1 /* Copyright (c) 2008-2019. The SimGrid Team. All rights reserved. */
3 /* This program is free software; you can redistribute it and/or modify it
4 * under the terms of the license (GNU LGPL) which comes with this package. */
6 /** \file compare.cpp Memory snapshotting and comparison */
8 #include "src/mc/mc_config.hpp"
9 #include "src/mc/mc_private.hpp"
10 #include "src/mc/mc_smx.hpp"
11 #include "src/mc/sosp/Snapshot.hpp"
13 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_compare, xbt, "Logging specific to mc_compare in mc");
15 using simgrid::mc::remote;
20 /*********************************** Heap comparison ***********************************/
21 /***************************************************************************************/
28 HeapLocation() = default;
29 explicit HeapLocation(int block, int fragment = 0) : block_(block), fragment_(fragment) {}
31 bool operator==(HeapLocation const& that) const
33 return block_ == that.block_ && fragment_ == that.fragment_;
35 bool operator<(HeapLocation const& that) const
37 return std::make_pair(block_, fragment_) < std::make_pair(that.block_, that.fragment_);
41 typedef std::array<HeapLocation, 2> HeapLocationPair;
42 typedef std::set<HeapLocationPair> HeapLocationPairs;
44 class HeapArea : public HeapLocation {
48 explicit HeapArea(int block) : valid_(true) { block_ = block; }
49 HeapArea(int block, int fragment) : valid_(true)
56 class ProcessComparisonState {
58 const std::vector<IgnoredHeapRegion>* to_ignore = nullptr;
59 std::vector<HeapArea> equals_to;
60 std::vector<Type*> types;
61 std::size_t heapsize = 0;
63 void initHeapInformation(xbt_mheap_t heap, const std::vector<IgnoredHeapRegion>& i);
66 class StateComparator {
68 s_xbt_mheap_t std_heap_copy;
69 std::size_t heaplimit;
70 std::array<ProcessComparisonState, 2> processStates;
72 std::unordered_set<std::pair<const void*, const void*>, simgrid::xbt::hash<std::pair<const void*, const void*>>>
77 compared_pointers.clear();
80 int initHeapInformation(xbt_mheap_t heap1, xbt_mheap_t heap2, const std::vector<IgnoredHeapRegion>& i1,
81 const std::vector<IgnoredHeapRegion>& i2);
83 template <int rank> HeapArea& equals_to_(std::size_t i, std::size_t j)
85 return processStates[rank - 1].equals_to[MAX_FRAGMENT_PER_BLOCK * i + j];
87 template <int rank> Type*& types_(std::size_t i, std::size_t j)
89 return processStates[rank - 1].types[MAX_FRAGMENT_PER_BLOCK * i + j];
92 template <int rank> HeapArea const& equals_to_(std::size_t i, std::size_t j) const
94 return processStates[rank - 1].equals_to[MAX_FRAGMENT_PER_BLOCK * i + j];
96 template <int rank> Type* const& types_(std::size_t i, std::size_t j) const
98 return processStates[rank - 1].types[MAX_FRAGMENT_PER_BLOCK * i + j];
101 /** Check whether two blocks are known to be matching
103 * @param b1 Block of state 1
104 * @param b2 Block of state 2
105 * @return if the blocks are known to be matching
107 bool blocksEqual(int b1, int b2) const
109 return this->equals_to_<1>(b1, 0).block_ == b2 && this->equals_to_<2>(b2, 0).block_ == b1;
112 /** Check whether two fragments are known to be matching
114 * @param b1 Block of state 1
115 * @param f1 Fragment of state 1
116 * @param b2 Block of state 2
117 * @param f2 Fragment of state 2
118 * @return if the fragments are known to be matching
120 int fragmentsEqual(int b1, int f1, int b2, int f2) const
122 return this->equals_to_<1>(b1, f1).block_ == b2 && this->equals_to_<1>(b1, f1).fragment_ == f2 &&
123 this->equals_to_<2>(b2, f2).block_ == b1 && this->equals_to_<2>(b2, f2).fragment_ == f1;
126 void match_equals(HeapLocationPairs* list);
130 } // namespace simgrid
132 /************************************************************************************/
134 static ssize_t heap_comparison_ignore_size(const std::vector<simgrid::mc::IgnoredHeapRegion>* ignore_list,
138 int end = ignore_list->size() - 1;
140 while (start <= end) {
141 unsigned int cursor = (start + end) / 2;
142 simgrid::mc::IgnoredHeapRegion const& region = (*ignore_list)[cursor];
143 if (region.address == address)
145 if (region.address < address)
147 if (region.address > address)
154 static bool is_stack(const void *address)
156 for (auto const& stack : mc_model_checker->process().stack_areas())
157 if (address == stack.address)
162 // TODO, this should depend on the snapshot?
163 static bool is_block_stack(int block)
165 for (auto const& stack : mc_model_checker->process().stack_areas())
166 if (block == stack.block)
174 void StateComparator::match_equals(HeapLocationPairs* list)
176 for (auto const& pair : *list) {
177 if (pair[0].fragment_ != -1) {
178 this->equals_to_<1>(pair[0].block_, pair[0].fragment_) = HeapArea(pair[1].block_, pair[1].fragment_);
179 this->equals_to_<2>(pair[1].block_, pair[1].fragment_) = HeapArea(pair[0].block_, pair[0].fragment_);
181 this->equals_to_<1>(pair[0].block_, 0) = HeapArea(pair[1].block_, pair[1].fragment_);
182 this->equals_to_<2>(pair[1].block_, 0) = HeapArea(pair[0].block_, pair[0].fragment_);
187 void ProcessComparisonState::initHeapInformation(xbt_mheap_t heap, const std::vector<IgnoredHeapRegion>& i)
189 auto heaplimit = heap->heaplimit;
190 this->heapsize = heap->heapsize;
191 this->to_ignore = &i;
192 this->equals_to.assign(heaplimit * MAX_FRAGMENT_PER_BLOCK, HeapArea());
193 this->types.assign(heaplimit * MAX_FRAGMENT_PER_BLOCK, nullptr);
196 int StateComparator::initHeapInformation(xbt_mheap_t heap1, xbt_mheap_t heap2, const std::vector<IgnoredHeapRegion>& i1,
197 const std::vector<IgnoredHeapRegion>& i2)
199 if ((heap1->heaplimit != heap2->heaplimit) || (heap1->heapsize != heap2->heapsize))
201 this->heaplimit = heap1->heaplimit;
202 this->std_heap_copy = *mc_model_checker->process().get_heap();
203 this->processStates[0].initHeapInformation(heap1, i1);
204 this->processStates[1].initHeapInformation(heap2, i2);
208 // TODO, have a robust way to find it in O(1)
209 static inline Region* MC_get_heap_region(const Snapshot& snapshot)
211 for (auto const& region : snapshot.snapshot_regions_)
212 if (region->region_type() == RegionType::Heap)
214 xbt_die("No heap region");
217 static bool heap_area_differ(StateComparator& state, const void* area1, const void* area2, const Snapshot& snapshot1,
218 const Snapshot& snapshot2, HeapLocationPairs* previous, Type* type, int pointer_level);
220 static bool mmalloc_heap_differ(StateComparator& state, const Snapshot& snapshot1, const Snapshot& snapshot2)
222 const RemoteClient& process = mc_model_checker->process();
224 /* Check busy blocks */
227 malloc_info heapinfo_temp1;
228 malloc_info heapinfo_temp2;
229 malloc_info heapinfo_temp2b;
231 Region* heap_region1 = MC_get_heap_region(snapshot1);
232 Region* heap_region2 = MC_get_heap_region(snapshot2);
234 // This is the address of std_heap->heapinfo in the application process:
235 void* heapinfo_address = &((xbt_mheap_t)process.heap_address)->heapinfo;
237 // This is in snapshot do not use them directly:
238 const malloc_info* heapinfos1 =
239 snapshot1.read<malloc_info*>(RemotePtr<malloc_info*>((std::uint64_t)heapinfo_address));
240 const malloc_info* heapinfos2 =
241 snapshot2.read<malloc_info*>(RemotePtr<malloc_info*>((std::uint64_t)heapinfo_address));
243 while (i1 < state.heaplimit) {
244 const malloc_info* heapinfo1 =
245 (const malloc_info*)heap_region1->read(&heapinfo_temp1, &heapinfos1[i1], sizeof(malloc_info));
246 const malloc_info* heapinfo2 =
247 (const malloc_info*)heap_region2->read(&heapinfo_temp2, &heapinfos2[i1], sizeof(malloc_info));
249 if (heapinfo1->type == MMALLOC_TYPE_FREE || heapinfo1->type == MMALLOC_TYPE_HEAPINFO) { /* Free block */
254 xbt_assert(heapinfo1->type >= 0, "Unkown mmalloc block type: %d", heapinfo1->type);
256 void* addr_block1 = ((void*)(((ADDR2UINT(i1)) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase));
258 if (heapinfo1->type == MMALLOC_TYPE_UNFRAGMENTED) { /* Large block */
259 if (is_stack(addr_block1)) {
260 for (size_t k = 0; k < heapinfo1->busy_block.size; k++)
261 state.equals_to_<1>(i1 + k, 0) = HeapArea(i1, -1);
262 for (size_t k = 0; k < heapinfo2->busy_block.size; k++)
263 state.equals_to_<2>(i1 + k, 0) = HeapArea(i1, -1);
264 i1 += heapinfo1->busy_block.size;
268 if (state.equals_to_<1>(i1, 0).valid_) {
276 /* Try first to associate to same block in the other heap */
277 if (heapinfo2->type == heapinfo1->type && state.equals_to_<2>(i1, 0).valid_ == 0) {
278 void* addr_block2 = (ADDR2UINT(i1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
279 if (not heap_area_differ(state, addr_block1, addr_block2, snapshot1, snapshot2, nullptr, nullptr, 0)) {
280 for (size_t k = 1; k < heapinfo2->busy_block.size; k++)
281 state.equals_to_<2>(i1 + k, 0) = HeapArea(i1, -1);
282 for (size_t k = 1; k < heapinfo1->busy_block.size; k++)
283 state.equals_to_<1>(i1 + k, 0) = HeapArea(i1, -1);
285 i1 += heapinfo1->busy_block.size;
289 while (i2 < state.heaplimit && not equal) {
290 void* addr_block2 = (ADDR2UINT(i2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
297 const malloc_info* heapinfo2b =
298 (const malloc_info*)heap_region2->read(&heapinfo_temp2b, &heapinfos2[i2], sizeof(malloc_info));
300 if (heapinfo2b->type != MMALLOC_TYPE_UNFRAGMENTED) {
305 if (state.equals_to_<2>(i2, 0).valid_) {
310 if (not heap_area_differ(state, addr_block1, addr_block2, snapshot1, snapshot2, nullptr, nullptr, 0)) {
311 for (size_t k = 1; k < heapinfo2b->busy_block.size; k++)
312 state.equals_to_<2>(i2 + k, 0) = HeapArea(i1, -1);
313 for (size_t k = 1; k < heapinfo1->busy_block.size; k++)
314 state.equals_to_<1>(i1 + k, 0) = HeapArea(i2, -1);
316 i1 += heapinfo1->busy_block.size;
322 XBT_DEBUG("Block %zu not found (size_used = %zu, addr = %p)", i1, heapinfo1->busy_block.busy_size, addr_block1);
325 } else { /* Fragmented block */
326 for (size_t j1 = 0; j1 < (size_t)(BLOCKSIZE >> heapinfo1->type); j1++) {
327 if (heapinfo1->busy_frag.frag_size[j1] == -1) /* Free fragment_ */
330 if (state.equals_to_<1>(i1, j1).valid_)
333 void* addr_frag1 = (void*)((char*)addr_block1 + (j1 << heapinfo1->type));
338 /* Try first to associate to same fragment_ in the other heap */
339 if (heapinfo2->type == heapinfo1->type && not state.equals_to_<2>(i1, j1).valid_) {
340 void* addr_block2 = (ADDR2UINT(i1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
341 void* addr_frag2 = (void*)((char*)addr_block2 + (j1 << heapinfo2->type));
342 if (not heap_area_differ(state, addr_frag1, addr_frag2, snapshot1, snapshot2, nullptr, nullptr, 0))
346 while (i2 < state.heaplimit && not equal) {
347 const malloc_info* heapinfo2b =
348 (const malloc_info*)heap_region2->read(&heapinfo_temp2b, &heapinfos2[i2], sizeof(malloc_info));
350 if (heapinfo2b->type == MMALLOC_TYPE_FREE || heapinfo2b->type == MMALLOC_TYPE_HEAPINFO) {
355 // We currently do not match fragments with unfragmented blocks (maybe we should).
356 if (heapinfo2b->type == MMALLOC_TYPE_UNFRAGMENTED) {
361 xbt_assert(heapinfo2b->type >= 0, "Unkown mmalloc block type: %d", heapinfo2b->type);
363 for (size_t j2 = 0; j2 < (size_t)(BLOCKSIZE >> heapinfo2b->type); j2++) {
364 if (i2 == i1 && j2 == j1)
367 if (state.equals_to_<2>(i2, j2).valid_)
370 void* addr_block2 = (ADDR2UINT(i2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
371 void* addr_frag2 = (void*)((char*)addr_block2 + (j2 << heapinfo2b->type));
373 if (not heap_area_differ(state, addr_frag1, addr_frag2, snapshot1, snapshot2, nullptr, nullptr, 0)) {
382 XBT_DEBUG("Block %zu, fragment_ %zu not found (size_used = %zd, address = %p)\n", i1, j1,
383 heapinfo1->busy_frag.frag_size[j1], addr_frag1);
391 /* All blocks/fragments are equal to another block/fragment_ ? */
392 for (size_t i = 1; i < state.heaplimit; i++) {
393 const malloc_info* heapinfo1 =
394 (const malloc_info*)heap_region1->read(&heapinfo_temp1, &heapinfos1[i], sizeof(malloc_info));
396 if (heapinfo1->type == MMALLOC_TYPE_UNFRAGMENTED && i1 == state.heaplimit && heapinfo1->busy_block.busy_size > 0 &&
397 not state.equals_to_<1>(i, 0).valid_) {
398 XBT_DEBUG("Block %zu not found (size used = %zu)", i, heapinfo1->busy_block.busy_size);
402 if (heapinfo1->type <= 0)
404 for (size_t j = 0; j < (size_t)(BLOCKSIZE >> heapinfo1->type); j++)
405 if (i1 == state.heaplimit && heapinfo1->busy_frag.frag_size[j] > 0 && not state.equals_to_<1>(i, j).valid_) {
406 XBT_DEBUG("Block %zu, Fragment %zu not found (size used = %zd)", i, j, heapinfo1->busy_frag.frag_size[j]);
411 for (size_t i = 1; i < state.heaplimit; i++) {
412 const malloc_info* heapinfo2 =
413 (const malloc_info*)heap_region2->read(&heapinfo_temp2, &heapinfos2[i], sizeof(malloc_info));
414 if (heapinfo2->type == MMALLOC_TYPE_UNFRAGMENTED && i1 == state.heaplimit && heapinfo2->busy_block.busy_size > 0 &&
415 not state.equals_to_<2>(i, 0).valid_) {
416 XBT_DEBUG("Block %zu not found (size used = %zu)", i,
417 heapinfo2->busy_block.busy_size);
421 if (heapinfo2->type <= 0)
424 for (size_t j = 0; j < (size_t)(BLOCKSIZE >> heapinfo2->type); j++)
425 if (i1 == state.heaplimit && heapinfo2->busy_frag.frag_size[j] > 0 && not state.equals_to_<2>(i, j).valid_) {
426 XBT_DEBUG("Block %zu, Fragment %zu not found (size used = %zd)",
427 i, j, heapinfo2->busy_frag.frag_size[j]);
437 * @param real_area1 Process address for state 1
438 * @param real_area2 Process address for state 2
439 * @param snapshot1 Snapshot of state 1
440 * @param snapshot2 Snapshot of state 2
443 * @param check_ignore
444 * @return true when different, false otherwise (same or unknown)
446 static bool heap_area_differ_without_type(StateComparator& state, const void* real_area1, const void* real_area2,
447 const Snapshot& snapshot1, const Snapshot& snapshot2,
448 HeapLocationPairs* previous, int size, int check_ignore)
450 const RemoteClient& process = mc_model_checker->process();
451 Region* heap_region1 = MC_get_heap_region(snapshot1);
452 Region* heap_region2 = MC_get_heap_region(snapshot2);
454 for (int i = 0; i < size; ) {
455 if (check_ignore > 0) {
456 ssize_t ignore1 = heap_comparison_ignore_size(state.processStates[0].to_ignore, (const char*)real_area1 + i);
458 ssize_t ignore2 = heap_comparison_ignore_size(state.processStates[1].to_ignore, (const char*)real_area2 + i);
459 if (ignore2 == ignore1) {
471 if (MC_snapshot_region_memcmp((const char*)real_area1 + i, heap_region1, (const char*)real_area2 + i, heap_region2,
473 int pointer_align = (i / sizeof(void *)) * sizeof(void *);
474 const void* addr_pointed1 = snapshot1.read(remote((void* const*)((const char*)real_area1 + pointer_align)));
475 const void* addr_pointed2 = snapshot2.read(remote((void* const*)((const char*)real_area2 + pointer_align)));
477 if (process.in_maestro_stack(remote(addr_pointed1)) && process.in_maestro_stack(remote(addr_pointed2))) {
478 i = pointer_align + sizeof(void *);
482 if (snapshot1.on_heap(addr_pointed1) && snapshot2.on_heap(addr_pointed2)) {
483 // Both addresses are in the heap:
484 if (heap_area_differ(state, addr_pointed1, addr_pointed2, snapshot1, snapshot2, previous, nullptr, 0))
486 i = pointer_align + sizeof(void *);
499 * @param real_area1 Process address for state 1
500 * @param real_area2 Process address for state 2
501 * @param snapshot1 Snapshot of state 1
502 * @param snapshot2 Snapshot of state 2
505 * @param area_size either a byte_size or an elements_count (?)
506 * @param check_ignore
507 * @param pointer_level
508 * @return true when different, false otherwise (same or unknown)
510 static bool heap_area_differ_with_type(StateComparator& state, const void* real_area1, const void* real_area2,
511 const Snapshot& snapshot1, const Snapshot& snapshot2,
512 HeapLocationPairs* previous, Type* type, int area_size, int check_ignore,
515 // HACK: This should not happen but in practice, there are some
516 // DW_TAG_typedef without an associated DW_AT_type:
517 //<1><538832>: Abbrev Number: 111 (DW_TAG_typedef)
518 // <538833> DW_AT_name : (indirect string, offset: 0x2292f3): gregset_t
519 // <538837> DW_AT_decl_file : 98
520 // <538838> DW_AT_decl_line : 37
524 if (is_stack(real_area1) && is_stack(real_area2))
527 if (check_ignore > 0) {
528 ssize_t ignore1 = heap_comparison_ignore_size(state.processStates[0].to_ignore, real_area1);
529 if (ignore1 > 0 && heap_comparison_ignore_size(state.processStates[1].to_ignore, real_area2) == ignore1)
536 const void* addr_pointed1;
537 const void* addr_pointed2;
539 Region* heap_region1 = MC_get_heap_region(snapshot1);
540 Region* heap_region2 = MC_get_heap_region(snapshot2);
542 switch (type->type) {
543 case DW_TAG_unspecified_type:
546 case DW_TAG_base_type:
547 if (not type->name.empty() && type->name == "char") { /* String, hence random (arbitrary ?) size */
548 if (real_area1 == real_area2)
551 return MC_snapshot_region_memcmp(real_area1, heap_region1, real_area2, heap_region2, area_size) != 0;
553 if (area_size != -1 && type->byte_size != area_size)
556 return MC_snapshot_region_memcmp(real_area1, heap_region1, real_area2, heap_region2, type->byte_size) != 0;
559 case DW_TAG_enumeration_type:
560 if (area_size != -1 && type->byte_size != area_size)
562 return MC_snapshot_region_memcmp(real_area1, heap_region1, real_area2, heap_region2, type->byte_size) != 0;
565 case DW_TAG_const_type:
566 case DW_TAG_volatile_type:
567 return heap_area_differ_with_type(state, real_area1, real_area2, snapshot1, snapshot2, previous, type->subtype,
568 area_size, check_ignore, pointer_level);
570 case DW_TAG_array_type:
571 subtype = type->subtype;
572 switch (subtype->type) {
573 case DW_TAG_unspecified_type:
576 case DW_TAG_base_type:
577 case DW_TAG_enumeration_type:
578 case DW_TAG_pointer_type:
579 case DW_TAG_reference_type:
580 case DW_TAG_rvalue_reference_type:
581 case DW_TAG_structure_type:
582 case DW_TAG_class_type:
583 case DW_TAG_union_type:
584 if (subtype->full_type)
585 subtype = subtype->full_type;
586 elm_size = subtype->byte_size;
588 // TODO, just remove the type indirection?
589 case DW_TAG_const_type:
591 case DW_TAG_volatile_type:
592 subsubtype = subtype->subtype;
593 if (subsubtype->full_type)
594 subsubtype = subsubtype->full_type;
595 elm_size = subsubtype->byte_size;
600 for (int i = 0; i < type->element_count; i++) {
601 // TODO, add support for variable stride (DW_AT_byte_stride)
602 if (heap_area_differ_with_type(state, (const char*)real_area1 + (i * elm_size),
603 (const char*)real_area2 + (i * elm_size), snapshot1, snapshot2, previous,
604 type->subtype, subtype->byte_size, check_ignore, pointer_level))
609 case DW_TAG_reference_type:
610 case DW_TAG_rvalue_reference_type:
611 case DW_TAG_pointer_type:
612 if (type->subtype && type->subtype->type == DW_TAG_subroutine_type) {
613 addr_pointed1 = snapshot1.read(remote((void* const*)real_area1));
614 addr_pointed2 = snapshot2.read(remote((void* const*)real_area2));
615 return (addr_pointed1 != addr_pointed2);
618 if (pointer_level <= 1) {
619 addr_pointed1 = snapshot1.read(remote((void* const*)real_area1));
620 addr_pointed2 = snapshot2.read(remote((void* const*)real_area2));
621 if (snapshot1.on_heap(addr_pointed1) && snapshot2.on_heap(addr_pointed2))
622 return heap_area_differ(state, addr_pointed1, addr_pointed2, snapshot1, snapshot2, previous, type->subtype,
625 return (addr_pointed1 != addr_pointed2);
627 for (size_t i = 0; i < (area_size / sizeof(void*)); i++) {
628 addr_pointed1 = snapshot1.read(remote((void* const*)((const char*)real_area1 + i * sizeof(void*))));
629 addr_pointed2 = snapshot2.read(remote((void* const*)((const char*)real_area2 + i * sizeof(void*))));
630 bool differ = snapshot1.on_heap(addr_pointed1) && snapshot2.on_heap(addr_pointed2)
631 ? heap_area_differ(state, addr_pointed1, addr_pointed2, snapshot1, snapshot2, previous,
632 type->subtype, pointer_level)
633 : addr_pointed1 != addr_pointed2;
639 case DW_TAG_structure_type:
640 case DW_TAG_class_type:
642 type = type->full_type;
643 if (type->byte_size == 0)
645 if (area_size != -1 && type->byte_size != area_size) {
646 if (area_size <= type->byte_size || area_size % type->byte_size != 0)
648 for (size_t i = 0; i < (size_t)(area_size / type->byte_size); i++) {
649 if (heap_area_differ_with_type(state, (const char*)real_area1 + i * type->byte_size,
650 (const char*)real_area2 + i * type->byte_size, snapshot1, snapshot2, previous,
651 type, -1, check_ignore, 0))
655 for (simgrid::mc::Member& member : type->members) {
656 // TODO, optimize this? (for the offset case)
657 void* real_member1 = dwarf::resolve_member(real_area1, type, &member, &snapshot1);
658 void* real_member2 = dwarf::resolve_member(real_area2, type, &member, &snapshot2);
659 if (heap_area_differ_with_type(state, real_member1, real_member2, snapshot1, snapshot2, previous,
660 member.type, -1, check_ignore, 0))
666 case DW_TAG_union_type:
667 return heap_area_differ_without_type(state, real_area1, real_area2, snapshot1, snapshot2, previous,
668 type->byte_size, check_ignore);
675 /** Infer the type of a part of the block from the type of the block
677 * TODO, handle DW_TAG_array_type as well as arrays of the object ((*p)[5], p[5])
679 * TODO, handle subfields ((*p).bar.foo, (*p)[5].bar…)
681 * @param type DWARF type ID of the root address
683 * @return DWARF type ID for given offset
685 static Type* get_offset_type(void* real_base_address, Type* type, int offset, int area_size, const Snapshot& snapshot)
687 // Beginning of the block, the inferred variable type if the type of the block:
691 switch (type->type) {
692 case DW_TAG_structure_type:
693 case DW_TAG_class_type:
695 type = type->full_type;
696 if (area_size != -1 && type->byte_size != area_size) {
697 if (area_size > type->byte_size && area_size % type->byte_size == 0)
703 for (simgrid::mc::Member& member : type->members) {
704 if (member.has_offset_location()) {
705 // We have the offset, use it directly (shortcut):
706 if (member.offset() == offset)
709 void* real_member = dwarf::resolve_member(real_base_address, type, &member, &snapshot);
710 if ((char*)real_member - (char*)real_base_address == offset)
717 /* FIXME: other cases ? */
724 * @param area1 Process address for state 1
725 * @param area2 Process address for state 2
726 * @param snapshot1 Snapshot of state 1
727 * @param snapshot2 Snapshot of state 2
728 * @param previous Pairs of blocks already compared on the current path (or nullptr)
729 * @param type_id Type of variable
730 * @param pointer_level
731 * @return true when different, false otherwise (same or unknown)
733 static bool heap_area_differ(StateComparator& state, const void* area1, const void* area2, const Snapshot& snapshot1,
734 const Snapshot& snapshot2, HeapLocationPairs* previous, Type* type, int pointer_level)
736 const simgrid::mc::RemoteClient& process = mc_model_checker->process();
741 int check_ignore = 0;
749 Type* new_type1 = nullptr;
750 Type* new_type2 = nullptr;
752 bool match_pairs = false;
754 // This is the address of std_heap->heapinfo in the application process:
755 void* heapinfo_address = &((xbt_mheap_t)process.heap_address)->heapinfo;
757 const malloc_info* heapinfos1 = snapshot1.read(remote((const malloc_info**)heapinfo_address));
758 const malloc_info* heapinfos2 = snapshot2.read(remote((const malloc_info**)heapinfo_address));
760 malloc_info heapinfo_temp1;
761 malloc_info heapinfo_temp2;
763 simgrid::mc::HeapLocationPairs current;
764 if (previous == nullptr) {
770 block1 = ((char*)area1 - (char*)state.std_heap_copy.heapbase) / BLOCKSIZE + 1;
771 block2 = ((char*)area2 - (char*)state.std_heap_copy.heapbase) / BLOCKSIZE + 1;
773 // If either block is a stack block:
774 if (is_block_stack((int) block1) && is_block_stack((int) block2)) {
775 previous->insert(HeapLocationPair{{HeapLocation(block1, -1), HeapLocation(block2, -1)}});
777 state.match_equals(previous);
781 // If either block is not in the expected area of memory:
782 if (((char*)area1 < (char*)state.std_heap_copy.heapbase) || (block1 > (ssize_t)state.processStates[0].heapsize) ||
783 (block1 < 1) || ((char*)area2 < (char*)state.std_heap_copy.heapbase) ||
784 (block2 > (ssize_t)state.processStates[1].heapsize) || (block2 < 1)) {
788 // Process address of the block:
789 void* real_addr_block1 = (ADDR2UINT(block1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
790 void* real_addr_block2 = (ADDR2UINT(block2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
794 type = type->full_type;
796 // This assume that for "boring" types (volatile ...) byte_size is absent:
797 while (type->byte_size == 0 && type->subtype != nullptr)
798 type = type->subtype;
801 if (type->type == DW_TAG_pointer_type ||
802 (type->type == DW_TAG_base_type && not type->name.empty() && type->name == "char"))
805 type_size = type->byte_size;
808 simgrid::mc::Region* heap_region1 = MC_get_heap_region(snapshot1);
809 simgrid::mc::Region* heap_region2 = MC_get_heap_region(snapshot2);
811 const malloc_info* heapinfo1 =
812 (const malloc_info*)heap_region1->read(&heapinfo_temp1, &heapinfos1[block1], sizeof(malloc_info));
813 const malloc_info* heapinfo2 =
814 (const malloc_info*)heap_region2->read(&heapinfo_temp2, &heapinfos2[block2], sizeof(malloc_info));
816 if ((heapinfo1->type == MMALLOC_TYPE_FREE || heapinfo1->type==MMALLOC_TYPE_HEAPINFO)
817 && (heapinfo2->type == MMALLOC_TYPE_FREE || heapinfo2->type ==MMALLOC_TYPE_HEAPINFO)) {
820 state.match_equals(previous);
824 if (heapinfo1->type == MMALLOC_TYPE_UNFRAGMENTED && heapinfo2->type == MMALLOC_TYPE_UNFRAGMENTED) {
827 // TODO, lookup variable type from block type as done for fragmented blocks
829 if (state.equals_to_<1>(block1, 0).valid_ && state.equals_to_<2>(block2, 0).valid_ &&
830 state.blocksEqual(block1, block2)) {
832 state.match_equals(previous);
836 if (type_size != -1 && type_size != (ssize_t)heapinfo1->busy_block.busy_size &&
837 type_size != (ssize_t)heapinfo2->busy_block.busy_size &&
838 (type->name.empty() || type->name == "struct s_smx_context")) {
840 state.match_equals(previous);
844 if (heapinfo1->busy_block.size != heapinfo2->busy_block.size ||
845 heapinfo1->busy_block.busy_size != heapinfo2->busy_block.busy_size)
848 if (not previous->insert(HeapLocationPair{{HeapLocation(block1, -1), HeapLocation(block2, -1)}}).second) {
850 state.match_equals(previous);
854 size = heapinfo1->busy_block.busy_size;
856 // Remember (basic) type inference.
857 // The current data structure only allows us to do this for the whole block.
858 if (type != nullptr && area1 == real_addr_block1)
859 state.types_<1>(block1, 0) = type;
860 if (type != nullptr && area2 == real_addr_block2)
861 state.types_<2>(block2, 0) = type;
865 state.match_equals(previous);
869 if (heapinfo1->busy_block.ignore > 0 && heapinfo2->busy_block.ignore == heapinfo1->busy_block.ignore)
870 check_ignore = heapinfo1->busy_block.ignore;
872 } else if ((heapinfo1->type > 0) && (heapinfo2->type > 0)) { /* Fragmented block */
874 ssize_t frag1 = ((uintptr_t)(ADDR2UINT(area1) % (BLOCKSIZE))) >> heapinfo1->type;
875 ssize_t frag2 = ((uintptr_t)(ADDR2UINT(area2) % (BLOCKSIZE))) >> heapinfo2->type;
877 // Process address of the fragment_:
878 void* real_addr_frag1 = (void*)((char*)real_addr_block1 + (frag1 << heapinfo1->type));
879 void* real_addr_frag2 = (void*)((char*)real_addr_block2 + (frag2 << heapinfo2->type));
881 // Check the size of the fragments against the size of the type:
882 if (type_size != -1) {
883 if (heapinfo1->busy_frag.frag_size[frag1] == -1 || heapinfo2->busy_frag.frag_size[frag2] == -1) {
885 state.match_equals(previous);
889 if (type_size != heapinfo1->busy_frag.frag_size[frag1]
890 || type_size != heapinfo2->busy_frag.frag_size[frag2]) {
892 state.match_equals(previous);
897 // Check if the blocks are already matched together:
898 if (state.equals_to_<1>(block1, frag1).valid_ && state.equals_to_<2>(block2, frag2).valid_ && offset1 == offset2 &&
899 state.fragmentsEqual(block1, frag1, block2, frag2)) {
901 state.match_equals(previous);
904 // Compare the size of both fragments:
905 if (heapinfo1->busy_frag.frag_size[frag1] != heapinfo2->busy_frag.frag_size[frag2]) {
906 if (type_size == -1) {
908 state.match_equals(previous);
914 // Size of the fragment_:
915 size = heapinfo1->busy_frag.frag_size[frag1];
917 // Remember (basic) type inference.
918 // The current data structure only allows us to do this for the whole fragment_.
919 if (type != nullptr && area1 == real_addr_frag1)
920 state.types_<1>(block1, frag1) = type;
921 if (type != nullptr && area2 == real_addr_frag2)
922 state.types_<2>(block2, frag2) = type;
924 // The type of the variable is already known:
926 new_type1 = new_type2 = type;
928 // Type inference from the block type.
929 else if (state.types_<1>(block1, frag1) != nullptr || state.types_<2>(block2, frag2) != nullptr) {
930 offset1 = (char*)area1 - (char*)real_addr_frag1;
931 offset2 = (char*)area2 - (char*)real_addr_frag2;
933 if (state.types_<1>(block1, frag1) != nullptr && state.types_<2>(block2, frag2) != nullptr) {
934 new_type1 = get_offset_type(real_addr_frag1, state.types_<1>(block1, frag1), offset1, size, snapshot1);
935 new_type2 = get_offset_type(real_addr_frag2, state.types_<2>(block2, frag2), offset1, size, snapshot2);
936 } else if (state.types_<1>(block1, frag1) != nullptr) {
937 new_type1 = get_offset_type(real_addr_frag1, state.types_<1>(block1, frag1), offset1, size, snapshot1);
938 new_type2 = get_offset_type(real_addr_frag2, state.types_<1>(block1, frag1), offset2, size, snapshot2);
939 } else if (state.types_<2>(block2, frag2) != nullptr) {
940 new_type1 = get_offset_type(real_addr_frag1, state.types_<2>(block2, frag2), offset1, size, snapshot1);
941 new_type2 = get_offset_type(real_addr_frag2, state.types_<2>(block2, frag2), offset2, size, snapshot2);
944 state.match_equals(previous);
948 if (new_type1 != nullptr && new_type2 != nullptr && new_type1 != new_type2) {
950 while (type->byte_size == 0 && type->subtype != nullptr)
951 type = type->subtype;
952 new_size1 = type->byte_size;
955 while (type->byte_size == 0 && type->subtype != nullptr)
956 type = type->subtype;
957 new_size2 = type->byte_size;
961 state.match_equals(previous);
966 if (new_size1 > 0 && new_size1 == new_size2) {
971 if (offset1 == 0 && offset2 == 0 &&
972 not previous->insert(HeapLocationPair{{HeapLocation(block1, frag1), HeapLocation(block2, frag2)}}).second) {
974 state.match_equals(previous);
980 state.match_equals(previous);
984 if ((heapinfo1->busy_frag.ignore[frag1] > 0) &&
985 (heapinfo2->busy_frag.ignore[frag2] == heapinfo1->busy_frag.ignore[frag1]))
986 check_ignore = heapinfo1->busy_frag.ignore[frag1];
990 /* Start comparison */
992 type ? heap_area_differ_with_type(state, area1, area2, snapshot1, snapshot2, previous, type, size, check_ignore,
994 : heap_area_differ_without_type(state, area1, area2, snapshot1, snapshot2, previous, size, check_ignore);
999 state.match_equals(previous);
1003 } // namespace simgrid
1005 /************************** Snapshot comparison *******************************/
1006 /******************************************************************************/
1008 static bool areas_differ_with_type(simgrid::mc::StateComparator& state, const void* real_area1,
1009 const simgrid::mc::Snapshot& snapshot1, simgrid::mc::Region* region1,
1010 const void* real_area2, const simgrid::mc::Snapshot& snapshot2,
1011 simgrid::mc::Region* region2, simgrid::mc::Type* type, int pointer_level)
1013 simgrid::mc::Type* subtype;
1014 simgrid::mc::Type* subsubtype;
1018 xbt_assert(type != nullptr);
1019 switch (type->type) {
1020 case DW_TAG_unspecified_type:
1023 case DW_TAG_base_type:
1024 case DW_TAG_enumeration_type:
1025 case DW_TAG_union_type:
1026 return MC_snapshot_region_memcmp(real_area1, region1, real_area2, region2, type->byte_size) != 0;
1027 case DW_TAG_typedef:
1028 case DW_TAG_volatile_type:
1029 case DW_TAG_const_type:
1030 return areas_differ_with_type(state, real_area1, snapshot1, region1, real_area2, snapshot2, region2,
1031 type->subtype, pointer_level);
1032 case DW_TAG_array_type:
1033 subtype = type->subtype;
1034 switch (subtype->type) {
1035 case DW_TAG_unspecified_type:
1038 case DW_TAG_base_type:
1039 case DW_TAG_enumeration_type:
1040 case DW_TAG_pointer_type:
1041 case DW_TAG_reference_type:
1042 case DW_TAG_rvalue_reference_type:
1043 case DW_TAG_structure_type:
1044 case DW_TAG_class_type:
1045 case DW_TAG_union_type:
1046 if (subtype->full_type)
1047 subtype = subtype->full_type;
1048 elm_size = subtype->byte_size;
1050 case DW_TAG_const_type:
1051 case DW_TAG_typedef:
1052 case DW_TAG_volatile_type:
1053 subsubtype = subtype->subtype;
1054 if (subsubtype->full_type)
1055 subsubtype = subsubtype->full_type;
1056 elm_size = subsubtype->byte_size;
1061 for (i = 0; i < type->element_count; i++) {
1062 size_t off = i * elm_size;
1063 if (areas_differ_with_type(state, (const char*)real_area1 + off, snapshot1, region1,
1064 (const char*)real_area2 + off, snapshot2, region2, type->subtype, pointer_level))
1068 case DW_TAG_pointer_type:
1069 case DW_TAG_reference_type:
1070 case DW_TAG_rvalue_reference_type: {
1071 const void* addr_pointed1 = MC_region_read_pointer(region1, real_area1);
1072 const void* addr_pointed2 = MC_region_read_pointer(region2, real_area2);
1074 if (type->subtype && type->subtype->type == DW_TAG_subroutine_type)
1075 return (addr_pointed1 != addr_pointed2);
1076 if (addr_pointed1 == nullptr && addr_pointed2 == nullptr)
1078 if (addr_pointed1 == nullptr || addr_pointed2 == nullptr)
1080 if (not state.compared_pointers.insert(std::make_pair(addr_pointed1, addr_pointed2)).second)
1085 // Some cases are not handled here:
1086 // * the pointers lead to different areas (one to the heap, the other to the RW segment ...)
1087 // * a pointer leads to the read-only segment of the current object
1088 // * a pointer lead to a different ELF object
1090 if (snapshot1.on_heap(addr_pointed1)) {
1091 if (not snapshot2.on_heap(addr_pointed2))
1093 // The pointers are both in the heap:
1094 return simgrid::mc::heap_area_differ(state, addr_pointed1, addr_pointed2, snapshot1, snapshot2, nullptr,
1095 type->subtype, pointer_level);
1097 } else if (region1->contain(simgrid::mc::remote(addr_pointed1))) {
1098 // The pointers are both in the current object R/W segment:
1099 if (not region2->contain(simgrid::mc::remote(addr_pointed2)))
1101 if (not type->type_id)
1102 return (addr_pointed1 != addr_pointed2);
1104 return areas_differ_with_type(state, addr_pointed1, snapshot1, region1, addr_pointed2, snapshot2, region2,
1105 type->subtype, pointer_level);
1107 // TODO, We do not handle very well the case where
1108 // it belongs to a different (non-heap) region from the current one.
1110 return (addr_pointed1 != addr_pointed2);
1113 case DW_TAG_structure_type:
1114 case DW_TAG_class_type:
1115 for (simgrid::mc::Member& member : type->members) {
1116 void* member1 = simgrid::dwarf::resolve_member(real_area1, type, &member, &snapshot1);
1117 void* member2 = simgrid::dwarf::resolve_member(real_area2, type, &member, &snapshot2);
1118 simgrid::mc::Region* subregion1 = snapshot1.get_region(member1, region1); // region1 is hinted
1119 simgrid::mc::Region* subregion2 = snapshot2.get_region(member2, region2); // region2 is hinted
1120 if (areas_differ_with_type(state, member1, snapshot1, subregion1, member2, snapshot2, subregion2, member.type,
1125 case DW_TAG_subroutine_type:
1128 XBT_VERB("Unknown case: %d", type->type);
1135 static bool global_variables_differ(simgrid::mc::StateComparator& state, simgrid::mc::ObjectInformation* object_info,
1136 simgrid::mc::Region* r1, simgrid::mc::Region* r2,
1137 const simgrid::mc::Snapshot& snapshot1, const simgrid::mc::Snapshot& snapshot2)
1139 xbt_assert(r1 && r2, "Missing region.");
1141 const std::vector<simgrid::mc::Variable>& variables = object_info->global_variables;
1143 for (simgrid::mc::Variable const& current_var : variables) {
1144 // If the variable is not in this object, skip it:
1145 // We do not expect to find a pointer to something which is not reachable
1146 // by the global variables.
1147 if ((char *) current_var.address < (char *) object_info->start_rw
1148 || (char *) current_var.address > (char *) object_info->end_rw)
1151 simgrid::mc::Type* bvariable_type = current_var.type;
1152 if (areas_differ_with_type(state, current_var.address, snapshot1, r1, current_var.address, snapshot2, r2,
1153 bvariable_type, 0)) {
1154 XBT_VERB("Global variable %s (%p) is different between snapshots", current_var.name.c_str(), current_var.address);
1162 static bool local_variables_differ(simgrid::mc::StateComparator& state, const simgrid::mc::Snapshot& snapshot1,
1163 const simgrid::mc::Snapshot& snapshot2, const_mc_snapshot_stack_t stack1,
1164 const_mc_snapshot_stack_t stack2)
1166 if (stack1->local_variables.size() != stack2->local_variables.size()) {
1167 XBT_VERB("Different number of local variables");
1171 for (unsigned int cursor = 0; cursor < stack1->local_variables.size(); cursor++) {
1172 const_local_variable_t current_var1 = &stack1->local_variables[cursor];
1173 const_local_variable_t current_var2 = &stack2->local_variables[cursor];
1174 if (current_var1->name != current_var2->name || current_var1->subprogram != current_var2->subprogram ||
1175 current_var1->ip != current_var2->ip) {
1176 // TODO, fix current_varX->subprogram->name to include name if DW_TAG_inlined_subprogram
1177 XBT_VERB("Different name of variable (%s - %s) or frame (%s - %s) or ip (%lu - %lu)", current_var1->name.c_str(),
1178 current_var2->name.c_str(), current_var1->subprogram->name.c_str(),
1179 current_var2->subprogram->name.c_str(), current_var1->ip, current_var2->ip);
1183 if (areas_differ_with_type(state, current_var1->address, snapshot1, snapshot1.get_region(current_var1->address),
1184 current_var2->address, snapshot2, snapshot2.get_region(current_var2->address),
1185 current_var1->type, 0)) {
1186 XBT_VERB("Local variable %s (%p - %p) in frame %s is different between snapshots", current_var1->name.c_str(),
1187 current_var1->address, current_var2->address, current_var1->subprogram->name.c_str());
1197 bool snapshot_equal(const Snapshot* s1, const Snapshot* s2)
1199 // TODO, make this a field of ModelChecker or something similar
1200 static StateComparator state_comparator;
1202 const RemoteClient& process = mc_model_checker->process();
1204 if (s1->hash_ != s2->hash_) {
1205 XBT_VERB("(%d - %d) Different hash: 0x%" PRIx64 "--0x%" PRIx64, s1->num_state_, s2->num_state_, s1->hash_,
1209 XBT_VERB("(%d - %d) Same hash: 0x%" PRIx64, s1->num_state_, s2->num_state_, s1->hash_);
1211 /* Compare enabled processes */
1212 if (s1->enabled_processes_ != s2->enabled_processes_) {
1213 XBT_VERB("(%d - %d) Different amount of enabled processes", s1->num_state_, s2->num_state_);
1217 /* Compare size of stacks */
1218 for (unsigned long i = 0; i < s1->stacks_.size(); i++) {
1219 size_t size_used1 = s1->stack_sizes_[i];
1220 size_t size_used2 = s2->stack_sizes_[i];
1221 if (size_used1 != size_used2) {
1222 XBT_VERB("(%d - %d) Different size used in stacks: %zu - %zu", s1->num_state_, s2->num_state_, size_used1,
1228 /* Init heap information used in heap comparison algorithm */
1229 xbt_mheap_t heap1 = static_cast<xbt_mheap_t>(s1->read_bytes(alloca(sizeof(struct mdesc)), sizeof(struct mdesc),
1230 remote(process.heap_address), ReadOptions::lazy()));
1231 xbt_mheap_t heap2 = static_cast<xbt_mheap_t>(s2->read_bytes(alloca(sizeof(struct mdesc)), sizeof(struct mdesc),
1232 remote(process.heap_address), ReadOptions::lazy()));
1233 if (state_comparator.initHeapInformation(heap1, heap2, s1->to_ignore_, s2->to_ignore_) == -1) {
1234 XBT_VERB("(%d - %d) Different heap information", s1->num_state_, s2->num_state_);
1238 /* Stacks comparison */
1239 for (unsigned int cursor = 0; cursor < s1->stacks_.size(); cursor++) {
1240 const_mc_snapshot_stack_t stack1 = &s1->stacks_[cursor];
1241 const_mc_snapshot_stack_t stack2 = &s2->stacks_[cursor];
1243 if (local_variables_differ(state_comparator, *s1, *s2, stack1, stack2)) {
1244 XBT_VERB("(%d - %d) Different local variables between stacks %u", s1->num_state_, s2->num_state_, cursor + 1);
1249 size_t regions_count = s1->snapshot_regions_.size();
1250 if (regions_count != s2->snapshot_regions_.size())
1253 for (size_t k = 0; k != regions_count; ++k) {
1254 Region* region1 = s1->snapshot_regions_[k].get();
1255 Region* region2 = s2->snapshot_regions_[k].get();
1258 if (region1->region_type() != RegionType::Data)
1261 xbt_assert(region1->region_type() == region2->region_type());
1262 xbt_assert(region1->object_info() == region2->object_info());
1263 xbt_assert(region1->object_info());
1265 /* Compare global variables */
1266 if (global_variables_differ(state_comparator, region1->object_info(), region1, region2, *s1, *s2)) {
1267 std::string const& name = region1->object_info()->file_name;
1268 XBT_VERB("(%d - %d) Different global variables in %s", s1->num_state_, s2->num_state_, name.c_str());
1274 if (mmalloc_heap_differ(state_comparator, *s1, *s2)) {
1275 XBT_VERB("(%d - %d) Different heap (mmalloc_compare)", s1->num_state_, s2->num_state_);
1279 XBT_VERB("(%d - %d) No difference found", s1->num_state_, s2->num_state_);
1284 } // namespace simgrid