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 = object_info && object_info->privatized();
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(
200 std::vector<simgrid::mc::VmMap> const& maps, mc_object_info_t result)
202 const char* file_name = xbt_strdup(result->file_name.c_str());
203 const char *name = basename(file_name);
204 for (size_t i = 0; i < maps.size(); ++i) {
205 simgrid::mc::VmMap const& reg = maps[i];
206 if (maps[i].pathname.empty()
207 || strcmp(basename(maps[i].pathname.c_str()), name)) {
209 } else if ((reg.prot & PROT_WRITE)) {
210 xbt_assert(!result->start_rw,
211 "Multiple read-write segments for %s, not supported",
212 maps[i].pathname.c_str());
213 result->start_rw = (char*) reg.start_addr;
214 result->end_rw = (char*) reg.end_addr;
215 // .bss is usually after the .data:
216 simgrid::mc::VmMap const& next = maps[i + 1];
217 if (next.pathname.empty() && (next.prot & PROT_WRITE)
218 && next.start_addr == reg.end_addr) {
219 result->end_rw = (char*) maps[i + 1].end_addr;
221 } else if ((reg.prot & PROT_READ) && (reg.prot & PROT_EXEC)) {
222 xbt_assert(!result->start_exec,
223 "Multiple executable segments for %s, not supported",
224 maps[i].pathname.c_str());
225 result->start_exec = (char*) reg.start_addr;
226 result->end_exec = (char*) reg.end_addr;
227 } else if ((reg.prot & PROT_READ) && !(reg.prot & PROT_EXEC)) {
228 xbt_assert(!result->start_ro,
229 "Multiple read only segments for %s, not supported",
230 maps[i].pathname.c_str());
231 result->start_ro = (char*) reg.start_addr;
232 result->end_ro = (char*) reg.end_addr;
236 result->start = result->start_rw;
237 if ((const void*) result->start_ro > result->start)
238 result->start = result->start_ro;
239 if ((const void*) result->start_exec > result->start)
240 result->start = result->start_exec;
242 result->end = result->end_rw;
243 if (result->end_ro && (const void*) result->end_ro < result->end)
244 result->end = result->end_ro;
245 if (result->end_exec && (const void*) result->end_exec > result->end)
246 result->end = result->end_exec;
248 xbt_assert(result->start_rw);
249 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(mc_variable_t var, mc_frame_t 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 mc_frame_t scope, int process_index,
276 std::vector<s_local_variable>& result)
278 mc_process_t 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 s_mc_location_t location;
309 mc_dwarf_resolve_locations(
310 &location, ¤t_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 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 for(simgrid::mc::Frame& nested_scope : scope->scopes)
334 mc_fill_local_variables_values(
335 stack_frame, &nested_scope, process_index, result);
338 static std::vector<s_local_variable> MC_get_local_variables_values(
339 std::vector<s_mc_stack_frame_t>& stack_frames, int process_index)
341 std::vector<s_local_variable> variables;
342 for (s_mc_stack_frame_t& stack_frame : stack_frames)
343 mc_fill_local_variables_values(&stack_frame, stack_frame.frame, process_index, variables);
344 return std::move(variables);
347 static void MC_stack_frame_free_voipd(void *s)
349 mc_stack_frame_t stack_frame = *(mc_stack_frame_t *) s;
353 static std::vector<s_mc_stack_frame_t> MC_unwind_stack_frames(mc_unw_context_t stack_context)
355 mc_process_t process = &mc_model_checker->process();
356 std::vector<s_mc_stack_frame_t> result;
360 // TODO, check condition check (unw_init_local==0 means end of frame)
361 if (mc_unw_init_cursor(&c, stack_context) != 0) {
363 xbt_die("Could not initialize stack unwinding");
368 s_mc_stack_frame_t stack_frame;
370 stack_frame.unw_cursor = c;
374 unw_get_reg(&c, UNW_REG_IP, &ip);
375 unw_get_reg(&c, UNW_REG_SP, &sp);
380 // TODO, use real addresses in frame_t instead of fixing it here
382 mc_frame_t frame = process->find_function(remote(ip));
383 stack_frame.frame = frame;
386 stack_frame.frame_name = frame->name;
387 stack_frame.frame_base =
388 (unw_word_t) mc_find_frame_base(frame, frame->object_info, &c);
390 stack_frame.frame_base = 0;
391 stack_frame.frame_name = std::string();
394 result.push_back(std::move(stack_frame));
396 /* Stop before context switch with maestro */
397 if (frame != nullptr &&
398 frame->name == "smx_ctx_sysv_wrapper")
401 int ret = unw_step(&c);
403 xbt_die("Unexpected end of stack.");
404 } else if (ret < 0) {
405 xbt_die("Error while unwinding stack");
409 if (result.empty()) {
410 XBT_INFO("unw_init_local failed");
414 return std::move(result);
417 static std::vector<s_mc_snapshot_stack_t> MC_take_snapshot_stacks(mc_snapshot_t * snapshot)
419 std::vector<s_mc_snapshot_stack_t> res;
421 unsigned int cursor = 0;
422 stack_region_t current_stack;
424 // FIXME, cross-process support (stack_areas)
425 xbt_dynar_foreach(stacks_areas, cursor, current_stack) {
426 s_mc_snapshot_stack_t st;
428 // Read the context from remote process:
429 unw_context_t context;
430 mc_model_checker->process().read_bytes(
431 &context, sizeof(context), remote(current_stack->context));
433 if (mc_unw_init_context(&st.context, &mc_model_checker->process(),
435 xbt_die("Could not initialise the libunwind context.");
437 st.stack_frames = MC_unwind_stack_frames(&st.context);
438 st.local_variables = MC_get_local_variables_values(st.stack_frames, current_stack->process_index);
439 st.process_index = current_stack->process_index;
441 unw_word_t sp = st.stack_frames[0].sp;
443 res.push_back(std::move(st));
446 (char*) current_stack->address + current_stack->size - (char*) sp;
447 (*snapshot)->stack_sizes.push_back(stack_size);
450 return std::move(res);
454 static std::vector<s_mc_heap_ignore_region_t> MC_take_snapshot_ignore()
456 std::vector<s_mc_heap_ignore_region_t> res;
458 if (mc_heap_comparison_ignore == NULL)
459 return std::move(res);
461 unsigned int cursor = 0;
462 mc_heap_ignore_region_t current_region;
464 xbt_dynar_foreach(mc_heap_comparison_ignore, cursor, current_region) {
465 s_mc_heap_ignore_region_t new_region;
466 new_region.address = current_region->address;
467 new_region.size = current_region->size;
468 new_region.block = current_region->block;
469 new_region.fragment = current_region->fragment;
470 res.push_back(std::move(new_region));
473 return std::move(res);
476 static void MC_snapshot_handle_ignore(mc_snapshot_t snapshot)
478 xbt_assert(snapshot->process);
481 for (auto const& region : mc_model_checker->process().ignored_regions()) {
482 s_mc_snapshot_ignored_data_t ignored_data;
483 ignored_data.start = (void*)region.addr;
484 ignored_data.data.resize(region.size);
485 // TODO, we should do this once per privatization segment:
486 snapshot->process->read_bytes(
487 ignored_data.data.data(), region.size, remote(region.addr),
488 simgrid::mc::ProcessIndexDisabled);
489 snapshot->ignored_data.push_back(std::move(ignored_data));
493 for(auto const& region : mc_model_checker->process().ignored_regions()) {
494 snapshot->process->clear_bytes(remote(region.addr), region.size);
499 static void MC_snapshot_ignore_restore(mc_snapshot_t snapshot)
501 for (auto const& ignored_data : snapshot->ignored_data)
502 snapshot->process->write_bytes(
503 ignored_data.data.data(), ignored_data.data.size(),
504 remote(ignored_data.start));
507 static std::vector<s_fd_infos_t> MC_get_current_fds(pid_t pid)
509 const size_t fd_dir_path_size = 20;
510 char fd_dir_path[fd_dir_path_size];
511 int res = snprintf(fd_dir_path, fd_dir_path_size,
512 "/proc/%lli/fd", (long long int) pid);
513 xbt_assert(res >= 0);
514 if ((size_t) res > fd_dir_path_size)
515 xbt_die("Unexpected buffer is too small for fd_dir_path");
517 DIR* fd_dir = opendir(fd_dir_path);
519 xbt_die("Cannot open directory '/proc/self/fd'\n");
521 std::vector<s_fd_infos_t> fds;
523 struct dirent* fd_number;
524 while ((fd_number = readdir(fd_dir))) {
526 int fd_value = atoi(fd_number->d_name);
531 const size_t source_size = 25;
533 int res = snprintf(source, source_size, "/proc/%lli/fd/%s",
534 (long long int) pid, fd_number->d_name);
535 xbt_assert(res >= 0);
536 if ((size_t) res > source_size)
537 xbt_die("Unexpected buffer is too small for fd %s", fd_number->d_name);
539 const size_t link_size = 200;
541 res = readlink(source, link, link_size);
543 xbt_die("Could not read link for %s", source);
546 xbt_die("Buffer to small for link of %s", source);
550 if(smpi_is_privatisation_file(link))
553 // This is (probably) the DIR* we are reading:
554 // TODO, read all the file entries at once and close the DIR.*
555 if(strcmp(fd_dir_path, link) == 0)
558 // We don't handle them.
559 // It does not mean we should silently ignore them however.
560 if (strncmp(link, "pipe:", 5) == 0 || strncmp(link, "socket:", 7) == 0)
563 // If dot_output enabled, do not handle the corresponding file
564 if (dot_output != NULL && strcmp(basename(link), _sg_mc_dot_output_file) == 0)
567 // This is probably a shared memory used by lttng-ust:
568 if(strncmp("/dev/shm/ust-shm-tmp-", link, 21)==0)
571 // Add an entry for this FD in the snapshot:
573 fd.filename = std::string(link);
574 fd.number = fd_value;
575 fd.flags = fcntl(fd_value, F_GETFL) | fcntl(fd_value, F_GETFD) ;
576 fd.current_position = lseek(fd_value, 0, SEEK_CUR);
577 fds.push_back(std::move(fd));
581 return std::move(fds);
584 mc_snapshot_t MC_take_snapshot(int num_state)
586 XBT_DEBUG("Taking snapshot %i", num_state);
588 mc_process_t mc_process = &mc_model_checker->process();
590 mc_snapshot_t snapshot = new simgrid::mc::Snapshot();
592 snapshot->process = mc_process;
593 snapshot->num_state = num_state;
595 smx_process_t process;
596 MC_EACH_SIMIX_PROCESS(process,
597 snapshot->enabled_processes.insert(process->pid));
599 MC_snapshot_handle_ignore(snapshot);
601 if (_sg_mc_snapshot_fds)
602 snapshot->current_fds = MC_get_current_fds(process->pid);
604 /* Save the std heap and the writable mapped pages of libsimgrid and binary */
605 MC_get_memory_regions(mc_process, snapshot);
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);
612 if (_sg_mc_hash && !snapshot->stacks.empty()) {
613 snapshot->hash = simgrid::mc::hash(*snapshot);
621 MC_snapshot_ignore_restore(snapshot);
626 void MC_restore_snapshot_regions(mc_snapshot_t snapshot)
628 for(std::unique_ptr<s_mc_mem_region_t> const& region : snapshot->snapshot_regions) {
629 // For privatized, variables we decided it was not necessary to take the snapshot:
631 MC_region_restore(region.get());
635 // TODO, send a message to implement this in the MCed process
636 if(snapshot->privatization_index >= 0) {
637 // We just rewrote the global variables.
638 // The privatisation segment SMPI thinks
639 // is mapped might be inconsistent with the segment which
640 // is really mapped in memory (kernel state).
641 // We ask politely SMPI to map the segment anyway,
642 // even if it thinks it is the current one:
643 smpi_really_switch_data_segment(snapshot->privatization_index);
649 void MC_restore_snapshot_fds(mc_snapshot_t snapshot)
651 if (mc_mode == MC_MODE_SERVER)
652 xbt_die("FD snapshot not implemented in client/server mode.");
654 for (auto const& fd : snapshot->current_fds) {
656 int new_fd = open(fd.filename.c_str(), fd.flags);
658 xbt_die("Could not reopen the file %s fo restoring the file descriptor",
659 fd.filename.c_str());
661 if (new_fd != fd.number) {
662 dup2(new_fd, fd.number);
665 lseek(fd.number, fd.current_position, SEEK_SET);
669 void MC_restore_snapshot(mc_snapshot_t snapshot)
671 XBT_DEBUG("Restore snapshot %i", snapshot->num_state);
672 MC_restore_snapshot_regions(snapshot);
673 if (_sg_mc_snapshot_fds)
674 MC_restore_snapshot_fds(snapshot);
675 MC_snapshot_ignore_restore(snapshot);
676 mc_model_checker->process().cache_flags = 0;
679 mc_snapshot_t simcall_HANDLER_mc_snapshot(smx_simcall_t simcall)
681 return MC_take_snapshot(1);