1 /* Copyright (c) 2008-2015. The SimGrid Team.
2 * All rights reserved. */
4 /* This program is free software; you can redistribute it and/or modify it
5 * under the terms of the license (GNU LGPL) which comes with this package. */
18 #include "src/internal_config.h"
19 #include "src/mc/mc_private.h"
20 #include "xbt/module.h"
21 #include <xbt/mmalloc.h>
22 #include <xbt/memory.hpp>
23 #include "src/smpi/private.h"
25 #include "src/xbt/mmalloc/mmprivate.h"
27 #include "src/simix/smx_private.h"
29 #include <libunwind.h>
32 #include "src/mc/mc_private.h"
35 #include "src/mc/mc_snapshot.h"
36 #include "src/mc/mc_mmu.h"
37 #include "src/mc/mc_unw.h"
38 #include "src/mc/mc_protocol.h"
39 #include "src/mc/mc_smx.h"
40 #include "mc_hash.hpp"
42 #include "src/mc/RegionSnapshot.hpp"
43 #include "src/mc/ObjectInformation.hpp"
44 #include "src/mc/Frame.hpp"
45 #include "src/mc/Variable.hpp"
47 using simgrid::mc::remote;
49 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_checkpoint, mc,
50 "Logging specific to mc_checkpoint");
55 /************************************ Free functions **************************************/
56 /*****************************************************************************************/
58 /** @brief Restore a region from a snapshot
60 * @param reg Target region
62 static void restore(mc_mem_region_t region)
64 switch(region->storage_type()) {
65 case simgrid::mc::StorageType::NoData:
67 xbt_die("Storage type not supported");
70 case simgrid::mc::StorageType::Flat:
71 mc_model_checker->process().write_bytes(region->flat_data().get(),
72 region->size(), region->permanent_address());
75 case simgrid::mc::StorageType::Chunked:
76 mc_region_restore_sparse(&mc_model_checker->process(), region);
79 case simgrid::mc::StorageType::Privatized:
80 for (auto& p : region->privatized_data())
87 RegionSnapshot privatized_region(
88 RegionType region_type, void *start_addr, void* permanent_addr,
89 std::size_t size, const RegionSnapshot* ref_region
92 size_t process_count = MC_smpi_process_count();
94 // Read smpi_privatisation_regions from MCed:
95 smpi_privatisation_region_t remote_smpi_privatisation_regions;
96 mc_model_checker->process().read_variable(
97 "smpi_privatisation_regions",
98 &remote_smpi_privatisation_regions, sizeof(remote_smpi_privatisation_regions));
99 s_smpi_privatisation_region_t privatisation_regions[process_count];
100 mc_model_checker->process().read_bytes(
101 &privatisation_regions, sizeof(privatisation_regions),
102 remote(remote_smpi_privatisation_regions));
104 std::vector<simgrid::mc::RegionSnapshot> data;
105 data.reserve(process_count);
106 for (size_t i = 0; i < process_count; i++) {
107 const simgrid::mc::RegionSnapshot* ref_privatized_region = nullptr;
108 if (ref_region && ref_region->storage_type() == StorageType::Privatized)
109 ref_privatized_region = &ref_region->privatized_data()[i];
110 data.push_back(simgrid::mc::region(region_type, start_addr,
111 privatisation_regions[i].address, size, ref_privatized_region));
114 simgrid::mc::RegionSnapshot region = simgrid::mc::RegionSnapshot(
115 region_type, start_addr, permanent_addr, size);
116 region.privatized_data(std::move(data));
122 void add_region(int index, simgrid::mc::Snapshot* snapshot,
123 simgrid::mc::RegionType type,
124 simgrid::mc::ObjectInformation* object_info,
125 void *start_addr, void* permanent_addr,
128 if (type == simgrid::mc::RegionType::Data)
129 xbt_assert(object_info, "Missing object info for object.");
130 else if (type == simgrid::mc::RegionType::Heap)
131 xbt_assert(!object_info, "Unexpected object info for heap region.");
133 simgrid::mc::RegionSnapshot const* ref_region = nullptr;
134 if (mc_model_checker->parent_snapshot_)
135 ref_region = mc_model_checker->parent_snapshot_->snapshot_regions[index].get();
137 simgrid::mc::RegionSnapshot region;
139 const bool privatization_aware = object_info
140 && mc_model_checker->process().privatized(*object_info);
141 if (privatization_aware && MC_smpi_process_count())
142 region = simgrid::mc::privatized_region(
143 type, start_addr, permanent_addr, size, ref_region);
146 region = simgrid::mc::region(type, start_addr, permanent_addr, size, ref_region);
148 region.object_info(object_info);
149 snapshot->snapshot_regions[index]
150 = std::unique_ptr<simgrid::mc::RegionSnapshot>(
151 new simgrid::mc::RegionSnapshot(std::move(region)));
155 static void get_memory_regions(simgrid::mc::Process* process, simgrid::mc::Snapshot* snapshot)
157 const size_t n = process->object_infos.size();
158 snapshot->snapshot_regions.resize(n + 1);
160 for (auto const& object_info : process->object_infos)
161 add_region(i++, snapshot, simgrid::mc::RegionType::Data,
163 object_info->start_rw, object_info->start_rw,
164 object_info->end_rw - object_info->start_rw);
166 xbt_mheap_t heap = process->get_heap();
167 void *start_heap = heap->base;
168 void *end_heap = heap->breakval;
170 add_region(n, snapshot, simgrid::mc::RegionType::Heap, nullptr,
171 start_heap, start_heap,
172 (char *) end_heap - (char *) start_heap);
173 snapshot->heap_bytes_used = mmalloc_get_bytes_used_remote(
175 process->get_malloc_info());
178 if (mc_model_checker->process().privatized() && MC_smpi_process_count())
179 // snapshot->privatization_index = smpi_loaded_page
180 mc_model_checker->process().read_variable(
181 "smpi_loaded_page", &snapshot->privatization_index,
182 sizeof(snapshot->privatization_index));
185 snapshot->privatization_index = simgrid::mc::ProcessIndexMissing;
188 #define PROT_RWX (PROT_READ | PROT_WRITE | PROT_EXEC)
189 #define PROT_RW (PROT_READ | PROT_WRITE)
190 #define PROT_RX (PROT_READ | PROT_EXEC)
192 /** \brief Fills the position of the segments (executable, read-only, read/write).
194 // TODO, use the ELF segment information for more robustness
195 void find_object_address(
196 std::vector<simgrid::xbt::VmMap> const& maps,
197 simgrid::mc::ObjectInformation* result)
199 char* name = xbt_basename(result->file_name.c_str());
201 for (size_t i = 0; i < maps.size(); ++i) {
202 simgrid::xbt::VmMap const& reg = maps[i];
203 if (maps[i].pathname.empty())
205 char* map_basename = xbt_basename(maps[i].pathname.c_str());
206 if (strcmp(name, map_basename) != 0) {
212 // This is the non-GNU_RELRO-part of the data segment:
213 if (reg.prot == PROT_RW) {
214 xbt_assert(!result->start_rw,
215 "Multiple read-write segments for %s, not supported",
216 maps[i].pathname.c_str());
217 result->start_rw = (char*) reg.start_addr;
218 result->end_rw = (char*) reg.end_addr;
220 // The next VMA might be end of the data segment:
221 if (i + 1 < maps.size()
222 && maps[i + 1].pathname.empty()
223 && maps[i + 1].prot == PROT_RW
224 && maps[i + 1].start_addr == reg.end_addr)
225 result->end_rw = (char*) maps[i + 1].end_addr;
228 // This is the text segment:
229 else if (reg.prot == PROT_RX) {
230 xbt_assert(!result->start_exec,
231 "Multiple executable segments for %s, not supported",
232 maps[i].pathname.c_str());
233 result->start_exec = (char*) reg.start_addr;
234 result->end_exec = (char*) reg.end_addr;
236 // The next VMA might be end of the data segment:
237 if (i + 1 < maps.size()
238 && maps[i + 1].pathname.empty()
239 && maps[i + 1].prot == PROT_RW
240 && maps[i + 1].start_addr == reg.end_addr) {
241 result->start_rw = (char*) maps[i + 1].start_addr;
242 result->end_rw = (char*) maps[i + 1].end_addr;
246 // This is the GNU_RELRO-part of the data segment:
247 else if (reg.prot == PROT_READ) {
248 xbt_assert(!result->start_ro,
249 "Multiple read only segments for %s, not supported",
250 maps[i].pathname.c_str());
251 result->start_ro = (char*) reg.start_addr;
252 result->end_ro = (char*) reg.end_addr;
256 result->start = result->start_rw;
257 if ((const void*) result->start_ro > result->start)
258 result->start = result->start_ro;
259 if ((const void*) result->start_exec > result->start)
260 result->start = result->start_exec;
262 result->end = result->end_rw;
263 if (result->end_ro && (const void*) result->end_ro < result->end)
264 result->end = result->end_ro;
265 if (result->end_exec && (const void*) result->end_exec > result->end)
266 result->end = result->end_exec;
268 xbt_assert(result->start_exec || result->start_rw || result->start_ro);
273 /************************************* Take Snapshot ************************************/
274 /****************************************************************************************/
276 /** \brief Checks whether the variable is in scope for a given IP.
278 * A variable may be defined only from a given value of IP.
280 * \param var Variable description
281 * \param frame Scope description
282 * \param ip Instruction pointer
283 * \return true if the variable is valid
285 static bool valid_variable(simgrid::mc::Variable* var,
286 simgrid::mc::Frame* scope,
289 // The variable is not yet valid:
290 if (scope->range.begin() + var->start_scope > (std::uint64_t) ip)
296 static void fill_local_variables_values(mc_stack_frame_t stack_frame,
297 simgrid::mc::Frame* scope,
299 std::vector<s_local_variable>& result)
301 simgrid::mc::Process* process = &mc_model_checker->process();
303 if (!scope->range.contain(stack_frame->ip))
306 for(simgrid::mc::Variable& current_variable :
309 if (!valid_variable(¤t_variable, scope, (void *) stack_frame->ip))
313 // FIXME, get rid of `region_type`
314 if ((long) stack_frame->ip > (long) process->libsimgrid_info->start_exec)
319 s_local_variable_t new_var;
320 new_var.subprogram = stack_frame->frame;
321 new_var.ip = stack_frame->ip;
322 new_var.name = current_variable.name;
323 new_var.type = current_variable.type;
324 new_var.region = region_type;
325 new_var.address = nullptr;
327 if (current_variable.address != nullptr)
328 new_var.address = current_variable.address;
329 else if (!current_variable.location_list.empty()) {
330 simgrid::dwarf::Location location =
331 simgrid::dwarf::resolve(
332 current_variable.location_list,
333 current_variable.object_info,
334 &(stack_frame->unw_cursor),
335 (void *) stack_frame->frame_base,
336 &mc_model_checker->process(), process_index);
338 if (!location.in_memory())
339 xbt_die("Cannot handle non-address variable");
340 new_var.address = location.address();
343 xbt_die("No address");
345 result.push_back(std::move(new_var));
348 // Recursive processing of nested scopes:
349 for(simgrid::mc::Frame& nested_scope : scope->scopes)
350 fill_local_variables_values(
351 stack_frame, &nested_scope, process_index, result);
354 static std::vector<s_local_variable> get_local_variables_values(
355 std::vector<s_mc_stack_frame_t>& stack_frames, int process_index)
357 std::vector<s_local_variable> variables;
358 for (s_mc_stack_frame_t& stack_frame : stack_frames)
359 fill_local_variables_values(&stack_frame, stack_frame.frame, process_index, variables);
363 static std::vector<s_mc_stack_frame_t> unwind_stack_frames(simgrid::mc::UnwindContext* stack_context)
365 simgrid::mc::Process* process = &mc_model_checker->process();
366 std::vector<s_mc_stack_frame_t> result;
368 unw_cursor_t c = stack_context->cursor();
370 // TODO, check condition check (unw_init_local==0 means end of frame)
374 s_mc_stack_frame_t stack_frame;
376 stack_frame.unw_cursor = c;
380 unw_get_reg(&c, UNW_REG_IP, &ip);
381 unw_get_reg(&c, UNW_REG_SP, &sp);
386 // TODO, use real addresses in frame_t instead of fixing it here
388 simgrid::mc::Frame* frame = process->find_function(remote(ip));
389 stack_frame.frame = frame;
392 stack_frame.frame_name = frame->name;
393 stack_frame.frame_base =
394 (unw_word_t) frame->frame_base(c);
396 stack_frame.frame_base = 0;
397 stack_frame.frame_name = std::string();
400 result.push_back(std::move(stack_frame));
402 /* Stop before context switch with maestro */
403 if (frame != nullptr &&
404 frame->name == "smx_ctx_sysv_wrapper")
407 int ret = unw_step(&c);
409 xbt_die("Unexpected end of stack.");
411 xbt_die("Error while unwinding stack");
414 if (result.empty()) {
415 XBT_INFO("unw_init_local failed");
422 static std::vector<s_mc_snapshot_stack_t> take_snapshot_stacks(simgrid::mc::Snapshot* snapshot)
424 std::vector<s_mc_snapshot_stack_t> res;
426 for (auto const& stack : mc_model_checker->process().stack_areas()) {
427 s_mc_snapshot_stack_t st;
429 // Read the context from remote process:
430 unw_context_t context;
431 mc_model_checker->process().read_bytes(
432 &context, sizeof(context), remote(stack.context));
434 st.context.initialize(&mc_model_checker->process(), &context);
436 st.stack_frames = unwind_stack_frames(&st.context);
437 st.local_variables = get_local_variables_values(st.stack_frames, stack.process_index);
438 st.process_index = stack.process_index;
440 unw_word_t sp = st.stack_frames[0].sp;
442 res.push_back(std::move(st));
445 (char*) stack.address + stack.size - (char*) sp;
446 snapshot->stack_sizes.push_back(stack_size);
453 static void snapshot_handle_ignore(simgrid::mc::Snapshot* snapshot)
455 xbt_assert(snapshot->process());
458 for (auto const& region : mc_model_checker->process().ignored_regions()) {
459 s_mc_snapshot_ignored_data_t ignored_data;
460 ignored_data.start = (void*)region.addr;
461 ignored_data.data.resize(region.size);
462 // TODO, we should do this once per privatization segment:
463 snapshot->process()->read_bytes(
464 ignored_data.data.data(), region.size, remote(region.addr),
465 simgrid::mc::ProcessIndexDisabled);
466 snapshot->ignored_data.push_back(std::move(ignored_data));
470 for(auto const& region : mc_model_checker->process().ignored_regions())
471 snapshot->process()->clear_bytes(remote(region.addr), region.size);
475 static void snapshot_ignore_restore(simgrid::mc::Snapshot* snapshot)
477 for (auto const& ignored_data : snapshot->ignored_data)
478 snapshot->process()->write_bytes(
479 ignored_data.data.data(), ignored_data.data.size(),
480 remote(ignored_data.start));
483 static std::vector<s_fd_infos_t> get_current_fds(pid_t pid)
485 const size_t fd_dir_path_size = 20;
486 char fd_dir_path[fd_dir_path_size];
487 int res = snprintf(fd_dir_path, fd_dir_path_size,
488 "/proc/%lli/fd", (long long int) pid);
489 xbt_assert(res >= 0);
490 if ((size_t) res > fd_dir_path_size)
491 xbt_die("Unexpected buffer is too small for fd_dir_path");
493 DIR* fd_dir = opendir(fd_dir_path);
494 if (fd_dir == nullptr)
495 xbt_die("Cannot open directory '/proc/self/fd'\n");
497 std::vector<s_fd_infos_t> fds;
499 struct dirent* fd_number;
500 while ((fd_number = readdir(fd_dir))) {
502 int fd_value = xbt_str_parse_int(fd_number->d_name, "Found a non-numerical FD: %s. Freaking out!");
507 const size_t source_size = 25;
509 int res = snprintf(source, source_size, "/proc/%lli/fd/%s",
510 (long long int) pid, fd_number->d_name);
511 xbt_assert(res >= 0);
512 if ((size_t) res > source_size)
513 xbt_die("Unexpected buffer is too small for fd %s", fd_number->d_name);
515 const size_t link_size = 200;
517 res = readlink(source, link, link_size);
520 xbt_die("Could not read link for %s", source);
522 xbt_die("Buffer to small for link of %s", source);
527 if(smpi_is_privatisation_file(link))
531 // This is (probably) the DIR* we are reading:
532 // TODO, read all the file entries at once and close the DIR.*
533 if(strcmp(fd_dir_path, link) == 0)
536 // We don't handle them.
537 // It does not mean we should silently ignore them however.
538 if (strncmp(link, "pipe:", 5) == 0 || strncmp(link, "socket:", 7) == 0)
541 // If dot_output enabled, do not handle the corresponding file
542 if (dot_output != nullptr) {
543 char* link_basename = xbt_basename(link);
544 if (strcmp(link_basename, _sg_mc_dot_output_file) == 0) {
551 // This is probably a shared memory used by lttng-ust:
552 if(strncmp("/dev/shm/ust-shm-tmp-", link, 21)==0)
555 // Add an entry for this FD in the snapshot:
557 fd.filename = std::string(link);
558 fd.number = fd_value;
559 fd.flags = fcntl(fd_value, F_GETFL) | fcntl(fd_value, F_GETFD) ;
560 fd.current_position = lseek(fd_value, 0, SEEK_CUR);
561 fds.push_back(std::move(fd));
568 std::shared_ptr<simgrid::mc::Snapshot> take_snapshot(int num_state)
570 XBT_DEBUG("Taking snapshot %i", num_state);
572 simgrid::mc::Process* mc_process = &mc_model_checker->process();
574 std::shared_ptr<simgrid::mc::Snapshot> snapshot =
575 std::make_shared<simgrid::mc::Snapshot>(mc_process);
577 snapshot->num_state = num_state;
579 for (auto& p : mc_model_checker->process().simix_processes())
580 snapshot->enabled_processes.insert(p.copy.pid);
582 snapshot_handle_ignore(snapshot.get());
584 if (_sg_mc_snapshot_fds)
585 snapshot->current_fds = get_current_fds(mc_model_checker->process().pid());
587 const bool use_soft_dirty = _sg_mc_sparse_checkpoint && _sg_mc_soft_dirty;
589 /* Save the std heap and the writable mapped pages of libsimgrid and binary */
590 get_memory_regions(mc_process, snapshot.get());
592 mc_process->reset_soft_dirty();
594 snapshot->to_ignore = mc_model_checker->process().ignored_heap();
596 if (_sg_mc_visited > 0 || strcmp(_sg_mc_property_file, "")) {
597 snapshot->stacks = take_snapshot_stacks(snapshot.get());
599 snapshot->hash = simgrid::mc::hash(*snapshot);
605 snapshot_ignore_restore(snapshot.get());
607 mc_model_checker->parent_snapshot_ = snapshot;
612 void restore_snapshot_regions(simgrid::mc::Snapshot* snapshot)
614 for(std::unique_ptr<s_mc_mem_region_t> const& region : snapshot->snapshot_regions) {
615 // For privatized, variables we decided it was not necessary to take the snapshot:
617 restore(region.get());
621 // TODO, send a message to implement this in the MCed process
622 if(snapshot->privatization_index >= 0) {
623 // Fix the privatization mmap:
624 s_mc_restore_message message;
625 message.type = MC_MESSAGE_RESTORE;
626 message.index = snapshot->privatization_index;
627 mc_model_checker->process().getChannel().send(message);
633 void restore_snapshot_fds(simgrid::mc::Snapshot* snapshot)
635 if (mc_mode == MC_MODE_SERVER)
636 xbt_die("FD snapshot not implemented in client/server mode.");
638 for (auto const& fd : snapshot->current_fds) {
640 int new_fd = open(fd.filename.c_str(), fd.flags);
642 xbt_die("Could not reopen the file %s fo restoring the file descriptor",
643 fd.filename.c_str());
644 if (new_fd != fd.number) {
645 dup2(new_fd, fd.number);
648 lseek(fd.number, fd.current_position, SEEK_SET);
652 void restore_snapshot(std::shared_ptr<simgrid::mc::Snapshot> snapshot)
654 XBT_DEBUG("Restore snapshot %i", snapshot->num_state);
655 const bool use_soft_dirty = _sg_mc_sparse_checkpoint && _sg_mc_soft_dirty;
656 restore_snapshot_regions(snapshot.get());
657 if (_sg_mc_snapshot_fds)
658 restore_snapshot_fds(snapshot.get());
660 mc_model_checker->process().reset_soft_dirty();
661 snapshot_ignore_restore(snapshot.get());
662 mc_model_checker->process().clear_cache();
664 mc_model_checker->parent_snapshot_ = snapshot;