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 namespace simgrid::mc {
18 /*********************************** Heap comparison ***********************************/
19 /***************************************************************************************/
26 HeapLocation() = default;
27 explicit HeapLocation(int block, int fragment = 0) : block_(block), fragment_(fragment) {}
29 bool operator==(HeapLocation const& that) const
31 return block_ == that.block_ && fragment_ == that.fragment_;
33 bool operator<(HeapLocation const& that) const
35 return std::make_pair(block_, fragment_) < std::make_pair(that.block_, that.fragment_);
39 using HeapLocationPair = std::array<HeapLocation, 2>;
40 using HeapLocationPairs = std::set<HeapLocationPair>;
42 class HeapArea : public HeapLocation {
46 explicit HeapArea(int block) : valid_(true) { block_ = block; }
47 HeapArea(int block, int fragment) : valid_(true)
54 class ProcessComparisonState {
56 const std::vector<IgnoredHeapRegion>* to_ignore = nullptr;
57 std::vector<HeapArea> equals_to;
58 std::vector<Type*> types;
59 std::size_t heapsize = 0;
61 void initHeapInformation(const s_xbt_mheap_t* heap, const std::vector<IgnoredHeapRegion>& i);
64 class StateComparator {
66 s_xbt_mheap_t std_heap_copy;
67 std::size_t heaplimit;
68 std::array<ProcessComparisonState, 2> processStates;
70 std::unordered_set<std::pair<const void*, const void*>, simgrid::xbt::hash<std::pair<const void*, const void*>>>
75 compared_pointers.clear();
78 int initHeapInformation(const s_xbt_mheap_t* heap1, const s_xbt_mheap_t* heap2,
79 const std::vector<IgnoredHeapRegion>& i1, const std::vector<IgnoredHeapRegion>& i2);
81 template <int rank> HeapArea& equals_to_(std::size_t i, std::size_t j)
83 return processStates[rank - 1].equals_to[MAX_FRAGMENT_PER_BLOCK * i + j];
85 template <int rank> Type*& types_(std::size_t i, std::size_t j)
87 return processStates[rank - 1].types[MAX_FRAGMENT_PER_BLOCK * i + j];
90 template <int rank> HeapArea const& equals_to_(std::size_t i, std::size_t j) const
92 return processStates[rank - 1].equals_to[MAX_FRAGMENT_PER_BLOCK * i + j];
94 template <int rank> Type* const& types_(std::size_t i, std::size_t j) const
96 return processStates[rank - 1].types[MAX_FRAGMENT_PER_BLOCK * i + j];
99 /** Check whether two blocks are known to be matching
101 * @param b1 Block of state 1
102 * @param b2 Block of state 2
103 * @return if the blocks are known to be matching
105 bool blocksEqual(int b1, int b2) const
107 return this->equals_to_<1>(b1, 0).block_ == b2 && this->equals_to_<2>(b2, 0).block_ == b1;
110 /** Check whether two fragments are known to be matching
112 * @param b1 Block of state 1
113 * @param f1 Fragment of state 1
114 * @param b2 Block of state 2
115 * @param f2 Fragment of state 2
116 * @return if the fragments are known to be matching
118 int fragmentsEqual(int b1, int f1, int b2, int f2) const
120 return this->equals_to_<1>(b1, f1).block_ == b2 && this->equals_to_<1>(b1, f1).fragment_ == f2 &&
121 this->equals_to_<2>(b2, f2).block_ == b1 && this->equals_to_<2>(b2, f2).fragment_ == f1;
124 void match_equals(const HeapLocationPairs* list);
127 } // namespace simgrid::mc
129 /************************************************************************************/
131 static ssize_t heap_comparison_ignore_size(const std::vector<simgrid::mc::IgnoredHeapRegion>* ignore_list,
134 auto pos = std::lower_bound(ignore_list->begin(), ignore_list->end(), address,
135 [](auto const& reg, auto const* addr) { return reg.address < addr; });
136 return (pos != ignore_list->end() && pos->address == address) ? pos->size : -1;
139 static bool is_stack(const simgrid::mc::RemoteProcess& process, const void* address)
141 auto const& stack_areas = process.stack_areas();
142 return std::any_of(stack_areas.begin(), stack_areas.end(),
143 [address](auto const& stack) { return stack.address == address; });
146 // TODO, this should depend on the snapshot?
147 static bool is_block_stack(const simgrid::mc::RemoteProcess& process, int block)
149 auto const& stack_areas = process.stack_areas();
150 return std::any_of(stack_areas.begin(), stack_areas.end(),
151 [block](auto const& stack) { return stack.block == block; });
154 namespace simgrid::mc {
156 void StateComparator::match_equals(const HeapLocationPairs* list)
158 for (auto const& pair : *list) {
159 if (pair[0].fragment_ != -1) {
160 this->equals_to_<1>(pair[0].block_, pair[0].fragment_) = HeapArea(pair[1].block_, pair[1].fragment_);
161 this->equals_to_<2>(pair[1].block_, pair[1].fragment_) = HeapArea(pair[0].block_, pair[0].fragment_);
163 this->equals_to_<1>(pair[0].block_, 0) = HeapArea(pair[1].block_, pair[1].fragment_);
164 this->equals_to_<2>(pair[1].block_, 0) = HeapArea(pair[0].block_, pair[0].fragment_);
169 void ProcessComparisonState::initHeapInformation(const s_xbt_mheap_t* heap, const std::vector<IgnoredHeapRegion>& i)
171 auto heaplimit = heap->heaplimit;
172 this->heapsize = heap->heapsize;
173 this->to_ignore = &i;
174 this->equals_to.assign(heaplimit * MAX_FRAGMENT_PER_BLOCK, HeapArea());
175 this->types.assign(heaplimit * MAX_FRAGMENT_PER_BLOCK, nullptr);
178 int StateComparator::initHeapInformation(const s_xbt_mheap_t* heap1, const s_xbt_mheap_t* heap2,
179 const std::vector<IgnoredHeapRegion>& i1,
180 const std::vector<IgnoredHeapRegion>& i2)
182 if ((heap1->heaplimit != heap2->heaplimit) || (heap1->heapsize != heap2->heapsize))
184 this->heaplimit = heap1->heaplimit;
185 this->std_heap_copy = *mc_model_checker->get_remote_process().get_heap();
186 this->processStates[0].initHeapInformation(heap1, i1);
187 this->processStates[1].initHeapInformation(heap2, i2);
191 // TODO, have a robust way to find it in O(1)
192 static inline Region* MC_get_heap_region(const Snapshot& snapshot)
194 for (auto const& region : snapshot.snapshot_regions_)
195 if (region->region_type() == RegionType::Heap)
197 xbt_die("No heap region");
200 static bool heap_area_differ(const RemoteProcess& process, StateComparator& state, const void* area1, const void* area2,
201 const Snapshot& snapshot1, const Snapshot& snapshot2, HeapLocationPairs* previous,
202 Type* type, int pointer_level);
204 static bool mmalloc_heap_differ(const RemoteProcess& process, StateComparator& state, const Snapshot& snapshot1,
205 const Snapshot& snapshot2)
207 /* Check busy blocks */
210 malloc_info heapinfo_temp1;
211 malloc_info heapinfo_temp2;
212 malloc_info heapinfo_temp2b;
214 const Region* heap_region1 = MC_get_heap_region(snapshot1);
215 const Region* heap_region2 = MC_get_heap_region(snapshot2);
217 // This is the address of std_heap->heapinfo in the application process:
218 uint64_t heapinfo_address = process.heap_address.address() + offsetof(s_xbt_mheap_t, heapinfo);
220 // This is in snapshot do not use them directly:
221 const malloc_info* heapinfos1 = snapshot1.read(remote<malloc_info*>(heapinfo_address));
222 const malloc_info* heapinfos2 = snapshot2.read(remote<malloc_info*>(heapinfo_address));
224 while (i1 < state.heaplimit) {
225 const auto* heapinfo1 =
226 static_cast<malloc_info*>(heap_region1->read(&heapinfo_temp1, &heapinfos1[i1], sizeof(malloc_info)));
227 const auto* heapinfo2 =
228 static_cast<malloc_info*>(heap_region2->read(&heapinfo_temp2, &heapinfos2[i1], sizeof(malloc_info)));
230 if (heapinfo1->type == MMALLOC_TYPE_FREE || heapinfo1->type == MMALLOC_TYPE_HEAPINFO) { /* Free block */
235 xbt_assert(heapinfo1->type >= 0, "Unknown mmalloc block type: %d", heapinfo1->type);
237 void* addr_block1 = (ADDR2UINT(i1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
239 if (heapinfo1->type == MMALLOC_TYPE_UNFRAGMENTED) { /* Large block */
240 if (is_stack(process, addr_block1)) {
241 for (size_t k = 0; k < heapinfo1->busy_block.size; k++)
242 state.equals_to_<1>(i1 + k, 0) = HeapArea(i1, -1);
243 for (size_t k = 0; k < heapinfo2->busy_block.size; k++)
244 state.equals_to_<2>(i1 + k, 0) = HeapArea(i1, -1);
245 i1 += heapinfo1->busy_block.size;
249 if (state.equals_to_<1>(i1, 0).valid_) {
257 /* Try first to associate to same block in the other heap */
258 if (heapinfo2->type == heapinfo1->type && state.equals_to_<2>(i1, 0).valid_ == 0) {
259 const void* addr_block2 = (ADDR2UINT(i1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
260 if (not heap_area_differ(process, state, addr_block1, addr_block2, snapshot1, snapshot2, nullptr, nullptr, 0)) {
261 for (size_t k = 1; k < heapinfo2->busy_block.size; k++)
262 state.equals_to_<2>(i1 + k, 0) = HeapArea(i1, -1);
263 for (size_t k = 1; k < heapinfo1->busy_block.size; k++)
264 state.equals_to_<1>(i1 + k, 0) = HeapArea(i1, -1);
266 i1 += heapinfo1->busy_block.size;
270 while (i2 < state.heaplimit && not equal) {
271 const void* addr_block2 = (ADDR2UINT(i2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
278 const auto* heapinfo2b =
279 static_cast<malloc_info*>(heap_region2->read(&heapinfo_temp2b, &heapinfos2[i2], sizeof(malloc_info)));
281 if (heapinfo2b->type != MMALLOC_TYPE_UNFRAGMENTED) {
286 if (state.equals_to_<2>(i2, 0).valid_) {
291 if (not heap_area_differ(process, state, addr_block1, addr_block2, snapshot1, snapshot2, nullptr, nullptr, 0)) {
292 for (size_t k = 1; k < heapinfo2b->busy_block.size; k++)
293 state.equals_to_<2>(i2 + k, 0) = HeapArea(i1, -1);
294 for (size_t k = 1; k < heapinfo1->busy_block.size; k++)
295 state.equals_to_<1>(i1 + k, 0) = HeapArea(i2, -1);
297 i1 += heapinfo1->busy_block.size;
303 XBT_DEBUG("Block %zu not found (size_used = %zu, addr = %p)", i1, heapinfo1->busy_block.busy_size, addr_block1);
306 } else { /* Fragmented block */
307 for (size_t j1 = 0; j1 < (size_t)(BLOCKSIZE >> heapinfo1->type); j1++) {
308 if (heapinfo1->busy_frag.frag_size[j1] == -1) /* Free fragment_ */
311 if (state.equals_to_<1>(i1, j1).valid_)
314 void* addr_frag1 = (char*)addr_block1 + (j1 << heapinfo1->type);
319 /* Try first to associate to same fragment_ in the other heap */
320 if (heapinfo2->type == heapinfo1->type && not state.equals_to_<2>(i1, j1).valid_) {
321 const void* addr_block2 = (ADDR2UINT(i1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
322 const void* addr_frag2 = (const char*)addr_block2 + (j1 << heapinfo2->type);
323 if (not heap_area_differ(process, state, addr_frag1, addr_frag2, snapshot1, snapshot2, nullptr, nullptr, 0))
327 while (i2 < state.heaplimit && not equal) {
328 const auto* heapinfo2b =
329 static_cast<malloc_info*>(heap_region2->read(&heapinfo_temp2b, &heapinfos2[i2], sizeof(malloc_info)));
331 if (heapinfo2b->type == MMALLOC_TYPE_FREE || heapinfo2b->type == MMALLOC_TYPE_HEAPINFO) {
336 // We currently do not match fragments with unfragmented blocks (maybe we should).
337 if (heapinfo2b->type == MMALLOC_TYPE_UNFRAGMENTED) {
342 xbt_assert(heapinfo2b->type >= 0, "Unknown mmalloc block type: %d", heapinfo2b->type);
344 for (size_t j2 = 0; j2 < (size_t)(BLOCKSIZE >> heapinfo2b->type); j2++) {
345 if (i2 == i1 && j2 == j1)
348 if (state.equals_to_<2>(i2, j2).valid_)
351 const void* addr_block2 = (ADDR2UINT(i2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
352 const void* addr_frag2 = (const char*)addr_block2 + (j2 << heapinfo2b->type);
354 if (not heap_area_differ(process, state, addr_frag1, addr_frag2, snapshot1, snapshot2, nullptr, nullptr,
364 XBT_DEBUG("Block %zu, fragment_ %zu not found (size_used = %zd, address = %p)\n", i1, j1,
365 heapinfo1->busy_frag.frag_size[j1], addr_frag1);
373 /* All blocks/fragments are equal to another block/fragment_ ? */
374 for (size_t i = 1; i < state.heaplimit; i++) {
375 const auto* heapinfo1 =
376 static_cast<malloc_info*>(heap_region1->read(&heapinfo_temp1, &heapinfos1[i], sizeof(malloc_info)));
378 if (heapinfo1->type == MMALLOC_TYPE_UNFRAGMENTED && i1 == state.heaplimit && heapinfo1->busy_block.busy_size > 0 &&
379 not state.equals_to_<1>(i, 0).valid_) {
380 XBT_DEBUG("Block %zu not found (size used = %zu)", i, heapinfo1->busy_block.busy_size);
384 if (heapinfo1->type <= 0)
386 for (size_t j = 0; j < (size_t)(BLOCKSIZE >> heapinfo1->type); j++)
387 if (i1 == state.heaplimit && heapinfo1->busy_frag.frag_size[j] > 0 && not state.equals_to_<1>(i, j).valid_) {
388 XBT_DEBUG("Block %zu, Fragment %zu not found (size used = %zd)", i, j, heapinfo1->busy_frag.frag_size[j]);
393 for (size_t i = 1; i < state.heaplimit; i++) {
394 const auto* heapinfo2 =
395 static_cast<malloc_info*>(heap_region2->read(&heapinfo_temp2, &heapinfos2[i], sizeof(malloc_info)));
396 if (heapinfo2->type == MMALLOC_TYPE_UNFRAGMENTED && i1 == state.heaplimit && heapinfo2->busy_block.busy_size > 0 &&
397 not state.equals_to_<2>(i, 0).valid_) {
398 XBT_DEBUG("Block %zu not found (size used = %zu)", i,
399 heapinfo2->busy_block.busy_size);
403 if (heapinfo2->type <= 0)
406 for (size_t j = 0; j < (size_t)(BLOCKSIZE >> heapinfo2->type); j++)
407 if (i1 == state.heaplimit && heapinfo2->busy_frag.frag_size[j] > 0 && not state.equals_to_<2>(i, j).valid_) {
408 XBT_DEBUG("Block %zu, Fragment %zu not found (size used = %zd)",
409 i, j, heapinfo2->busy_frag.frag_size[j]);
419 * @param real_area1 Process address for state 1
420 * @param real_area2 Process address for state 2
421 * @param snapshot1 Snapshot of state 1
422 * @param snapshot2 Snapshot of state 2
425 * @param check_ignore
426 * @return true when different, false otherwise (same or unknown)
428 static bool heap_area_differ_without_type(const RemoteProcess& process, StateComparator& state, const void* real_area1,
429 const void* real_area2, const Snapshot& snapshot1, const Snapshot& snapshot2,
430 HeapLocationPairs* previous, int size, int check_ignore)
432 const Region* heap_region1 = MC_get_heap_region(snapshot1);
433 const Region* heap_region2 = MC_get_heap_region(snapshot2);
435 for (int i = 0; i < size; ) {
436 if (check_ignore > 0) {
437 ssize_t ignore1 = heap_comparison_ignore_size(state.processStates[0].to_ignore, (const char*)real_area1 + i);
439 ssize_t ignore2 = heap_comparison_ignore_size(state.processStates[1].to_ignore, (const char*)real_area2 + i);
440 if (ignore2 == ignore1) {
452 if (MC_snapshot_region_memcmp((const char*)real_area1 + i, heap_region1, (const char*)real_area2 + i, heap_region2,
454 int pointer_align = (i / sizeof(void *)) * sizeof(void *);
455 const void* addr_pointed1 = snapshot1.read(remote((void* const*)((const char*)real_area1 + pointer_align)));
456 const void* addr_pointed2 = snapshot2.read(remote((void* const*)((const char*)real_area2 + pointer_align)));
458 if (process.in_maestro_stack(remote(addr_pointed1)) && process.in_maestro_stack(remote(addr_pointed2))) {
459 i = pointer_align + sizeof(void *);
463 if (snapshot1.on_heap(addr_pointed1) && snapshot2.on_heap(addr_pointed2)) {
464 // Both addresses are in the heap:
465 if (heap_area_differ(process, state, addr_pointed1, addr_pointed2, snapshot1, snapshot2, previous, nullptr, 0))
467 i = pointer_align + sizeof(void *);
480 * @param real_area1 Process address for state 1
481 * @param real_area2 Process address for state 2
482 * @param snapshot1 Snapshot of state 1
483 * @param snapshot2 Snapshot of state 2
486 * @param area_size either a byte_size or an elements_count (?)
487 * @param check_ignore
488 * @param pointer_level
489 * @return true when different, false otherwise (same or unknown)
491 static bool heap_area_differ_with_type(const simgrid::mc::RemoteProcess& process, StateComparator& state,
492 const void* real_area1, const void* real_area2, const Snapshot& snapshot1,
493 const Snapshot& snapshot2, HeapLocationPairs* previous, const Type* type,
494 int area_size, int check_ignore, int pointer_level)
496 // HACK: This should not happen but in practice, there are some
497 // DW_TAG_typedef without an associated DW_AT_type:
498 //<1><538832>: Abbrev Number: 111 (DW_TAG_typedef)
499 // <538833> DW_AT_name : (indirect string, offset: 0x2292f3): gregset_t
500 // <538837> DW_AT_decl_file : 98
501 // <538838> DW_AT_decl_line : 37
505 if (is_stack(process, real_area1) && is_stack(process, real_area2))
508 if (check_ignore > 0) {
509 ssize_t ignore1 = heap_comparison_ignore_size(state.processStates[0].to_ignore, real_area1);
510 if (ignore1 > 0 && heap_comparison_ignore_size(state.processStates[1].to_ignore, real_area2) == ignore1)
515 const Type* subsubtype;
517 const void* addr_pointed1;
518 const void* addr_pointed2;
520 const Region* heap_region1 = MC_get_heap_region(snapshot1);
521 const Region* heap_region2 = MC_get_heap_region(snapshot2);
523 switch (type->type) {
524 case DW_TAG_unspecified_type:
527 case DW_TAG_base_type:
528 if (not type->name.empty() && type->name == "char") { /* String, hence random (arbitrary ?) size */
529 if (real_area1 == real_area2)
532 return MC_snapshot_region_memcmp(real_area1, heap_region1, real_area2, heap_region2, area_size) != 0;
534 if (area_size != -1 && type->byte_size != area_size)
537 return MC_snapshot_region_memcmp(real_area1, heap_region1, real_area2, heap_region2, type->byte_size) != 0;
540 case DW_TAG_enumeration_type:
541 if (area_size != -1 && type->byte_size != area_size)
543 return MC_snapshot_region_memcmp(real_area1, heap_region1, real_area2, heap_region2, type->byte_size) != 0;
546 case DW_TAG_const_type:
547 case DW_TAG_volatile_type:
548 return heap_area_differ_with_type(process, state, real_area1, real_area2, snapshot1, snapshot2, previous,
549 type->subtype, area_size, check_ignore, pointer_level);
551 case DW_TAG_array_type:
552 subtype = type->subtype;
553 switch (subtype->type) {
554 case DW_TAG_unspecified_type:
557 case DW_TAG_base_type:
558 case DW_TAG_enumeration_type:
559 case DW_TAG_pointer_type:
560 case DW_TAG_reference_type:
561 case DW_TAG_rvalue_reference_type:
562 case DW_TAG_structure_type:
563 case DW_TAG_class_type:
564 case DW_TAG_union_type:
565 if (subtype->full_type)
566 subtype = subtype->full_type;
567 elm_size = subtype->byte_size;
569 // TODO, just remove the type indirection?
570 case DW_TAG_const_type:
572 case DW_TAG_volatile_type:
573 subsubtype = subtype->subtype;
574 if (subsubtype->full_type)
575 subsubtype = subsubtype->full_type;
576 elm_size = subsubtype->byte_size;
581 for (int i = 0; i < type->element_count; i++) {
582 // TODO, add support for variable stride (DW_AT_byte_stride)
583 if (heap_area_differ_with_type(process, state, (const char*)real_area1 + (i * elm_size),
584 (const char*)real_area2 + (i * elm_size), snapshot1, snapshot2, previous,
585 type->subtype, subtype->byte_size, check_ignore, pointer_level))
590 case DW_TAG_reference_type:
591 case DW_TAG_rvalue_reference_type:
592 case DW_TAG_pointer_type:
593 if (type->subtype && type->subtype->type == DW_TAG_subroutine_type) {
594 addr_pointed1 = snapshot1.read(remote((void* const*)real_area1));
595 addr_pointed2 = snapshot2.read(remote((void* const*)real_area2));
596 return (addr_pointed1 != addr_pointed2);
599 if (pointer_level <= 1) {
600 addr_pointed1 = snapshot1.read(remote((void* const*)real_area1));
601 addr_pointed2 = snapshot2.read(remote((void* const*)real_area2));
602 if (snapshot1.on_heap(addr_pointed1) && snapshot2.on_heap(addr_pointed2))
603 return heap_area_differ(process, state, addr_pointed1, addr_pointed2, snapshot1, snapshot2, previous,
604 type->subtype, pointer_level);
606 return (addr_pointed1 != addr_pointed2);
608 for (size_t i = 0; i < (area_size / sizeof(void*)); i++) {
609 addr_pointed1 = snapshot1.read(remote((void* const*)((const char*)real_area1 + i * sizeof(void*))));
610 addr_pointed2 = snapshot2.read(remote((void* const*)((const char*)real_area2 + i * sizeof(void*))));
611 bool differ = snapshot1.on_heap(addr_pointed1) && snapshot2.on_heap(addr_pointed2)
612 ? heap_area_differ(process, state, addr_pointed1, addr_pointed2, snapshot1, snapshot2,
613 previous, type->subtype, pointer_level)
614 : addr_pointed1 != addr_pointed2;
620 case DW_TAG_structure_type:
621 case DW_TAG_class_type:
623 type = type->full_type;
624 if (type->byte_size == 0)
626 if (area_size != -1 && type->byte_size != area_size) {
627 if (area_size <= type->byte_size || area_size % type->byte_size != 0)
629 for (size_t i = 0; i < (size_t)(area_size / type->byte_size); i++) {
630 if (heap_area_differ_with_type(process, state, (const char*)real_area1 + i * type->byte_size,
631 (const char*)real_area2 + i * type->byte_size, snapshot1, snapshot2, previous,
632 type, -1, check_ignore, 0))
636 for (const simgrid::mc::Member& member : type->members) {
637 // TODO, optimize this? (for the offset case)
638 const void* real_member1 = dwarf::resolve_member(real_area1, type, &member, &snapshot1);
639 const void* real_member2 = dwarf::resolve_member(real_area2, type, &member, &snapshot2);
640 if (heap_area_differ_with_type(process, state, real_member1, real_member2, snapshot1, snapshot2, previous,
641 member.type, -1, check_ignore, 0))
647 case DW_TAG_union_type:
648 return heap_area_differ_without_type(process, state, real_area1, real_area2, snapshot1, snapshot2, previous,
649 type->byte_size, check_ignore);
656 /** Infer the type of a part of the block from the type of the block
658 * TODO, handle DW_TAG_array_type as well as arrays of the object ((*p)[5], p[5])
660 * TODO, handle subfields ((*p).bar.foo, (*p)[5].bar…)
662 * @param type DWARF type ID of the root address
664 * @return DWARF type ID for given offset
666 static Type* get_offset_type(void* real_base_address, Type* type, int offset, int area_size, const Snapshot& snapshot)
668 // Beginning of the block, the inferred variable type if the type of the block:
672 switch (type->type) {
673 case DW_TAG_structure_type:
674 case DW_TAG_class_type:
676 type = type->full_type;
677 if (area_size != -1 && type->byte_size != area_size) {
678 if (area_size > type->byte_size && area_size % type->byte_size == 0)
684 for (const simgrid::mc::Member& member : type->members) {
685 if (member.has_offset_location()) {
686 // We have the offset, use it directly (shortcut):
687 if (member.offset() == offset)
690 void* real_member = dwarf::resolve_member(real_base_address, type, &member, &snapshot);
691 if ((char*)real_member - (char*)real_base_address == offset)
698 /* FIXME: other cases ? */
705 * @param area1 Process address for state 1
706 * @param area2 Process address for state 2
707 * @param snapshot1 Snapshot of state 1
708 * @param snapshot2 Snapshot of state 2
709 * @param previous Pairs of blocks already compared on the current path (or nullptr)
710 * @param type_id Type of variable
711 * @param pointer_level
712 * @return true when different, false otherwise (same or unknown)
714 static bool heap_area_differ(const RemoteProcess& process, StateComparator& state, const void* area1, const void* area2,
715 const Snapshot& snapshot1, const Snapshot& snapshot2, HeapLocationPairs* previous,
716 Type* type, int pointer_level)
721 int check_ignore = 0;
729 Type* new_type1 = nullptr;
731 bool match_pairs = false;
733 // This is the address of std_heap->heapinfo in the application process:
734 uint64_t heapinfo_address = process.heap_address.address() + offsetof(s_xbt_mheap_t, heapinfo);
736 const malloc_info* heapinfos1 = snapshot1.read(remote<malloc_info*>(heapinfo_address));
737 const malloc_info* heapinfos2 = snapshot2.read(remote<malloc_info*>(heapinfo_address));
739 malloc_info heapinfo_temp1;
740 malloc_info heapinfo_temp2;
742 simgrid::mc::HeapLocationPairs current;
743 if (previous == nullptr) {
749 block1 = ((const char*)area1 - (const char*)state.std_heap_copy.heapbase) / BLOCKSIZE + 1;
750 block2 = ((const char*)area2 - (const char*)state.std_heap_copy.heapbase) / BLOCKSIZE + 1;
752 // If either block is a stack block:
753 if (is_block_stack(process, (int)block1) && is_block_stack(process, (int)block2)) {
754 previous->insert(HeapLocationPair{{HeapLocation(block1, -1), HeapLocation(block2, -1)}});
756 state.match_equals(previous);
760 // If either block is not in the expected area of memory:
761 if (((const char*)area1 < (const char*)state.std_heap_copy.heapbase) ||
762 (block1 > (ssize_t)state.processStates[0].heapsize) || (block1 < 1) ||
763 ((const char*)area2 < (const char*)state.std_heap_copy.heapbase) ||
764 (block2 > (ssize_t)state.processStates[1].heapsize) || (block2 < 1)) {
768 // Process address of the block:
769 void* real_addr_block1 = (ADDR2UINT(block1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
770 void* real_addr_block2 = (ADDR2UINT(block2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
774 type = type->full_type;
776 // This assume that for "boring" types (volatile ...) byte_size is absent:
777 while (type->byte_size == 0 && type->subtype != nullptr)
778 type = type->subtype;
781 if (type->type == DW_TAG_pointer_type ||
782 (type->type == DW_TAG_base_type && not type->name.empty() && type->name == "char"))
785 type_size = type->byte_size;
788 const Region* heap_region1 = MC_get_heap_region(snapshot1);
789 const Region* heap_region2 = MC_get_heap_region(snapshot2);
791 const auto* heapinfo1 =
792 static_cast<malloc_info*>(heap_region1->read(&heapinfo_temp1, &heapinfos1[block1], sizeof(malloc_info)));
793 const auto* heapinfo2 =
794 static_cast<malloc_info*>(heap_region2->read(&heapinfo_temp2, &heapinfos2[block2], sizeof(malloc_info)));
796 if ((heapinfo1->type == MMALLOC_TYPE_FREE || heapinfo1->type==MMALLOC_TYPE_HEAPINFO)
797 && (heapinfo2->type == MMALLOC_TYPE_FREE || heapinfo2->type ==MMALLOC_TYPE_HEAPINFO)) {
800 state.match_equals(previous);
804 if (heapinfo1->type == MMALLOC_TYPE_UNFRAGMENTED && heapinfo2->type == MMALLOC_TYPE_UNFRAGMENTED) {
807 // TODO, lookup variable type from block type as done for fragmented blocks
809 if (state.equals_to_<1>(block1, 0).valid_ && state.equals_to_<2>(block2, 0).valid_ &&
810 state.blocksEqual(block1, block2)) {
812 state.match_equals(previous);
816 if (type_size != -1 && type_size != (ssize_t)heapinfo1->busy_block.busy_size &&
817 type_size != (ssize_t)heapinfo2->busy_block.busy_size &&
818 (type->name.empty() ||
819 type->name == "struct s_smx_context")) { // FIXME: there is no struct s_smx_context anymore
821 state.match_equals(previous);
825 if (heapinfo1->busy_block.size != heapinfo2->busy_block.size ||
826 heapinfo1->busy_block.busy_size != heapinfo2->busy_block.busy_size)
829 if (not previous->insert(HeapLocationPair{{HeapLocation(block1, -1), HeapLocation(block2, -1)}}).second) {
831 state.match_equals(previous);
835 size = heapinfo1->busy_block.busy_size;
837 // Remember (basic) type inference.
838 // The current data structure only allows us to do this for the whole block.
839 if (type != nullptr && area1 == real_addr_block1)
840 state.types_<1>(block1, 0) = type;
841 if (type != nullptr && area2 == real_addr_block2)
842 state.types_<2>(block2, 0) = type;
846 state.match_equals(previous);
850 if (heapinfo1->busy_block.ignore > 0 && heapinfo2->busy_block.ignore == heapinfo1->busy_block.ignore)
851 check_ignore = heapinfo1->busy_block.ignore;
853 } else if ((heapinfo1->type > 0) && (heapinfo2->type > 0)) { /* Fragmented block */
855 ssize_t frag1 = (ADDR2UINT(area1) % BLOCKSIZE) >> heapinfo1->type;
856 ssize_t frag2 = (ADDR2UINT(area2) % BLOCKSIZE) >> heapinfo2->type;
858 // Process address of the fragment_:
859 void* real_addr_frag1 = (char*)real_addr_block1 + (frag1 << heapinfo1->type);
860 void* real_addr_frag2 = (char*)real_addr_block2 + (frag2 << heapinfo2->type);
862 // Check the size of the fragments against the size of the type:
863 if (type_size != -1) {
864 if (heapinfo1->busy_frag.frag_size[frag1] == -1 || heapinfo2->busy_frag.frag_size[frag2] == -1) {
866 state.match_equals(previous);
870 if (type_size != heapinfo1->busy_frag.frag_size[frag1]
871 || type_size != heapinfo2->busy_frag.frag_size[frag2]) {
873 state.match_equals(previous);
878 // Check if the blocks are already matched together:
879 if (state.equals_to_<1>(block1, frag1).valid_ && state.equals_to_<2>(block2, frag2).valid_ &&
880 state.fragmentsEqual(block1, frag1, block2, frag2)) {
882 state.match_equals(previous);
885 // Compare the size of both fragments:
886 if (heapinfo1->busy_frag.frag_size[frag1] != heapinfo2->busy_frag.frag_size[frag2]) {
887 if (type_size == -1) {
889 state.match_equals(previous);
895 // Size of the fragment_:
896 size = heapinfo1->busy_frag.frag_size[frag1];
898 // Remember (basic) type inference.
899 // The current data structure only allows us to do this for the whole fragment_.
900 if (type != nullptr && area1 == real_addr_frag1)
901 state.types_<1>(block1, frag1) = type;
902 if (type != nullptr && area2 == real_addr_frag2)
903 state.types_<2>(block2, frag2) = type;
905 // The type of the variable is already known:
909 // Type inference from the block type.
910 else if (state.types_<1>(block1, frag1) != nullptr || state.types_<2>(block2, frag2) != nullptr) {
911 Type* new_type2 = nullptr;
913 offset1 = (const char*)area1 - (const char*)real_addr_frag1;
914 offset2 = (const char*)area2 - (const char*)real_addr_frag2;
916 if (state.types_<1>(block1, frag1) != nullptr && state.types_<2>(block2, frag2) != nullptr) {
917 new_type1 = get_offset_type(real_addr_frag1, state.types_<1>(block1, frag1), offset1, size, snapshot1);
918 new_type2 = get_offset_type(real_addr_frag2, state.types_<2>(block2, frag2), offset1, size, snapshot2);
919 } else if (state.types_<1>(block1, frag1) != nullptr) {
920 new_type1 = get_offset_type(real_addr_frag1, state.types_<1>(block1, frag1), offset1, size, snapshot1);
921 new_type2 = get_offset_type(real_addr_frag2, state.types_<1>(block1, frag1), offset2, size, snapshot2);
922 } else if (state.types_<2>(block2, frag2) != nullptr) {
923 new_type1 = get_offset_type(real_addr_frag1, state.types_<2>(block2, frag2), offset1, size, snapshot1);
924 new_type2 = get_offset_type(real_addr_frag2, state.types_<2>(block2, frag2), offset2, size, snapshot2);
927 state.match_equals(previous);
931 if (new_type1 != nullptr && new_type2 != nullptr && new_type1 != new_type2) {
933 while (type->byte_size == 0 && type->subtype != nullptr)
934 type = type->subtype;
935 new_size1 = type->byte_size;
938 while (type->byte_size == 0 && type->subtype != nullptr)
939 type = type->subtype;
940 new_size2 = type->byte_size;
944 state.match_equals(previous);
949 if (new_size1 > 0 && new_size1 == new_size2) {
954 if (offset1 == 0 && offset2 == 0 &&
955 not previous->insert(HeapLocationPair{{HeapLocation(block1, frag1), HeapLocation(block2, frag2)}}).second) {
957 state.match_equals(previous);
963 state.match_equals(previous);
967 if ((heapinfo1->busy_frag.ignore[frag1] > 0) &&
968 (heapinfo2->busy_frag.ignore[frag2] == heapinfo1->busy_frag.ignore[frag1]))
969 check_ignore = heapinfo1->busy_frag.ignore[frag1];
973 /* Start comparison */
974 if (type ? heap_area_differ_with_type(process, state, area1, area2, snapshot1, snapshot2, previous, type, size,
975 check_ignore, pointer_level)
976 : heap_area_differ_without_type(process, state, area1, area2, snapshot1, snapshot2, previous, size,
981 state.match_equals(previous);
984 } // namespace simgrid::mc
986 /************************** Snapshot comparison *******************************/
987 /******************************************************************************/
989 static bool areas_differ_with_type(const simgrid::mc::RemoteProcess& process, simgrid::mc::StateComparator& state,
990 const void* real_area1, const simgrid::mc::Snapshot& snapshot1,
991 simgrid::mc::Region* region1, const void* real_area2,
992 const simgrid::mc::Snapshot& snapshot2, simgrid::mc::Region* region2,
993 const simgrid::mc::Type* type, int pointer_level)
995 const simgrid::mc::Type* subtype;
996 const simgrid::mc::Type* subsubtype;
999 xbt_assert(type != nullptr);
1000 switch (type->type) {
1001 case DW_TAG_unspecified_type:
1004 case DW_TAG_base_type:
1005 case DW_TAG_enumeration_type:
1006 case DW_TAG_union_type:
1007 return MC_snapshot_region_memcmp(real_area1, region1, real_area2, region2, type->byte_size) != 0;
1008 case DW_TAG_typedef:
1009 case DW_TAG_volatile_type:
1010 case DW_TAG_const_type:
1011 return areas_differ_with_type(process, state, real_area1, snapshot1, region1, real_area2, snapshot2, region2,
1012 type->subtype, pointer_level);
1013 case DW_TAG_array_type:
1014 subtype = type->subtype;
1015 switch (subtype->type) {
1016 case DW_TAG_unspecified_type:
1019 case DW_TAG_base_type:
1020 case DW_TAG_enumeration_type:
1021 case DW_TAG_pointer_type:
1022 case DW_TAG_reference_type:
1023 case DW_TAG_rvalue_reference_type:
1024 case DW_TAG_structure_type:
1025 case DW_TAG_class_type:
1026 case DW_TAG_union_type:
1027 if (subtype->full_type)
1028 subtype = subtype->full_type;
1029 elm_size = subtype->byte_size;
1031 case DW_TAG_const_type:
1032 case DW_TAG_typedef:
1033 case DW_TAG_volatile_type:
1034 subsubtype = subtype->subtype;
1035 if (subsubtype->full_type)
1036 subsubtype = subsubtype->full_type;
1037 elm_size = subsubtype->byte_size;
1042 for (int i = 0; i < type->element_count; i++) {
1043 size_t off = i * elm_size;
1044 if (areas_differ_with_type(process, state, (const char*)real_area1 + off, snapshot1, region1,
1045 (const char*)real_area2 + off, snapshot2, region2, type->subtype, pointer_level))
1049 case DW_TAG_pointer_type:
1050 case DW_TAG_reference_type:
1051 case DW_TAG_rvalue_reference_type: {
1052 const void* addr_pointed1 = MC_region_read_pointer(region1, real_area1);
1053 const void* addr_pointed2 = MC_region_read_pointer(region2, real_area2);
1055 if (type->subtype && type->subtype->type == DW_TAG_subroutine_type)
1056 return (addr_pointed1 != addr_pointed2);
1057 if (addr_pointed1 == nullptr && addr_pointed2 == nullptr)
1059 if (addr_pointed1 == nullptr || addr_pointed2 == nullptr)
1061 if (not state.compared_pointers.insert(std::make_pair(addr_pointed1, addr_pointed2)).second)
1066 // Some cases are not handled here:
1067 // * the pointers lead to different areas (one to the heap, the other to the RW segment ...)
1068 // * a pointer leads to the read-only segment of the current object
1069 // * a pointer lead to a different ELF object
1071 if (snapshot1.on_heap(addr_pointed1)) {
1072 if (not snapshot2.on_heap(addr_pointed2))
1074 // The pointers are both in the heap:
1075 return simgrid::mc::heap_area_differ(process, state, addr_pointed1, addr_pointed2, snapshot1, snapshot2,
1076 nullptr, type->subtype, pointer_level);
1078 } else if (region1->contain(simgrid::mc::remote(addr_pointed1))) {
1079 // The pointers are both in the current object R/W segment:
1080 if (not region2->contain(simgrid::mc::remote(addr_pointed2)))
1082 if (not type->type_id)
1083 return (addr_pointed1 != addr_pointed2);
1085 return areas_differ_with_type(process, state, addr_pointed1, snapshot1, region1, addr_pointed2, snapshot2,
1086 region2, type->subtype, pointer_level);
1088 // TODO, We do not handle very well the case where
1089 // it belongs to a different (non-heap) region from the current one.
1091 return (addr_pointed1 != addr_pointed2);
1094 case DW_TAG_structure_type:
1095 case DW_TAG_class_type:
1096 for (const simgrid::mc::Member& member : type->members) {
1097 const void* member1 = simgrid::dwarf::resolve_member(real_area1, type, &member, &snapshot1);
1098 const void* member2 = simgrid::dwarf::resolve_member(real_area2, type, &member, &snapshot2);
1099 simgrid::mc::Region* subregion1 = snapshot1.get_region(member1, region1); // region1 is hinted
1100 simgrid::mc::Region* subregion2 = snapshot2.get_region(member2, region2); // region2 is hinted
1101 if (areas_differ_with_type(process, state, member1, snapshot1, subregion1, member2, snapshot2, subregion2,
1102 member.type, pointer_level))
1106 case DW_TAG_subroutine_type:
1109 XBT_VERB("Unknown case: %d", type->type);
1116 static bool global_variables_differ(const simgrid::mc::RemoteProcess& process, simgrid::mc::StateComparator& state,
1117 const simgrid::mc::ObjectInformation* object_info, simgrid::mc::Region* r1,
1118 simgrid::mc::Region* r2, const simgrid::mc::Snapshot& snapshot1,
1119 const simgrid::mc::Snapshot& snapshot2)
1121 xbt_assert(r1 && r2, "Missing region.");
1123 const std::vector<simgrid::mc::Variable>& variables = object_info->global_variables;
1125 for (simgrid::mc::Variable const& current_var : variables) {
1126 // If the variable is not in this object, skip it:
1127 // We do not expect to find a pointer to something which is not reachable
1128 // by the global variables.
1129 if ((char*)current_var.address < object_info->start_rw || (char*)current_var.address > object_info->end_rw)
1132 const simgrid::mc::Type* bvariable_type = current_var.type;
1133 if (areas_differ_with_type(process, state, current_var.address, snapshot1, r1, current_var.address, snapshot2, r2,
1134 bvariable_type, 0)) {
1135 XBT_VERB("Global variable %s (%p) is different between snapshots", current_var.name.c_str(), current_var.address);
1143 static bool local_variables_differ(const simgrid::mc::RemoteProcess& process, simgrid::mc::StateComparator& state,
1144 const simgrid::mc::Snapshot& snapshot1, const simgrid::mc::Snapshot& snapshot2,
1145 const_mc_snapshot_stack_t stack1, const_mc_snapshot_stack_t stack2)
1147 if (stack1->local_variables.size() != stack2->local_variables.size()) {
1148 XBT_VERB("Different number of local variables");
1152 for (unsigned int cursor = 0; cursor < stack1->local_variables.size(); cursor++) {
1153 const_local_variable_t current_var1 = &stack1->local_variables[cursor];
1154 const_local_variable_t current_var2 = &stack2->local_variables[cursor];
1155 if (current_var1->name != current_var2->name || current_var1->subprogram != current_var2->subprogram ||
1156 current_var1->ip != current_var2->ip) {
1157 // TODO, fix current_varX->subprogram->name to include name if DW_TAG_inlined_subprogram
1158 XBT_VERB("Different name of variable (%s - %s) or frame (%s - %s) or ip (%lu - %lu)", current_var1->name.c_str(),
1159 current_var2->name.c_str(), current_var1->subprogram->name.c_str(),
1160 current_var2->subprogram->name.c_str(), current_var1->ip, current_var2->ip);
1164 if (areas_differ_with_type(process, state, current_var1->address, snapshot1,
1165 snapshot1.get_region(current_var1->address), current_var2->address, snapshot2,
1166 snapshot2.get_region(current_var2->address), current_var1->type, 0)) {
1167 XBT_VERB("Local variable %s (%p - %p) in frame %s is different between snapshots", current_var1->name.c_str(),
1168 current_var1->address, current_var2->address, current_var1->subprogram->name.c_str());
1175 namespace simgrid::mc {
1177 bool snapshot_equal(const Snapshot* s1, const Snapshot* s2)
1179 // TODO, make this a field of ModelChecker or something similar
1180 static StateComparator state_comparator;
1182 const RemoteProcess& process = mc_model_checker->get_remote_process();
1184 if (s1->hash_ != s2->hash_) {
1185 XBT_VERB("(%ld - %ld) Different hash: 0x%" PRIx64 "--0x%" PRIx64, s1->num_state_, s2->num_state_, s1->hash_,
1189 XBT_VERB("(%ld - %ld) Same hash: 0x%" PRIx64, s1->num_state_, s2->num_state_, s1->hash_);
1191 /* Compare enabled processes */
1192 if (s1->enabled_processes_ != s2->enabled_processes_) {
1193 XBT_VERB("(%ld - %ld) Different amount of enabled processes", s1->num_state_, s2->num_state_);
1197 /* Compare size of stacks */
1198 for (unsigned long i = 0; i < s1->stacks_.size(); i++) {
1199 size_t size_used1 = s1->stack_sizes_[i];
1200 size_t size_used2 = s2->stack_sizes_[i];
1201 if (size_used1 != size_used2) {
1202 XBT_VERB("(%ld - %ld) Different size used in stacks: %zu - %zu", s1->num_state_, s2->num_state_, size_used1,
1208 /* Init heap information used in heap comparison algorithm */
1209 const s_xbt_mheap_t* heap1 = static_cast<xbt_mheap_t>(
1210 s1->read_bytes(alloca(sizeof(s_xbt_mheap_t)), sizeof(s_xbt_mheap_t), process.heap_address, ReadOptions::lazy()));
1211 const s_xbt_mheap_t* heap2 = static_cast<xbt_mheap_t>(
1212 s2->read_bytes(alloca(sizeof(s_xbt_mheap_t)), sizeof(s_xbt_mheap_t), process.heap_address, ReadOptions::lazy()));
1213 if (state_comparator.initHeapInformation(heap1, heap2, s1->to_ignore_, s2->to_ignore_) == -1) {
1214 XBT_VERB("(%ld - %ld) Different heap information", s1->num_state_, s2->num_state_);
1218 /* Stacks comparison */
1219 for (unsigned int cursor = 0; cursor < s1->stacks_.size(); cursor++) {
1220 const_mc_snapshot_stack_t stack1 = &s1->stacks_[cursor];
1221 const_mc_snapshot_stack_t stack2 = &s2->stacks_[cursor];
1223 if (local_variables_differ(process, state_comparator, *s1, *s2, stack1, stack2)) {
1224 XBT_VERB("(%ld - %ld) Different local variables between stacks %u", s1->num_state_, s2->num_state_, cursor + 1);
1229 size_t regions_count = s1->snapshot_regions_.size();
1230 if (regions_count != s2->snapshot_regions_.size())
1233 for (size_t k = 0; k != regions_count; ++k) {
1234 Region* region1 = s1->snapshot_regions_[k].get();
1235 Region* region2 = s2->snapshot_regions_[k].get();
1238 if (region1->region_type() != RegionType::Data)
1241 xbt_assert(region1->region_type() == region2->region_type());
1242 xbt_assert(region1->object_info() == region2->object_info());
1243 xbt_assert(region1->object_info());
1245 /* Compare global variables */
1246 if (global_variables_differ(process, state_comparator, region1->object_info(), region1, region2, *s1, *s2)) {
1247 std::string const& name = region1->object_info()->file_name;
1248 XBT_VERB("(%ld - %ld) Different global variables in %s", s1->num_state_, s2->num_state_, name.c_str());
1254 if (mmalloc_heap_differ(process, state_comparator, *s1, *s2)) {
1255 XBT_VERB("(%ld - %ld) Different heap (mmalloc_compare)", s1->num_state_, s2->num_state_);
1259 XBT_VERB("(%ld - %ld) No difference found", s1->num_state_, s2->num_state_);
1263 } // namespace simgrid::mc