1 /* Copyright (c) 2008-2021. 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"
15 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_compare, xbt, "Logging specific to mc_compare in mc");
17 using simgrid::mc::remote;
22 /*********************************** Heap comparison ***********************************/
23 /***************************************************************************************/
30 HeapLocation() = default;
31 explicit HeapLocation(int block, int fragment = 0) : block_(block), fragment_(fragment) {}
33 bool operator==(HeapLocation const& that) const
35 return block_ == that.block_ && fragment_ == that.fragment_;
37 bool operator<(HeapLocation const& that) const
39 return std::make_pair(block_, fragment_) < std::make_pair(that.block_, that.fragment_);
43 using HeapLocationPair = std::array<HeapLocation, 2>;
44 using HeapLocationPairs = std::set<HeapLocationPair>;
46 class HeapArea : public HeapLocation {
50 explicit HeapArea(int block) : valid_(true) { block_ = block; }
51 HeapArea(int block, int fragment) : valid_(true)
58 class ProcessComparisonState {
60 const std::vector<IgnoredHeapRegion>* to_ignore = nullptr;
61 std::vector<HeapArea> equals_to;
62 std::vector<Type*> types;
63 std::size_t heapsize = 0;
65 void initHeapInformation(const s_xbt_mheap_t* heap, const std::vector<IgnoredHeapRegion>& i);
68 class StateComparator {
70 s_xbt_mheap_t std_heap_copy;
71 std::size_t heaplimit;
72 std::array<ProcessComparisonState, 2> processStates;
74 std::unordered_set<std::pair<const void*, const void*>, simgrid::xbt::hash<std::pair<const void*, const void*>>>
79 compared_pointers.clear();
82 int initHeapInformation(const s_xbt_mheap_t* heap1, const s_xbt_mheap_t* heap2,
83 const std::vector<IgnoredHeapRegion>& i1, const std::vector<IgnoredHeapRegion>& i2);
85 template <int rank> HeapArea& equals_to_(std::size_t i, std::size_t j)
87 return processStates[rank - 1].equals_to[MAX_FRAGMENT_PER_BLOCK * i + j];
89 template <int rank> Type*& types_(std::size_t i, std::size_t j)
91 return processStates[rank - 1].types[MAX_FRAGMENT_PER_BLOCK * i + j];
94 template <int rank> HeapArea const& equals_to_(std::size_t i, std::size_t j) const
96 return processStates[rank - 1].equals_to[MAX_FRAGMENT_PER_BLOCK * i + j];
98 template <int rank> Type* const& types_(std::size_t i, std::size_t j) const
100 return processStates[rank - 1].types[MAX_FRAGMENT_PER_BLOCK * i + j];
103 /** Check whether two blocks are known to be matching
105 * @param b1 Block of state 1
106 * @param b2 Block of state 2
107 * @return if the blocks are known to be matching
109 bool blocksEqual(int b1, int b2) const
111 return this->equals_to_<1>(b1, 0).block_ == b2 && this->equals_to_<2>(b2, 0).block_ == b1;
114 /** Check whether two fragments are known to be matching
116 * @param b1 Block of state 1
117 * @param f1 Fragment of state 1
118 * @param b2 Block of state 2
119 * @param f2 Fragment of state 2
120 * @return if the fragments are known to be matching
122 int fragmentsEqual(int b1, int f1, int b2, int f2) const
124 return this->equals_to_<1>(b1, f1).block_ == b2 && this->equals_to_<1>(b1, f1).fragment_ == f2 &&
125 this->equals_to_<2>(b2, f2).block_ == b1 && this->equals_to_<2>(b2, f2).fragment_ == f1;
128 void match_equals(const HeapLocationPairs* list);
132 } // namespace simgrid
134 /************************************************************************************/
136 static ssize_t heap_comparison_ignore_size(const std::vector<simgrid::mc::IgnoredHeapRegion>* ignore_list,
139 auto pos = std::lower_bound(ignore_list->begin(), ignore_list->end(), address,
140 [](auto const& reg, auto const* addr) { return reg.address < addr; });
141 return (pos != ignore_list->end() && pos->address == address) ? pos->size : -1;
144 static bool is_stack(const void *address)
146 auto const& stack_areas = mc_model_checker->get_remote_simulation().stack_areas();
147 return std::any_of(stack_areas.begin(), stack_areas.end(),
148 [address](auto const& stack) { return stack.address == address; });
151 // TODO, this should depend on the snapshot?
152 static bool is_block_stack(int block)
154 auto const& stack_areas = mc_model_checker->get_remote_simulation().stack_areas();
155 return std::any_of(stack_areas.begin(), stack_areas.end(),
156 [block](auto const& stack) { return stack.block == block; });
162 void StateComparator::match_equals(const HeapLocationPairs* list)
164 for (auto const& pair : *list) {
165 if (pair[0].fragment_ != -1) {
166 this->equals_to_<1>(pair[0].block_, pair[0].fragment_) = HeapArea(pair[1].block_, pair[1].fragment_);
167 this->equals_to_<2>(pair[1].block_, pair[1].fragment_) = HeapArea(pair[0].block_, pair[0].fragment_);
169 this->equals_to_<1>(pair[0].block_, 0) = HeapArea(pair[1].block_, pair[1].fragment_);
170 this->equals_to_<2>(pair[1].block_, 0) = HeapArea(pair[0].block_, pair[0].fragment_);
175 void ProcessComparisonState::initHeapInformation(const s_xbt_mheap_t* heap, const std::vector<IgnoredHeapRegion>& i)
177 auto heaplimit = heap->heaplimit;
178 this->heapsize = heap->heapsize;
179 this->to_ignore = &i;
180 this->equals_to.assign(heaplimit * MAX_FRAGMENT_PER_BLOCK, HeapArea());
181 this->types.assign(heaplimit * MAX_FRAGMENT_PER_BLOCK, nullptr);
184 int StateComparator::initHeapInformation(const s_xbt_mheap_t* heap1, const s_xbt_mheap_t* heap2,
185 const std::vector<IgnoredHeapRegion>& i1,
186 const std::vector<IgnoredHeapRegion>& i2)
188 if ((heap1->heaplimit != heap2->heaplimit) || (heap1->heapsize != heap2->heapsize))
190 this->heaplimit = heap1->heaplimit;
191 this->std_heap_copy = *mc_model_checker->get_remote_simulation().get_heap();
192 this->processStates[0].initHeapInformation(heap1, i1);
193 this->processStates[1].initHeapInformation(heap2, i2);
197 // TODO, have a robust way to find it in O(1)
198 static inline Region* MC_get_heap_region(const Snapshot& snapshot)
200 for (auto const& region : snapshot.snapshot_regions_)
201 if (region->region_type() == RegionType::Heap)
203 xbt_die("No heap region");
206 static bool heap_area_differ(StateComparator& state, const void* area1, const void* area2, const Snapshot& snapshot1,
207 const Snapshot& snapshot2, HeapLocationPairs* previous, Type* type, int pointer_level);
209 static bool mmalloc_heap_differ(StateComparator& state, const Snapshot& snapshot1, const Snapshot& snapshot2)
211 const RemoteSimulation& process = mc_model_checker->get_remote_simulation();
213 /* Check busy blocks */
216 malloc_info heapinfo_temp1;
217 malloc_info heapinfo_temp2;
218 malloc_info heapinfo_temp2b;
220 const Region* heap_region1 = MC_get_heap_region(snapshot1);
221 const Region* heap_region2 = MC_get_heap_region(snapshot2);
223 // This is the address of std_heap->heapinfo in the application process:
224 void* heapinfo_address = &((xbt_mheap_t)process.heap_address)->heapinfo;
226 // This is in snapshot do not use them directly:
227 const malloc_info* heapinfos1 =
228 snapshot1.read<malloc_info*>(RemotePtr<malloc_info*>((std::uint64_t)heapinfo_address));
229 const malloc_info* heapinfos2 =
230 snapshot2.read<malloc_info*>(RemotePtr<malloc_info*>((std::uint64_t)heapinfo_address));
232 while (i1 < state.heaplimit) {
233 const auto* heapinfo1 =
234 static_cast<malloc_info*>(heap_region1->read(&heapinfo_temp1, &heapinfos1[i1], sizeof(malloc_info)));
235 const auto* heapinfo2 =
236 static_cast<malloc_info*>(heap_region2->read(&heapinfo_temp2, &heapinfos2[i1], sizeof(malloc_info)));
238 if (heapinfo1->type == MMALLOC_TYPE_FREE || heapinfo1->type == MMALLOC_TYPE_HEAPINFO) { /* Free block */
243 xbt_assert(heapinfo1->type >= 0, "Unknown mmalloc block type: %d", heapinfo1->type);
245 void* addr_block1 = ((void*)(((ADDR2UINT(i1)) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase));
247 if (heapinfo1->type == MMALLOC_TYPE_UNFRAGMENTED) { /* Large block */
248 if (is_stack(addr_block1)) {
249 for (size_t k = 0; k < heapinfo1->busy_block.size; k++)
250 state.equals_to_<1>(i1 + k, 0) = HeapArea(i1, -1);
251 for (size_t k = 0; k < heapinfo2->busy_block.size; k++)
252 state.equals_to_<2>(i1 + k, 0) = HeapArea(i1, -1);
253 i1 += heapinfo1->busy_block.size;
257 if (state.equals_to_<1>(i1, 0).valid_) {
265 /* Try first to associate to same block in the other heap */
266 if (heapinfo2->type == heapinfo1->type && state.equals_to_<2>(i1, 0).valid_ == 0) {
267 const void* addr_block2 = (ADDR2UINT(i1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
268 if (not heap_area_differ(state, addr_block1, addr_block2, snapshot1, snapshot2, nullptr, nullptr, 0)) {
269 for (size_t k = 1; k < heapinfo2->busy_block.size; k++)
270 state.equals_to_<2>(i1 + k, 0) = HeapArea(i1, -1);
271 for (size_t k = 1; k < heapinfo1->busy_block.size; k++)
272 state.equals_to_<1>(i1 + k, 0) = HeapArea(i1, -1);
274 i1 += heapinfo1->busy_block.size;
278 while (i2 < state.heaplimit && not equal) {
279 const void* addr_block2 = (ADDR2UINT(i2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
286 const auto* heapinfo2b =
287 static_cast<malloc_info*>(heap_region2->read(&heapinfo_temp2b, &heapinfos2[i2], sizeof(malloc_info)));
289 if (heapinfo2b->type != MMALLOC_TYPE_UNFRAGMENTED) {
294 if (state.equals_to_<2>(i2, 0).valid_) {
299 if (not heap_area_differ(state, addr_block1, addr_block2, snapshot1, snapshot2, nullptr, nullptr, 0)) {
300 for (size_t k = 1; k < heapinfo2b->busy_block.size; k++)
301 state.equals_to_<2>(i2 + k, 0) = HeapArea(i1, -1);
302 for (size_t k = 1; k < heapinfo1->busy_block.size; k++)
303 state.equals_to_<1>(i1 + k, 0) = HeapArea(i2, -1);
305 i1 += heapinfo1->busy_block.size;
311 XBT_DEBUG("Block %zu not found (size_used = %zu, addr = %p)", i1, heapinfo1->busy_block.busy_size, addr_block1);
314 } else { /* Fragmented block */
315 for (size_t j1 = 0; j1 < (size_t)(BLOCKSIZE >> heapinfo1->type); j1++) {
316 if (heapinfo1->busy_frag.frag_size[j1] == -1) /* Free fragment_ */
319 if (state.equals_to_<1>(i1, j1).valid_)
322 void* addr_frag1 = (char*)addr_block1 + (j1 << heapinfo1->type);
327 /* Try first to associate to same fragment_ in the other heap */
328 if (heapinfo2->type == heapinfo1->type && not state.equals_to_<2>(i1, j1).valid_) {
329 const void* addr_block2 = (ADDR2UINT(i1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
330 const void* addr_frag2 = (const char*)addr_block2 + (j1 << heapinfo2->type);
331 if (not heap_area_differ(state, addr_frag1, addr_frag2, snapshot1, snapshot2, nullptr, nullptr, 0))
335 while (i2 < state.heaplimit && not equal) {
336 const auto* heapinfo2b =
337 static_cast<malloc_info*>(heap_region2->read(&heapinfo_temp2b, &heapinfos2[i2], sizeof(malloc_info)));
339 if (heapinfo2b->type == MMALLOC_TYPE_FREE || heapinfo2b->type == MMALLOC_TYPE_HEAPINFO) {
344 // We currently do not match fragments with unfragmented blocks (maybe we should).
345 if (heapinfo2b->type == MMALLOC_TYPE_UNFRAGMENTED) {
350 xbt_assert(heapinfo2b->type >= 0, "Unknown mmalloc block type: %d", heapinfo2b->type);
352 for (size_t j2 = 0; j2 < (size_t)(BLOCKSIZE >> heapinfo2b->type); j2++) {
353 if (i2 == i1 && j2 == j1)
356 if (state.equals_to_<2>(i2, j2).valid_)
359 const void* addr_block2 = (ADDR2UINT(i2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
360 const void* addr_frag2 = (const char*)addr_block2 + (j2 << heapinfo2b->type);
362 if (not heap_area_differ(state, addr_frag1, addr_frag2, snapshot1, snapshot2, nullptr, nullptr, 0)) {
371 XBT_DEBUG("Block %zu, fragment_ %zu not found (size_used = %zd, address = %p)\n", i1, j1,
372 heapinfo1->busy_frag.frag_size[j1], addr_frag1);
380 /* All blocks/fragments are equal to another block/fragment_ ? */
381 for (size_t i = 1; i < state.heaplimit; i++) {
382 const auto* heapinfo1 =
383 static_cast<malloc_info*>(heap_region1->read(&heapinfo_temp1, &heapinfos1[i], sizeof(malloc_info)));
385 if (heapinfo1->type == MMALLOC_TYPE_UNFRAGMENTED && i1 == state.heaplimit && heapinfo1->busy_block.busy_size > 0 &&
386 not state.equals_to_<1>(i, 0).valid_) {
387 XBT_DEBUG("Block %zu not found (size used = %zu)", i, heapinfo1->busy_block.busy_size);
391 if (heapinfo1->type <= 0)
393 for (size_t j = 0; j < (size_t)(BLOCKSIZE >> heapinfo1->type); j++)
394 if (i1 == state.heaplimit && heapinfo1->busy_frag.frag_size[j] > 0 && not state.equals_to_<1>(i, j).valid_) {
395 XBT_DEBUG("Block %zu, Fragment %zu not found (size used = %zd)", i, j, heapinfo1->busy_frag.frag_size[j]);
400 for (size_t i = 1; i < state.heaplimit; i++) {
401 const auto* heapinfo2 =
402 static_cast<malloc_info*>(heap_region2->read(&heapinfo_temp2, &heapinfos2[i], sizeof(malloc_info)));
403 if (heapinfo2->type == MMALLOC_TYPE_UNFRAGMENTED && i1 == state.heaplimit && heapinfo2->busy_block.busy_size > 0 &&
404 not state.equals_to_<2>(i, 0).valid_) {
405 XBT_DEBUG("Block %zu not found (size used = %zu)", i,
406 heapinfo2->busy_block.busy_size);
410 if (heapinfo2->type <= 0)
413 for (size_t j = 0; j < (size_t)(BLOCKSIZE >> heapinfo2->type); j++)
414 if (i1 == state.heaplimit && heapinfo2->busy_frag.frag_size[j] > 0 && not state.equals_to_<2>(i, j).valid_) {
415 XBT_DEBUG("Block %zu, Fragment %zu not found (size used = %zd)",
416 i, j, heapinfo2->busy_frag.frag_size[j]);
426 * @param real_area1 Process address for state 1
427 * @param real_area2 Process address for state 2
428 * @param snapshot1 Snapshot of state 1
429 * @param snapshot2 Snapshot of state 2
432 * @param check_ignore
433 * @return true when different, false otherwise (same or unknown)
435 static bool heap_area_differ_without_type(StateComparator& state, const void* real_area1, const void* real_area2,
436 const Snapshot& snapshot1, const Snapshot& snapshot2,
437 HeapLocationPairs* previous, int size, int check_ignore)
439 const RemoteSimulation& process = mc_model_checker->get_remote_simulation();
440 const Region* heap_region1 = MC_get_heap_region(snapshot1);
441 const Region* heap_region2 = MC_get_heap_region(snapshot2);
443 for (int i = 0; i < size; ) {
444 if (check_ignore > 0) {
445 ssize_t ignore1 = heap_comparison_ignore_size(state.processStates[0].to_ignore, (const char*)real_area1 + i);
447 ssize_t ignore2 = heap_comparison_ignore_size(state.processStates[1].to_ignore, (const char*)real_area2 + i);
448 if (ignore2 == ignore1) {
460 if (MC_snapshot_region_memcmp((const char*)real_area1 + i, heap_region1, (const char*)real_area2 + i, heap_region2,
462 int pointer_align = (i / sizeof(void *)) * sizeof(void *);
463 const void* addr_pointed1 = snapshot1.read(remote((void* const*)((const char*)real_area1 + pointer_align)));
464 const void* addr_pointed2 = snapshot2.read(remote((void* const*)((const char*)real_area2 + pointer_align)));
466 if (process.in_maestro_stack(remote(addr_pointed1)) && process.in_maestro_stack(remote(addr_pointed2))) {
467 i = pointer_align + sizeof(void *);
471 if (snapshot1.on_heap(addr_pointed1) && snapshot2.on_heap(addr_pointed2)) {
472 // Both addresses are in the heap:
473 if (heap_area_differ(state, addr_pointed1, addr_pointed2, snapshot1, snapshot2, previous, nullptr, 0))
475 i = pointer_align + sizeof(void *);
488 * @param real_area1 Process address for state 1
489 * @param real_area2 Process address for state 2
490 * @param snapshot1 Snapshot of state 1
491 * @param snapshot2 Snapshot of state 2
494 * @param area_size either a byte_size or an elements_count (?)
495 * @param check_ignore
496 * @param pointer_level
497 * @return true when different, false otherwise (same or unknown)
499 static bool heap_area_differ_with_type(StateComparator& state, const void* real_area1, const void* real_area2,
500 const Snapshot& snapshot1, const Snapshot& snapshot2,
501 HeapLocationPairs* previous, const Type* type, int area_size, int check_ignore,
504 // HACK: This should not happen but in practice, there are some
505 // DW_TAG_typedef without an associated DW_AT_type:
506 //<1><538832>: Abbrev Number: 111 (DW_TAG_typedef)
507 // <538833> DW_AT_name : (indirect string, offset: 0x2292f3): gregset_t
508 // <538837> DW_AT_decl_file : 98
509 // <538838> DW_AT_decl_line : 37
513 if (is_stack(real_area1) && is_stack(real_area2))
516 if (check_ignore > 0) {
517 ssize_t ignore1 = heap_comparison_ignore_size(state.processStates[0].to_ignore, real_area1);
518 if (ignore1 > 0 && heap_comparison_ignore_size(state.processStates[1].to_ignore, real_area2) == ignore1)
523 const Type* subsubtype;
525 const void* addr_pointed1;
526 const void* addr_pointed2;
528 const Region* heap_region1 = MC_get_heap_region(snapshot1);
529 const Region* heap_region2 = MC_get_heap_region(snapshot2);
531 switch (type->type) {
532 case DW_TAG_unspecified_type:
535 case DW_TAG_base_type:
536 if (not type->name.empty() && type->name == "char") { /* String, hence random (arbitrary ?) size */
537 if (real_area1 == real_area2)
540 return MC_snapshot_region_memcmp(real_area1, heap_region1, real_area2, heap_region2, area_size) != 0;
542 if (area_size != -1 && type->byte_size != area_size)
545 return MC_snapshot_region_memcmp(real_area1, heap_region1, real_area2, heap_region2, type->byte_size) != 0;
548 case DW_TAG_enumeration_type:
549 if (area_size != -1 && type->byte_size != area_size)
551 return MC_snapshot_region_memcmp(real_area1, heap_region1, real_area2, heap_region2, type->byte_size) != 0;
554 case DW_TAG_const_type:
555 case DW_TAG_volatile_type:
556 return heap_area_differ_with_type(state, real_area1, real_area2, snapshot1, snapshot2, previous, type->subtype,
557 area_size, check_ignore, pointer_level);
559 case DW_TAG_array_type:
560 subtype = type->subtype;
561 switch (subtype->type) {
562 case DW_TAG_unspecified_type:
565 case DW_TAG_base_type:
566 case DW_TAG_enumeration_type:
567 case DW_TAG_pointer_type:
568 case DW_TAG_reference_type:
569 case DW_TAG_rvalue_reference_type:
570 case DW_TAG_structure_type:
571 case DW_TAG_class_type:
572 case DW_TAG_union_type:
573 if (subtype->full_type)
574 subtype = subtype->full_type;
575 elm_size = subtype->byte_size;
577 // TODO, just remove the type indirection?
578 case DW_TAG_const_type:
580 case DW_TAG_volatile_type:
581 subsubtype = subtype->subtype;
582 if (subsubtype->full_type)
583 subsubtype = subsubtype->full_type;
584 elm_size = subsubtype->byte_size;
589 for (int i = 0; i < type->element_count; i++) {
590 // TODO, add support for variable stride (DW_AT_byte_stride)
591 if (heap_area_differ_with_type(state, (const char*)real_area1 + (i * elm_size),
592 (const char*)real_area2 + (i * elm_size), snapshot1, snapshot2, previous,
593 type->subtype, subtype->byte_size, check_ignore, pointer_level))
598 case DW_TAG_reference_type:
599 case DW_TAG_rvalue_reference_type:
600 case DW_TAG_pointer_type:
601 if (type->subtype && type->subtype->type == DW_TAG_subroutine_type) {
602 addr_pointed1 = snapshot1.read(remote((void* const*)real_area1));
603 addr_pointed2 = snapshot2.read(remote((void* const*)real_area2));
604 return (addr_pointed1 != addr_pointed2);
607 if (pointer_level <= 1) {
608 addr_pointed1 = snapshot1.read(remote((void* const*)real_area1));
609 addr_pointed2 = snapshot2.read(remote((void* const*)real_area2));
610 if (snapshot1.on_heap(addr_pointed1) && snapshot2.on_heap(addr_pointed2))
611 return heap_area_differ(state, addr_pointed1, addr_pointed2, snapshot1, snapshot2, previous, type->subtype,
614 return (addr_pointed1 != addr_pointed2);
616 for (size_t i = 0; i < (area_size / sizeof(void*)); i++) {
617 addr_pointed1 = snapshot1.read(remote((void* const*)((const char*)real_area1 + i * sizeof(void*))));
618 addr_pointed2 = snapshot2.read(remote((void* const*)((const char*)real_area2 + i * sizeof(void*))));
619 bool differ = snapshot1.on_heap(addr_pointed1) && snapshot2.on_heap(addr_pointed2)
620 ? heap_area_differ(state, addr_pointed1, addr_pointed2, snapshot1, snapshot2, previous,
621 type->subtype, pointer_level)
622 : addr_pointed1 != addr_pointed2;
628 case DW_TAG_structure_type:
629 case DW_TAG_class_type:
631 type = type->full_type;
632 if (type->byte_size == 0)
634 if (area_size != -1 && type->byte_size != area_size) {
635 if (area_size <= type->byte_size || area_size % type->byte_size != 0)
637 for (size_t i = 0; i < (size_t)(area_size / type->byte_size); i++) {
638 if (heap_area_differ_with_type(state, (const char*)real_area1 + i * type->byte_size,
639 (const char*)real_area2 + i * type->byte_size, snapshot1, snapshot2, previous,
640 type, -1, check_ignore, 0))
644 for (const simgrid::mc::Member& member : type->members) {
645 // TODO, optimize this? (for the offset case)
646 const void* real_member1 = dwarf::resolve_member(real_area1, type, &member, &snapshot1);
647 const void* real_member2 = dwarf::resolve_member(real_area2, type, &member, &snapshot2);
648 if (heap_area_differ_with_type(state, real_member1, real_member2, snapshot1, snapshot2, previous,
649 member.type, -1, check_ignore, 0))
655 case DW_TAG_union_type:
656 return heap_area_differ_without_type(state, real_area1, real_area2, snapshot1, snapshot2, previous,
657 type->byte_size, check_ignore);
664 /** Infer the type of a part of the block from the type of the block
666 * TODO, handle DW_TAG_array_type as well as arrays of the object ((*p)[5], p[5])
668 * TODO, handle subfields ((*p).bar.foo, (*p)[5].bar…)
670 * @param type DWARF type ID of the root address
672 * @return DWARF type ID for given offset
674 static Type* get_offset_type(void* real_base_address, Type* type, int offset, int area_size, const Snapshot& snapshot)
676 // Beginning of the block, the inferred variable type if the type of the block:
680 switch (type->type) {
681 case DW_TAG_structure_type:
682 case DW_TAG_class_type:
684 type = type->full_type;
685 if (area_size != -1 && type->byte_size != area_size) {
686 if (area_size > type->byte_size && area_size % type->byte_size == 0)
692 for (const simgrid::mc::Member& member : type->members) {
693 if (member.has_offset_location()) {
694 // We have the offset, use it directly (shortcut):
695 if (member.offset() == offset)
698 void* real_member = dwarf::resolve_member(real_base_address, type, &member, &snapshot);
699 if ((char*)real_member - (char*)real_base_address == offset)
706 /* FIXME: other cases ? */
713 * @param area1 Process address for state 1
714 * @param area2 Process address for state 2
715 * @param snapshot1 Snapshot of state 1
716 * @param snapshot2 Snapshot of state 2
717 * @param previous Pairs of blocks already compared on the current path (or nullptr)
718 * @param type_id Type of variable
719 * @param pointer_level
720 * @return true when different, false otherwise (same or unknown)
722 static bool heap_area_differ(StateComparator& state, const void* area1, const void* area2, const Snapshot& snapshot1,
723 const Snapshot& snapshot2, HeapLocationPairs* previous, Type* type, int pointer_level)
725 const simgrid::mc::RemoteSimulation& process = mc_model_checker->get_remote_simulation();
730 int check_ignore = 0;
738 Type* new_type1 = nullptr;
740 bool match_pairs = false;
742 // This is the address of std_heap->heapinfo in the application process:
743 void* heapinfo_address = &((xbt_mheap_t)process.heap_address)->heapinfo;
745 const malloc_info* heapinfos1 = snapshot1.read(remote((const malloc_info**)heapinfo_address));
746 const malloc_info* heapinfos2 = snapshot2.read(remote((const malloc_info**)heapinfo_address));
748 malloc_info heapinfo_temp1;
749 malloc_info heapinfo_temp2;
751 simgrid::mc::HeapLocationPairs current;
752 if (previous == nullptr) {
758 block1 = ((const char*)area1 - (const char*)state.std_heap_copy.heapbase) / BLOCKSIZE + 1;
759 block2 = ((const char*)area2 - (const char*)state.std_heap_copy.heapbase) / BLOCKSIZE + 1;
761 // If either block is a stack block:
762 if (is_block_stack((int) block1) && is_block_stack((int) block2)) {
763 previous->insert(HeapLocationPair{{HeapLocation(block1, -1), HeapLocation(block2, -1)}});
765 state.match_equals(previous);
769 // If either block is not in the expected area of memory:
770 if (((const char*)area1 < (const char*)state.std_heap_copy.heapbase) ||
771 (block1 > (ssize_t)state.processStates[0].heapsize) || (block1 < 1) ||
772 ((const char*)area2 < (const char*)state.std_heap_copy.heapbase) ||
773 (block2 > (ssize_t)state.processStates[1].heapsize) || (block2 < 1)) {
777 // Process address of the block:
778 void* real_addr_block1 = (ADDR2UINT(block1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
779 void* real_addr_block2 = (ADDR2UINT(block2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
783 type = type->full_type;
785 // This assume that for "boring" types (volatile ...) byte_size is absent:
786 while (type->byte_size == 0 && type->subtype != nullptr)
787 type = type->subtype;
790 if (type->type == DW_TAG_pointer_type ||
791 (type->type == DW_TAG_base_type && not type->name.empty() && type->name == "char"))
794 type_size = type->byte_size;
797 const Region* heap_region1 = MC_get_heap_region(snapshot1);
798 const Region* heap_region2 = MC_get_heap_region(snapshot2);
800 const auto* heapinfo1 =
801 static_cast<malloc_info*>(heap_region1->read(&heapinfo_temp1, &heapinfos1[block1], sizeof(malloc_info)));
802 const auto* heapinfo2 =
803 static_cast<malloc_info*>(heap_region2->read(&heapinfo_temp2, &heapinfos2[block2], sizeof(malloc_info)));
805 if ((heapinfo1->type == MMALLOC_TYPE_FREE || heapinfo1->type==MMALLOC_TYPE_HEAPINFO)
806 && (heapinfo2->type == MMALLOC_TYPE_FREE || heapinfo2->type ==MMALLOC_TYPE_HEAPINFO)) {
809 state.match_equals(previous);
813 if (heapinfo1->type == MMALLOC_TYPE_UNFRAGMENTED && heapinfo2->type == MMALLOC_TYPE_UNFRAGMENTED) {
816 // TODO, lookup variable type from block type as done for fragmented blocks
818 if (state.equals_to_<1>(block1, 0).valid_ && state.equals_to_<2>(block2, 0).valid_ &&
819 state.blocksEqual(block1, block2)) {
821 state.match_equals(previous);
825 if (type_size != -1 && type_size != (ssize_t)heapinfo1->busy_block.busy_size &&
826 type_size != (ssize_t)heapinfo2->busy_block.busy_size &&
827 (type->name.empty() || type->name == "struct s_smx_context")) {
829 state.match_equals(previous);
833 if (heapinfo1->busy_block.size != heapinfo2->busy_block.size ||
834 heapinfo1->busy_block.busy_size != heapinfo2->busy_block.busy_size)
837 if (not previous->insert(HeapLocationPair{{HeapLocation(block1, -1), HeapLocation(block2, -1)}}).second) {
839 state.match_equals(previous);
843 size = heapinfo1->busy_block.busy_size;
845 // Remember (basic) type inference.
846 // The current data structure only allows us to do this for the whole block.
847 if (type != nullptr && area1 == real_addr_block1)
848 state.types_<1>(block1, 0) = type;
849 if (type != nullptr && area2 == real_addr_block2)
850 state.types_<2>(block2, 0) = type;
854 state.match_equals(previous);
858 if (heapinfo1->busy_block.ignore > 0 && heapinfo2->busy_block.ignore == heapinfo1->busy_block.ignore)
859 check_ignore = heapinfo1->busy_block.ignore;
861 } else if ((heapinfo1->type > 0) && (heapinfo2->type > 0)) { /* Fragmented block */
863 ssize_t frag1 = (ADDR2UINT(area1) % BLOCKSIZE) >> heapinfo1->type;
864 ssize_t frag2 = (ADDR2UINT(area2) % BLOCKSIZE) >> heapinfo2->type;
866 // Process address of the fragment_:
867 void* real_addr_frag1 = (char*)real_addr_block1 + (frag1 << heapinfo1->type);
868 void* real_addr_frag2 = (char*)real_addr_block2 + (frag2 << heapinfo2->type);
870 // Check the size of the fragments against the size of the type:
871 if (type_size != -1) {
872 if (heapinfo1->busy_frag.frag_size[frag1] == -1 || heapinfo2->busy_frag.frag_size[frag2] == -1) {
874 state.match_equals(previous);
878 if (type_size != heapinfo1->busy_frag.frag_size[frag1]
879 || type_size != heapinfo2->busy_frag.frag_size[frag2]) {
881 state.match_equals(previous);
886 // Check if the blocks are already matched together:
887 if (state.equals_to_<1>(block1, frag1).valid_ && state.equals_to_<2>(block2, frag2).valid_ && offset1 == offset2 &&
888 state.fragmentsEqual(block1, frag1, block2, frag2)) {
890 state.match_equals(previous);
893 // Compare the size of both fragments:
894 if (heapinfo1->busy_frag.frag_size[frag1] != heapinfo2->busy_frag.frag_size[frag2]) {
895 if (type_size == -1) {
897 state.match_equals(previous);
903 // Size of the fragment_:
904 size = heapinfo1->busy_frag.frag_size[frag1];
906 // Remember (basic) type inference.
907 // The current data structure only allows us to do this for the whole fragment_.
908 if (type != nullptr && area1 == real_addr_frag1)
909 state.types_<1>(block1, frag1) = type;
910 if (type != nullptr && area2 == real_addr_frag2)
911 state.types_<2>(block2, frag2) = type;
913 // The type of the variable is already known:
917 // Type inference from the block type.
918 else if (state.types_<1>(block1, frag1) != nullptr || state.types_<2>(block2, frag2) != nullptr) {
919 Type* new_type2 = nullptr;
921 offset1 = (const char*)area1 - (const char*)real_addr_frag1;
922 offset2 = (const char*)area2 - (const char*)real_addr_frag2;
924 if (state.types_<1>(block1, frag1) != nullptr && state.types_<2>(block2, frag2) != nullptr) {
925 new_type1 = get_offset_type(real_addr_frag1, state.types_<1>(block1, frag1), offset1, size, snapshot1);
926 new_type2 = get_offset_type(real_addr_frag2, state.types_<2>(block2, frag2), offset1, size, snapshot2);
927 } else if (state.types_<1>(block1, frag1) != nullptr) {
928 new_type1 = get_offset_type(real_addr_frag1, state.types_<1>(block1, frag1), offset1, size, snapshot1);
929 new_type2 = get_offset_type(real_addr_frag2, state.types_<1>(block1, frag1), offset2, size, snapshot2);
930 } else if (state.types_<2>(block2, frag2) != nullptr) {
931 new_type1 = get_offset_type(real_addr_frag1, state.types_<2>(block2, frag2), offset1, size, snapshot1);
932 new_type2 = get_offset_type(real_addr_frag2, state.types_<2>(block2, frag2), offset2, size, snapshot2);
935 state.match_equals(previous);
939 if (new_type1 != nullptr && new_type2 != nullptr && new_type1 != new_type2) {
941 while (type->byte_size == 0 && type->subtype != nullptr)
942 type = type->subtype;
943 new_size1 = type->byte_size;
946 while (type->byte_size == 0 && type->subtype != nullptr)
947 type = type->subtype;
948 new_size2 = type->byte_size;
952 state.match_equals(previous);
957 if (new_size1 > 0 && new_size1 == new_size2) {
962 if (offset1 == 0 && offset2 == 0 &&
963 not previous->insert(HeapLocationPair{{HeapLocation(block1, frag1), HeapLocation(block2, frag2)}}).second) {
965 state.match_equals(previous);
971 state.match_equals(previous);
975 if ((heapinfo1->busy_frag.ignore[frag1] > 0) &&
976 (heapinfo2->busy_frag.ignore[frag2] == heapinfo1->busy_frag.ignore[frag1]))
977 check_ignore = heapinfo1->busy_frag.ignore[frag1];
981 /* Start comparison */
983 type ? heap_area_differ_with_type(state, area1, area2, snapshot1, snapshot2, previous, type, size, check_ignore,
985 : heap_area_differ_without_type(state, area1, area2, snapshot1, snapshot2, previous, size, check_ignore);
990 state.match_equals(previous);
994 } // namespace simgrid
996 /************************** Snapshot comparison *******************************/
997 /******************************************************************************/
999 static bool areas_differ_with_type(simgrid::mc::StateComparator& state, const void* real_area1,
1000 const simgrid::mc::Snapshot& snapshot1, simgrid::mc::Region* region1,
1001 const void* real_area2, const simgrid::mc::Snapshot& snapshot2,
1002 simgrid::mc::Region* region2, const simgrid::mc::Type* type, int pointer_level)
1004 const simgrid::mc::Type* subtype;
1005 const simgrid::mc::Type* subsubtype;
1008 xbt_assert(type != nullptr);
1009 switch (type->type) {
1010 case DW_TAG_unspecified_type:
1013 case DW_TAG_base_type:
1014 case DW_TAG_enumeration_type:
1015 case DW_TAG_union_type:
1016 return MC_snapshot_region_memcmp(real_area1, region1, real_area2, region2, type->byte_size) != 0;
1017 case DW_TAG_typedef:
1018 case DW_TAG_volatile_type:
1019 case DW_TAG_const_type:
1020 return areas_differ_with_type(state, real_area1, snapshot1, region1, real_area2, snapshot2, region2,
1021 type->subtype, pointer_level);
1022 case DW_TAG_array_type:
1023 subtype = type->subtype;
1024 switch (subtype->type) {
1025 case DW_TAG_unspecified_type:
1028 case DW_TAG_base_type:
1029 case DW_TAG_enumeration_type:
1030 case DW_TAG_pointer_type:
1031 case DW_TAG_reference_type:
1032 case DW_TAG_rvalue_reference_type:
1033 case DW_TAG_structure_type:
1034 case DW_TAG_class_type:
1035 case DW_TAG_union_type:
1036 if (subtype->full_type)
1037 subtype = subtype->full_type;
1038 elm_size = subtype->byte_size;
1040 case DW_TAG_const_type:
1041 case DW_TAG_typedef:
1042 case DW_TAG_volatile_type:
1043 subsubtype = subtype->subtype;
1044 if (subsubtype->full_type)
1045 subsubtype = subsubtype->full_type;
1046 elm_size = subsubtype->byte_size;
1051 for (int i = 0; i < type->element_count; i++) {
1052 size_t off = i * elm_size;
1053 if (areas_differ_with_type(state, (const char*)real_area1 + off, snapshot1, region1,
1054 (const char*)real_area2 + off, snapshot2, region2, type->subtype, pointer_level))
1058 case DW_TAG_pointer_type:
1059 case DW_TAG_reference_type:
1060 case DW_TAG_rvalue_reference_type: {
1061 const void* addr_pointed1 = MC_region_read_pointer(region1, real_area1);
1062 const void* addr_pointed2 = MC_region_read_pointer(region2, real_area2);
1064 if (type->subtype && type->subtype->type == DW_TAG_subroutine_type)
1065 return (addr_pointed1 != addr_pointed2);
1066 if (addr_pointed1 == nullptr && addr_pointed2 == nullptr)
1068 if (addr_pointed1 == nullptr || addr_pointed2 == nullptr)
1070 if (not state.compared_pointers.insert(std::make_pair(addr_pointed1, addr_pointed2)).second)
1075 // Some cases are not handled here:
1076 // * the pointers lead to different areas (one to the heap, the other to the RW segment ...)
1077 // * a pointer leads to the read-only segment of the current object
1078 // * a pointer lead to a different ELF object
1080 if (snapshot1.on_heap(addr_pointed1)) {
1081 if (not snapshot2.on_heap(addr_pointed2))
1083 // The pointers are both in the heap:
1084 return simgrid::mc::heap_area_differ(state, addr_pointed1, addr_pointed2, snapshot1, snapshot2, nullptr,
1085 type->subtype, pointer_level);
1087 } else if (region1->contain(simgrid::mc::remote(addr_pointed1))) {
1088 // The pointers are both in the current object R/W segment:
1089 if (not region2->contain(simgrid::mc::remote(addr_pointed2)))
1091 if (not type->type_id)
1092 return (addr_pointed1 != addr_pointed2);
1094 return areas_differ_with_type(state, addr_pointed1, snapshot1, region1, addr_pointed2, snapshot2, region2,
1095 type->subtype, pointer_level);
1097 // TODO, We do not handle very well the case where
1098 // it belongs to a different (non-heap) region from the current one.
1100 return (addr_pointed1 != addr_pointed2);
1103 case DW_TAG_structure_type:
1104 case DW_TAG_class_type:
1105 for (const simgrid::mc::Member& member : type->members) {
1106 const void* member1 = simgrid::dwarf::resolve_member(real_area1, type, &member, &snapshot1);
1107 const void* member2 = simgrid::dwarf::resolve_member(real_area2, type, &member, &snapshot2);
1108 simgrid::mc::Region* subregion1 = snapshot1.get_region(member1, region1); // region1 is hinted
1109 simgrid::mc::Region* subregion2 = snapshot2.get_region(member2, region2); // region2 is hinted
1110 if (areas_differ_with_type(state, member1, snapshot1, subregion1, member2, snapshot2, subregion2, member.type,
1115 case DW_TAG_subroutine_type:
1118 XBT_VERB("Unknown case: %d", type->type);
1125 static bool global_variables_differ(simgrid::mc::StateComparator& state,
1126 const simgrid::mc::ObjectInformation* object_info, simgrid::mc::Region* r1,
1127 simgrid::mc::Region* r2, const simgrid::mc::Snapshot& snapshot1,
1128 const simgrid::mc::Snapshot& snapshot2)
1130 xbt_assert(r1 && r2, "Missing region.");
1132 const std::vector<simgrid::mc::Variable>& variables = object_info->global_variables;
1134 for (simgrid::mc::Variable const& current_var : variables) {
1135 // If the variable is not in this object, skip it:
1136 // We do not expect to find a pointer to something which is not reachable
1137 // by the global variables.
1138 if ((char*)current_var.address < object_info->start_rw || (char*)current_var.address > object_info->end_rw)
1141 const simgrid::mc::Type* bvariable_type = current_var.type;
1142 if (areas_differ_with_type(state, current_var.address, snapshot1, r1, current_var.address, snapshot2, r2,
1143 bvariable_type, 0)) {
1144 XBT_VERB("Global variable %s (%p) is different between snapshots", current_var.name.c_str(), current_var.address);
1152 static bool local_variables_differ(simgrid::mc::StateComparator& state, const simgrid::mc::Snapshot& snapshot1,
1153 const simgrid::mc::Snapshot& snapshot2, const_mc_snapshot_stack_t stack1,
1154 const_mc_snapshot_stack_t stack2)
1156 if (stack1->local_variables.size() != stack2->local_variables.size()) {
1157 XBT_VERB("Different number of local variables");
1161 for (unsigned int cursor = 0; cursor < stack1->local_variables.size(); cursor++) {
1162 const_local_variable_t current_var1 = &stack1->local_variables[cursor];
1163 const_local_variable_t current_var2 = &stack2->local_variables[cursor];
1164 if (current_var1->name != current_var2->name || current_var1->subprogram != current_var2->subprogram ||
1165 current_var1->ip != current_var2->ip) {
1166 // TODO, fix current_varX->subprogram->name to include name if DW_TAG_inlined_subprogram
1167 XBT_VERB("Different name of variable (%s - %s) or frame (%s - %s) or ip (%lu - %lu)", current_var1->name.c_str(),
1168 current_var2->name.c_str(), current_var1->subprogram->name.c_str(),
1169 current_var2->subprogram->name.c_str(), current_var1->ip, current_var2->ip);
1173 if (areas_differ_with_type(state, current_var1->address, snapshot1, snapshot1.get_region(current_var1->address),
1174 current_var2->address, snapshot2, snapshot2.get_region(current_var2->address),
1175 current_var1->type, 0)) {
1176 XBT_VERB("Local variable %s (%p - %p) in frame %s is different between snapshots", current_var1->name.c_str(),
1177 current_var1->address, current_var2->address, current_var1->subprogram->name.c_str());
1187 bool snapshot_equal(const Snapshot* s1, const Snapshot* s2)
1189 // TODO, make this a field of ModelChecker or something similar
1190 static StateComparator state_comparator;
1192 const RemoteSimulation& process = mc_model_checker->get_remote_simulation();
1194 if (s1->hash_ != s2->hash_) {
1195 XBT_VERB("(%d - %d) Different hash: 0x%" PRIx64 "--0x%" PRIx64, s1->num_state_, s2->num_state_, s1->hash_,
1199 XBT_VERB("(%d - %d) Same hash: 0x%" PRIx64, s1->num_state_, s2->num_state_, s1->hash_);
1201 /* Compare enabled processes */
1202 if (s1->enabled_processes_ != s2->enabled_processes_) {
1203 XBT_VERB("(%d - %d) Different amount of enabled processes", s1->num_state_, s2->num_state_);
1207 /* Compare size of stacks */
1208 for (unsigned long i = 0; i < s1->stacks_.size(); i++) {
1209 size_t size_used1 = s1->stack_sizes_[i];
1210 size_t size_used2 = s2->stack_sizes_[i];
1211 if (size_used1 != size_used2) {
1212 XBT_VERB("(%d - %d) Different size used in stacks: %zu - %zu", s1->num_state_, s2->num_state_, size_used1,
1218 /* Init heap information used in heap comparison algorithm */
1219 const s_xbt_mheap_t* heap1 = static_cast<xbt_mheap_t>(s1->read_bytes(
1220 alloca(sizeof(s_xbt_mheap_t)), sizeof(s_xbt_mheap_t), remote(process.heap_address), ReadOptions::lazy()));
1221 const s_xbt_mheap_t* heap2 = static_cast<xbt_mheap_t>(s2->read_bytes(
1222 alloca(sizeof(s_xbt_mheap_t)), sizeof(s_xbt_mheap_t), remote(process.heap_address), ReadOptions::lazy()));
1223 if (state_comparator.initHeapInformation(heap1, heap2, s1->to_ignore_, s2->to_ignore_) == -1) {
1224 XBT_VERB("(%d - %d) Different heap information", s1->num_state_, s2->num_state_);
1228 /* Stacks comparison */
1229 for (unsigned int cursor = 0; cursor < s1->stacks_.size(); cursor++) {
1230 const_mc_snapshot_stack_t stack1 = &s1->stacks_[cursor];
1231 const_mc_snapshot_stack_t stack2 = &s2->stacks_[cursor];
1233 if (local_variables_differ(state_comparator, *s1, *s2, stack1, stack2)) {
1234 XBT_VERB("(%d - %d) Different local variables between stacks %u", s1->num_state_, s2->num_state_, cursor + 1);
1239 size_t regions_count = s1->snapshot_regions_.size();
1240 if (regions_count != s2->snapshot_regions_.size())
1243 for (size_t k = 0; k != regions_count; ++k) {
1244 Region* region1 = s1->snapshot_regions_[k].get();
1245 Region* region2 = s2->snapshot_regions_[k].get();
1248 if (region1->region_type() != RegionType::Data)
1251 xbt_assert(region1->region_type() == region2->region_type());
1252 xbt_assert(region1->object_info() == region2->object_info());
1253 xbt_assert(region1->object_info());
1255 /* Compare global variables */
1256 if (global_variables_differ(state_comparator, region1->object_info(), region1, region2, *s1, *s2)) {
1257 std::string const& name = region1->object_info()->file_name;
1258 XBT_VERB("(%d - %d) Different global variables in %s", s1->num_state_, s2->num_state_, name.c_str());
1264 if (mmalloc_heap_differ(state_comparator, *s1, *s2)) {
1265 XBT_VERB("(%d - %d) Different heap (mmalloc_compare)", s1->num_state_, s2->num_state_);
1269 XBT_VERB("(%d - %d) No difference found", s1->num_state_, s2->num_state_);
1274 } // namespace simgrid