1 /* Copyright (c) 2008-2014. 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"
38 using simgrid::mc::remote;
42 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_checkpoint, mc,
43 "Logging specific to mc_checkpoint");
45 /************************************ Free functions **************************************/
46 /*****************************************************************************************/
48 s_mc_snapshot_stack::~s_mc_snapshot_stack()
50 xbt_dynar_free(&(this->stack_frames));
51 mc_unw_destroy_context(this->context);
52 xbt_free(this->context);
55 static void MC_snapshot_stack_free(mc_snapshot_stack_t s)
61 static void MC_snapshot_stack_free_voidp(void *s)
63 mc_snapshot_stack_t stack = (mc_snapshot_stack_t) * (void **) s;
64 MC_snapshot_stack_free(stack);
67 static void local_variable_free_voidp(void *v)
69 local_variable_t var = *(local_variable_t*)v;
77 /** @brief Restore a region from a snapshot
79 * @param reg Target region
81 static void MC_region_restore(mc_mem_region_t region)
83 switch(region->storage_type()) {
84 case simgrid::mc::StorageType::NoData:
86 xbt_die("Storage type not supported");
89 case simgrid::mc::StorageType::Flat:
90 mc_model_checker->process().write_bytes(region->flat_data().data(),
91 region->size(), region->permanent_address());
94 case simgrid::mc::StorageType::Chunked:
95 mc_region_restore_sparse(&mc_model_checker->process(), region);
98 case simgrid::mc::StorageType::Privatized:
99 for (auto& p : region->privatized_data())
100 MC_region_restore(&p);
110 simgrid::mc::RegionSnapshot privatized_region(
111 RegionType region_type, void *start_addr, void* permanent_addr, size_t size
114 size_t process_count = MC_smpi_process_count();
116 // Read smpi_privatisation_regions from MCed:
117 smpi_privatisation_region_t remote_smpi_privatisation_regions;
118 mc_model_checker->process().read_variable(
119 "smpi_privatisation_regions",
120 &remote_smpi_privatisation_regions, sizeof(remote_smpi_privatisation_regions));
121 s_smpi_privatisation_region_t privatisation_regions[process_count];
122 mc_model_checker->process().read_bytes(
123 &privatisation_regions, sizeof(privatisation_regions),
124 remote(remote_smpi_privatisation_regions));
126 std::vector<simgrid::mc::RegionSnapshot> data;
127 data.reserve(process_count);
128 for (size_t i = 0; i < process_count; i++)
130 simgrid::mc::region(region_type, start_addr,
131 privatisation_regions[i].address, size)
134 simgrid::mc::RegionSnapshot region = simgrid::mc::RegionSnapshot(
135 region_type, start_addr, permanent_addr, size);
136 region.privatized_data(std::move(data));
137 return std::move(region);
145 static void MC_snapshot_add_region(int index, mc_snapshot_t snapshot,
146 simgrid::mc::RegionType type,
147 mc_object_info_t object_info,
148 void *start_addr, void* permanent_addr, size_t size)
150 if (type == simgrid::mc::RegionType::Data)
151 xbt_assert(object_info, "Missing object info for object.");
152 else if (type == simgrid::mc::RegionType::Heap)
153 xbt_assert(!object_info, "Unexpected object info for heap region.");
155 const bool privatization_aware = MC_object_info_is_privatized(object_info);
157 simgrid::mc::RegionSnapshot region;
158 if (privatization_aware && MC_smpi_process_count())
159 region = simgrid::mc::privatized_region(type, start_addr, permanent_addr, size);
161 region = simgrid::mc::region(type, start_addr, permanent_addr, size);
163 region.object_info(object_info);
164 snapshot->snapshot_regions[index]
165 = std::unique_ptr<simgrid::mc::RegionSnapshot>(
166 new simgrid::mc::RegionSnapshot(std::move(region)));
170 static void MC_get_memory_regions(mc_process_t process, mc_snapshot_t snapshot)
172 const size_t n = process->object_infos_size;
173 snapshot->snapshot_regions.resize(n + 1);
174 for (size_t i = 0; i != n; ++i) {
175 mc_object_info_t object_info = process->object_infos[i];
176 MC_snapshot_add_region(i, snapshot, simgrid::mc::RegionType::Data, object_info,
177 object_info->start_rw, object_info->start_rw,
178 object_info->end_rw - object_info->start_rw);
181 xbt_mheap_t heap = process->get_heap();
182 void *start_heap = heap->base;
183 void *end_heap = heap->breakval;
185 MC_snapshot_add_region(n, snapshot, simgrid::mc::RegionType::Heap, NULL,
186 start_heap, start_heap,
187 (char *) end_heap - (char *) start_heap);
188 snapshot->heap_bytes_used = mmalloc_get_bytes_used_remote(
190 process->get_malloc_info());
193 if (smpi_privatize_global_variables && MC_smpi_process_count()) {
194 // snapshot->privatization_index = smpi_loaded_page
195 mc_model_checker->process().read_variable(
196 "smpi_loaded_page", &snapshot->privatization_index,
197 sizeof(snapshot->privatization_index));
201 snapshot->privatization_index = simgrid::mc::ProcessIndexMissing;
205 /** \brief Fills the position of the segments (executable, read-only, read/write).
207 * `dl_iterate_phdr` would be more robust but would not work in cross-process.
209 void MC_find_object_address(std::vector<simgrid::mc::VmMap> const& maps, mc_object_info_t result)
211 const char *name = basename(result->file_name);
212 for (size_t i = 0; i < maps.size(); ++i) {
213 simgrid::mc::VmMap const& reg = maps[i];
214 if (maps[i].pathname.empty()
215 || strcmp(basename(maps[i].pathname.c_str()), name)) {
217 } else if ((reg.prot & PROT_WRITE)) {
218 xbt_assert(!result->start_rw,
219 "Multiple read-write segments for %s, not supported",
220 maps[i].pathname.c_str());
221 result->start_rw = (char*) reg.start_addr;
222 result->end_rw = (char*) reg.end_addr;
223 // .bss is usually after the .data:
224 simgrid::mc::VmMap const& next = maps[i + 1];
225 if (next.pathname.empty() && (next.prot & PROT_WRITE)
226 && next.start_addr == reg.end_addr) {
227 result->end_rw = (char*) maps[i + 1].end_addr;
229 } else if ((reg.prot & PROT_READ) && (reg.prot & PROT_EXEC)) {
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;
235 } else if ((reg.prot & PROT_READ) && !(reg.prot & PROT_EXEC)) {
236 xbt_assert(!result->start_ro,
237 "Multiple read only segments for %s, not supported",
238 maps[i].pathname.c_str());
239 result->start_ro = (char*) reg.start_addr;
240 result->end_ro = (char*) reg.end_addr;
244 result->start = result->start_rw;
245 if ((const void*) result->start_ro > result->start)
246 result->start = result->start_ro;
247 if ((const void*) result->start_exec > result->start)
248 result->start = result->start_exec;
250 result->end = result->end_rw;
251 if (result->end_ro && (const void*) result->end_ro < result->end)
252 result->end = result->end_ro;
253 if (result->end_exec && (const void*) result->end_exec > result->end)
254 result->end = result->end_exec;
256 xbt_assert(result->file_name);
257 xbt_assert(result->start_rw);
258 xbt_assert(result->start_exec);
261 /************************************* Take Snapshot ************************************/
262 /****************************************************************************************/
264 /** \brief Checks whether the variable is in scope for a given IP.
266 * A variable may be defined only from a given value of IP.
268 * \param var Variable description
269 * \param frame Scope description
270 * \param ip Instruction pointer
271 * \return true if the variable is valid
273 static bool mc_valid_variable(dw_variable_t var, dw_frame_t scope,
276 // The variable is not yet valid:
277 if ((const void *) ((const char *) scope->low_pc + var->start_scope) > ip)
283 static void mc_fill_local_variables_values(mc_stack_frame_t stack_frame,
284 dw_frame_t scope, int process_index,
285 std::vector<s_local_variable>& result)
287 mc_process_t process = &mc_model_checker->process();
289 void *ip = (void *) stack_frame->ip;
290 if (ip < scope->low_pc || ip >= scope->high_pc)
294 dw_variable_t current_variable;
295 xbt_dynar_foreach(scope->variables, cursor, current_variable) {
297 if (!mc_valid_variable(current_variable, scope, (void *) stack_frame->ip))
301 // FIXME, get rid of `region_type`
302 if ((long) stack_frame->ip > (long) process->libsimgrid_info->start_exec)
307 s_local_variable_t new_var;
308 new_var.subprogram = stack_frame->frame;
309 new_var.ip = stack_frame->ip;
310 new_var.name = current_variable->name;
311 new_var.type = current_variable->type;
312 new_var.region = region_type;
313 new_var.address = nullptr;
315 if (current_variable->address != NULL) {
316 new_var.address = current_variable->address;
317 } else if (current_variable->locations.size != 0) {
318 s_mc_location_t location;
319 mc_dwarf_resolve_locations(
320 &location, ¤t_variable->locations,
321 current_variable->object_info,
322 &(stack_frame->unw_cursor),
323 (void *) stack_frame->frame_base,
324 &mc_model_checker->process(), process_index);
326 switch(mc_get_location_type(&location)) {
327 case MC_LOCATION_TYPE_ADDRESS:
328 new_var.address = location.memory_location;
330 case MC_LOCATION_TYPE_REGISTER:
332 xbt_die("Cannot handle non-address variable");
336 xbt_die("No address");
339 result.push_back(std::move(new_var));
342 // Recursive processing of nested scopes:
343 dw_frame_t nested_scope = NULL;
344 xbt_dynar_foreach(scope->scopes, cursor, nested_scope) {
345 mc_fill_local_variables_values(stack_frame, nested_scope, process_index, result);
349 static std::vector<s_local_variable> MC_get_local_variables_values(xbt_dynar_t stack_frames, int process_index)
352 unsigned cursor1 = 0;
353 mc_stack_frame_t stack_frame;
355 std::vector<s_local_variable> variables;
356 xbt_dynar_foreach(stack_frames, cursor1, stack_frame) {
357 mc_fill_local_variables_values(stack_frame, stack_frame->frame, process_index, variables);
359 return std::move(variables);
362 static void MC_stack_frame_free_voipd(void *s)
364 mc_stack_frame_t stack_frame = *(mc_stack_frame_t *) s;
366 xbt_free(stack_frame->frame_name);
367 xbt_free(stack_frame);
371 static xbt_dynar_t MC_unwind_stack_frames(mc_unw_context_t stack_context)
373 mc_process_t process = &mc_model_checker->process();
375 xbt_dynar_new(sizeof(mc_stack_frame_t), MC_stack_frame_free_voipd);
379 // TODO, check condition check (unw_init_local==0 means end of frame)
380 if (mc_unw_init_cursor(&c, stack_context) != 0) {
382 xbt_die("Could not initialize stack unwinding");
387 mc_stack_frame_t stack_frame = xbt_new(s_mc_stack_frame_t, 1);
388 xbt_dynar_push(result, &stack_frame);
390 stack_frame->unw_cursor = c;
394 unw_get_reg(&c, UNW_REG_IP, &ip);
395 unw_get_reg(&c, UNW_REG_SP, &sp);
397 stack_frame->ip = ip;
398 stack_frame->sp = sp;
400 // TODO, use real addresses in frame_t instead of fixing it here
402 dw_frame_t frame = process->find_function(remote(ip));
403 stack_frame->frame = frame;
406 stack_frame->frame_name = xbt_strdup(frame->name);
407 stack_frame->frame_base =
408 (unw_word_t) mc_find_frame_base(frame, frame->object_info, &c);
410 stack_frame->frame_base = 0;
411 stack_frame->frame_name = NULL;
414 /* Stop before context switch with maestro */
415 if (frame != NULL && frame->name != NULL
416 && !strcmp(frame->name, "smx_ctx_sysv_wrapper"))
419 int ret = unw_step(&c);
421 xbt_die("Unexpected end of stack.");
422 } else if (ret < 0) {
423 xbt_die("Error while unwinding stack");
427 if (xbt_dynar_length(result) == 0) {
428 XBT_INFO("unw_init_local failed");
435 static xbt_dynar_t MC_take_snapshot_stacks(mc_snapshot_t * snapshot)
439 xbt_dynar_new(sizeof(s_mc_snapshot_stack_t),
440 MC_snapshot_stack_free_voidp);
442 unsigned int cursor = 0;
443 stack_region_t current_stack;
445 // FIXME, cross-process support (stack_areas)
446 xbt_dynar_foreach(stacks_areas, cursor, current_stack) {
447 mc_snapshot_stack_t st = new s_mc_snapshot_stack();
449 // Read the context from remote process:
450 unw_context_t context;
451 mc_model_checker->process().read_bytes(
452 &context, sizeof(context), remote(current_stack->context));
454 st->context = xbt_new0(s_mc_unw_context_t, 1);
455 if (mc_unw_init_context(st->context, &mc_model_checker->process(),
457 xbt_die("Could not initialise the libunwind context.");
460 st->stack_frames = MC_unwind_stack_frames(st->context);
461 st->local_variables = MC_get_local_variables_values(st->stack_frames, current_stack->process_index);
462 st->process_index = current_stack->process_index;
464 unw_word_t sp = xbt_dynar_get_as(st->stack_frames, 0, mc_stack_frame_t)->sp;
466 xbt_dynar_push(res, &st);
468 (char*) current_stack->address + current_stack->size - (char*) sp;
469 (*snapshot)->stack_sizes.push_back(stack_size);
476 static std::vector<s_mc_heap_ignore_region_t> MC_take_snapshot_ignore()
478 std::vector<s_mc_heap_ignore_region_t> res;
480 if (mc_heap_comparison_ignore == NULL)
481 return std::move(res);
483 unsigned int cursor = 0;
484 mc_heap_ignore_region_t current_region;
486 xbt_dynar_foreach(mc_heap_comparison_ignore, cursor, current_region) {
487 s_mc_heap_ignore_region_t new_region;
488 new_region.address = current_region->address;
489 new_region.size = current_region->size;
490 new_region.block = current_region->block;
491 new_region.fragment = current_region->fragment;
492 res.push_back(std::move(new_region));
495 return std::move(res);
498 static void MC_snapshot_handle_ignore(mc_snapshot_t snapshot)
500 xbt_assert(snapshot->process);
503 for (auto const& region : mc_model_checker->process().ignored_regions()) {
504 s_mc_snapshot_ignored_data_t ignored_data;
505 ignored_data.start = (void*)region.addr;
506 ignored_data.data.resize(region.size);
507 // TODO, we should do this once per privatization segment:
508 snapshot->process->read_bytes(
509 ignored_data.data.data(), region.size, remote(region.addr),
510 simgrid::mc::ProcessIndexDisabled);
511 snapshot->ignored_data.push_back(std::move(ignored_data));
515 for(auto const& region : mc_model_checker->process().ignored_regions()) {
516 snapshot->process->clear_bytes(remote(region.addr), region.size);
521 static void MC_snapshot_ignore_restore(mc_snapshot_t snapshot)
523 for (auto const& ignored_data : snapshot->ignored_data)
524 snapshot->process->write_bytes(
525 ignored_data.data.data(), ignored_data.data.size(),
526 remote(ignored_data.start));
529 static std::vector<s_fd_infos_t> MC_get_current_fds(pid_t pid)
531 const size_t fd_dir_path_size = 20;
532 char fd_dir_path[fd_dir_path_size];
533 int res = snprintf(fd_dir_path, fd_dir_path_size,
534 "/proc/%lli/fd", (long long int) pid);
535 xbt_assert(res >= 0);
536 if ((size_t) res > fd_dir_path_size)
537 xbt_die("Unexpected buffer is too small for fd_dir_path");
539 DIR* fd_dir = opendir(fd_dir_path);
541 xbt_die("Cannot open directory '/proc/self/fd'\n");
543 std::vector<s_fd_infos_t> fds;
545 struct dirent* fd_number;
546 while ((fd_number = readdir(fd_dir))) {
548 int fd_value = atoi(fd_number->d_name);
553 const size_t source_size = 25;
555 int res = snprintf(source, source_size, "/proc/%lli/fd/%s",
556 (long long int) pid, fd_number->d_name);
557 xbt_assert(res >= 0);
558 if ((size_t) res > source_size)
559 xbt_die("Unexpected buffer is too small for fd %s", fd_number->d_name);
561 const size_t link_size = 200;
563 res = readlink(source, link, link_size);
565 xbt_die("Could not read link for %s", source);
568 xbt_die("Buffer to small for link of %s", source);
572 if(smpi_is_privatisation_file(link))
575 // This is (probably) the DIR* we are reading:
576 // TODO, read all the file entries at once and close the DIR.*
577 if(strcmp(fd_dir_path, link) == 0)
580 // We don't handle them.
581 // It does not mean we should silently ignore them however.
582 if (strncmp(link, "pipe:", 5) == 0 || strncmp(link, "socket:", 7) == 0)
585 // If dot_output enabled, do not handle the corresponding file
586 if (dot_output != NULL && strcmp(basename(link), _sg_mc_dot_output_file) == 0)
589 // This is probably a shared memory used by lttng-ust:
590 if(strncmp("/dev/shm/ust-shm-tmp-", link, 21)==0)
593 // Add an entry for this FD in the snapshot:
595 fd.filename = std::string(link);
596 fd.number = fd_value;
597 fd.flags = fcntl(fd_value, F_GETFL) | fcntl(fd_value, F_GETFD) ;
598 fd.current_position = lseek(fd_value, 0, SEEK_CUR);
599 fds.push_back(std::move(fd));
603 return std::move(fds);
606 mc_snapshot_t MC_take_snapshot(int num_state)
608 XBT_DEBUG("Taking snapshot %i", num_state);
610 mc_process_t mc_process = &mc_model_checker->process();
612 mc_snapshot_t snapshot = new simgrid::mc::Snapshot();
614 snapshot->process = mc_process;
615 snapshot->num_state = num_state;
617 smx_process_t process;
618 MC_EACH_SIMIX_PROCESS(process,
619 snapshot->enabled_processes.insert(process->pid));
621 MC_snapshot_handle_ignore(snapshot);
623 if (_sg_mc_snapshot_fds)
624 snapshot->current_fds = MC_get_current_fds(process->pid);
626 /* Save the std heap and the writable mapped pages of libsimgrid and binary */
627 MC_get_memory_regions(mc_process, snapshot);
629 snapshot->to_ignore = MC_take_snapshot_ignore();
631 if (_sg_mc_visited > 0 || strcmp(_sg_mc_property_file, "")) {
633 MC_take_snapshot_stacks(&snapshot);
634 if (_sg_mc_hash && snapshot->stacks != NULL) {
635 snapshot->hash = mc_hash_processes_state(num_state, snapshot->stacks);
643 MC_snapshot_ignore_restore(snapshot);
648 void MC_restore_snapshot_regions(mc_snapshot_t snapshot)
650 for(std::unique_ptr<s_mc_mem_region_t> const& region : snapshot->snapshot_regions) {
651 // For privatized, variables we decided it was not necessary to take the snapshot:
653 MC_region_restore(region.get());
657 // TODO, send a message to implement this in the MCed process
658 if(snapshot->privatization_index >= 0) {
659 // We just rewrote the global variables.
660 // The privatisation segment SMPI thinks
661 // is mapped might be inconsistent with the segment which
662 // is really mapped in memory (kernel state).
663 // We ask politely SMPI to map the segment anyway,
664 // even if it thinks it is the current one:
665 smpi_really_switch_data_segment(snapshot->privatization_index);
671 void MC_restore_snapshot_fds(mc_snapshot_t snapshot)
673 if (mc_mode == MC_MODE_SERVER)
674 xbt_die("FD snapshot not implemented in client/server mode.");
676 for (auto const& fd : snapshot->current_fds) {
678 int new_fd = open(fd.filename.c_str(), fd.flags);
680 xbt_die("Could not reopen the file %s fo restoring the file descriptor",
681 fd.filename.c_str());
683 if (new_fd != fd.number) {
684 dup2(new_fd, fd.number);
687 lseek(fd.number, fd.current_position, SEEK_SET);
691 void MC_restore_snapshot(mc_snapshot_t snapshot)
693 XBT_DEBUG("Restore snapshot %i", snapshot->num_state);
694 MC_restore_snapshot_regions(snapshot);
695 if (_sg_mc_snapshot_fds)
696 MC_restore_snapshot_fds(snapshot);
697 MC_snapshot_ignore_restore(snapshot);
698 mc_model_checker->process().cache_flags = 0;
701 mc_snapshot_t simcall_HANDLER_mc_snapshot(smx_simcall_t simcall)
703 return MC_take_snapshot(1);