,
3323 hash_map<tree, tree> &shadow_vars_mapping)
3325 tree *slot = shadow_vars_mapping.get (var_decl);
3326 if (slot == NULL)
3328 tree shadow_var = copy_node (var_decl);
3330 copy_body_data id;
3331 memset (&id, 0, sizeof (copy_body_data));
3332 id.src_fn = id.dst_fn = current_function_decl;
3333 copy_decl_for_dup_finish (&id, var_decl, shadow_var);
3335 DECL_ARTIFICIAL (shadow_var) = 1;
3336 DECL_IGNORED_P (shadow_var) = 1;
3337 DECL_SEEN_IN_BIND_EXPR_P (shadow_var) = 0;
3338 gimple_add_tmp_var (shadow_var);
3340 shadow_vars_mapping.put (var_decl, shadow_var);
3341 return shadow_var;
3343 else
3344 return *slot;
3347 /* Expand ASAN_POISON ifn. */
3349 bool
3350 asan_expand_poison_ifn (gimple_stmt_iterator *iter,
3351 bool *need_commit_edge_insert,
3352 hash_map<tree, tree> &shadow_vars_mapping)
3354 gimple *g = gsi_stmt (*iter);
3355 tree poisoned_var = gimple_call_lhs (g);
3356 if (!poisoned_var || has_zero_uses (poisoned_var))
3358 gsi_remove (iter, true);
3359 return true;
3362 if (SSA_NAME_VAR (poisoned_var) == NULL_TREE)
3363 SET_SSA_NAME_VAR_OR_IDENTIFIER (poisoned_var,
3364 create_tmp_var (TREE_TYPE (poisoned_var)));
3366 tree shadow_var = create_asan_shadow_var (SSA_NAME_VAR (poisoned_var),
3367 shadow_vars_mapping);
3369 bool recover_p;
3370 if (flag_sanitize & SANITIZE_USER_ADDRESS)
3371 recover_p = (flag_sanitize_recover & SANITIZE_USER_ADDRESS) != 0;
3372 else
3373 recover_p = (flag_sanitize_recover & SANITIZE_KERNEL_ADDRESS) != 0;
3374 tree size = DECL_SIZE_UNIT (shadow_var);
3375 gimple *poison_call
3376 = gimple_build_call_internal (IFN_ASAN_MARK, 3,
3377 build_int_cst (integer_type_node,
3378 ASAN_MARK_POISON),
3379 build_fold_addr_expr (shadow_var), size);
3381 gimple *use;
3382 imm_use_iterator imm_iter;
3383 FOR_EACH_IMM_USE_STMT (use, imm_iter, poisoned_var)
3385 if (is_gimple_debug (use))
3386 continue;
3388 int nargs;
3389 bool store_p = gimple_call_internal_p (use, IFN_ASAN_POISON_USE);
3390 tree fun = report_error_func (store_p, recover_p, tree_to_uhwi (size),
3391 &nargs);
3393 gcall *call = gimple_build_call (fun, 1,
3394 build_fold_addr_expr (shadow_var));
3395 gimple_set_location (call, gimple_location (use));
3396 gimple *call_to_insert = call;
3398 /* The USE can be a gimple PHI node. If so, insert the call on
3399 all edges leading to the PHI node. */
3400 if (is_a <gphi *> (use))
3402 gphi *phi = dyn_cast<gphi *> (use);
3403 for (unsigned i = 0; i < gimple_phi_num_args (phi); ++i)
3404 if (gimple_phi_arg_def (phi, i) == poisoned_var)
3406 edge e = gimple_phi_arg_edge (phi, i);
3408 /* Do not insert on an edge we can't split. */
3409 if (e->flags & EDGE_ABNORMAL)
3410 continue;
3412 if (call_to_insert == NULL)
3413 call_to_insert = gimple_copy (call);
3415 gsi_insert_seq_on_edge (e, call_to_insert);
3416 *need_commit_edge_insert = true;
3417 call_to_insert = NULL;
3420 else
3422 gimple_stmt_iterator gsi = gsi_for_stmt (use);
3423 if (store_p)
3424 gsi_replace (&gsi, call, true);
3425 else
3426 gsi_insert_before (&gsi, call, GSI_NEW_STMT);
3430 SSA_NAME_IS_DEFAULT_DEF (poisoned_var) = true;
3431 SSA_NAME_DEF_STMT (poisoned_var) = gimple_build_nop ();
3432 gsi_replace (iter, poison_call, false);
3434 return true;
3437 /* Instrument the current function. */
3439 static unsigned int
3440 asan_instrument (void)
3442 if (shadow_ptr_types[0] == NULL_TREE)
3443 asan_init_shadow_ptr_types ();
3444 transform_statements ();
3445 last_alloca_addr = NULL_TREE;
3446 return 0;
3449 static bool
3450 gate_asan (void)
3452 return sanitize_flags_p (SANITIZE_ADDRESS);
3455 namespace {
3457 const pass_data pass_data_asan =
3459 GIMPLE_PASS, /* type */
3460 "asan", /* name */
3461 OPTGROUP_NONE, /* optinfo_flags */
3462 TV_NONE, /* tv_id */
3463 ( PROP_ssa | PROP_cfg | PROP_gimple_leh ), /* properties_required */
3464 0, /* properties_provided */
3465 0, /* properties_destroyed */
3466 0, /* todo_flags_start */
3467 TODO_update_ssa, /* todo_flags_finish */
3470 class pass_asan : public gimple_opt_pass
3472 public:
3473 pass_asan (gcc::context *ctxt)
3474 : gimple_opt_pass (pass_data_asan, ctxt)
3477 /* opt_pass methods: */
3478 opt_pass * clone () { return new pass_asan (m_ctxt); }
3479 virtual bool gate (function *) { return gate_asan (); }
3480 virtual unsigned int execute (function *) { return asan_instrument (); }
3482 }; // class pass_asan
3484 } // anon namespace
3486 gimple_opt_pass *
3487 make_pass_asan (gcc::context *ctxt)
3489 return new pass_asan (ctxt);
3492 namespace {
3494 const pass_data pass_data_asan_O0 =
3496 GIMPLE_PASS, /* type */
3497 "asan0", /* name */
3498 OPTGROUP_NONE, /* optinfo_flags */
3499 TV_NONE, /* tv_id */
3500 ( PROP_ssa | PROP_cfg | PROP_gimple_leh ), /* properties_required */
3501 0, /* properties_provided */
3502 0, /* properties_destroyed */
3503 0, /* todo_flags_start */
3504 TODO_update_ssa, /* todo_flags_finish */
3507 class pass_asan_O0 : public gimple_opt_pass
3509 public:
3510 pass_asan_O0 (gcc::context *ctxt)
3511 : gimple_opt_pass (pass_data_asan_O0, ctxt)
3514 /* opt_pass methods: */
3515 virtual bool gate (function *) { return !optimize && gate_asan (); }
3516 virtual unsigned int execute (function *) { return asan_instrument (); }
3518 }; // class pass_asan_O0
3520 } // anon namespace
3522 gimple_opt_pass *
3523 make_pass_asan_O0 (gcc::context *ctxt)
3525 return new pass_asan_O0 (ctxt);
3528 #include "gt-asan.h"