1 /* Copyright (c) 2008-2020. 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 for (auto const& stack : mc_model_checker->get_remote_simulation().stack_areas())
147 if (address == stack.address)
152 // TODO, this should depend on the snapshot?
153 static bool is_block_stack(int block)
155 for (auto const& stack : mc_model_checker->get_remote_simulation().stack_areas())
156 if (block == stack.block)
164 void StateComparator::match_equals(const HeapLocationPairs* list)
166 for (auto const& pair : *list) {
167 if (pair[0].fragment_ != -1) {
168 this->equals_to_<1>(pair[0].block_, pair[0].fragment_) = HeapArea(pair[1].block_, pair[1].fragment_);
169 this->equals_to_<2>(pair[1].block_, pair[1].fragment_) = HeapArea(pair[0].block_, pair[0].fragment_);
171 this->equals_to_<1>(pair[0].block_, 0) = HeapArea(pair[1].block_, pair[1].fragment_);
172 this->equals_to_<2>(pair[1].block_, 0) = HeapArea(pair[0].block_, pair[0].fragment_);
177 void ProcessComparisonState::initHeapInformation(const s_xbt_mheap_t* heap, const std::vector<IgnoredHeapRegion>& i)
179 auto heaplimit = heap->heaplimit;
180 this->heapsize = heap->heapsize;
181 this->to_ignore = &i;
182 this->equals_to.assign(heaplimit * MAX_FRAGMENT_PER_BLOCK, HeapArea());
183 this->types.assign(heaplimit * MAX_FRAGMENT_PER_BLOCK, nullptr);
186 int StateComparator::initHeapInformation(const s_xbt_mheap_t* heap1, const s_xbt_mheap_t* heap2,
187 const std::vector<IgnoredHeapRegion>& i1,
188 const std::vector<IgnoredHeapRegion>& i2)
190 if ((heap1->heaplimit != heap2->heaplimit) || (heap1->heapsize != heap2->heapsize))
192 this->heaplimit = heap1->heaplimit;
193 this->std_heap_copy = *mc_model_checker->get_remote_simulation().get_heap();
194 this->processStates[0].initHeapInformation(heap1, i1);
195 this->processStates[1].initHeapInformation(heap2, i2);
199 // TODO, have a robust way to find it in O(1)
200 static inline Region* MC_get_heap_region(const Snapshot& snapshot)
202 for (auto const& region : snapshot.snapshot_regions_)
203 if (region->region_type() == RegionType::Heap)
205 xbt_die("No heap region");
208 static bool heap_area_differ(StateComparator& state, const void* area1, const void* area2, const Snapshot& snapshot1,
209 const Snapshot& snapshot2, HeapLocationPairs* previous, Type* type, int pointer_level);
211 static bool mmalloc_heap_differ(StateComparator& state, const Snapshot& snapshot1, const Snapshot& snapshot2)
213 const RemoteSimulation& process = mc_model_checker->get_remote_simulation();
215 /* Check busy blocks */
218 malloc_info heapinfo_temp1;
219 malloc_info heapinfo_temp2;
220 malloc_info heapinfo_temp2b;
222 const Region* heap_region1 = MC_get_heap_region(snapshot1);
223 const Region* heap_region2 = MC_get_heap_region(snapshot2);
225 // This is the address of std_heap->heapinfo in the application process:
226 void* heapinfo_address = &((xbt_mheap_t)process.heap_address)->heapinfo;
228 // This is in snapshot do not use them directly:
229 const malloc_info* heapinfos1 =
230 snapshot1.read<malloc_info*>(RemotePtr<malloc_info*>((std::uint64_t)heapinfo_address));
231 const malloc_info* heapinfos2 =
232 snapshot2.read<malloc_info*>(RemotePtr<malloc_info*>((std::uint64_t)heapinfo_address));
234 while (i1 < state.heaplimit) {
235 const auto* heapinfo1 =
236 static_cast<malloc_info*>(heap_region1->read(&heapinfo_temp1, &heapinfos1[i1], sizeof(malloc_info)));
237 const auto* heapinfo2 =
238 static_cast<malloc_info*>(heap_region2->read(&heapinfo_temp2, &heapinfos2[i1], sizeof(malloc_info)));
240 if (heapinfo1->type == MMALLOC_TYPE_FREE || heapinfo1->type == MMALLOC_TYPE_HEAPINFO) { /* Free block */
245 xbt_assert(heapinfo1->type >= 0, "Unknown mmalloc block type: %d", heapinfo1->type);
247 void* addr_block1 = ((void*)(((ADDR2UINT(i1)) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase));
249 if (heapinfo1->type == MMALLOC_TYPE_UNFRAGMENTED) { /* Large block */
250 if (is_stack(addr_block1)) {
251 for (size_t k = 0; k < heapinfo1->busy_block.size; k++)
252 state.equals_to_<1>(i1 + k, 0) = HeapArea(i1, -1);
253 for (size_t k = 0; k < heapinfo2->busy_block.size; k++)
254 state.equals_to_<2>(i1 + k, 0) = HeapArea(i1, -1);
255 i1 += heapinfo1->busy_block.size;
259 if (state.equals_to_<1>(i1, 0).valid_) {
267 /* Try first to associate to same block in the other heap */
268 if (heapinfo2->type == heapinfo1->type && state.equals_to_<2>(i1, 0).valid_ == 0) {
269 const void* addr_block2 = (ADDR2UINT(i1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
270 if (not heap_area_differ(state, addr_block1, addr_block2, snapshot1, snapshot2, nullptr, nullptr, 0)) {
271 for (size_t k = 1; k < heapinfo2->busy_block.size; k++)
272 state.equals_to_<2>(i1 + k, 0) = HeapArea(i1, -1);
273 for (size_t k = 1; k < heapinfo1->busy_block.size; k++)
274 state.equals_to_<1>(i1 + k, 0) = HeapArea(i1, -1);
276 i1 += heapinfo1->busy_block.size;
280 while (i2 < state.heaplimit && not equal) {
281 const void* addr_block2 = (ADDR2UINT(i2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
288 const auto* heapinfo2b =
289 static_cast<malloc_info*>(heap_region2->read(&heapinfo_temp2b, &heapinfos2[i2], sizeof(malloc_info)));
291 if (heapinfo2b->type != MMALLOC_TYPE_UNFRAGMENTED) {
296 if (state.equals_to_<2>(i2, 0).valid_) {
301 if (not heap_area_differ(state, addr_block1, addr_block2, snapshot1, snapshot2, nullptr, nullptr, 0)) {
302 for (size_t k = 1; k < heapinfo2b->busy_block.size; k++)
303 state.equals_to_<2>(i2 + k, 0) = HeapArea(i1, -1);
304 for (size_t k = 1; k < heapinfo1->busy_block.size; k++)
305 state.equals_to_<1>(i1 + k, 0) = HeapArea(i2, -1);
307 i1 += heapinfo1->busy_block.size;
313 XBT_DEBUG("Block %zu not found (size_used = %zu, addr = %p)", i1, heapinfo1->busy_block.busy_size, addr_block1);
316 } else { /* Fragmented block */
317 for (size_t j1 = 0; j1 < (size_t)(BLOCKSIZE >> heapinfo1->type); j1++) {
318 if (heapinfo1->busy_frag.frag_size[j1] == -1) /* Free fragment_ */
321 if (state.equals_to_<1>(i1, j1).valid_)
324 void* addr_frag1 = (char*)addr_block1 + (j1 << heapinfo1->type);
329 /* Try first to associate to same fragment_ in the other heap */
330 if (heapinfo2->type == heapinfo1->type && not state.equals_to_<2>(i1, j1).valid_) {
331 const void* addr_block2 = (ADDR2UINT(i1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
332 const void* addr_frag2 = (const char*)addr_block2 + (j1 << heapinfo2->type);
333 if (not heap_area_differ(state, addr_frag1, addr_frag2, snapshot1, snapshot2, nullptr, nullptr, 0))
337 while (i2 < state.heaplimit && not equal) {
338 const auto* heapinfo2b =
339 static_cast<malloc_info*>(heap_region2->read(&heapinfo_temp2b, &heapinfos2[i2], sizeof(malloc_info)));
341 if (heapinfo2b->type == MMALLOC_TYPE_FREE || heapinfo2b->type == MMALLOC_TYPE_HEAPINFO) {
346 // We currently do not match fragments with unfragmented blocks (maybe we should).
347 if (heapinfo2b->type == MMALLOC_TYPE_UNFRAGMENTED) {
352 xbt_assert(heapinfo2b->type >= 0, "Unknown mmalloc block type: %d", heapinfo2b->type);
354 for (size_t j2 = 0; j2 < (size_t)(BLOCKSIZE >> heapinfo2b->type); j2++) {
355 if (i2 == i1 && j2 == j1)
358 if (state.equals_to_<2>(i2, j2).valid_)
361 const void* addr_block2 = (ADDR2UINT(i2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
362 const void* addr_frag2 = (const char*)addr_block2 + (j2 << heapinfo2b->type);
364 if (not heap_area_differ(state, addr_frag1, addr_frag2, snapshot1, snapshot2, nullptr, nullptr, 0)) {
373 XBT_DEBUG("Block %zu, fragment_ %zu not found (size_used = %zd, address = %p)\n", i1, j1,
374 heapinfo1->busy_frag.frag_size[j1], addr_frag1);
382 /* All blocks/fragments are equal to another block/fragment_ ? */
383 for (size_t i = 1; i < state.heaplimit; i++) {
384 const auto* heapinfo1 =
385 static_cast<malloc_info*>(heap_region1->read(&heapinfo_temp1, &heapinfos1[i], sizeof(malloc_info)));
387 if (heapinfo1->type == MMALLOC_TYPE_UNFRAGMENTED && i1 == state.heaplimit && heapinfo1->busy_block.busy_size > 0 &&
388 not state.equals_to_<1>(i, 0).valid_) {
389 XBT_DEBUG("Block %zu not found (size used = %zu)", i, heapinfo1->busy_block.busy_size);
393 if (heapinfo1->type <= 0)
395 for (size_t j = 0; j < (size_t)(BLOCKSIZE >> heapinfo1->type); j++)
396 if (i1 == state.heaplimit && heapinfo1->busy_frag.frag_size[j] > 0 && not state.equals_to_<1>(i, j).valid_) {
397 XBT_DEBUG("Block %zu, Fragment %zu not found (size used = %zd)", i, j, heapinfo1->busy_frag.frag_size[j]);
402 for (size_t i = 1; i < state.heaplimit; i++) {
403 const auto* heapinfo2 =
404 static_cast<malloc_info*>(heap_region2->read(&heapinfo_temp2, &heapinfos2[i], sizeof(malloc_info)));
405 if (heapinfo2->type == MMALLOC_TYPE_UNFRAGMENTED && i1 == state.heaplimit && heapinfo2->busy_block.busy_size > 0 &&
406 not state.equals_to_<2>(i, 0).valid_) {
407 XBT_DEBUG("Block %zu not found (size used = %zu)", i,
408 heapinfo2->busy_block.busy_size);
412 if (heapinfo2->type <= 0)
415 for (size_t j = 0; j < (size_t)(BLOCKSIZE >> heapinfo2->type); j++)
416 if (i1 == state.heaplimit && heapinfo2->busy_frag.frag_size[j] > 0 && not state.equals_to_<2>(i, j).valid_) {
417 XBT_DEBUG("Block %zu, Fragment %zu not found (size used = %zd)",
418 i, j, heapinfo2->busy_frag.frag_size[j]);
428 * @param real_area1 Process address for state 1
429 * @param real_area2 Process address for state 2
430 * @param snapshot1 Snapshot of state 1
431 * @param snapshot2 Snapshot of state 2
434 * @param check_ignore
435 * @return true when different, false otherwise (same or unknown)
437 static bool heap_area_differ_without_type(StateComparator& state, const void* real_area1, const void* real_area2,
438 const Snapshot& snapshot1, const Snapshot& snapshot2,
439 HeapLocationPairs* previous, int size, int check_ignore)
441 const RemoteSimulation& process = mc_model_checker->get_remote_simulation();
442 const Region* heap_region1 = MC_get_heap_region(snapshot1);
443 const Region* heap_region2 = MC_get_heap_region(snapshot2);
445 for (int i = 0; i < size; ) {
446 if (check_ignore > 0) {
447 ssize_t ignore1 = heap_comparison_ignore_size(state.processStates[0].to_ignore, (const char*)real_area1 + i);
449 ssize_t ignore2 = heap_comparison_ignore_size(state.processStates[1].to_ignore, (const char*)real_area2 + i);
450 if (ignore2 == ignore1) {
462 if (MC_snapshot_region_memcmp((const char*)real_area1 + i, heap_region1, (const char*)real_area2 + i, heap_region2,
464 int pointer_align = (i / sizeof(void *)) * sizeof(void *);
465 const void* addr_pointed1 = snapshot1.read(remote((void* const*)((const char*)real_area1 + pointer_align)));
466 const void* addr_pointed2 = snapshot2.read(remote((void* const*)((const char*)real_area2 + pointer_align)));
468 if (process.in_maestro_stack(remote(addr_pointed1)) && process.in_maestro_stack(remote(addr_pointed2))) {
469 i = pointer_align + sizeof(void *);
473 if (snapshot1.on_heap(addr_pointed1) && snapshot2.on_heap(addr_pointed2)) {
474 // Both addresses are in the heap:
475 if (heap_area_differ(state, addr_pointed1, addr_pointed2, snapshot1, snapshot2, previous, nullptr, 0))
477 i = pointer_align + sizeof(void *);
490 * @param real_area1 Process address for state 1
491 * @param real_area2 Process address for state 2
492 * @param snapshot1 Snapshot of state 1
493 * @param snapshot2 Snapshot of state 2
496 * @param area_size either a byte_size or an elements_count (?)
497 * @param check_ignore
498 * @param pointer_level
499 * @return true when different, false otherwise (same or unknown)
501 static bool heap_area_differ_with_type(StateComparator& state, const void* real_area1, const void* real_area2,
502 const Snapshot& snapshot1, const Snapshot& snapshot2,
503 HeapLocationPairs* previous, const Type* type, int area_size, int check_ignore,
506 // HACK: This should not happen but in practice, there are some
507 // DW_TAG_typedef without an associated DW_AT_type:
508 //<1><538832>: Abbrev Number: 111 (DW_TAG_typedef)
509 // <538833> DW_AT_name : (indirect string, offset: 0x2292f3): gregset_t
510 // <538837> DW_AT_decl_file : 98
511 // <538838> DW_AT_decl_line : 37
515 if (is_stack(real_area1) && is_stack(real_area2))
518 if (check_ignore > 0) {
519 ssize_t ignore1 = heap_comparison_ignore_size(state.processStates[0].to_ignore, real_area1);
520 if (ignore1 > 0 && heap_comparison_ignore_size(state.processStates[1].to_ignore, real_area2) == ignore1)
525 const Type* subsubtype;
527 const void* addr_pointed1;
528 const void* addr_pointed2;
530 const Region* heap_region1 = MC_get_heap_region(snapshot1);
531 const Region* heap_region2 = MC_get_heap_region(snapshot2);
533 switch (type->type) {
534 case DW_TAG_unspecified_type:
537 case DW_TAG_base_type:
538 if (not type->name.empty() && type->name == "char") { /* String, hence random (arbitrary ?) size */
539 if (real_area1 == real_area2)
542 return MC_snapshot_region_memcmp(real_area1, heap_region1, real_area2, heap_region2, area_size) != 0;
544 if (area_size != -1 && type->byte_size != area_size)
547 return MC_snapshot_region_memcmp(real_area1, heap_region1, real_area2, heap_region2, type->byte_size) != 0;
550 case DW_TAG_enumeration_type:
551 if (area_size != -1 && type->byte_size != area_size)
553 return MC_snapshot_region_memcmp(real_area1, heap_region1, real_area2, heap_region2, type->byte_size) != 0;
556 case DW_TAG_const_type:
557 case DW_TAG_volatile_type:
558 return heap_area_differ_with_type(state, real_area1, real_area2, snapshot1, snapshot2, previous, type->subtype,
559 area_size, check_ignore, pointer_level);
561 case DW_TAG_array_type:
562 subtype = type->subtype;
563 switch (subtype->type) {
564 case DW_TAG_unspecified_type:
567 case DW_TAG_base_type:
568 case DW_TAG_enumeration_type:
569 case DW_TAG_pointer_type:
570 case DW_TAG_reference_type:
571 case DW_TAG_rvalue_reference_type:
572 case DW_TAG_structure_type:
573 case DW_TAG_class_type:
574 case DW_TAG_union_type:
575 if (subtype->full_type)
576 subtype = subtype->full_type;
577 elm_size = subtype->byte_size;
579 // TODO, just remove the type indirection?
580 case DW_TAG_const_type:
582 case DW_TAG_volatile_type:
583 subsubtype = subtype->subtype;
584 if (subsubtype->full_type)
585 subsubtype = subsubtype->full_type;
586 elm_size = subsubtype->byte_size;
591 for (int i = 0; i < type->element_count; i++) {
592 // TODO, add support for variable stride (DW_AT_byte_stride)
593 if (heap_area_differ_with_type(state, (const char*)real_area1 + (i * elm_size),
594 (const char*)real_area2 + (i * elm_size), snapshot1, snapshot2, previous,
595 type->subtype, subtype->byte_size, check_ignore, pointer_level))
600 case DW_TAG_reference_type:
601 case DW_TAG_rvalue_reference_type:
602 case DW_TAG_pointer_type:
603 if (type->subtype && type->subtype->type == DW_TAG_subroutine_type) {
604 addr_pointed1 = snapshot1.read(remote((void* const*)real_area1));
605 addr_pointed2 = snapshot2.read(remote((void* const*)real_area2));
606 return (addr_pointed1 != addr_pointed2);
609 if (pointer_level <= 1) {
610 addr_pointed1 = snapshot1.read(remote((void* const*)real_area1));
611 addr_pointed2 = snapshot2.read(remote((void* const*)real_area2));
612 if (snapshot1.on_heap(addr_pointed1) && snapshot2.on_heap(addr_pointed2))
613 return heap_area_differ(state, addr_pointed1, addr_pointed2, snapshot1, snapshot2, previous, type->subtype,
616 return (addr_pointed1 != addr_pointed2);
618 for (size_t i = 0; i < (area_size / sizeof(void*)); i++) {
619 addr_pointed1 = snapshot1.read(remote((void* const*)((const char*)real_area1 + i * sizeof(void*))));
620 addr_pointed2 = snapshot2.read(remote((void* const*)((const char*)real_area2 + i * sizeof(void*))));
621 bool differ = snapshot1.on_heap(addr_pointed1) && snapshot2.on_heap(addr_pointed2)
622 ? heap_area_differ(state, addr_pointed1, addr_pointed2, snapshot1, snapshot2, previous,
623 type->subtype, pointer_level)
624 : addr_pointed1 != addr_pointed2;
630 case DW_TAG_structure_type:
631 case DW_TAG_class_type:
633 type = type->full_type;
634 if (type->byte_size == 0)
636 if (area_size != -1 && type->byte_size != area_size) {
637 if (area_size <= type->byte_size || area_size % type->byte_size != 0)
639 for (size_t i = 0; i < (size_t)(area_size / type->byte_size); i++) {
640 if (heap_area_differ_with_type(state, (const char*)real_area1 + i * type->byte_size,
641 (const char*)real_area2 + i * type->byte_size, snapshot1, snapshot2, previous,
642 type, -1, check_ignore, 0))
646 for (const simgrid::mc::Member& member : type->members) {
647 // TODO, optimize this? (for the offset case)
648 const void* real_member1 = dwarf::resolve_member(real_area1, type, &member, &snapshot1);
649 const void* real_member2 = dwarf::resolve_member(real_area2, type, &member, &snapshot2);
650 if (heap_area_differ_with_type(state, real_member1, real_member2, snapshot1, snapshot2, previous,
651 member.type, -1, check_ignore, 0))
657 case DW_TAG_union_type:
658 return heap_area_differ_without_type(state, real_area1, real_area2, snapshot1, snapshot2, previous,
659 type->byte_size, check_ignore);
666 /** Infer the type of a part of the block from the type of the block
668 * TODO, handle DW_TAG_array_type as well as arrays of the object ((*p)[5], p[5])
670 * TODO, handle subfields ((*p).bar.foo, (*p)[5].bar…)
672 * @param type DWARF type ID of the root address
674 * @return DWARF type ID for given offset
676 static Type* get_offset_type(void* real_base_address, Type* type, int offset, int area_size, const Snapshot& snapshot)
678 // Beginning of the block, the inferred variable type if the type of the block:
682 switch (type->type) {
683 case DW_TAG_structure_type:
684 case DW_TAG_class_type:
686 type = type->full_type;
687 if (area_size != -1 && type->byte_size != area_size) {
688 if (area_size > type->byte_size && area_size % type->byte_size == 0)
694 for (const simgrid::mc::Member& member : type->members) {
695 if (member.has_offset_location()) {
696 // We have the offset, use it directly (shortcut):
697 if (member.offset() == offset)
700 void* real_member = dwarf::resolve_member(real_base_address, type, &member, &snapshot);
701 if ((char*)real_member - (char*)real_base_address == offset)
708 /* FIXME: other cases ? */
715 * @param area1 Process address for state 1
716 * @param area2 Process address for state 2
717 * @param snapshot1 Snapshot of state 1
718 * @param snapshot2 Snapshot of state 2
719 * @param previous Pairs of blocks already compared on the current path (or nullptr)
720 * @param type_id Type of variable
721 * @param pointer_level
722 * @return true when different, false otherwise (same or unknown)
724 static bool heap_area_differ(StateComparator& state, const void* area1, const void* area2, const Snapshot& snapshot1,
725 const Snapshot& snapshot2, HeapLocationPairs* previous, Type* type, int pointer_level)
727 const simgrid::mc::RemoteSimulation& process = mc_model_checker->get_remote_simulation();
732 int check_ignore = 0;
740 Type* new_type1 = nullptr;
742 bool match_pairs = false;
744 // This is the address of std_heap->heapinfo in the application process:
745 void* heapinfo_address = &((xbt_mheap_t)process.heap_address)->heapinfo;
747 const malloc_info* heapinfos1 = snapshot1.read(remote((const malloc_info**)heapinfo_address));
748 const malloc_info* heapinfos2 = snapshot2.read(remote((const malloc_info**)heapinfo_address));
750 malloc_info heapinfo_temp1;
751 malloc_info heapinfo_temp2;
753 simgrid::mc::HeapLocationPairs current;
754 if (previous == nullptr) {
760 block1 = ((const char*)area1 - (const char*)state.std_heap_copy.heapbase) / BLOCKSIZE + 1;
761 block2 = ((const char*)area2 - (const char*)state.std_heap_copy.heapbase) / BLOCKSIZE + 1;
763 // If either block is a stack block:
764 if (is_block_stack((int) block1) && is_block_stack((int) block2)) {
765 previous->insert(HeapLocationPair{{HeapLocation(block1, -1), HeapLocation(block2, -1)}});
767 state.match_equals(previous);
771 // If either block is not in the expected area of memory:
772 if (((const char*)area1 < (const char*)state.std_heap_copy.heapbase) ||
773 (block1 > (ssize_t)state.processStates[0].heapsize) || (block1 < 1) ||
774 ((const char*)area2 < (const char*)state.std_heap_copy.heapbase) ||
775 (block2 > (ssize_t)state.processStates[1].heapsize) || (block2 < 1)) {
779 // Process address of the block:
780 void* real_addr_block1 = (ADDR2UINT(block1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
781 void* real_addr_block2 = (ADDR2UINT(block2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
785 type = type->full_type;
787 // This assume that for "boring" types (volatile ...) byte_size is absent:
788 while (type->byte_size == 0 && type->subtype != nullptr)
789 type = type->subtype;
792 if (type->type == DW_TAG_pointer_type ||
793 (type->type == DW_TAG_base_type && not type->name.empty() && type->name == "char"))
796 type_size = type->byte_size;
799 const Region* heap_region1 = MC_get_heap_region(snapshot1);
800 const Region* heap_region2 = MC_get_heap_region(snapshot2);
802 const auto* heapinfo1 =
803 static_cast<malloc_info*>(heap_region1->read(&heapinfo_temp1, &heapinfos1[block1], sizeof(malloc_info)));
804 const auto* heapinfo2 =
805 static_cast<malloc_info*>(heap_region2->read(&heapinfo_temp2, &heapinfos2[block2], sizeof(malloc_info)));
807 if ((heapinfo1->type == MMALLOC_TYPE_FREE || heapinfo1->type==MMALLOC_TYPE_HEAPINFO)
808 && (heapinfo2->type == MMALLOC_TYPE_FREE || heapinfo2->type ==MMALLOC_TYPE_HEAPINFO)) {
811 state.match_equals(previous);
815 if (heapinfo1->type == MMALLOC_TYPE_UNFRAGMENTED && heapinfo2->type == MMALLOC_TYPE_UNFRAGMENTED) {
818 // TODO, lookup variable type from block type as done for fragmented blocks
820 if (state.equals_to_<1>(block1, 0).valid_ && state.equals_to_<2>(block2, 0).valid_ &&
821 state.blocksEqual(block1, block2)) {
823 state.match_equals(previous);
827 if (type_size != -1 && type_size != (ssize_t)heapinfo1->busy_block.busy_size &&
828 type_size != (ssize_t)heapinfo2->busy_block.busy_size &&
829 (type->name.empty() || type->name == "struct s_smx_context")) {
831 state.match_equals(previous);
835 if (heapinfo1->busy_block.size != heapinfo2->busy_block.size ||
836 heapinfo1->busy_block.busy_size != heapinfo2->busy_block.busy_size)
839 if (not previous->insert(HeapLocationPair{{HeapLocation(block1, -1), HeapLocation(block2, -1)}}).second) {
841 state.match_equals(previous);
845 size = heapinfo1->busy_block.busy_size;
847 // Remember (basic) type inference.
848 // The current data structure only allows us to do this for the whole block.
849 if (type != nullptr && area1 == real_addr_block1)
850 state.types_<1>(block1, 0) = type;
851 if (type != nullptr && area2 == real_addr_block2)
852 state.types_<2>(block2, 0) = type;
856 state.match_equals(previous);
860 if (heapinfo1->busy_block.ignore > 0 && heapinfo2->busy_block.ignore == heapinfo1->busy_block.ignore)
861 check_ignore = heapinfo1->busy_block.ignore;
863 } else if ((heapinfo1->type > 0) && (heapinfo2->type > 0)) { /* Fragmented block */
865 ssize_t frag1 = (ADDR2UINT(area1) % BLOCKSIZE) >> heapinfo1->type;
866 ssize_t frag2 = (ADDR2UINT(area2) % BLOCKSIZE) >> heapinfo2->type;
868 // Process address of the fragment_:
869 void* real_addr_frag1 = (char*)real_addr_block1 + (frag1 << heapinfo1->type);
870 void* real_addr_frag2 = (char*)real_addr_block2 + (frag2 << heapinfo2->type);
872 // Check the size of the fragments against the size of the type:
873 if (type_size != -1) {
874 if (heapinfo1->busy_frag.frag_size[frag1] == -1 || heapinfo2->busy_frag.frag_size[frag2] == -1) {
876 state.match_equals(previous);
880 if (type_size != heapinfo1->busy_frag.frag_size[frag1]
881 || type_size != heapinfo2->busy_frag.frag_size[frag2]) {
883 state.match_equals(previous);
888 // Check if the blocks are already matched together:
889 if (state.equals_to_<1>(block1, frag1).valid_ && state.equals_to_<2>(block2, frag2).valid_ && offset1 == offset2 &&
890 state.fragmentsEqual(block1, frag1, block2, frag2)) {
892 state.match_equals(previous);
895 // Compare the size of both fragments:
896 if (heapinfo1->busy_frag.frag_size[frag1] != heapinfo2->busy_frag.frag_size[frag2]) {
897 if (type_size == -1) {
899 state.match_equals(previous);
905 // Size of the fragment_:
906 size = heapinfo1->busy_frag.frag_size[frag1];
908 // Remember (basic) type inference.
909 // The current data structure only allows us to do this for the whole fragment_.
910 if (type != nullptr && area1 == real_addr_frag1)
911 state.types_<1>(block1, frag1) = type;
912 if (type != nullptr && area2 == real_addr_frag2)
913 state.types_<2>(block2, frag2) = type;
915 // The type of the variable is already known:
919 // Type inference from the block type.
920 else if (state.types_<1>(block1, frag1) != nullptr || state.types_<2>(block2, frag2) != nullptr) {
921 Type* new_type2 = nullptr;
923 offset1 = (const char*)area1 - (const char*)real_addr_frag1;
924 offset2 = (const char*)area2 - (const char*)real_addr_frag2;
926 if (state.types_<1>(block1, frag1) != nullptr && state.types_<2>(block2, frag2) != nullptr) {
927 new_type1 = get_offset_type(real_addr_frag1, state.types_<1>(block1, frag1), offset1, size, snapshot1);
928 new_type2 = get_offset_type(real_addr_frag2, state.types_<2>(block2, frag2), offset1, size, snapshot2);
929 } else if (state.types_<1>(block1, frag1) != nullptr) {
930 new_type1 = get_offset_type(real_addr_frag1, state.types_<1>(block1, frag1), offset1, size, snapshot1);
931 new_type2 = get_offset_type(real_addr_frag2, state.types_<1>(block1, frag1), offset2, size, snapshot2);
932 } else if (state.types_<2>(block2, frag2) != nullptr) {
933 new_type1 = get_offset_type(real_addr_frag1, state.types_<2>(block2, frag2), offset1, size, snapshot1);
934 new_type2 = get_offset_type(real_addr_frag2, state.types_<2>(block2, frag2), offset2, size, snapshot2);
937 state.match_equals(previous);
941 if (new_type1 != nullptr && new_type2 != nullptr && new_type1 != new_type2) {
943 while (type->byte_size == 0 && type->subtype != nullptr)
944 type = type->subtype;
945 new_size1 = type->byte_size;
948 while (type->byte_size == 0 && type->subtype != nullptr)
949 type = type->subtype;
950 new_size2 = type->byte_size;
954 state.match_equals(previous);
959 if (new_size1 > 0 && new_size1 == new_size2) {
964 if (offset1 == 0 && offset2 == 0 &&
965 not previous->insert(HeapLocationPair{{HeapLocation(block1, frag1), HeapLocation(block2, frag2)}}).second) {
967 state.match_equals(previous);
973 state.match_equals(previous);
977 if ((heapinfo1->busy_frag.ignore[frag1] > 0) &&
978 (heapinfo2->busy_frag.ignore[frag2] == heapinfo1->busy_frag.ignore[frag1]))
979 check_ignore = heapinfo1->busy_frag.ignore[frag1];
983 /* Start comparison */
985 type ? heap_area_differ_with_type(state, area1, area2, snapshot1, snapshot2, previous, type, size, check_ignore,
987 : heap_area_differ_without_type(state, area1, area2, snapshot1, snapshot2, previous, size, check_ignore);
992 state.match_equals(previous);
996 } // namespace simgrid
998 /************************** Snapshot comparison *******************************/
999 /******************************************************************************/
1001 static bool areas_differ_with_type(simgrid::mc::StateComparator& state, const void* real_area1,
1002 const simgrid::mc::Snapshot& snapshot1, simgrid::mc::Region* region1,
1003 const void* real_area2, const simgrid::mc::Snapshot& snapshot2,
1004 simgrid::mc::Region* region2, const simgrid::mc::Type* type, int pointer_level)
1006 const simgrid::mc::Type* subtype;
1007 const simgrid::mc::Type* subsubtype;
1010 xbt_assert(type != nullptr);
1011 switch (type->type) {
1012 case DW_TAG_unspecified_type:
1015 case DW_TAG_base_type:
1016 case DW_TAG_enumeration_type:
1017 case DW_TAG_union_type:
1018 return MC_snapshot_region_memcmp(real_area1, region1, real_area2, region2, type->byte_size) != 0;
1019 case DW_TAG_typedef:
1020 case DW_TAG_volatile_type:
1021 case DW_TAG_const_type:
1022 return areas_differ_with_type(state, real_area1, snapshot1, region1, real_area2, snapshot2, region2,
1023 type->subtype, pointer_level);
1024 case DW_TAG_array_type:
1025 subtype = type->subtype;
1026 switch (subtype->type) {
1027 case DW_TAG_unspecified_type:
1030 case DW_TAG_base_type:
1031 case DW_TAG_enumeration_type:
1032 case DW_TAG_pointer_type:
1033 case DW_TAG_reference_type:
1034 case DW_TAG_rvalue_reference_type:
1035 case DW_TAG_structure_type:
1036 case DW_TAG_class_type:
1037 case DW_TAG_union_type:
1038 if (subtype->full_type)
1039 subtype = subtype->full_type;
1040 elm_size = subtype->byte_size;
1042 case DW_TAG_const_type:
1043 case DW_TAG_typedef:
1044 case DW_TAG_volatile_type:
1045 subsubtype = subtype->subtype;
1046 if (subsubtype->full_type)
1047 subsubtype = subsubtype->full_type;
1048 elm_size = subsubtype->byte_size;
1053 for (int i = 0; i < type->element_count; i++) {
1054 size_t off = i * elm_size;
1055 if (areas_differ_with_type(state, (const char*)real_area1 + off, snapshot1, region1,
1056 (const char*)real_area2 + off, snapshot2, region2, type->subtype, pointer_level))
1060 case DW_TAG_pointer_type:
1061 case DW_TAG_reference_type:
1062 case DW_TAG_rvalue_reference_type: {
1063 const void* addr_pointed1 = MC_region_read_pointer(region1, real_area1);
1064 const void* addr_pointed2 = MC_region_read_pointer(region2, real_area2);
1066 if (type->subtype && type->subtype->type == DW_TAG_subroutine_type)
1067 return (addr_pointed1 != addr_pointed2);
1068 if (addr_pointed1 == nullptr && addr_pointed2 == nullptr)
1070 if (addr_pointed1 == nullptr || addr_pointed2 == nullptr)
1072 if (not state.compared_pointers.insert(std::make_pair(addr_pointed1, addr_pointed2)).second)
1077 // Some cases are not handled here:
1078 // * the pointers lead to different areas (one to the heap, the other to the RW segment ...)
1079 // * a pointer leads to the read-only segment of the current object
1080 // * a pointer lead to a different ELF object
1082 if (snapshot1.on_heap(addr_pointed1)) {
1083 if (not snapshot2.on_heap(addr_pointed2))
1085 // The pointers are both in the heap:
1086 return simgrid::mc::heap_area_differ(state, addr_pointed1, addr_pointed2, snapshot1, snapshot2, nullptr,
1087 type->subtype, pointer_level);
1089 } else if (region1->contain(simgrid::mc::remote(addr_pointed1))) {
1090 // The pointers are both in the current object R/W segment:
1091 if (not region2->contain(simgrid::mc::remote(addr_pointed2)))
1093 if (not type->type_id)
1094 return (addr_pointed1 != addr_pointed2);
1096 return areas_differ_with_type(state, addr_pointed1, snapshot1, region1, addr_pointed2, snapshot2, region2,
1097 type->subtype, pointer_level);
1099 // TODO, We do not handle very well the case where
1100 // it belongs to a different (non-heap) region from the current one.
1102 return (addr_pointed1 != addr_pointed2);
1105 case DW_TAG_structure_type:
1106 case DW_TAG_class_type:
1107 for (const simgrid::mc::Member& member : type->members) {
1108 const void* member1 = simgrid::dwarf::resolve_member(real_area1, type, &member, &snapshot1);
1109 const void* member2 = simgrid::dwarf::resolve_member(real_area2, type, &member, &snapshot2);
1110 simgrid::mc::Region* subregion1 = snapshot1.get_region(member1, region1); // region1 is hinted
1111 simgrid::mc::Region* subregion2 = snapshot2.get_region(member2, region2); // region2 is hinted
1112 if (areas_differ_with_type(state, member1, snapshot1, subregion1, member2, snapshot2, subregion2, member.type,
1117 case DW_TAG_subroutine_type:
1120 XBT_VERB("Unknown case: %d", type->type);
1127 static bool global_variables_differ(simgrid::mc::StateComparator& state,
1128 const simgrid::mc::ObjectInformation* object_info, simgrid::mc::Region* r1,
1129 simgrid::mc::Region* r2, const simgrid::mc::Snapshot& snapshot1,
1130 const simgrid::mc::Snapshot& snapshot2)
1132 xbt_assert(r1 && r2, "Missing region.");
1134 const std::vector<simgrid::mc::Variable>& variables = object_info->global_variables;
1136 for (simgrid::mc::Variable const& current_var : variables) {
1137 // If the variable is not in this object, skip it:
1138 // We do not expect to find a pointer to something which is not reachable
1139 // by the global variables.
1140 if ((char*)current_var.address < object_info->start_rw || (char*)current_var.address > object_info->end_rw)
1143 const simgrid::mc::Type* bvariable_type = current_var.type;
1144 if (areas_differ_with_type(state, current_var.address, snapshot1, r1, current_var.address, snapshot2, r2,
1145 bvariable_type, 0)) {
1146 XBT_VERB("Global variable %s (%p) is different between snapshots", current_var.name.c_str(), current_var.address);
1154 static bool local_variables_differ(simgrid::mc::StateComparator& state, const simgrid::mc::Snapshot& snapshot1,
1155 const simgrid::mc::Snapshot& snapshot2, const_mc_snapshot_stack_t stack1,
1156 const_mc_snapshot_stack_t stack2)
1158 if (stack1->local_variables.size() != stack2->local_variables.size()) {
1159 XBT_VERB("Different number of local variables");
1163 for (unsigned int cursor = 0; cursor < stack1->local_variables.size(); cursor++) {
1164 const_local_variable_t current_var1 = &stack1->local_variables[cursor];
1165 const_local_variable_t current_var2 = &stack2->local_variables[cursor];
1166 if (current_var1->name != current_var2->name || current_var1->subprogram != current_var2->subprogram ||
1167 current_var1->ip != current_var2->ip) {
1168 // TODO, fix current_varX->subprogram->name to include name if DW_TAG_inlined_subprogram
1169 XBT_VERB("Different name of variable (%s - %s) or frame (%s - %s) or ip (%lu - %lu)", current_var1->name.c_str(),
1170 current_var2->name.c_str(), current_var1->subprogram->name.c_str(),
1171 current_var2->subprogram->name.c_str(), current_var1->ip, current_var2->ip);
1175 if (areas_differ_with_type(state, current_var1->address, snapshot1, snapshot1.get_region(current_var1->address),
1176 current_var2->address, snapshot2, snapshot2.get_region(current_var2->address),
1177 current_var1->type, 0)) {
1178 XBT_VERB("Local variable %s (%p - %p) in frame %s is different between snapshots", current_var1->name.c_str(),
1179 current_var1->address, current_var2->address, current_var1->subprogram->name.c_str());
1189 bool snapshot_equal(const Snapshot* s1, const Snapshot* s2)
1191 // TODO, make this a field of ModelChecker or something similar
1192 static StateComparator state_comparator;
1194 const RemoteSimulation& process = mc_model_checker->get_remote_simulation();
1196 if (s1->hash_ != s2->hash_) {
1197 XBT_VERB("(%d - %d) Different hash: 0x%" PRIx64 "--0x%" PRIx64, s1->num_state_, s2->num_state_, s1->hash_,
1201 XBT_VERB("(%d - %d) Same hash: 0x%" PRIx64, s1->num_state_, s2->num_state_, s1->hash_);
1203 /* Compare enabled processes */
1204 if (s1->enabled_processes_ != s2->enabled_processes_) {
1205 XBT_VERB("(%d - %d) Different amount of enabled processes", s1->num_state_, s2->num_state_);
1209 /* Compare size of stacks */
1210 for (unsigned long i = 0; i < s1->stacks_.size(); i++) {
1211 size_t size_used1 = s1->stack_sizes_[i];
1212 size_t size_used2 = s2->stack_sizes_[i];
1213 if (size_used1 != size_used2) {
1214 XBT_VERB("(%d - %d) Different size used in stacks: %zu - %zu", s1->num_state_, s2->num_state_, size_used1,
1220 /* Init heap information used in heap comparison algorithm */
1221 const s_xbt_mheap_t* heap1 = static_cast<xbt_mheap_t>(s1->read_bytes(
1222 alloca(sizeof(s_xbt_mheap_t)), sizeof(s_xbt_mheap_t), remote(process.heap_address), ReadOptions::lazy()));
1223 const s_xbt_mheap_t* heap2 = static_cast<xbt_mheap_t>(s2->read_bytes(
1224 alloca(sizeof(s_xbt_mheap_t)), sizeof(s_xbt_mheap_t), remote(process.heap_address), ReadOptions::lazy()));
1225 if (state_comparator.initHeapInformation(heap1, heap2, s1->to_ignore_, s2->to_ignore_) == -1) {
1226 XBT_VERB("(%d - %d) Different heap information", s1->num_state_, s2->num_state_);
1230 /* Stacks comparison */
1231 for (unsigned int cursor = 0; cursor < s1->stacks_.size(); cursor++) {
1232 const_mc_snapshot_stack_t stack1 = &s1->stacks_[cursor];
1233 const_mc_snapshot_stack_t stack2 = &s2->stacks_[cursor];
1235 if (local_variables_differ(state_comparator, *s1, *s2, stack1, stack2)) {
1236 XBT_VERB("(%d - %d) Different local variables between stacks %u", s1->num_state_, s2->num_state_, cursor + 1);
1241 size_t regions_count = s1->snapshot_regions_.size();
1242 if (regions_count != s2->snapshot_regions_.size())
1245 for (size_t k = 0; k != regions_count; ++k) {
1246 Region* region1 = s1->snapshot_regions_[k].get();
1247 Region* region2 = s2->snapshot_regions_[k].get();
1250 if (region1->region_type() != RegionType::Data)
1253 xbt_assert(region1->region_type() == region2->region_type());
1254 xbt_assert(region1->object_info() == region2->object_info());
1255 xbt_assert(region1->object_info());
1257 /* Compare global variables */
1258 if (global_variables_differ(state_comparator, region1->object_info(), region1, region2, *s1, *s2)) {
1259 std::string const& name = region1->object_info()->file_name;
1260 XBT_VERB("(%d - %d) Different global variables in %s", s1->num_state_, s2->num_state_, name.c_str());
1266 if (mmalloc_heap_differ(state_comparator, *s1, *s2)) {
1267 XBT_VERB("(%d - %d) Different heap (mmalloc_compare)", s1->num_state_, s2->num_state_);
1271 XBT_VERB("(%d - %d) No difference found", s1->num_state_, s2->num_state_);
1276 } // namespace simgrid