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 s_mc_snapshot_stack::~s_mc_snapshot_stack()
52 mc_unw_destroy_context(this->context);
53 xbt_free(this->context);
56 static void MC_snapshot_stack_free_voidp(void *s)
58 mc_snapshot_stack_t stack = (mc_snapshot_stack_t) * (void **) s;
62 static void local_variable_free_voidp(void *v)
64 local_variable_t var = *(local_variable_t*)v;
72 /** @brief Restore a region from a snapshot
74 * @param reg Target region
76 static void MC_region_restore(mc_mem_region_t region)
78 switch(region->storage_type()) {
79 case simgrid::mc::StorageType::NoData:
81 xbt_die("Storage type not supported");
84 case simgrid::mc::StorageType::Flat:
85 mc_model_checker->process().write_bytes(region->flat_data().data(),
86 region->size(), region->permanent_address());
89 case simgrid::mc::StorageType::Chunked:
90 mc_region_restore_sparse(&mc_model_checker->process(), region);
93 case simgrid::mc::StorageType::Privatized:
94 for (auto& p : region->privatized_data())
95 MC_region_restore(&p);
105 simgrid::mc::RegionSnapshot privatized_region(
106 RegionType region_type, void *start_addr, void* permanent_addr, size_t size
109 size_t process_count = MC_smpi_process_count();
111 // Read smpi_privatisation_regions from MCed:
112 smpi_privatisation_region_t remote_smpi_privatisation_regions;
113 mc_model_checker->process().read_variable(
114 "smpi_privatisation_regions",
115 &remote_smpi_privatisation_regions, sizeof(remote_smpi_privatisation_regions));
116 s_smpi_privatisation_region_t privatisation_regions[process_count];
117 mc_model_checker->process().read_bytes(
118 &privatisation_regions, sizeof(privatisation_regions),
119 remote(remote_smpi_privatisation_regions));
121 std::vector<simgrid::mc::RegionSnapshot> data;
122 data.reserve(process_count);
123 for (size_t i = 0; i < process_count; i++)
125 simgrid::mc::region(region_type, start_addr,
126 privatisation_regions[i].address, size)
129 simgrid::mc::RegionSnapshot region = simgrid::mc::RegionSnapshot(
130 region_type, start_addr, permanent_addr, size);
131 region.privatized_data(std::move(data));
132 return std::move(region);
140 static void MC_snapshot_add_region(int index, mc_snapshot_t snapshot,
141 simgrid::mc::RegionType type,
142 mc_object_info_t object_info,
143 void *start_addr, void* permanent_addr, size_t size)
145 if (type == simgrid::mc::RegionType::Data)
146 xbt_assert(object_info, "Missing object info for object.");
147 else if (type == simgrid::mc::RegionType::Heap)
148 xbt_assert(!object_info, "Unexpected object info for heap region.");
150 const bool privatization_aware = MC_object_info_is_privatized(object_info);
152 simgrid::mc::RegionSnapshot region;
153 if (privatization_aware && MC_smpi_process_count())
154 region = simgrid::mc::privatized_region(type, start_addr, permanent_addr, size);
156 region = simgrid::mc::region(type, start_addr, permanent_addr, size);
158 region.object_info(object_info);
159 snapshot->snapshot_regions[index]
160 = std::unique_ptr<simgrid::mc::RegionSnapshot>(
161 new simgrid::mc::RegionSnapshot(std::move(region)));
165 static void MC_get_memory_regions(mc_process_t process, mc_snapshot_t snapshot)
167 const size_t n = process->object_infos_size;
168 snapshot->snapshot_regions.resize(n + 1);
169 for (size_t i = 0; i != n; ++i) {
170 mc_object_info_t object_info = process->object_infos[i];
171 MC_snapshot_add_region(i, snapshot, simgrid::mc::RegionType::Data, object_info,
172 object_info->start_rw, object_info->start_rw,
173 object_info->end_rw - object_info->start_rw);
176 xbt_mheap_t heap = process->get_heap();
177 void *start_heap = heap->base;
178 void *end_heap = heap->breakval;
180 MC_snapshot_add_region(n, snapshot, simgrid::mc::RegionType::Heap, NULL,
181 start_heap, start_heap,
182 (char *) end_heap - (char *) start_heap);
183 snapshot->heap_bytes_used = mmalloc_get_bytes_used_remote(
185 process->get_malloc_info());
188 if (smpi_privatize_global_variables && MC_smpi_process_count()) {
189 // snapshot->privatization_index = smpi_loaded_page
190 mc_model_checker->process().read_variable(
191 "smpi_loaded_page", &snapshot->privatization_index,
192 sizeof(snapshot->privatization_index));
196 snapshot->privatization_index = simgrid::mc::ProcessIndexMissing;
200 /** \brief Fills the position of the segments (executable, read-only, read/write).
202 * `dl_iterate_phdr` would be more robust but would not work in cross-process.
204 void MC_find_object_address(std::vector<simgrid::mc::VmMap> const& maps, mc_object_info_t result)
206 const char *name = basename(result->file_name);
207 for (size_t i = 0; i < maps.size(); ++i) {
208 simgrid::mc::VmMap const& reg = maps[i];
209 if (maps[i].pathname.empty()
210 || strcmp(basename(maps[i].pathname.c_str()), name)) {
212 } else if ((reg.prot & PROT_WRITE)) {
213 xbt_assert(!result->start_rw,
214 "Multiple read-write segments for %s, not supported",
215 maps[i].pathname.c_str());
216 result->start_rw = (char*) reg.start_addr;
217 result->end_rw = (char*) reg.end_addr;
218 // .bss is usually after the .data:
219 simgrid::mc::VmMap const& next = maps[i + 1];
220 if (next.pathname.empty() && (next.prot & PROT_WRITE)
221 && next.start_addr == reg.end_addr) {
222 result->end_rw = (char*) maps[i + 1].end_addr;
224 } else if ((reg.prot & PROT_READ) && (reg.prot & PROT_EXEC)) {
225 xbt_assert(!result->start_exec,
226 "Multiple executable segments for %s, not supported",
227 maps[i].pathname.c_str());
228 result->start_exec = (char*) reg.start_addr;
229 result->end_exec = (char*) reg.end_addr;
230 } else if ((reg.prot & PROT_READ) && !(reg.prot & PROT_EXEC)) {
231 xbt_assert(!result->start_ro,
232 "Multiple read only segments for %s, not supported",
233 maps[i].pathname.c_str());
234 result->start_ro = (char*) reg.start_addr;
235 result->end_ro = (char*) reg.end_addr;
239 result->start = result->start_rw;
240 if ((const void*) result->start_ro > result->start)
241 result->start = result->start_ro;
242 if ((const void*) result->start_exec > result->start)
243 result->start = result->start_exec;
245 result->end = result->end_rw;
246 if (result->end_ro && (const void*) result->end_ro < result->end)
247 result->end = result->end_ro;
248 if (result->end_exec && (const void*) result->end_exec > result->end)
249 result->end = result->end_exec;
251 xbt_assert(result->file_name);
252 xbt_assert(result->start_rw);
253 xbt_assert(result->start_exec);
256 /************************************* Take Snapshot ************************************/
257 /****************************************************************************************/
259 /** \brief Checks whether the variable is in scope for a given IP.
261 * A variable may be defined only from a given value of IP.
263 * \param var Variable description
264 * \param frame Scope description
265 * \param ip Instruction pointer
266 * \return true if the variable is valid
268 static bool mc_valid_variable(dw_variable_t var, dw_frame_t scope,
271 // The variable is not yet valid:
272 if ((const void *) ((const char *) scope->low_pc + var->start_scope) > ip)
278 static void mc_fill_local_variables_values(mc_stack_frame_t stack_frame,
279 dw_frame_t scope, int process_index,
280 std::vector<s_local_variable>& result)
282 mc_process_t process = &mc_model_checker->process();
284 void *ip = (void *) stack_frame->ip;
285 if (ip < scope->low_pc || ip >= scope->high_pc)
289 dw_variable_t current_variable;
290 xbt_dynar_foreach(scope->variables, cursor, current_variable) {
292 if (!mc_valid_variable(current_variable, scope, (void *) stack_frame->ip))
296 // FIXME, get rid of `region_type`
297 if ((long) stack_frame->ip > (long) process->libsimgrid_info->start_exec)
302 s_local_variable_t new_var;
303 new_var.subprogram = stack_frame->frame;
304 new_var.ip = stack_frame->ip;
305 new_var.name = current_variable->name;
306 new_var.type = current_variable->type;
307 new_var.region = region_type;
308 new_var.address = nullptr;
310 if (current_variable->address != NULL) {
311 new_var.address = current_variable->address;
312 } else if (current_variable->locations.size != 0) {
313 s_mc_location_t location;
314 mc_dwarf_resolve_locations(
315 &location, ¤t_variable->locations,
316 current_variable->object_info,
317 &(stack_frame->unw_cursor),
318 (void *) stack_frame->frame_base,
319 &mc_model_checker->process(), process_index);
321 switch(mc_get_location_type(&location)) {
322 case MC_LOCATION_TYPE_ADDRESS:
323 new_var.address = location.memory_location;
325 case MC_LOCATION_TYPE_REGISTER:
327 xbt_die("Cannot handle non-address variable");
331 xbt_die("No address");
334 result.push_back(std::move(new_var));
337 // Recursive processing of nested scopes:
338 dw_frame_t nested_scope = NULL;
339 xbt_dynar_foreach(scope->scopes, cursor, nested_scope) {
340 mc_fill_local_variables_values(stack_frame, nested_scope, process_index, result);
344 static std::vector<s_local_variable> MC_get_local_variables_values(
345 std::vector<s_mc_stack_frame_t>& stack_frames, int process_index)
347 std::vector<s_local_variable> variables;
348 for (s_mc_stack_frame_t& stack_frame : stack_frames)
349 mc_fill_local_variables_values(&stack_frame, stack_frame.frame, process_index, variables);
350 return std::move(variables);
353 static void MC_stack_frame_free_voipd(void *s)
355 mc_stack_frame_t stack_frame = *(mc_stack_frame_t *) s;
359 static std::vector<s_mc_stack_frame_t> MC_unwind_stack_frames(mc_unw_context_t stack_context)
361 mc_process_t process = &mc_model_checker->process();
362 std::vector<s_mc_stack_frame_t> result;
366 // TODO, check condition check (unw_init_local==0 means end of frame)
367 if (mc_unw_init_cursor(&c, stack_context) != 0) {
369 xbt_die("Could not initialize stack unwinding");
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 dw_frame_t 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) mc_find_frame_base(frame, frame->object_info, &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 != NULL && frame->name != NULL
404 && !strcmp(frame->name, "smx_ctx_sysv_wrapper"))
407 int ret = unw_step(&c);
409 xbt_die("Unexpected end of stack.");
410 } else if (ret < 0) {
411 xbt_die("Error while unwinding stack");
415 if (result.empty()) {
416 XBT_INFO("unw_init_local failed");
420 return std::move(result);
423 static std::vector<s_mc_snapshot_stack_t> MC_take_snapshot_stacks(mc_snapshot_t * snapshot)
425 std::vector<s_mc_snapshot_stack_t> res;
427 unsigned int cursor = 0;
428 stack_region_t current_stack;
430 // FIXME, cross-process support (stack_areas)
431 xbt_dynar_foreach(stacks_areas, cursor, current_stack) {
432 s_mc_snapshot_stack_t st;
434 // Read the context from remote process:
435 unw_context_t context;
436 mc_model_checker->process().read_bytes(
437 &context, sizeof(context), remote(current_stack->context));
439 st.context = xbt_new0(s_mc_unw_context_t, 1);
440 if (mc_unw_init_context(st.context, &mc_model_checker->process(),
442 xbt_die("Could not initialise the libunwind context.");
444 st.stack_frames = MC_unwind_stack_frames(st.context);
445 st.local_variables = MC_get_local_variables_values(st.stack_frames, current_stack->process_index);
446 st.process_index = current_stack->process_index;
448 unw_word_t sp = st.stack_frames[0].sp;
450 res.push_back(std::move(st));
453 (char*) current_stack->address + current_stack->size - (char*) sp;
454 (*snapshot)->stack_sizes.push_back(stack_size);
457 return std::move(res);
461 static std::vector<s_mc_heap_ignore_region_t> MC_take_snapshot_ignore()
463 std::vector<s_mc_heap_ignore_region_t> res;
465 if (mc_heap_comparison_ignore == NULL)
466 return std::move(res);
468 unsigned int cursor = 0;
469 mc_heap_ignore_region_t current_region;
471 xbt_dynar_foreach(mc_heap_comparison_ignore, cursor, current_region) {
472 s_mc_heap_ignore_region_t new_region;
473 new_region.address = current_region->address;
474 new_region.size = current_region->size;
475 new_region.block = current_region->block;
476 new_region.fragment = current_region->fragment;
477 res.push_back(std::move(new_region));
480 return std::move(res);
483 static void MC_snapshot_handle_ignore(mc_snapshot_t snapshot)
485 xbt_assert(snapshot->process);
488 for (auto const& region : mc_model_checker->process().ignored_regions()) {
489 s_mc_snapshot_ignored_data_t ignored_data;
490 ignored_data.start = (void*)region.addr;
491 ignored_data.data.resize(region.size);
492 // TODO, we should do this once per privatization segment:
493 snapshot->process->read_bytes(
494 ignored_data.data.data(), region.size, remote(region.addr),
495 simgrid::mc::ProcessIndexDisabled);
496 snapshot->ignored_data.push_back(std::move(ignored_data));
500 for(auto const& region : mc_model_checker->process().ignored_regions()) {
501 snapshot->process->clear_bytes(remote(region.addr), region.size);
506 static void MC_snapshot_ignore_restore(mc_snapshot_t snapshot)
508 for (auto const& ignored_data : snapshot->ignored_data)
509 snapshot->process->write_bytes(
510 ignored_data.data.data(), ignored_data.data.size(),
511 remote(ignored_data.start));
514 static std::vector<s_fd_infos_t> MC_get_current_fds(pid_t pid)
516 const size_t fd_dir_path_size = 20;
517 char fd_dir_path[fd_dir_path_size];
518 int res = snprintf(fd_dir_path, fd_dir_path_size,
519 "/proc/%lli/fd", (long long int) pid);
520 xbt_assert(res >= 0);
521 if ((size_t) res > fd_dir_path_size)
522 xbt_die("Unexpected buffer is too small for fd_dir_path");
524 DIR* fd_dir = opendir(fd_dir_path);
526 xbt_die("Cannot open directory '/proc/self/fd'\n");
528 std::vector<s_fd_infos_t> fds;
530 struct dirent* fd_number;
531 while ((fd_number = readdir(fd_dir))) {
533 int fd_value = atoi(fd_number->d_name);
538 const size_t source_size = 25;
540 int res = snprintf(source, source_size, "/proc/%lli/fd/%s",
541 (long long int) pid, fd_number->d_name);
542 xbt_assert(res >= 0);
543 if ((size_t) res > source_size)
544 xbt_die("Unexpected buffer is too small for fd %s", fd_number->d_name);
546 const size_t link_size = 200;
548 res = readlink(source, link, link_size);
550 xbt_die("Could not read link for %s", source);
553 xbt_die("Buffer to small for link of %s", source);
557 if(smpi_is_privatisation_file(link))
560 // This is (probably) the DIR* we are reading:
561 // TODO, read all the file entries at once and close the DIR.*
562 if(strcmp(fd_dir_path, link) == 0)
565 // We don't handle them.
566 // It does not mean we should silently ignore them however.
567 if (strncmp(link, "pipe:", 5) == 0 || strncmp(link, "socket:", 7) == 0)
570 // If dot_output enabled, do not handle the corresponding file
571 if (dot_output != NULL && strcmp(basename(link), _sg_mc_dot_output_file) == 0)
574 // This is probably a shared memory used by lttng-ust:
575 if(strncmp("/dev/shm/ust-shm-tmp-", link, 21)==0)
578 // Add an entry for this FD in the snapshot:
580 fd.filename = std::string(link);
581 fd.number = fd_value;
582 fd.flags = fcntl(fd_value, F_GETFL) | fcntl(fd_value, F_GETFD) ;
583 fd.current_position = lseek(fd_value, 0, SEEK_CUR);
584 fds.push_back(std::move(fd));
588 return std::move(fds);
591 mc_snapshot_t MC_take_snapshot(int num_state)
593 XBT_DEBUG("Taking snapshot %i", num_state);
595 mc_process_t mc_process = &mc_model_checker->process();
597 mc_snapshot_t snapshot = new simgrid::mc::Snapshot();
599 snapshot->process = mc_process;
600 snapshot->num_state = num_state;
602 smx_process_t process;
603 MC_EACH_SIMIX_PROCESS(process,
604 snapshot->enabled_processes.insert(process->pid));
606 MC_snapshot_handle_ignore(snapshot);
608 if (_sg_mc_snapshot_fds)
609 snapshot->current_fds = MC_get_current_fds(process->pid);
611 /* Save the std heap and the writable mapped pages of libsimgrid and binary */
612 MC_get_memory_regions(mc_process, snapshot);
614 snapshot->to_ignore = MC_take_snapshot_ignore();
616 if (_sg_mc_visited > 0 || strcmp(_sg_mc_property_file, "")) {
618 MC_take_snapshot_stacks(&snapshot);
619 if (_sg_mc_hash && !snapshot->stacks.empty()) {
620 snapshot->hash = mc_hash_processes_state(num_state, snapshot->stacks);
628 MC_snapshot_ignore_restore(snapshot);
633 void MC_restore_snapshot_regions(mc_snapshot_t snapshot)
635 for(std::unique_ptr<s_mc_mem_region_t> const& region : snapshot->snapshot_regions) {
636 // For privatized, variables we decided it was not necessary to take the snapshot:
638 MC_region_restore(region.get());
642 // TODO, send a message to implement this in the MCed process
643 if(snapshot->privatization_index >= 0) {
644 // We just rewrote the global variables.
645 // The privatisation segment SMPI thinks
646 // is mapped might be inconsistent with the segment which
647 // is really mapped in memory (kernel state).
648 // We ask politely SMPI to map the segment anyway,
649 // even if it thinks it is the current one:
650 smpi_really_switch_data_segment(snapshot->privatization_index);
656 void MC_restore_snapshot_fds(mc_snapshot_t snapshot)
658 if (mc_mode == MC_MODE_SERVER)
659 xbt_die("FD snapshot not implemented in client/server mode.");
661 for (auto const& fd : snapshot->current_fds) {
663 int new_fd = open(fd.filename.c_str(), fd.flags);
665 xbt_die("Could not reopen the file %s fo restoring the file descriptor",
666 fd.filename.c_str());
668 if (new_fd != fd.number) {
669 dup2(new_fd, fd.number);
672 lseek(fd.number, fd.current_position, SEEK_SET);
676 void MC_restore_snapshot(mc_snapshot_t snapshot)
678 XBT_DEBUG("Restore snapshot %i", snapshot->num_state);
679 MC_restore_snapshot_regions(snapshot);
680 if (_sg_mc_snapshot_fds)
681 MC_restore_snapshot_fds(snapshot);
682 MC_snapshot_ignore_restore(snapshot);
683 mc_model_checker->process().cache_flags = 0;
686 mc_snapshot_t simcall_HANDLER_mc_snapshot(smx_simcall_t simcall)
688 return MC_take_snapshot(1);