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. */
13 #include "internal_config.h"
14 #include "mc_memory_map.h"
15 #include "mc_private.h"
16 #include "xbt/module.h"
17 #include <xbt/mmalloc.h>
18 #include "../smpi/private.h"
21 #include "xbt/mmalloc/mmprivate.h"
23 #include "../simix/smx_private.h"
25 #include <libunwind.h>
28 #include "mc_private.h"
31 #include "mc_snapshot.h"
32 #include "mc_object_info.h"
35 #include "mc_protocol.h"
37 #include "mc_hash.hpp"
39 #include "mc/ObjectInformation.hpp"
40 #include "mc/Frame.hpp"
41 #include "mc/Variable.hpp"
43 using simgrid::mc::remote;
47 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_checkpoint, mc,
48 "Logging specific to mc_checkpoint");
50 /************************************ Free functions **************************************/
51 /*****************************************************************************************/
53 /** @brief Restore a region from a snapshot
55 * @param reg Target region
57 static void MC_region_restore(mc_mem_region_t region)
59 switch(region->storage_type()) {
60 case simgrid::mc::StorageType::NoData:
62 xbt_die("Storage type not supported");
65 case simgrid::mc::StorageType::Flat:
66 mc_model_checker->process().write_bytes(region->flat_data(),
67 region->size(), region->permanent_address());
70 case simgrid::mc::StorageType::Chunked:
71 mc_region_restore_sparse(&mc_model_checker->process(), region);
74 case simgrid::mc::StorageType::Privatized:
75 for (auto& p : region->privatized_data())
76 MC_region_restore(&p);
87 simgrid::mc::RegionSnapshot privatized_region(
88 RegionType region_type, void *start_addr, void* permanent_addr, size_t size,
89 const simgrid::mc::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));
117 return std::move(region);
126 static void MC_snapshot_add_region(int index, mc_snapshot_t snapshot,
127 simgrid::mc::RegionType type,
128 simgrid::mc::ObjectInformation* object_info,
129 void *start_addr, void* permanent_addr, size_t size)
131 if (type == simgrid::mc::RegionType::Data)
132 xbt_assert(object_info, "Missing object info for object.");
133 else if (type == simgrid::mc::RegionType::Heap)
134 xbt_assert(!object_info, "Unexpected object info for heap region.");
136 simgrid::mc::RegionSnapshot const* ref_region = nullptr;
137 if (mc_model_checker->parent_snapshot_)
138 ref_region = mc_model_checker->parent_snapshot_->snapshot_regions[index].get();
140 simgrid::mc::RegionSnapshot region;
142 const bool privatization_aware = object_info && object_info->privatized();
143 if (privatization_aware && MC_smpi_process_count())
144 region = simgrid::mc::privatized_region(
145 type, start_addr, permanent_addr, size, ref_region);
148 region = simgrid::mc::region(type, start_addr, permanent_addr, size, ref_region);
150 region.object_info(object_info);
151 snapshot->snapshot_regions[index]
152 = std::unique_ptr<simgrid::mc::RegionSnapshot>(
153 new simgrid::mc::RegionSnapshot(std::move(region)));
157 static void MC_get_memory_regions(simgrid::mc::Process* process, mc_snapshot_t snapshot)
159 const size_t n = process->object_infos.size();
160 snapshot->snapshot_regions.resize(n + 1);
162 for (auto const& object_info : process->object_infos) {
163 MC_snapshot_add_region(i, snapshot, simgrid::mc::RegionType::Data,
165 object_info->start_rw, object_info->start_rw,
166 object_info->end_rw - object_info->start_rw);
170 xbt_mheap_t heap = process->get_heap();
171 void *start_heap = heap->base;
172 void *end_heap = heap->breakval;
174 MC_snapshot_add_region(n, snapshot, simgrid::mc::RegionType::Heap, NULL,
175 start_heap, start_heap,
176 (char *) end_heap - (char *) start_heap);
177 snapshot->heap_bytes_used = mmalloc_get_bytes_used_remote(
179 process->get_malloc_info());
182 if (smpi_privatize_global_variables && MC_smpi_process_count()) {
183 // snapshot->privatization_index = smpi_loaded_page
184 mc_model_checker->process().read_variable(
185 "smpi_loaded_page", &snapshot->privatization_index,
186 sizeof(snapshot->privatization_index));
190 snapshot->privatization_index = simgrid::mc::ProcessIndexMissing;
194 /** \brief Fills the position of the segments (executable, read-only, read/write).
196 * `dl_iterate_phdr` would be more robust but would not work in cross-process.
198 void MC_find_object_address(
199 std::vector<simgrid::mc::VmMap> const& maps, simgrid::mc::ObjectInformation* result)
201 char* file_name = xbt_strdup(result->file_name.c_str());
202 const char *name = basename(file_name);
203 for (size_t i = 0; i < maps.size(); ++i) {
204 simgrid::mc::VmMap const& reg = maps[i];
205 if (maps[i].pathname.empty()
206 || strcmp(basename(maps[i].pathname.c_str()), name)) {
208 } else if ((reg.prot & PROT_WRITE)) {
209 xbt_assert(!result->start_rw,
210 "Multiple read-write segments for %s, not supported",
211 maps[i].pathname.c_str());
212 result->start_rw = (char*) reg.start_addr;
213 result->end_rw = (char*) reg.end_addr;
214 // .bss is usually after the .data:
215 simgrid::mc::VmMap const& next = maps[i + 1];
216 if (next.pathname.empty() && (next.prot & PROT_WRITE)
217 && next.start_addr == reg.end_addr) {
218 result->end_rw = (char*) maps[i + 1].end_addr;
220 } else if ((reg.prot & PROT_READ) && (reg.prot & PROT_EXEC)) {
221 xbt_assert(!result->start_exec,
222 "Multiple executable segments for %s, not supported",
223 maps[i].pathname.c_str());
224 result->start_exec = (char*) reg.start_addr;
225 result->end_exec = (char*) reg.end_addr;
226 } else if ((reg.prot & PROT_READ) && !(reg.prot & PROT_EXEC)) {
227 xbt_assert(!result->start_ro,
228 "Multiple read only segments for %s, not supported",
229 maps[i].pathname.c_str());
230 result->start_ro = (char*) reg.start_addr;
231 result->end_ro = (char*) reg.end_addr;
235 result->start = result->start_rw;
236 if ((const void*) result->start_ro > result->start)
237 result->start = result->start_ro;
238 if ((const void*) result->start_exec > result->start)
239 result->start = result->start_exec;
241 result->end = result->end_rw;
242 if (result->end_ro && (const void*) result->end_ro < result->end)
243 result->end = result->end_ro;
244 if (result->end_exec && (const void*) result->end_exec > result->end)
245 result->end = result->end_exec;
247 xbt_assert(result->start_rw);
248 xbt_assert(result->start_exec);
252 /************************************* Take Snapshot ************************************/
253 /****************************************************************************************/
255 /** \brief Checks whether the variable is in scope for a given IP.
257 * A variable may be defined only from a given value of IP.
259 * \param var Variable description
260 * \param frame Scope description
261 * \param ip Instruction pointer
262 * \return true if the variable is valid
264 static bool mc_valid_variable(simgrid::mc::Variable* var, simgrid::mc::Frame* scope,
267 // The variable is not yet valid:
268 if ((const void *) ((const char *) scope->low_pc + var->start_scope) > ip)
274 static void mc_fill_local_variables_values(mc_stack_frame_t stack_frame,
275 simgrid::mc::Frame* scope, int process_index,
276 std::vector<s_local_variable>& result)
278 simgrid::mc::Process* process = &mc_model_checker->process();
280 void *ip = (void *) stack_frame->ip;
281 if (ip < scope->low_pc || ip >= scope->high_pc)
284 for(simgrid::mc::Variable& current_variable :
287 if (!mc_valid_variable(¤t_variable, scope, (void *) stack_frame->ip))
291 // FIXME, get rid of `region_type`
292 if ((long) stack_frame->ip > (long) process->libsimgrid_info->start_exec)
297 s_local_variable_t new_var;
298 new_var.subprogram = stack_frame->frame;
299 new_var.ip = stack_frame->ip;
300 new_var.name = current_variable.name;
301 new_var.type = current_variable.type;
302 new_var.region = region_type;
303 new_var.address = nullptr;
305 if (current_variable.address != NULL) {
306 new_var.address = current_variable.address;
307 } else if (!current_variable.location_list.empty()) {
308 simgrid::dwarf::Location location =
309 simgrid::dwarf::resolve(
310 current_variable.location_list,
311 current_variable.object_info,
312 &(stack_frame->unw_cursor),
313 (void *) stack_frame->frame_base,
314 &mc_model_checker->process(), process_index);
316 if (!location.in_memory())
317 xbt_die("Cannot handle non-address variable");
318 new_var.address = location.address();
321 xbt_die("No address");
324 result.push_back(std::move(new_var));
327 // Recursive processing of nested scopes:
328 for(simgrid::mc::Frame& nested_scope : scope->scopes)
329 mc_fill_local_variables_values(
330 stack_frame, &nested_scope, process_index, result);
333 static std::vector<s_local_variable> MC_get_local_variables_values(
334 std::vector<s_mc_stack_frame_t>& stack_frames, int process_index)
336 std::vector<s_local_variable> variables;
337 for (s_mc_stack_frame_t& stack_frame : stack_frames)
338 mc_fill_local_variables_values(&stack_frame, stack_frame.frame, process_index, variables);
339 return std::move(variables);
342 static void MC_stack_frame_free_voipd(void *s)
344 mc_stack_frame_t stack_frame = *(mc_stack_frame_t *) s;
348 static std::vector<s_mc_stack_frame_t> MC_unwind_stack_frames(mc_unw_context_t stack_context)
350 simgrid::mc::Process* process = &mc_model_checker->process();
351 std::vector<s_mc_stack_frame_t> result;
355 // TODO, check condition check (unw_init_local==0 means end of frame)
356 if (mc_unw_init_cursor(&c, stack_context) != 0) {
358 xbt_die("Could not initialize stack unwinding");
363 s_mc_stack_frame_t stack_frame;
365 stack_frame.unw_cursor = c;
369 unw_get_reg(&c, UNW_REG_IP, &ip);
370 unw_get_reg(&c, UNW_REG_SP, &sp);
375 // TODO, use real addresses in frame_t instead of fixing it here
377 simgrid::mc::Frame* frame = process->find_function(remote(ip));
378 stack_frame.frame = frame;
381 stack_frame.frame_name = frame->name;
382 stack_frame.frame_base =
383 (unw_word_t) frame->frame_base(c);
385 stack_frame.frame_base = 0;
386 stack_frame.frame_name = std::string();
389 result.push_back(std::move(stack_frame));
391 /* Stop before context switch with maestro */
392 if (frame != nullptr &&
393 frame->name == "smx_ctx_sysv_wrapper")
396 int ret = unw_step(&c);
398 xbt_die("Unexpected end of stack.");
399 } else if (ret < 0) {
400 xbt_die("Error while unwinding stack");
404 if (result.empty()) {
405 XBT_INFO("unw_init_local failed");
409 return std::move(result);
412 static std::vector<s_mc_snapshot_stack_t> MC_take_snapshot_stacks(mc_snapshot_t * snapshot)
414 std::vector<s_mc_snapshot_stack_t> res;
416 unsigned int cursor = 0;
417 stack_region_t current_stack;
419 // FIXME, cross-process support (stack_areas)
420 xbt_dynar_foreach(stacks_areas, cursor, current_stack) {
421 s_mc_snapshot_stack_t st;
423 // Read the context from remote process:
424 unw_context_t context;
425 mc_model_checker->process().read_bytes(
426 &context, sizeof(context), remote(current_stack->context));
428 if (mc_unw_init_context(&st.context, &mc_model_checker->process(),
430 xbt_die("Could not initialise the libunwind context.");
432 st.stack_frames = MC_unwind_stack_frames(&st.context);
433 st.local_variables = MC_get_local_variables_values(st.stack_frames, current_stack->process_index);
434 st.process_index = current_stack->process_index;
436 unw_word_t sp = st.stack_frames[0].sp;
438 res.push_back(std::move(st));
441 (char*) current_stack->address + current_stack->size - (char*) sp;
442 (*snapshot)->stack_sizes.push_back(stack_size);
445 return std::move(res);
449 static std::vector<s_mc_heap_ignore_region_t> MC_take_snapshot_ignore()
451 std::vector<s_mc_heap_ignore_region_t> res;
453 if (mc_heap_comparison_ignore == NULL)
454 return std::move(res);
456 unsigned int cursor = 0;
457 mc_heap_ignore_region_t current_region;
459 xbt_dynar_foreach(mc_heap_comparison_ignore, cursor, current_region) {
460 s_mc_heap_ignore_region_t new_region;
461 new_region.address = current_region->address;
462 new_region.size = current_region->size;
463 new_region.block = current_region->block;
464 new_region.fragment = current_region->fragment;
465 res.push_back(std::move(new_region));
468 return std::move(res);
471 static void MC_snapshot_handle_ignore(mc_snapshot_t snapshot)
473 xbt_assert(snapshot->process());
476 for (auto const& region : mc_model_checker->process().ignored_regions()) {
477 s_mc_snapshot_ignored_data_t ignored_data;
478 ignored_data.start = (void*)region.addr;
479 ignored_data.data.resize(region.size);
480 // TODO, we should do this once per privatization segment:
481 snapshot->process()->read_bytes(
482 ignored_data.data.data(), region.size, remote(region.addr),
483 simgrid::mc::ProcessIndexDisabled);
484 snapshot->ignored_data.push_back(std::move(ignored_data));
488 for(auto const& region : mc_model_checker->process().ignored_regions()) {
489 snapshot->process()->clear_bytes(remote(region.addr), region.size);
494 static void MC_snapshot_ignore_restore(mc_snapshot_t snapshot)
496 for (auto const& ignored_data : snapshot->ignored_data)
497 snapshot->process()->write_bytes(
498 ignored_data.data.data(), ignored_data.data.size(),
499 remote(ignored_data.start));
502 static std::vector<s_fd_infos_t> MC_get_current_fds(pid_t pid)
504 const size_t fd_dir_path_size = 20;
505 char fd_dir_path[fd_dir_path_size];
506 int res = snprintf(fd_dir_path, fd_dir_path_size,
507 "/proc/%lli/fd", (long long int) pid);
508 xbt_assert(res >= 0);
509 if ((size_t) res > fd_dir_path_size)
510 xbt_die("Unexpected buffer is too small for fd_dir_path");
512 DIR* fd_dir = opendir(fd_dir_path);
514 xbt_die("Cannot open directory '/proc/self/fd'\n");
516 std::vector<s_fd_infos_t> fds;
518 struct dirent* fd_number;
519 while ((fd_number = readdir(fd_dir))) {
521 int fd_value = atoi(fd_number->d_name);
526 const size_t source_size = 25;
528 int res = snprintf(source, source_size, "/proc/%lli/fd/%s",
529 (long long int) pid, fd_number->d_name);
530 xbt_assert(res >= 0);
531 if ((size_t) res > source_size)
532 xbt_die("Unexpected buffer is too small for fd %s", fd_number->d_name);
534 const size_t link_size = 200;
536 res = readlink(source, link, link_size);
538 xbt_die("Could not read link for %s", source);
541 xbt_die("Buffer to small for link of %s", source);
546 if(smpi_is_privatisation_file(link))
550 // This is (probably) the DIR* we are reading:
551 // TODO, read all the file entries at once and close the DIR.*
552 if(strcmp(fd_dir_path, link) == 0)
555 // We don't handle them.
556 // It does not mean we should silently ignore them however.
557 if (strncmp(link, "pipe:", 5) == 0 || strncmp(link, "socket:", 7) == 0)
560 // If dot_output enabled, do not handle the corresponding file
561 if (dot_output != NULL && strcmp(basename(link), _sg_mc_dot_output_file) == 0)
564 // This is probably a shared memory used by lttng-ust:
565 if(strncmp("/dev/shm/ust-shm-tmp-", link, 21)==0)
568 // Add an entry for this FD in the snapshot:
570 fd.filename = std::string(link);
571 fd.number = fd_value;
572 fd.flags = fcntl(fd_value, F_GETFL) | fcntl(fd_value, F_GETFD) ;
573 fd.current_position = lseek(fd_value, 0, SEEK_CUR);
574 fds.push_back(std::move(fd));
578 return std::move(fds);
581 mc_snapshot_t MC_take_snapshot(int num_state)
583 XBT_DEBUG("Taking snapshot %i", num_state);
585 simgrid::mc::Process* mc_process = &mc_model_checker->process();
587 mc_snapshot_t snapshot = new simgrid::mc::Snapshot(mc_process);
589 snapshot->num_state = num_state;
591 smx_process_t process;
592 MC_EACH_SIMIX_PROCESS(process,
593 snapshot->enabled_processes.insert(process->pid));
595 MC_snapshot_handle_ignore(snapshot);
597 if (_sg_mc_snapshot_fds)
598 snapshot->current_fds = MC_get_current_fds(process->pid);
600 const bool use_soft_dirty = _sg_mc_sparse_checkpoint && _sg_mc_soft_dirty;
602 /* Save the std heap and the writable mapped pages of libsimgrid and binary */
603 MC_get_memory_regions(mc_process, snapshot);
605 mc_process->reset_soft_dirty();
607 snapshot->to_ignore = MC_take_snapshot_ignore();
609 if (_sg_mc_visited > 0 || strcmp(_sg_mc_property_file, "")) {
611 MC_take_snapshot_stacks(&snapshot);
613 snapshot->hash = simgrid::mc::hash(*snapshot);
621 MC_snapshot_ignore_restore(snapshot);
623 mc_model_checker->parent_snapshot_ = snapshot;
628 void MC_restore_snapshot_regions(mc_snapshot_t snapshot)
630 for(std::unique_ptr<s_mc_mem_region_t> const& region : snapshot->snapshot_regions) {
631 // For privatized, variables we decided it was not necessary to take the snapshot:
633 MC_region_restore(region.get());
637 // TODO, send a message to implement this in the MCed process
638 if(snapshot->privatization_index >= 0) {
639 // We just rewrote the global variables.
640 // The privatisation segment SMPI thinks
641 // is mapped might be inconsistent with the segment which
642 // is really mapped in memory (kernel state).
643 // We ask politely SMPI to map the segment anyway,
644 // even if it thinks it is the current one:
645 smpi_really_switch_data_segment(snapshot->privatization_index);
651 void MC_restore_snapshot_fds(mc_snapshot_t snapshot)
653 if (mc_mode == MC_MODE_SERVER)
654 xbt_die("FD snapshot not implemented in client/server mode.");
656 for (auto const& fd : snapshot->current_fds) {
658 int new_fd = open(fd.filename.c_str(), fd.flags);
660 xbt_die("Could not reopen the file %s fo restoring the file descriptor",
661 fd.filename.c_str());
663 if (new_fd != fd.number) {
664 dup2(new_fd, fd.number);
667 lseek(fd.number, fd.current_position, SEEK_SET);
671 void MC_restore_snapshot(mc_snapshot_t snapshot)
673 XBT_DEBUG("Restore snapshot %i", snapshot->num_state);
674 const bool use_soft_dirty = _sg_mc_sparse_checkpoint && _sg_mc_soft_dirty;
675 MC_restore_snapshot_regions(snapshot);
676 if (_sg_mc_snapshot_fds)
677 MC_restore_snapshot_fds(snapshot);
679 mc_model_checker->process().reset_soft_dirty();
680 MC_snapshot_ignore_restore(snapshot);
681 mc_model_checker->process().cache_flags = 0;
683 mc_model_checker->parent_snapshot_ = snapshot;
686 mc_snapshot_t simcall_HANDLER_mc_snapshot(smx_simcall_t simcall)
688 return MC_take_snapshot(1);