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"
37 #include "mc_hash.hpp"
39 using simgrid::mc::remote;
43 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_checkpoint, mc,
44 "Logging specific to mc_checkpoint");
46 /************************************ Free functions **************************************/
47 /*****************************************************************************************/
49 static void MC_snapshot_stack_free_voidp(void *s)
51 mc_snapshot_stack_t stack = (mc_snapshot_stack_t) * (void **) s;
55 static void local_variable_free_voidp(void *v)
57 local_variable_t var = *(local_variable_t*)v;
65 /** @brief Restore a region from a snapshot
67 * @param reg Target region
69 static void MC_region_restore(mc_mem_region_t region)
71 switch(region->storage_type()) {
72 case simgrid::mc::StorageType::NoData:
74 xbt_die("Storage type not supported");
77 case simgrid::mc::StorageType::Flat:
78 mc_model_checker->process().write_bytes(region->flat_data().data(),
79 region->size(), region->permanent_address());
82 case simgrid::mc::StorageType::Chunked:
83 mc_region_restore_sparse(&mc_model_checker->process(), region);
86 case simgrid::mc::StorageType::Privatized:
87 for (auto& p : region->privatized_data())
88 MC_region_restore(&p);
98 simgrid::mc::RegionSnapshot privatized_region(
99 RegionType region_type, void *start_addr, void* permanent_addr, size_t size
102 size_t process_count = MC_smpi_process_count();
104 // Read smpi_privatisation_regions from MCed:
105 smpi_privatisation_region_t remote_smpi_privatisation_regions;
106 mc_model_checker->process().read_variable(
107 "smpi_privatisation_regions",
108 &remote_smpi_privatisation_regions, sizeof(remote_smpi_privatisation_regions));
109 s_smpi_privatisation_region_t privatisation_regions[process_count];
110 mc_model_checker->process().read_bytes(
111 &privatisation_regions, sizeof(privatisation_regions),
112 remote(remote_smpi_privatisation_regions));
114 std::vector<simgrid::mc::RegionSnapshot> data;
115 data.reserve(process_count);
116 for (size_t i = 0; i < process_count; i++)
118 simgrid::mc::region(region_type, start_addr,
119 privatisation_regions[i].address, size)
122 simgrid::mc::RegionSnapshot region = simgrid::mc::RegionSnapshot(
123 region_type, start_addr, permanent_addr, size);
124 region.privatized_data(std::move(data));
125 return std::move(region);
133 static void MC_snapshot_add_region(int index, mc_snapshot_t snapshot,
134 simgrid::mc::RegionType type,
135 mc_object_info_t object_info,
136 void *start_addr, void* permanent_addr, size_t size)
138 if (type == simgrid::mc::RegionType::Data)
139 xbt_assert(object_info, "Missing object info for object.");
140 else if (type == simgrid::mc::RegionType::Heap)
141 xbt_assert(!object_info, "Unexpected object info for heap region.");
143 const bool privatization_aware = MC_object_info_is_privatized(object_info);
145 simgrid::mc::RegionSnapshot region;
146 if (privatization_aware && MC_smpi_process_count())
147 region = simgrid::mc::privatized_region(type, start_addr, permanent_addr, size);
149 region = simgrid::mc::region(type, start_addr, permanent_addr, size);
151 region.object_info(object_info);
152 snapshot->snapshot_regions[index]
153 = std::unique_ptr<simgrid::mc::RegionSnapshot>(
154 new simgrid::mc::RegionSnapshot(std::move(region)));
158 static void MC_get_memory_regions(mc_process_t process, mc_snapshot_t snapshot)
160 const size_t n = process->object_infos.size();
161 snapshot->snapshot_regions.resize(n + 1);
163 for (auto const& object_info : process->object_infos) {
164 MC_snapshot_add_region(i, snapshot, simgrid::mc::RegionType::Data,
166 object_info->start_rw, object_info->start_rw,
167 object_info->end_rw - object_info->start_rw);
171 xbt_mheap_t heap = process->get_heap();
172 void *start_heap = heap->base;
173 void *end_heap = heap->breakval;
175 MC_snapshot_add_region(n, snapshot, simgrid::mc::RegionType::Heap, NULL,
176 start_heap, start_heap,
177 (char *) end_heap - (char *) start_heap);
178 snapshot->heap_bytes_used = mmalloc_get_bytes_used_remote(
180 process->get_malloc_info());
183 if (smpi_privatize_global_variables && MC_smpi_process_count()) {
184 // snapshot->privatization_index = smpi_loaded_page
185 mc_model_checker->process().read_variable(
186 "smpi_loaded_page", &snapshot->privatization_index,
187 sizeof(snapshot->privatization_index));
191 snapshot->privatization_index = simgrid::mc::ProcessIndexMissing;
195 /** \brief Fills the position of the segments (executable, read-only, read/write).
197 * `dl_iterate_phdr` would be more robust but would not work in cross-process.
199 void MC_find_object_address(std::vector<simgrid::mc::VmMap> const& maps, mc_object_info_t result)
201 const char *name = basename(result->file_name);
202 for (size_t i = 0; i < maps.size(); ++i) {
203 simgrid::mc::VmMap const& reg = maps[i];
204 if (maps[i].pathname.empty()
205 || strcmp(basename(maps[i].pathname.c_str()), name)) {
207 } else if ((reg.prot & PROT_WRITE)) {
208 xbt_assert(!result->start_rw,
209 "Multiple read-write segments for %s, not supported",
210 maps[i].pathname.c_str());
211 result->start_rw = (char*) reg.start_addr;
212 result->end_rw = (char*) reg.end_addr;
213 // .bss is usually after the .data:
214 simgrid::mc::VmMap const& next = maps[i + 1];
215 if (next.pathname.empty() && (next.prot & PROT_WRITE)
216 && next.start_addr == reg.end_addr) {
217 result->end_rw = (char*) maps[i + 1].end_addr;
219 } else if ((reg.prot & PROT_READ) && (reg.prot & PROT_EXEC)) {
220 xbt_assert(!result->start_exec,
221 "Multiple executable segments for %s, not supported",
222 maps[i].pathname.c_str());
223 result->start_exec = (char*) reg.start_addr;
224 result->end_exec = (char*) reg.end_addr;
225 } else if ((reg.prot & PROT_READ) && !(reg.prot & PROT_EXEC)) {
226 xbt_assert(!result->start_ro,
227 "Multiple read only segments for %s, not supported",
228 maps[i].pathname.c_str());
229 result->start_ro = (char*) reg.start_addr;
230 result->end_ro = (char*) reg.end_addr;
234 result->start = result->start_rw;
235 if ((const void*) result->start_ro > result->start)
236 result->start = result->start_ro;
237 if ((const void*) result->start_exec > result->start)
238 result->start = result->start_exec;
240 result->end = result->end_rw;
241 if (result->end_ro && (const void*) result->end_ro < result->end)
242 result->end = result->end_ro;
243 if (result->end_exec && (const void*) result->end_exec > result->end)
244 result->end = result->end_exec;
246 xbt_assert(result->file_name);
247 xbt_assert(result->start_rw);
248 xbt_assert(result->start_exec);
251 /************************************* Take Snapshot ************************************/
252 /****************************************************************************************/
254 /** \brief Checks whether the variable is in scope for a given IP.
256 * A variable may be defined only from a given value of IP.
258 * \param var Variable description
259 * \param frame Scope description
260 * \param ip Instruction pointer
261 * \return true if the variable is valid
263 static bool mc_valid_variable(dw_variable_t var, dw_frame_t scope,
266 // The variable is not yet valid:
267 if ((const void *) ((const char *) scope->low_pc + var->start_scope) > ip)
273 static void mc_fill_local_variables_values(mc_stack_frame_t stack_frame,
274 dw_frame_t scope, int process_index,
275 std::vector<s_local_variable>& result)
277 mc_process_t process = &mc_model_checker->process();
279 void *ip = (void *) stack_frame->ip;
280 if (ip < scope->low_pc || ip >= scope->high_pc)
284 dw_variable_t current_variable;
285 xbt_dynar_foreach(scope->variables, cursor, current_variable) {
287 if (!mc_valid_variable(current_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->locations.size != 0) {
308 s_mc_location_t location;
309 mc_dwarf_resolve_locations(
310 &location, ¤t_variable->locations,
311 current_variable->object_info,
312 &(stack_frame->unw_cursor),
313 (void *) stack_frame->frame_base,
314 &mc_model_checker->process(), process_index);
316 switch(mc_get_location_type(&location)) {
317 case MC_LOCATION_TYPE_ADDRESS:
318 new_var.address = location.memory_location;
320 case MC_LOCATION_TYPE_REGISTER:
322 xbt_die("Cannot handle non-address variable");
326 xbt_die("No address");
329 result.push_back(std::move(new_var));
332 // Recursive processing of nested scopes:
333 dw_frame_t nested_scope = NULL;
334 xbt_dynar_foreach(scope->scopes, cursor, nested_scope) {
335 mc_fill_local_variables_values(stack_frame, nested_scope, process_index, result);
339 static std::vector<s_local_variable> MC_get_local_variables_values(
340 std::vector<s_mc_stack_frame_t>& stack_frames, int process_index)
342 std::vector<s_local_variable> variables;
343 for (s_mc_stack_frame_t& stack_frame : stack_frames)
344 mc_fill_local_variables_values(&stack_frame, stack_frame.frame, process_index, variables);
345 return std::move(variables);
348 static void MC_stack_frame_free_voipd(void *s)
350 mc_stack_frame_t stack_frame = *(mc_stack_frame_t *) s;
354 static std::vector<s_mc_stack_frame_t> MC_unwind_stack_frames(mc_unw_context_t stack_context)
356 mc_process_t process = &mc_model_checker->process();
357 std::vector<s_mc_stack_frame_t> result;
361 // TODO, check condition check (unw_init_local==0 means end of frame)
362 if (mc_unw_init_cursor(&c, stack_context) != 0) {
364 xbt_die("Could not initialize stack unwinding");
369 s_mc_stack_frame_t stack_frame;
371 stack_frame.unw_cursor = c;
375 unw_get_reg(&c, UNW_REG_IP, &ip);
376 unw_get_reg(&c, UNW_REG_SP, &sp);
381 // TODO, use real addresses in frame_t instead of fixing it here
383 dw_frame_t frame = process->find_function(remote(ip));
384 stack_frame.frame = frame;
387 stack_frame.frame_name = frame->name;
388 stack_frame.frame_base =
389 (unw_word_t) mc_find_frame_base(frame, frame->object_info, &c);
391 stack_frame.frame_base = 0;
392 stack_frame.frame_name = std::string();
395 result.push_back(std::move(stack_frame));
397 /* Stop before context switch with maestro */
398 if (frame != NULL && frame->name != NULL
399 && !strcmp(frame->name, "smx_ctx_sysv_wrapper"))
402 int ret = unw_step(&c);
404 xbt_die("Unexpected end of stack.");
405 } else if (ret < 0) {
406 xbt_die("Error while unwinding stack");
410 if (result.empty()) {
411 XBT_INFO("unw_init_local failed");
415 return std::move(result);
418 static std::vector<s_mc_snapshot_stack_t> MC_take_snapshot_stacks(mc_snapshot_t * snapshot)
420 std::vector<s_mc_snapshot_stack_t> res;
422 unsigned int cursor = 0;
423 stack_region_t current_stack;
425 // FIXME, cross-process support (stack_areas)
426 xbt_dynar_foreach(stacks_areas, cursor, current_stack) {
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(current_stack->context));
434 if (mc_unw_init_context(&st.context, &mc_model_checker->process(),
436 xbt_die("Could not initialise the libunwind context.");
438 st.stack_frames = MC_unwind_stack_frames(&st.context);
439 st.local_variables = MC_get_local_variables_values(st.stack_frames, current_stack->process_index);
440 st.process_index = current_stack->process_index;
442 unw_word_t sp = st.stack_frames[0].sp;
444 res.push_back(std::move(st));
447 (char*) current_stack->address + current_stack->size - (char*) sp;
448 (*snapshot)->stack_sizes.push_back(stack_size);
451 return std::move(res);
455 static std::vector<s_mc_heap_ignore_region_t> MC_take_snapshot_ignore()
457 std::vector<s_mc_heap_ignore_region_t> res;
459 if (mc_heap_comparison_ignore == NULL)
460 return std::move(res);
462 unsigned int cursor = 0;
463 mc_heap_ignore_region_t current_region;
465 xbt_dynar_foreach(mc_heap_comparison_ignore, cursor, current_region) {
466 s_mc_heap_ignore_region_t new_region;
467 new_region.address = current_region->address;
468 new_region.size = current_region->size;
469 new_region.block = current_region->block;
470 new_region.fragment = current_region->fragment;
471 res.push_back(std::move(new_region));
474 return std::move(res);
477 static void MC_snapshot_handle_ignore(mc_snapshot_t snapshot)
479 xbt_assert(snapshot->process);
482 for (auto const& region : mc_model_checker->process().ignored_regions()) {
483 s_mc_snapshot_ignored_data_t ignored_data;
484 ignored_data.start = (void*)region.addr;
485 ignored_data.data.resize(region.size);
486 // TODO, we should do this once per privatization segment:
487 snapshot->process->read_bytes(
488 ignored_data.data.data(), region.size, remote(region.addr),
489 simgrid::mc::ProcessIndexDisabled);
490 snapshot->ignored_data.push_back(std::move(ignored_data));
494 for(auto const& region : mc_model_checker->process().ignored_regions()) {
495 snapshot->process->clear_bytes(remote(region.addr), region.size);
500 static void MC_snapshot_ignore_restore(mc_snapshot_t snapshot)
502 for (auto const& ignored_data : snapshot->ignored_data)
503 snapshot->process->write_bytes(
504 ignored_data.data.data(), ignored_data.data.size(),
505 remote(ignored_data.start));
508 static std::vector<s_fd_infos_t> MC_get_current_fds(pid_t pid)
510 const size_t fd_dir_path_size = 20;
511 char fd_dir_path[fd_dir_path_size];
512 int res = snprintf(fd_dir_path, fd_dir_path_size,
513 "/proc/%lli/fd", (long long int) pid);
514 xbt_assert(res >= 0);
515 if ((size_t) res > fd_dir_path_size)
516 xbt_die("Unexpected buffer is too small for fd_dir_path");
518 DIR* fd_dir = opendir(fd_dir_path);
520 xbt_die("Cannot open directory '/proc/self/fd'\n");
522 std::vector<s_fd_infos_t> fds;
524 struct dirent* fd_number;
525 while ((fd_number = readdir(fd_dir))) {
527 int fd_value = atoi(fd_number->d_name);
532 const size_t source_size = 25;
534 int res = snprintf(source, source_size, "/proc/%lli/fd/%s",
535 (long long int) pid, fd_number->d_name);
536 xbt_assert(res >= 0);
537 if ((size_t) res > source_size)
538 xbt_die("Unexpected buffer is too small for fd %s", fd_number->d_name);
540 const size_t link_size = 200;
542 res = readlink(source, link, link_size);
544 xbt_die("Could not read link for %s", source);
547 xbt_die("Buffer to small for link of %s", source);
551 if(smpi_is_privatisation_file(link))
554 // This is (probably) the DIR* we are reading:
555 // TODO, read all the file entries at once and close the DIR.*
556 if(strcmp(fd_dir_path, link) == 0)
559 // We don't handle them.
560 // It does not mean we should silently ignore them however.
561 if (strncmp(link, "pipe:", 5) == 0 || strncmp(link, "socket:", 7) == 0)
564 // If dot_output enabled, do not handle the corresponding file
565 if (dot_output != NULL && strcmp(basename(link), _sg_mc_dot_output_file) == 0)
568 // This is probably a shared memory used by lttng-ust:
569 if(strncmp("/dev/shm/ust-shm-tmp-", link, 21)==0)
572 // Add an entry for this FD in the snapshot:
574 fd.filename = std::string(link);
575 fd.number = fd_value;
576 fd.flags = fcntl(fd_value, F_GETFL) | fcntl(fd_value, F_GETFD) ;
577 fd.current_position = lseek(fd_value, 0, SEEK_CUR);
578 fds.push_back(std::move(fd));
582 return std::move(fds);
585 mc_snapshot_t MC_take_snapshot(int num_state)
587 XBT_DEBUG("Taking snapshot %i", num_state);
589 mc_process_t mc_process = &mc_model_checker->process();
591 mc_snapshot_t snapshot = new simgrid::mc::Snapshot();
593 snapshot->process = mc_process;
594 snapshot->num_state = num_state;
596 smx_process_t process;
597 MC_EACH_SIMIX_PROCESS(process,
598 snapshot->enabled_processes.insert(process->pid));
600 MC_snapshot_handle_ignore(snapshot);
602 if (_sg_mc_snapshot_fds)
603 snapshot->current_fds = MC_get_current_fds(process->pid);
605 /* Save the std heap and the writable mapped pages of libsimgrid and binary */
606 MC_get_memory_regions(mc_process, snapshot);
608 snapshot->to_ignore = MC_take_snapshot_ignore();
610 if (_sg_mc_visited > 0 || strcmp(_sg_mc_property_file, "")) {
612 MC_take_snapshot_stacks(&snapshot);
613 if (_sg_mc_hash && !snapshot->stacks.empty()) {
614 snapshot->hash = mc_hash_processes_state(num_state, snapshot->stacks);
622 MC_snapshot_ignore_restore(snapshot);
627 void MC_restore_snapshot_regions(mc_snapshot_t snapshot)
629 for(std::unique_ptr<s_mc_mem_region_t> const& region : snapshot->snapshot_regions) {
630 // For privatized, variables we decided it was not necessary to take the snapshot:
632 MC_region_restore(region.get());
636 // TODO, send a message to implement this in the MCed process
637 if(snapshot->privatization_index >= 0) {
638 // We just rewrote the global variables.
639 // The privatisation segment SMPI thinks
640 // is mapped might be inconsistent with the segment which
641 // is really mapped in memory (kernel state).
642 // We ask politely SMPI to map the segment anyway,
643 // even if it thinks it is the current one:
644 smpi_really_switch_data_segment(snapshot->privatization_index);
650 void MC_restore_snapshot_fds(mc_snapshot_t snapshot)
652 if (mc_mode == MC_MODE_SERVER)
653 xbt_die("FD snapshot not implemented in client/server mode.");
655 for (auto const& fd : snapshot->current_fds) {
657 int new_fd = open(fd.filename.c_str(), fd.flags);
659 xbt_die("Could not reopen the file %s fo restoring the file descriptor",
660 fd.filename.c_str());
662 if (new_fd != fd.number) {
663 dup2(new_fd, fd.number);
666 lseek(fd.number, fd.current_position, SEEK_SET);
670 void MC_restore_snapshot(mc_snapshot_t snapshot)
672 XBT_DEBUG("Restore snapshot %i", snapshot->num_state);
673 MC_restore_snapshot_regions(snapshot);
674 if (_sg_mc_snapshot_fds)
675 MC_restore_snapshot_fds(snapshot);
676 MC_snapshot_ignore_restore(snapshot);
677 mc_model_checker->process().cache_flags = 0;
680 mc_snapshot_t simcall_HANDLER_mc_snapshot(smx_simcall_t simcall)
682 return MC_take_snapshot(1);