1 /* Copyright (c) 2008-2022. 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/sosp/Snapshot.hpp"
14 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_compare, mc, "Logging specific to mc_compare in mc");
16 using simgrid::mc::remote;
21 /*********************************** Heap comparison ***********************************/
22 /***************************************************************************************/
29 HeapLocation() = default;
30 explicit HeapLocation(int block, int fragment = 0) : block_(block), fragment_(fragment) {}
32 bool operator==(HeapLocation const& that) const
34 return block_ == that.block_ && fragment_ == that.fragment_;
36 bool operator<(HeapLocation const& that) const
38 return std::make_pair(block_, fragment_) < std::make_pair(that.block_, that.fragment_);
42 using HeapLocationPair = std::array<HeapLocation, 2>;
43 using HeapLocationPairs = std::set<HeapLocationPair>;
45 class HeapArea : public HeapLocation {
49 explicit HeapArea(int block) : valid_(true) { block_ = block; }
50 HeapArea(int block, int fragment) : valid_(true)
57 class ProcessComparisonState {
59 const std::vector<IgnoredHeapRegion>* to_ignore = nullptr;
60 std::vector<HeapArea> equals_to;
61 std::vector<Type*> types;
62 std::size_t heapsize = 0;
64 void initHeapInformation(const s_xbt_mheap_t* heap, const std::vector<IgnoredHeapRegion>& i);
67 class StateComparator {
69 s_xbt_mheap_t std_heap_copy;
70 std::size_t heaplimit;
71 std::array<ProcessComparisonState, 2> processStates;
73 std::unordered_set<std::pair<const void*, const void*>, simgrid::xbt::hash<std::pair<const void*, const void*>>>
78 compared_pointers.clear();
81 int initHeapInformation(const s_xbt_mheap_t* heap1, const s_xbt_mheap_t* heap2,
82 const std::vector<IgnoredHeapRegion>& i1, const std::vector<IgnoredHeapRegion>& i2);
84 template <int rank> HeapArea& equals_to_(std::size_t i, std::size_t j)
86 return processStates[rank - 1].equals_to[MAX_FRAGMENT_PER_BLOCK * i + j];
88 template <int rank> Type*& types_(std::size_t i, std::size_t j)
90 return processStates[rank - 1].types[MAX_FRAGMENT_PER_BLOCK * i + j];
93 template <int rank> HeapArea const& equals_to_(std::size_t i, std::size_t j) const
95 return processStates[rank - 1].equals_to[MAX_FRAGMENT_PER_BLOCK * i + j];
97 template <int rank> Type* const& types_(std::size_t i, std::size_t j) const
99 return processStates[rank - 1].types[MAX_FRAGMENT_PER_BLOCK * i + j];
102 /** Check whether two blocks are known to be matching
104 * @param b1 Block of state 1
105 * @param b2 Block of state 2
106 * @return if the blocks are known to be matching
108 bool blocksEqual(int b1, int b2) const
110 return this->equals_to_<1>(b1, 0).block_ == b2 && this->equals_to_<2>(b2, 0).block_ == b1;
113 /** Check whether two fragments are known to be matching
115 * @param b1 Block of state 1
116 * @param f1 Fragment of state 1
117 * @param b2 Block of state 2
118 * @param f2 Fragment of state 2
119 * @return if the fragments are known to be matching
121 int fragmentsEqual(int b1, int f1, int b2, int f2) const
123 return this->equals_to_<1>(b1, f1).block_ == b2 && this->equals_to_<1>(b1, f1).fragment_ == f2 &&
124 this->equals_to_<2>(b2, f2).block_ == b1 && this->equals_to_<2>(b2, f2).fragment_ == f1;
127 void match_equals(const HeapLocationPairs* list);
131 } // namespace simgrid
133 /************************************************************************************/
135 static ssize_t heap_comparison_ignore_size(const std::vector<simgrid::mc::IgnoredHeapRegion>* ignore_list,
138 auto pos = std::lower_bound(ignore_list->begin(), ignore_list->end(), address,
139 [](auto const& reg, auto const* addr) { return reg.address < addr; });
140 return (pos != ignore_list->end() && pos->address == address) ? pos->size : -1;
143 static bool is_stack(const simgrid::mc::RemoteProcess& process, const void* address)
145 auto const& stack_areas = process.stack_areas();
146 return std::any_of(stack_areas.begin(), stack_areas.end(),
147 [address](auto const& stack) { return stack.address == address; });
150 // TODO, this should depend on the snapshot?
151 static bool is_block_stack(const simgrid::mc::RemoteProcess& process, int block)
153 auto const& stack_areas = process.stack_areas();
154 return std::any_of(stack_areas.begin(), stack_areas.end(),
155 [block](auto const& stack) { return stack.block == block; });
161 void StateComparator::match_equals(const HeapLocationPairs* list)
163 for (auto const& pair : *list) {
164 if (pair[0].fragment_ != -1) {
165 this->equals_to_<1>(pair[0].block_, pair[0].fragment_) = HeapArea(pair[1].block_, pair[1].fragment_);
166 this->equals_to_<2>(pair[1].block_, pair[1].fragment_) = HeapArea(pair[0].block_, pair[0].fragment_);
168 this->equals_to_<1>(pair[0].block_, 0) = HeapArea(pair[1].block_, pair[1].fragment_);
169 this->equals_to_<2>(pair[1].block_, 0) = HeapArea(pair[0].block_, pair[0].fragment_);
174 void ProcessComparisonState::initHeapInformation(const s_xbt_mheap_t* heap, const std::vector<IgnoredHeapRegion>& i)
176 auto heaplimit = heap->heaplimit;
177 this->heapsize = heap->heapsize;
178 this->to_ignore = &i;
179 this->equals_to.assign(heaplimit * MAX_FRAGMENT_PER_BLOCK, HeapArea());
180 this->types.assign(heaplimit * MAX_FRAGMENT_PER_BLOCK, nullptr);
183 int StateComparator::initHeapInformation(const s_xbt_mheap_t* heap1, const s_xbt_mheap_t* heap2,
184 const std::vector<IgnoredHeapRegion>& i1,
185 const std::vector<IgnoredHeapRegion>& i2)
187 if ((heap1->heaplimit != heap2->heaplimit) || (heap1->heapsize != heap2->heapsize))
189 this->heaplimit = heap1->heaplimit;
190 this->std_heap_copy = *mc_model_checker->get_remote_process().get_heap();
191 this->processStates[0].initHeapInformation(heap1, i1);
192 this->processStates[1].initHeapInformation(heap2, i2);
196 // TODO, have a robust way to find it in O(1)
197 static inline Region* MC_get_heap_region(const Snapshot& snapshot)
199 for (auto const& region : snapshot.snapshot_regions_)
200 if (region->region_type() == RegionType::Heap)
202 xbt_die("No heap region");
205 static bool heap_area_differ(const RemoteProcess& process, StateComparator& state, const void* area1, const void* area2,
206 const Snapshot& snapshot1, const Snapshot& snapshot2, HeapLocationPairs* previous,
207 Type* type, int pointer_level);
209 static bool mmalloc_heap_differ(const RemoteProcess& process, StateComparator& state, const Snapshot& snapshot1,
210 const Snapshot& snapshot2)
212 /* Check busy blocks */
215 malloc_info heapinfo_temp1;
216 malloc_info heapinfo_temp2;
217 malloc_info heapinfo_temp2b;
219 const Region* heap_region1 = MC_get_heap_region(snapshot1);
220 const Region* heap_region2 = MC_get_heap_region(snapshot2);
222 // This is the address of std_heap->heapinfo in the application process:
223 uint64_t heapinfo_address = process.heap_address.address() + offsetof(s_xbt_mheap_t, heapinfo);
225 // This is in snapshot do not use them directly:
226 const malloc_info* heapinfos1 = snapshot1.read(remote<malloc_info*>(heapinfo_address));
227 const malloc_info* heapinfos2 = snapshot2.read(remote<malloc_info*>(heapinfo_address));
229 while (i1 < state.heaplimit) {
230 const auto* heapinfo1 =
231 static_cast<malloc_info*>(heap_region1->read(&heapinfo_temp1, &heapinfos1[i1], sizeof(malloc_info)));
232 const auto* heapinfo2 =
233 static_cast<malloc_info*>(heap_region2->read(&heapinfo_temp2, &heapinfos2[i1], sizeof(malloc_info)));
235 if (heapinfo1->type == MMALLOC_TYPE_FREE || heapinfo1->type == MMALLOC_TYPE_HEAPINFO) { /* Free block */
240 xbt_assert(heapinfo1->type >= 0, "Unknown mmalloc block type: %d", heapinfo1->type);
242 void* addr_block1 = (ADDR2UINT(i1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
244 if (heapinfo1->type == MMALLOC_TYPE_UNFRAGMENTED) { /* Large block */
245 if (is_stack(process, addr_block1)) {
246 for (size_t k = 0; k < heapinfo1->busy_block.size; k++)
247 state.equals_to_<1>(i1 + k, 0) = HeapArea(i1, -1);
248 for (size_t k = 0; k < heapinfo2->busy_block.size; k++)
249 state.equals_to_<2>(i1 + k, 0) = HeapArea(i1, -1);
250 i1 += heapinfo1->busy_block.size;
254 if (state.equals_to_<1>(i1, 0).valid_) {
262 /* Try first to associate to same block in the other heap */
263 if (heapinfo2->type == heapinfo1->type && state.equals_to_<2>(i1, 0).valid_ == 0) {
264 const void* addr_block2 = (ADDR2UINT(i1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
265 if (not heap_area_differ(process, state, addr_block1, addr_block2, snapshot1, snapshot2, nullptr, nullptr, 0)) {
266 for (size_t k = 1; k < heapinfo2->busy_block.size; k++)
267 state.equals_to_<2>(i1 + k, 0) = HeapArea(i1, -1);
268 for (size_t k = 1; k < heapinfo1->busy_block.size; k++)
269 state.equals_to_<1>(i1 + k, 0) = HeapArea(i1, -1);
271 i1 += heapinfo1->busy_block.size;
275 while (i2 < state.heaplimit && not equal) {
276 const void* addr_block2 = (ADDR2UINT(i2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
283 const auto* heapinfo2b =
284 static_cast<malloc_info*>(heap_region2->read(&heapinfo_temp2b, &heapinfos2[i2], sizeof(malloc_info)));
286 if (heapinfo2b->type != MMALLOC_TYPE_UNFRAGMENTED) {
291 if (state.equals_to_<2>(i2, 0).valid_) {
296 if (not heap_area_differ(process, state, addr_block1, addr_block2, snapshot1, snapshot2, nullptr, nullptr, 0)) {
297 for (size_t k = 1; k < heapinfo2b->busy_block.size; k++)
298 state.equals_to_<2>(i2 + k, 0) = HeapArea(i1, -1);
299 for (size_t k = 1; k < heapinfo1->busy_block.size; k++)
300 state.equals_to_<1>(i1 + k, 0) = HeapArea(i2, -1);
302 i1 += heapinfo1->busy_block.size;
308 XBT_DEBUG("Block %zu not found (size_used = %zu, addr = %p)", i1, heapinfo1->busy_block.busy_size, addr_block1);
311 } else { /* Fragmented block */
312 for (size_t j1 = 0; j1 < (size_t)(BLOCKSIZE >> heapinfo1->type); j1++) {
313 if (heapinfo1->busy_frag.frag_size[j1] == -1) /* Free fragment_ */
316 if (state.equals_to_<1>(i1, j1).valid_)
319 void* addr_frag1 = (char*)addr_block1 + (j1 << heapinfo1->type);
324 /* Try first to associate to same fragment_ in the other heap */
325 if (heapinfo2->type == heapinfo1->type && not state.equals_to_<2>(i1, j1).valid_) {
326 const void* addr_block2 = (ADDR2UINT(i1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
327 const void* addr_frag2 = (const char*)addr_block2 + (j1 << heapinfo2->type);
328 if (not heap_area_differ(process, state, addr_frag1, addr_frag2, snapshot1, snapshot2, nullptr, nullptr, 0))
332 while (i2 < state.heaplimit && not equal) {
333 const auto* heapinfo2b =
334 static_cast<malloc_info*>(heap_region2->read(&heapinfo_temp2b, &heapinfos2[i2], sizeof(malloc_info)));
336 if (heapinfo2b->type == MMALLOC_TYPE_FREE || heapinfo2b->type == MMALLOC_TYPE_HEAPINFO) {
341 // We currently do not match fragments with unfragmented blocks (maybe we should).
342 if (heapinfo2b->type == MMALLOC_TYPE_UNFRAGMENTED) {
347 xbt_assert(heapinfo2b->type >= 0, "Unknown mmalloc block type: %d", heapinfo2b->type);
349 for (size_t j2 = 0; j2 < (size_t)(BLOCKSIZE >> heapinfo2b->type); j2++) {
350 if (i2 == i1 && j2 == j1)
353 if (state.equals_to_<2>(i2, j2).valid_)
356 const void* addr_block2 = (ADDR2UINT(i2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
357 const void* addr_frag2 = (const char*)addr_block2 + (j2 << heapinfo2b->type);
359 if (not heap_area_differ(process, state, addr_frag1, addr_frag2, snapshot1, snapshot2, nullptr, nullptr,
369 XBT_DEBUG("Block %zu, fragment_ %zu not found (size_used = %zd, address = %p)\n", i1, j1,
370 heapinfo1->busy_frag.frag_size[j1], addr_frag1);
378 /* All blocks/fragments are equal to another block/fragment_ ? */
379 for (size_t i = 1; i < state.heaplimit; i++) {
380 const auto* heapinfo1 =
381 static_cast<malloc_info*>(heap_region1->read(&heapinfo_temp1, &heapinfos1[i], sizeof(malloc_info)));
383 if (heapinfo1->type == MMALLOC_TYPE_UNFRAGMENTED && i1 == state.heaplimit && heapinfo1->busy_block.busy_size > 0 &&
384 not state.equals_to_<1>(i, 0).valid_) {
385 XBT_DEBUG("Block %zu not found (size used = %zu)", i, heapinfo1->busy_block.busy_size);
389 if (heapinfo1->type <= 0)
391 for (size_t j = 0; j < (size_t)(BLOCKSIZE >> heapinfo1->type); j++)
392 if (i1 == state.heaplimit && heapinfo1->busy_frag.frag_size[j] > 0 && not state.equals_to_<1>(i, j).valid_) {
393 XBT_DEBUG("Block %zu, Fragment %zu not found (size used = %zd)", i, j, heapinfo1->busy_frag.frag_size[j]);
398 for (size_t i = 1; i < state.heaplimit; i++) {
399 const auto* heapinfo2 =
400 static_cast<malloc_info*>(heap_region2->read(&heapinfo_temp2, &heapinfos2[i], sizeof(malloc_info)));
401 if (heapinfo2->type == MMALLOC_TYPE_UNFRAGMENTED && i1 == state.heaplimit && heapinfo2->busy_block.busy_size > 0 &&
402 not state.equals_to_<2>(i, 0).valid_) {
403 XBT_DEBUG("Block %zu not found (size used = %zu)", i,
404 heapinfo2->busy_block.busy_size);
408 if (heapinfo2->type <= 0)
411 for (size_t j = 0; j < (size_t)(BLOCKSIZE >> heapinfo2->type); j++)
412 if (i1 == state.heaplimit && heapinfo2->busy_frag.frag_size[j] > 0 && not state.equals_to_<2>(i, j).valid_) {
413 XBT_DEBUG("Block %zu, Fragment %zu not found (size used = %zd)",
414 i, j, heapinfo2->busy_frag.frag_size[j]);
424 * @param real_area1 Process address for state 1
425 * @param real_area2 Process address for state 2
426 * @param snapshot1 Snapshot of state 1
427 * @param snapshot2 Snapshot of state 2
430 * @param check_ignore
431 * @return true when different, false otherwise (same or unknown)
433 static bool heap_area_differ_without_type(const RemoteProcess& process, StateComparator& state, const void* real_area1,
434 const void* real_area2, const Snapshot& snapshot1, const Snapshot& snapshot2,
435 HeapLocationPairs* previous, int size, int check_ignore)
437 const Region* heap_region1 = MC_get_heap_region(snapshot1);
438 const Region* heap_region2 = MC_get_heap_region(snapshot2);
440 for (int i = 0; i < size; ) {
441 if (check_ignore > 0) {
442 ssize_t ignore1 = heap_comparison_ignore_size(state.processStates[0].to_ignore, (const char*)real_area1 + i);
444 ssize_t ignore2 = heap_comparison_ignore_size(state.processStates[1].to_ignore, (const char*)real_area2 + i);
445 if (ignore2 == ignore1) {
457 if (MC_snapshot_region_memcmp((const char*)real_area1 + i, heap_region1, (const char*)real_area2 + i, heap_region2,
459 int pointer_align = (i / sizeof(void *)) * sizeof(void *);
460 const void* addr_pointed1 = snapshot1.read(remote((void* const*)((const char*)real_area1 + pointer_align)));
461 const void* addr_pointed2 = snapshot2.read(remote((void* const*)((const char*)real_area2 + pointer_align)));
463 if (process.in_maestro_stack(remote(addr_pointed1)) && process.in_maestro_stack(remote(addr_pointed2))) {
464 i = pointer_align + sizeof(void *);
468 if (snapshot1.on_heap(addr_pointed1) && snapshot2.on_heap(addr_pointed2)) {
469 // Both addresses are in the heap:
470 if (heap_area_differ(process, state, addr_pointed1, addr_pointed2, snapshot1, snapshot2, previous, nullptr, 0))
472 i = pointer_align + sizeof(void *);
485 * @param real_area1 Process address for state 1
486 * @param real_area2 Process address for state 2
487 * @param snapshot1 Snapshot of state 1
488 * @param snapshot2 Snapshot of state 2
491 * @param area_size either a byte_size or an elements_count (?)
492 * @param check_ignore
493 * @param pointer_level
494 * @return true when different, false otherwise (same or unknown)
496 static bool heap_area_differ_with_type(const simgrid::mc::RemoteProcess& process, StateComparator& state,
497 const void* real_area1, const void* real_area2, const Snapshot& snapshot1,
498 const Snapshot& snapshot2, HeapLocationPairs* previous, const Type* type,
499 int area_size, int check_ignore, int pointer_level)
501 // HACK: This should not happen but in practice, there are some
502 // DW_TAG_typedef without an associated DW_AT_type:
503 //<1><538832>: Abbrev Number: 111 (DW_TAG_typedef)
504 // <538833> DW_AT_name : (indirect string, offset: 0x2292f3): gregset_t
505 // <538837> DW_AT_decl_file : 98
506 // <538838> DW_AT_decl_line : 37
510 if (is_stack(process, real_area1) && is_stack(process, real_area2))
513 if (check_ignore > 0) {
514 ssize_t ignore1 = heap_comparison_ignore_size(state.processStates[0].to_ignore, real_area1);
515 if (ignore1 > 0 && heap_comparison_ignore_size(state.processStates[1].to_ignore, real_area2) == ignore1)
520 const Type* subsubtype;
522 const void* addr_pointed1;
523 const void* addr_pointed2;
525 const Region* heap_region1 = MC_get_heap_region(snapshot1);
526 const Region* heap_region2 = MC_get_heap_region(snapshot2);
528 switch (type->type) {
529 case DW_TAG_unspecified_type:
532 case DW_TAG_base_type:
533 if (not type->name.empty() && type->name == "char") { /* String, hence random (arbitrary ?) size */
534 if (real_area1 == real_area2)
537 return MC_snapshot_region_memcmp(real_area1, heap_region1, real_area2, heap_region2, area_size) != 0;
539 if (area_size != -1 && type->byte_size != area_size)
542 return MC_snapshot_region_memcmp(real_area1, heap_region1, real_area2, heap_region2, type->byte_size) != 0;
545 case DW_TAG_enumeration_type:
546 if (area_size != -1 && type->byte_size != area_size)
548 return MC_snapshot_region_memcmp(real_area1, heap_region1, real_area2, heap_region2, type->byte_size) != 0;
551 case DW_TAG_const_type:
552 case DW_TAG_volatile_type:
553 return heap_area_differ_with_type(process, state, real_area1, real_area2, snapshot1, snapshot2, previous,
554 type->subtype, area_size, check_ignore, pointer_level);
556 case DW_TAG_array_type:
557 subtype = type->subtype;
558 switch (subtype->type) {
559 case DW_TAG_unspecified_type:
562 case DW_TAG_base_type:
563 case DW_TAG_enumeration_type:
564 case DW_TAG_pointer_type:
565 case DW_TAG_reference_type:
566 case DW_TAG_rvalue_reference_type:
567 case DW_TAG_structure_type:
568 case DW_TAG_class_type:
569 case DW_TAG_union_type:
570 if (subtype->full_type)
571 subtype = subtype->full_type;
572 elm_size = subtype->byte_size;
574 // TODO, just remove the type indirection?
575 case DW_TAG_const_type:
577 case DW_TAG_volatile_type:
578 subsubtype = subtype->subtype;
579 if (subsubtype->full_type)
580 subsubtype = subsubtype->full_type;
581 elm_size = subsubtype->byte_size;
586 for (int i = 0; i < type->element_count; i++) {
587 // TODO, add support for variable stride (DW_AT_byte_stride)
588 if (heap_area_differ_with_type(process, state, (const char*)real_area1 + (i * elm_size),
589 (const char*)real_area2 + (i * elm_size), snapshot1, snapshot2, previous,
590 type->subtype, subtype->byte_size, check_ignore, pointer_level))
595 case DW_TAG_reference_type:
596 case DW_TAG_rvalue_reference_type:
597 case DW_TAG_pointer_type:
598 if (type->subtype && type->subtype->type == DW_TAG_subroutine_type) {
599 addr_pointed1 = snapshot1.read(remote((void* const*)real_area1));
600 addr_pointed2 = snapshot2.read(remote((void* const*)real_area2));
601 return (addr_pointed1 != addr_pointed2);
604 if (pointer_level <= 1) {
605 addr_pointed1 = snapshot1.read(remote((void* const*)real_area1));
606 addr_pointed2 = snapshot2.read(remote((void* const*)real_area2));
607 if (snapshot1.on_heap(addr_pointed1) && snapshot2.on_heap(addr_pointed2))
608 return heap_area_differ(process, state, addr_pointed1, addr_pointed2, snapshot1, snapshot2, previous,
609 type->subtype, pointer_level);
611 return (addr_pointed1 != addr_pointed2);
613 for (size_t i = 0; i < (area_size / sizeof(void*)); i++) {
614 addr_pointed1 = snapshot1.read(remote((void* const*)((const char*)real_area1 + i * sizeof(void*))));
615 addr_pointed2 = snapshot2.read(remote((void* const*)((const char*)real_area2 + i * sizeof(void*))));
616 bool differ = snapshot1.on_heap(addr_pointed1) && snapshot2.on_heap(addr_pointed2)
617 ? heap_area_differ(process, state, addr_pointed1, addr_pointed2, snapshot1, snapshot2,
618 previous, type->subtype, pointer_level)
619 : addr_pointed1 != addr_pointed2;
625 case DW_TAG_structure_type:
626 case DW_TAG_class_type:
628 type = type->full_type;
629 if (type->byte_size == 0)
631 if (area_size != -1 && type->byte_size != area_size) {
632 if (area_size <= type->byte_size || area_size % type->byte_size != 0)
634 for (size_t i = 0; i < (size_t)(area_size / type->byte_size); i++) {
635 if (heap_area_differ_with_type(process, state, (const char*)real_area1 + i * type->byte_size,
636 (const char*)real_area2 + i * type->byte_size, snapshot1, snapshot2, previous,
637 type, -1, check_ignore, 0))
641 for (const simgrid::mc::Member& member : type->members) {
642 // TODO, optimize this? (for the offset case)
643 const void* real_member1 = dwarf::resolve_member(real_area1, type, &member, &snapshot1);
644 const void* real_member2 = dwarf::resolve_member(real_area2, type, &member, &snapshot2);
645 if (heap_area_differ_with_type(process, state, real_member1, real_member2, snapshot1, snapshot2, previous,
646 member.type, -1, check_ignore, 0))
652 case DW_TAG_union_type:
653 return heap_area_differ_without_type(process, state, real_area1, real_area2, snapshot1, snapshot2, previous,
654 type->byte_size, check_ignore);
661 /** Infer the type of a part of the block from the type of the block
663 * TODO, handle DW_TAG_array_type as well as arrays of the object ((*p)[5], p[5])
665 * TODO, handle subfields ((*p).bar.foo, (*p)[5].bar…)
667 * @param type DWARF type ID of the root address
669 * @return DWARF type ID for given offset
671 static Type* get_offset_type(void* real_base_address, Type* type, int offset, int area_size, const Snapshot& snapshot)
673 // Beginning of the block, the inferred variable type if the type of the block:
677 switch (type->type) {
678 case DW_TAG_structure_type:
679 case DW_TAG_class_type:
681 type = type->full_type;
682 if (area_size != -1 && type->byte_size != area_size) {
683 if (area_size > type->byte_size && area_size % type->byte_size == 0)
689 for (const simgrid::mc::Member& member : type->members) {
690 if (member.has_offset_location()) {
691 // We have the offset, use it directly (shortcut):
692 if (member.offset() == offset)
695 void* real_member = dwarf::resolve_member(real_base_address, type, &member, &snapshot);
696 if ((char*)real_member - (char*)real_base_address == offset)
703 /* FIXME: other cases ? */
710 * @param area1 Process address for state 1
711 * @param area2 Process address for state 2
712 * @param snapshot1 Snapshot of state 1
713 * @param snapshot2 Snapshot of state 2
714 * @param previous Pairs of blocks already compared on the current path (or nullptr)
715 * @param type_id Type of variable
716 * @param pointer_level
717 * @return true when different, false otherwise (same or unknown)
719 static bool heap_area_differ(const RemoteProcess& process, StateComparator& state, const void* area1, const void* area2,
720 const Snapshot& snapshot1, const Snapshot& snapshot2, HeapLocationPairs* previous,
721 Type* type, int pointer_level)
726 int check_ignore = 0;
734 Type* new_type1 = nullptr;
736 bool match_pairs = false;
738 // This is the address of std_heap->heapinfo in the application process:
739 uint64_t heapinfo_address = process.heap_address.address() + offsetof(s_xbt_mheap_t, heapinfo);
741 const malloc_info* heapinfos1 = snapshot1.read(remote<malloc_info*>(heapinfo_address));
742 const malloc_info* heapinfos2 = snapshot2.read(remote<malloc_info*>(heapinfo_address));
744 malloc_info heapinfo_temp1;
745 malloc_info heapinfo_temp2;
747 simgrid::mc::HeapLocationPairs current;
748 if (previous == nullptr) {
754 block1 = ((const char*)area1 - (const char*)state.std_heap_copy.heapbase) / BLOCKSIZE + 1;
755 block2 = ((const char*)area2 - (const char*)state.std_heap_copy.heapbase) / BLOCKSIZE + 1;
757 // If either block is a stack block:
758 if (is_block_stack(process, (int)block1) && is_block_stack(process, (int)block2)) {
759 previous->insert(HeapLocationPair{{HeapLocation(block1, -1), HeapLocation(block2, -1)}});
761 state.match_equals(previous);
765 // If either block is not in the expected area of memory:
766 if (((const char*)area1 < (const char*)state.std_heap_copy.heapbase) ||
767 (block1 > (ssize_t)state.processStates[0].heapsize) || (block1 < 1) ||
768 ((const char*)area2 < (const char*)state.std_heap_copy.heapbase) ||
769 (block2 > (ssize_t)state.processStates[1].heapsize) || (block2 < 1)) {
773 // Process address of the block:
774 void* real_addr_block1 = (ADDR2UINT(block1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
775 void* real_addr_block2 = (ADDR2UINT(block2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
779 type = type->full_type;
781 // This assume that for "boring" types (volatile ...) byte_size is absent:
782 while (type->byte_size == 0 && type->subtype != nullptr)
783 type = type->subtype;
786 if (type->type == DW_TAG_pointer_type ||
787 (type->type == DW_TAG_base_type && not type->name.empty() && type->name == "char"))
790 type_size = type->byte_size;
793 const Region* heap_region1 = MC_get_heap_region(snapshot1);
794 const Region* heap_region2 = MC_get_heap_region(snapshot2);
796 const auto* heapinfo1 =
797 static_cast<malloc_info*>(heap_region1->read(&heapinfo_temp1, &heapinfos1[block1], sizeof(malloc_info)));
798 const auto* heapinfo2 =
799 static_cast<malloc_info*>(heap_region2->read(&heapinfo_temp2, &heapinfos2[block2], sizeof(malloc_info)));
801 if ((heapinfo1->type == MMALLOC_TYPE_FREE || heapinfo1->type==MMALLOC_TYPE_HEAPINFO)
802 && (heapinfo2->type == MMALLOC_TYPE_FREE || heapinfo2->type ==MMALLOC_TYPE_HEAPINFO)) {
805 state.match_equals(previous);
809 if (heapinfo1->type == MMALLOC_TYPE_UNFRAGMENTED && heapinfo2->type == MMALLOC_TYPE_UNFRAGMENTED) {
812 // TODO, lookup variable type from block type as done for fragmented blocks
814 if (state.equals_to_<1>(block1, 0).valid_ && state.equals_to_<2>(block2, 0).valid_ &&
815 state.blocksEqual(block1, block2)) {
817 state.match_equals(previous);
821 if (type_size != -1 && type_size != (ssize_t)heapinfo1->busy_block.busy_size &&
822 type_size != (ssize_t)heapinfo2->busy_block.busy_size &&
823 (type->name.empty() || type->name == "struct s_smx_context")) {
825 state.match_equals(previous);
829 if (heapinfo1->busy_block.size != heapinfo2->busy_block.size ||
830 heapinfo1->busy_block.busy_size != heapinfo2->busy_block.busy_size)
833 if (not previous->insert(HeapLocationPair{{HeapLocation(block1, -1), HeapLocation(block2, -1)}}).second) {
835 state.match_equals(previous);
839 size = heapinfo1->busy_block.busy_size;
841 // Remember (basic) type inference.
842 // The current data structure only allows us to do this for the whole block.
843 if (type != nullptr && area1 == real_addr_block1)
844 state.types_<1>(block1, 0) = type;
845 if (type != nullptr && area2 == real_addr_block2)
846 state.types_<2>(block2, 0) = type;
850 state.match_equals(previous);
854 if (heapinfo1->busy_block.ignore > 0 && heapinfo2->busy_block.ignore == heapinfo1->busy_block.ignore)
855 check_ignore = heapinfo1->busy_block.ignore;
857 } else if ((heapinfo1->type > 0) && (heapinfo2->type > 0)) { /* Fragmented block */
859 ssize_t frag1 = (ADDR2UINT(area1) % BLOCKSIZE) >> heapinfo1->type;
860 ssize_t frag2 = (ADDR2UINT(area2) % BLOCKSIZE) >> heapinfo2->type;
862 // Process address of the fragment_:
863 void* real_addr_frag1 = (char*)real_addr_block1 + (frag1 << heapinfo1->type);
864 void* real_addr_frag2 = (char*)real_addr_block2 + (frag2 << heapinfo2->type);
866 // Check the size of the fragments against the size of the type:
867 if (type_size != -1) {
868 if (heapinfo1->busy_frag.frag_size[frag1] == -1 || heapinfo2->busy_frag.frag_size[frag2] == -1) {
870 state.match_equals(previous);
874 if (type_size != heapinfo1->busy_frag.frag_size[frag1]
875 || type_size != heapinfo2->busy_frag.frag_size[frag2]) {
877 state.match_equals(previous);
882 // Check if the blocks are already matched together:
883 if (state.equals_to_<1>(block1, frag1).valid_ && state.equals_to_<2>(block2, frag2).valid_ &&
884 state.fragmentsEqual(block1, frag1, block2, frag2)) {
886 state.match_equals(previous);
889 // Compare the size of both fragments:
890 if (heapinfo1->busy_frag.frag_size[frag1] != heapinfo2->busy_frag.frag_size[frag2]) {
891 if (type_size == -1) {
893 state.match_equals(previous);
899 // Size of the fragment_:
900 size = heapinfo1->busy_frag.frag_size[frag1];
902 // Remember (basic) type inference.
903 // The current data structure only allows us to do this for the whole fragment_.
904 if (type != nullptr && area1 == real_addr_frag1)
905 state.types_<1>(block1, frag1) = type;
906 if (type != nullptr && area2 == real_addr_frag2)
907 state.types_<2>(block2, frag2) = type;
909 // The type of the variable is already known:
913 // Type inference from the block type.
914 else if (state.types_<1>(block1, frag1) != nullptr || state.types_<2>(block2, frag2) != nullptr) {
915 Type* new_type2 = nullptr;
917 offset1 = (const char*)area1 - (const char*)real_addr_frag1;
918 offset2 = (const char*)area2 - (const char*)real_addr_frag2;
920 if (state.types_<1>(block1, frag1) != nullptr && state.types_<2>(block2, frag2) != nullptr) {
921 new_type1 = get_offset_type(real_addr_frag1, state.types_<1>(block1, frag1), offset1, size, snapshot1);
922 new_type2 = get_offset_type(real_addr_frag2, state.types_<2>(block2, frag2), offset1, size, snapshot2);
923 } else if (state.types_<1>(block1, frag1) != nullptr) {
924 new_type1 = get_offset_type(real_addr_frag1, state.types_<1>(block1, frag1), offset1, size, snapshot1);
925 new_type2 = get_offset_type(real_addr_frag2, state.types_<1>(block1, frag1), offset2, size, snapshot2);
926 } else if (state.types_<2>(block2, frag2) != nullptr) {
927 new_type1 = get_offset_type(real_addr_frag1, state.types_<2>(block2, frag2), offset1, size, snapshot1);
928 new_type2 = get_offset_type(real_addr_frag2, state.types_<2>(block2, frag2), offset2, size, snapshot2);
931 state.match_equals(previous);
935 if (new_type1 != nullptr && new_type2 != nullptr && new_type1 != new_type2) {
937 while (type->byte_size == 0 && type->subtype != nullptr)
938 type = type->subtype;
939 new_size1 = type->byte_size;
942 while (type->byte_size == 0 && type->subtype != nullptr)
943 type = type->subtype;
944 new_size2 = type->byte_size;
948 state.match_equals(previous);
953 if (new_size1 > 0 && new_size1 == new_size2) {
958 if (offset1 == 0 && offset2 == 0 &&
959 not previous->insert(HeapLocationPair{{HeapLocation(block1, frag1), HeapLocation(block2, frag2)}}).second) {
961 state.match_equals(previous);
967 state.match_equals(previous);
971 if ((heapinfo1->busy_frag.ignore[frag1] > 0) &&
972 (heapinfo2->busy_frag.ignore[frag2] == heapinfo1->busy_frag.ignore[frag1]))
973 check_ignore = heapinfo1->busy_frag.ignore[frag1];
977 /* Start comparison */
978 bool differ = type ? heap_area_differ_with_type(process, state, area1, area2, snapshot1, snapshot2, previous, type,
979 size, check_ignore, pointer_level)
980 : heap_area_differ_without_type(process, state, area1, area2, snapshot1, snapshot2, previous, size,
986 state.match_equals(previous);
990 } // namespace simgrid
992 /************************** Snapshot comparison *******************************/
993 /******************************************************************************/
995 static bool areas_differ_with_type(const simgrid::mc::RemoteProcess& process, simgrid::mc::StateComparator& state,
996 const void* real_area1, const simgrid::mc::Snapshot& snapshot1,
997 simgrid::mc::Region* region1, const void* real_area2,
998 const simgrid::mc::Snapshot& snapshot2, simgrid::mc::Region* region2,
999 const simgrid::mc::Type* type, int pointer_level)
1001 const simgrid::mc::Type* subtype;
1002 const simgrid::mc::Type* subsubtype;
1005 xbt_assert(type != nullptr);
1006 switch (type->type) {
1007 case DW_TAG_unspecified_type:
1010 case DW_TAG_base_type:
1011 case DW_TAG_enumeration_type:
1012 case DW_TAG_union_type:
1013 return MC_snapshot_region_memcmp(real_area1, region1, real_area2, region2, type->byte_size) != 0;
1014 case DW_TAG_typedef:
1015 case DW_TAG_volatile_type:
1016 case DW_TAG_const_type:
1017 return areas_differ_with_type(process, state, real_area1, snapshot1, region1, real_area2, snapshot2, region2,
1018 type->subtype, pointer_level);
1019 case DW_TAG_array_type:
1020 subtype = type->subtype;
1021 switch (subtype->type) {
1022 case DW_TAG_unspecified_type:
1025 case DW_TAG_base_type:
1026 case DW_TAG_enumeration_type:
1027 case DW_TAG_pointer_type:
1028 case DW_TAG_reference_type:
1029 case DW_TAG_rvalue_reference_type:
1030 case DW_TAG_structure_type:
1031 case DW_TAG_class_type:
1032 case DW_TAG_union_type:
1033 if (subtype->full_type)
1034 subtype = subtype->full_type;
1035 elm_size = subtype->byte_size;
1037 case DW_TAG_const_type:
1038 case DW_TAG_typedef:
1039 case DW_TAG_volatile_type:
1040 subsubtype = subtype->subtype;
1041 if (subsubtype->full_type)
1042 subsubtype = subsubtype->full_type;
1043 elm_size = subsubtype->byte_size;
1048 for (int i = 0; i < type->element_count; i++) {
1049 size_t off = i * elm_size;
1050 if (areas_differ_with_type(process, state, (const char*)real_area1 + off, snapshot1, region1,
1051 (const char*)real_area2 + off, snapshot2, region2, type->subtype, pointer_level))
1055 case DW_TAG_pointer_type:
1056 case DW_TAG_reference_type:
1057 case DW_TAG_rvalue_reference_type: {
1058 const void* addr_pointed1 = MC_region_read_pointer(region1, real_area1);
1059 const void* addr_pointed2 = MC_region_read_pointer(region2, real_area2);
1061 if (type->subtype && type->subtype->type == DW_TAG_subroutine_type)
1062 return (addr_pointed1 != addr_pointed2);
1063 if (addr_pointed1 == nullptr && addr_pointed2 == nullptr)
1065 if (addr_pointed1 == nullptr || addr_pointed2 == nullptr)
1067 if (not state.compared_pointers.insert(std::make_pair(addr_pointed1, addr_pointed2)).second)
1072 // Some cases are not handled here:
1073 // * the pointers lead to different areas (one to the heap, the other to the RW segment ...)
1074 // * a pointer leads to the read-only segment of the current object
1075 // * a pointer lead to a different ELF object
1077 if (snapshot1.on_heap(addr_pointed1)) {
1078 if (not snapshot2.on_heap(addr_pointed2))
1080 // The pointers are both in the heap:
1081 return simgrid::mc::heap_area_differ(process, state, addr_pointed1, addr_pointed2, snapshot1, snapshot2,
1082 nullptr, type->subtype, pointer_level);
1084 } else if (region1->contain(simgrid::mc::remote(addr_pointed1))) {
1085 // The pointers are both in the current object R/W segment:
1086 if (not region2->contain(simgrid::mc::remote(addr_pointed2)))
1088 if (not type->type_id)
1089 return (addr_pointed1 != addr_pointed2);
1091 return areas_differ_with_type(process, state, addr_pointed1, snapshot1, region1, addr_pointed2, snapshot2,
1092 region2, type->subtype, pointer_level);
1094 // TODO, We do not handle very well the case where
1095 // it belongs to a different (non-heap) region from the current one.
1097 return (addr_pointed1 != addr_pointed2);
1100 case DW_TAG_structure_type:
1101 case DW_TAG_class_type:
1102 for (const simgrid::mc::Member& member : type->members) {
1103 const void* member1 = simgrid::dwarf::resolve_member(real_area1, type, &member, &snapshot1);
1104 const void* member2 = simgrid::dwarf::resolve_member(real_area2, type, &member, &snapshot2);
1105 simgrid::mc::Region* subregion1 = snapshot1.get_region(member1, region1); // region1 is hinted
1106 simgrid::mc::Region* subregion2 = snapshot2.get_region(member2, region2); // region2 is hinted
1107 if (areas_differ_with_type(process, state, member1, snapshot1, subregion1, member2, snapshot2, subregion2,
1108 member.type, pointer_level))
1112 case DW_TAG_subroutine_type:
1115 XBT_VERB("Unknown case: %d", type->type);
1122 static bool global_variables_differ(const simgrid::mc::RemoteProcess& process, simgrid::mc::StateComparator& state,
1123 const simgrid::mc::ObjectInformation* object_info, simgrid::mc::Region* r1,
1124 simgrid::mc::Region* r2, const simgrid::mc::Snapshot& snapshot1,
1125 const simgrid::mc::Snapshot& snapshot2)
1127 xbt_assert(r1 && r2, "Missing region.");
1129 const std::vector<simgrid::mc::Variable>& variables = object_info->global_variables;
1131 for (simgrid::mc::Variable const& current_var : variables) {
1132 // If the variable is not in this object, skip it:
1133 // We do not expect to find a pointer to something which is not reachable
1134 // by the global variables.
1135 if ((char*)current_var.address < object_info->start_rw || (char*)current_var.address > object_info->end_rw)
1138 const simgrid::mc::Type* bvariable_type = current_var.type;
1139 if (areas_differ_with_type(process, state, current_var.address, snapshot1, r1, current_var.address, snapshot2, r2,
1140 bvariable_type, 0)) {
1141 XBT_VERB("Global variable %s (%p) is different between snapshots", current_var.name.c_str(), current_var.address);
1149 static bool local_variables_differ(const simgrid::mc::RemoteProcess& process, simgrid::mc::StateComparator& state,
1150 const simgrid::mc::Snapshot& snapshot1, const simgrid::mc::Snapshot& snapshot2,
1151 const_mc_snapshot_stack_t stack1, const_mc_snapshot_stack_t stack2)
1153 if (stack1->local_variables.size() != stack2->local_variables.size()) {
1154 XBT_VERB("Different number of local variables");
1158 for (unsigned int cursor = 0; cursor < stack1->local_variables.size(); cursor++) {
1159 const_local_variable_t current_var1 = &stack1->local_variables[cursor];
1160 const_local_variable_t current_var2 = &stack2->local_variables[cursor];
1161 if (current_var1->name != current_var2->name || current_var1->subprogram != current_var2->subprogram ||
1162 current_var1->ip != current_var2->ip) {
1163 // TODO, fix current_varX->subprogram->name to include name if DW_TAG_inlined_subprogram
1164 XBT_VERB("Different name of variable (%s - %s) or frame (%s - %s) or ip (%lu - %lu)", current_var1->name.c_str(),
1165 current_var2->name.c_str(), current_var1->subprogram->name.c_str(),
1166 current_var2->subprogram->name.c_str(), current_var1->ip, current_var2->ip);
1170 if (areas_differ_with_type(process, state, current_var1->address, snapshot1,
1171 snapshot1.get_region(current_var1->address), current_var2->address, snapshot2,
1172 snapshot2.get_region(current_var2->address), current_var1->type, 0)) {
1173 XBT_VERB("Local variable %s (%p - %p) in frame %s is different between snapshots", current_var1->name.c_str(),
1174 current_var1->address, current_var2->address, current_var1->subprogram->name.c_str());
1184 bool snapshot_equal(const Snapshot* s1, const Snapshot* s2)
1186 // TODO, make this a field of ModelChecker or something similar
1187 static StateComparator state_comparator;
1189 const RemoteProcess& process = mc_model_checker->get_remote_process();
1191 if (s1->hash_ != s2->hash_) {
1192 XBT_VERB("(%ld - %ld) Different hash: 0x%" PRIx64 "--0x%" PRIx64, s1->num_state_, s2->num_state_, s1->hash_,
1196 XBT_VERB("(%ld - %ld) Same hash: 0x%" PRIx64, s1->num_state_, s2->num_state_, s1->hash_);
1198 /* Compare enabled processes */
1199 if (s1->enabled_processes_ != s2->enabled_processes_) {
1200 XBT_VERB("(%ld - %ld) Different amount of enabled processes", s1->num_state_, s2->num_state_);
1204 /* Compare size of stacks */
1205 for (unsigned long i = 0; i < s1->stacks_.size(); i++) {
1206 size_t size_used1 = s1->stack_sizes_[i];
1207 size_t size_used2 = s2->stack_sizes_[i];
1208 if (size_used1 != size_used2) {
1209 XBT_VERB("(%ld - %ld) Different size used in stacks: %zu - %zu", s1->num_state_, s2->num_state_, size_used1,
1215 /* Init heap information used in heap comparison algorithm */
1216 const s_xbt_mheap_t* heap1 = static_cast<xbt_mheap_t>(
1217 s1->read_bytes(alloca(sizeof(s_xbt_mheap_t)), sizeof(s_xbt_mheap_t), process.heap_address, ReadOptions::lazy()));
1218 const s_xbt_mheap_t* heap2 = static_cast<xbt_mheap_t>(
1219 s2->read_bytes(alloca(sizeof(s_xbt_mheap_t)), sizeof(s_xbt_mheap_t), process.heap_address, ReadOptions::lazy()));
1220 if (state_comparator.initHeapInformation(heap1, heap2, s1->to_ignore_, s2->to_ignore_) == -1) {
1221 XBT_VERB("(%ld - %ld) Different heap information", s1->num_state_, s2->num_state_);
1225 /* Stacks comparison */
1226 for (unsigned int cursor = 0; cursor < s1->stacks_.size(); cursor++) {
1227 const_mc_snapshot_stack_t stack1 = &s1->stacks_[cursor];
1228 const_mc_snapshot_stack_t stack2 = &s2->stacks_[cursor];
1230 if (local_variables_differ(process, state_comparator, *s1, *s2, stack1, stack2)) {
1231 XBT_VERB("(%ld - %ld) Different local variables between stacks %u", s1->num_state_, s2->num_state_, cursor + 1);
1236 size_t regions_count = s1->snapshot_regions_.size();
1237 if (regions_count != s2->snapshot_regions_.size())
1240 for (size_t k = 0; k != regions_count; ++k) {
1241 Region* region1 = s1->snapshot_regions_[k].get();
1242 Region* region2 = s2->snapshot_regions_[k].get();
1245 if (region1->region_type() != RegionType::Data)
1248 xbt_assert(region1->region_type() == region2->region_type());
1249 xbt_assert(region1->object_info() == region2->object_info());
1250 xbt_assert(region1->object_info());
1252 /* Compare global variables */
1253 if (global_variables_differ(process, state_comparator, region1->object_info(), region1, region2, *s1, *s2)) {
1254 std::string const& name = region1->object_info()->file_name;
1255 XBT_VERB("(%ld - %ld) Different global variables in %s", s1->num_state_, s2->num_state_, name.c_str());
1261 if (mmalloc_heap_differ(process, state_comparator, *s1, *s2)) {
1262 XBT_VERB("(%ld - %ld) Different heap (mmalloc_compare)", s1->num_state_, s2->num_state_);
1266 XBT_VERB("(%ld - %ld) No difference found", s1->num_state_, s2->num_state_);
1271 } // namespace simgrid