1 /* Copyright (c) 2008-2018. The SimGrid Team. All rights reserved. */
3 /* This program is free software; you can redistribute it and/or modify it
4 * under the terms of the license (GNU LGPL) which comes with this package. */
17 #include "src/internal_config.h"
18 #include "src/mc/mc_private.hpp"
19 #include "src/smpi/include/private.hpp"
20 #include "xbt/file.hpp"
21 #include "xbt/mmalloc.h"
22 #include "xbt/module.h"
24 #include "src/xbt/mmalloc/mmprivate.h"
26 #include "src/simix/smx_private.hpp"
28 #include <libunwind.h>
31 #include "src/mc/mc_private.hpp"
34 #include "src/mc/mc_config.hpp"
35 #include "src/mc/mc_hash.hpp"
36 #include "src/mc/mc_mmu.hpp"
37 #include "src/mc/mc_smx.hpp"
38 #include "src/mc/mc_snapshot.hpp"
39 #include "src/mc/mc_unw.hpp"
40 #include "src/mc/remote/mc_protocol.h"
42 #include "src/mc/RegionSnapshot.hpp"
43 #include "src/mc/ObjectInformation.hpp"
44 #include "src/mc/Frame.hpp"
45 #include "src/mc/Variable.hpp"
47 using simgrid::mc::remote;
49 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_checkpoint, mc, "Logging specific to mc_checkpoint");
51 #define PROT_RWX (PROT_READ | PROT_WRITE | PROT_EXEC)
52 #define PROT_RW (PROT_READ | PROT_WRITE)
53 #define PROT_RX (PROT_READ | PROT_EXEC)
58 /************************************ Free functions **************************************/
59 /*****************************************************************************************/
61 /** @brief Restore a region from a snapshot
63 * @param region Target region
65 static void restore(mc_mem_region_t region)
67 switch(region->storage_type()) {
68 case simgrid::mc::StorageType::Flat:
69 mc_model_checker->process().write_bytes(region->flat_data().get(),
70 region->size(), region->permanent_address());
73 case simgrid::mc::StorageType::Chunked:
74 mc_region_restore_sparse(&mc_model_checker->process(), region);
77 case simgrid::mc::StorageType::Privatized:
78 for (auto& p : region->privatized_data())
82 default: // includes StorageType::NoData
83 xbt_die("Storage type not supported");
89 RegionSnapshot privatized_region(
90 RegionType region_type, void *start_addr, void* permanent_addr,
94 size_t process_count = MC_smpi_process_count();
96 // Read smpi_privatization_regions from MCed:
97 smpi_privatization_region_t remote_smpi_privatization_regions;
98 mc_model_checker->process().read_variable(
99 "smpi_privatization_regions",
100 &remote_smpi_privatization_regions, sizeof(remote_smpi_privatization_regions));
101 s_smpi_privatization_region_t privatization_regions[process_count];
102 mc_model_checker->process().read_bytes(
103 &privatization_regions, sizeof(privatization_regions),
104 remote(remote_smpi_privatization_regions));
106 std::vector<simgrid::mc::RegionSnapshot> data;
107 data.reserve(process_count);
108 for (size_t i = 0; i < process_count; i++)
109 data.push_back(simgrid::mc::region(region_type, start_addr,
110 privatization_regions[i].address, size));
112 simgrid::mc::RegionSnapshot region = simgrid::mc::RegionSnapshot(
113 region_type, start_addr, permanent_addr, size);
114 region.privatized_data(std::move(data));
120 void add_region(int index, simgrid::mc::Snapshot* snapshot,
121 simgrid::mc::RegionType type,
122 simgrid::mc::ObjectInformation* object_info,
123 void *start_addr, void* permanent_addr,
126 if (type == simgrid::mc::RegionType::Data)
127 xbt_assert(object_info, "Missing object info for object.");
128 else if (type == simgrid::mc::RegionType::Heap)
129 xbt_assert(not object_info, "Unexpected object info for heap region.");
131 simgrid::mc::RegionSnapshot region;
133 const bool privatization_aware = object_info
134 && mc_model_checker->process().privatized(*object_info);
135 if (privatization_aware && MC_smpi_process_count())
136 region = simgrid::mc::privatized_region(
137 type, start_addr, permanent_addr, size);
140 region = simgrid::mc::region(type, start_addr, permanent_addr, size);
142 region.object_info(object_info);
143 snapshot->snapshot_regions[index]
144 = std::unique_ptr<simgrid::mc::RegionSnapshot>(
145 new simgrid::mc::RegionSnapshot(std::move(region)));
148 static void get_memory_regions(simgrid::mc::RemoteClient* process, simgrid::mc::Snapshot* snapshot)
150 const size_t n = process->object_infos.size();
151 snapshot->snapshot_regions.resize(n + 1);
153 for (auto const& object_info : process->object_infos)
154 add_region(i++, snapshot, simgrid::mc::RegionType::Data,
156 object_info->start_rw, object_info->start_rw,
157 object_info->end_rw - object_info->start_rw);
159 xbt_mheap_t heap = process->get_heap();
160 void *start_heap = heap->base;
161 void *end_heap = heap->breakval;
163 add_region(n, snapshot, simgrid::mc::RegionType::Heap, nullptr,
164 start_heap, start_heap,
165 (char *) end_heap - (char *) start_heap);
166 snapshot->heap_bytes_used = mmalloc_get_bytes_used_remote(
168 process->get_malloc_info());
171 if (mc_model_checker->process().privatized() && MC_smpi_process_count())
172 // snapshot->privatization_index = smpi_loaded_page
173 mc_model_checker->process().read_variable(
174 "smpi_loaded_page", &snapshot->privatization_index,
175 sizeof(snapshot->privatization_index));
178 snapshot->privatization_index = simgrid::mc::ProcessIndexMissing;
181 /** \brief Fills the position of the segments (executable, read-only, read/write).
183 // TODO, use the ELF segment information for more robustness
184 void find_object_address(
185 std::vector<simgrid::xbt::VmMap> const& maps,
186 simgrid::mc::ObjectInformation* result)
188 std::string name = simgrid::xbt::Path(result->file_name).get_base_name();
190 for (size_t i = 0; i < maps.size(); ++i) {
191 simgrid::xbt::VmMap const& reg = maps[i];
192 if (maps[i].pathname.empty())
194 std::string map_basename = simgrid::xbt::Path(maps[i].pathname).get_base_name();
195 if (map_basename != name)
198 // This is the non-GNU_RELRO-part of the data segment:
199 if (reg.prot == PROT_RW) {
200 xbt_assert(not result->start_rw, "Multiple read-write segments for %s, not supported", maps[i].pathname.c_str());
201 result->start_rw = (char*) reg.start_addr;
202 result->end_rw = (char*) reg.end_addr;
204 // The next VMA might be end of the data segment:
205 if (i + 1 < maps.size()
206 && maps[i + 1].pathname.empty()
207 && maps[i + 1].prot == PROT_RW
208 && maps[i + 1].start_addr == reg.end_addr)
209 result->end_rw = (char*) maps[i + 1].end_addr;
212 // This is the text segment:
213 else if (reg.prot == PROT_RX) {
214 xbt_assert(not result->start_exec, "Multiple executable segments for %s, not supported",
215 maps[i].pathname.c_str());
216 result->start_exec = (char*) reg.start_addr;
217 result->end_exec = (char*) reg.end_addr;
219 // The next VMA might be end of the data segment:
220 if (i + 1 < maps.size()
221 && maps[i + 1].pathname.empty()
222 && maps[i + 1].prot == PROT_RW
223 && maps[i + 1].start_addr == reg.end_addr) {
224 result->start_rw = (char*) maps[i + 1].start_addr;
225 result->end_rw = (char*) maps[i + 1].end_addr;
229 // This is the GNU_RELRO-part of the data segment:
230 else if (reg.prot == PROT_READ) {
231 xbt_assert(not result->start_ro, "Multiple read only segments for %s, not supported", maps[i].pathname.c_str());
232 result->start_ro = (char*) reg.start_addr;
233 result->end_ro = (char*) reg.end_addr;
237 result->start = result->start_rw;
238 if ((const void*) result->start_ro < result->start)
239 result->start = result->start_ro;
240 if ((const void*) result->start_exec < result->start)
241 result->start = result->start_exec;
243 result->end = result->end_rw;
244 if (result->end_ro && (const void*) result->end_ro > result->end)
245 result->end = result->end_ro;
246 if (result->end_exec && (const void*) result->end_exec > result->end)
247 result->end = result->end_exec;
249 xbt_assert(result->start_exec || result->start_rw || result->start_ro);
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 scope Scope description
261 * \param ip Instruction pointer
262 * \return true if the variable is valid
264 static bool valid_variable(simgrid::mc::Variable* var,
265 simgrid::mc::Frame* scope,
268 // The variable is not yet valid:
269 if (scope->range.begin() + var->start_scope > (std::uint64_t) ip)
275 static void fill_local_variables_values(mc_stack_frame_t stack_frame, simgrid::mc::Frame* scope, int process_index,
276 std::vector<s_local_variable_t>& result)
278 simgrid::mc::RemoteClient* process = &mc_model_checker->process();
280 if (not scope || not scope->range.contain(stack_frame->ip))
283 for (simgrid::mc::Variable& current_variable : scope->variables) {
285 if (not valid_variable(¤t_variable, scope, (void*)stack_frame->ip))
289 // FIXME, get rid of `region_type`
290 if ((long) stack_frame->ip > (long) process->libsimgrid_info->start_exec)
295 s_local_variable_t new_var;
296 new_var.subprogram = stack_frame->frame;
297 new_var.ip = stack_frame->ip;
298 new_var.name = current_variable.name;
299 new_var.type = current_variable.type;
300 new_var.region = region_type;
301 new_var.address = nullptr;
303 if (current_variable.address != nullptr)
304 new_var.address = current_variable.address;
305 else if (not current_variable.location_list.empty()) {
306 simgrid::dwarf::Location location =
307 simgrid::dwarf::resolve(
308 current_variable.location_list,
309 current_variable.object_info,
310 &(stack_frame->unw_cursor),
311 (void *) stack_frame->frame_base,
312 &mc_model_checker->process(), process_index);
314 if (not location.in_memory())
315 xbt_die("Cannot handle non-address variable");
316 new_var.address = location.address();
319 xbt_die("No address");
321 result.push_back(std::move(new_var));
324 // Recursive processing of nested scopes:
325 for (simgrid::mc::Frame& nested_scope : scope->scopes)
326 fill_local_variables_values(
327 stack_frame, &nested_scope, process_index, result);
330 static std::vector<s_local_variable_t> get_local_variables_values(std::vector<s_mc_stack_frame_t>& stack_frames,
333 std::vector<s_local_variable_t> variables;
334 for (s_mc_stack_frame_t& stack_frame : stack_frames)
335 fill_local_variables_values(&stack_frame, stack_frame.frame, process_index, variables);
339 static std::vector<s_mc_stack_frame_t> unwind_stack_frames(simgrid::mc::UnwindContext* stack_context)
341 simgrid::mc::RemoteClient* process = &mc_model_checker->process();
342 std::vector<s_mc_stack_frame_t> result;
344 unw_cursor_t c = stack_context->cursor();
346 // TODO, check condition check (unw_init_local==0 means end of frame)
350 s_mc_stack_frame_t stack_frame;
352 stack_frame.unw_cursor = c;
357 unw_get_reg(&c, UNW_REG_IP, &ip);
358 unw_get_reg(&c, UNW_REG_SP, &sp);
363 // TODO, use real addresses in frame_t instead of fixing it here
365 simgrid::mc::Frame* frame = process->find_function(remote(ip));
366 stack_frame.frame = frame;
369 stack_frame.frame_name = frame->name;
370 stack_frame.frame_base =
371 (unw_word_t) frame->frame_base(c);
373 stack_frame.frame_base = 0;
374 stack_frame.frame_name = std::string();
377 result.push_back(std::move(stack_frame));
379 /* Stop before context switch with maestro */
380 if (frame != nullptr &&
381 frame->name == "smx_ctx_sysv_wrapper")
384 int ret = unw_step(&c);
386 xbt_die("Unexpected end of stack.");
388 xbt_die("Error while unwinding stack");
391 if (result.empty()) {
392 XBT_INFO("unw_init_local failed");
399 static std::vector<s_mc_snapshot_stack_t> take_snapshot_stacks(simgrid::mc::Snapshot* snapshot)
401 std::vector<s_mc_snapshot_stack_t> res;
403 for (auto const& stack : mc_model_checker->process().stack_areas()) {
404 s_mc_snapshot_stack_t st;
406 // Read the context from remote process:
407 unw_context_t context;
408 mc_model_checker->process().read_bytes(
409 &context, sizeof(context), remote(stack.context));
411 st.context.initialize(&mc_model_checker->process(), &context);
413 st.stack_frames = unwind_stack_frames(&st.context);
414 st.local_variables = get_local_variables_values(st.stack_frames, stack.process_index);
415 st.process_index = stack.process_index;
417 unw_word_t sp = st.stack_frames[0].sp;
419 res.push_back(std::move(st));
422 (char*) stack.address + stack.size - (char*) sp;
423 snapshot->stack_sizes.push_back(stack_size);
430 static void snapshot_handle_ignore(simgrid::mc::Snapshot* snapshot)
432 xbt_assert(snapshot->process());
435 for (auto const& region : mc_model_checker->process().ignored_regions()) {
436 s_mc_snapshot_ignored_data_t ignored_data;
437 ignored_data.start = (void*)region.addr;
438 ignored_data.data.resize(region.size);
439 // TODO, we should do this once per privatization segment:
440 snapshot->process()->read_bytes(
441 ignored_data.data.data(), region.size, remote(region.addr),
442 simgrid::mc::ProcessIndexDisabled);
443 snapshot->ignored_data.push_back(std::move(ignored_data));
447 for (auto const& region : mc_model_checker->process().ignored_regions())
448 snapshot->process()->clear_bytes(remote(region.addr), region.size);
452 static void snapshot_ignore_restore(simgrid::mc::Snapshot* snapshot)
454 for (auto const& ignored_data : snapshot->ignored_data)
455 snapshot->process()->write_bytes(
456 ignored_data.data.data(), ignored_data.data.size(),
457 remote(ignored_data.start));
460 static std::vector<s_fd_infos_t> get_current_fds(pid_t pid)
462 const size_t fd_dir_path_size = 20;
463 char fd_dir_path[fd_dir_path_size];
464 int res = snprintf(fd_dir_path, fd_dir_path_size,
465 "/proc/%lli/fd", (long long int) pid);
466 xbt_assert(res >= 0);
467 if ((size_t) res > fd_dir_path_size)
468 xbt_die("Unexpected buffer is too small for fd_dir_path");
470 DIR* fd_dir = opendir(fd_dir_path);
471 if (fd_dir == nullptr)
472 xbt_die("Cannot open directory '/proc/self/fd'\n");
474 std::vector<s_fd_infos_t> fds;
476 struct dirent* fd_number;
477 while ((fd_number = readdir(fd_dir))) {
479 int fd_value = xbt_str_parse_int(fd_number->d_name, "Found a non-numerical FD: %s. Freaking out!");
484 const size_t source_size = 25;
486 int res = snprintf(source, source_size, "/proc/%lli/fd/%s",
487 (long long int) pid, fd_number->d_name);
488 xbt_assert(res >= 0);
489 if ((size_t) res > source_size)
490 xbt_die("Unexpected buffer is too small for fd %s", fd_number->d_name);
492 const size_t link_size = 200;
494 res = readlink(source, link, link_size);
497 xbt_die("Could not read link for %s", source);
499 xbt_die("Buffer to small for link of %s", source);
504 if(smpi_is_privatization_file(link))
508 // This is (probably) the DIR* we are reading:
509 // TODO, read all the file entries at once and close the DIR.*
510 if(strcmp(fd_dir_path, link) == 0)
513 // We don't handle them.
514 // It does not mean we should silently ignore them however.
515 if (strncmp(link, "pipe:", std::strlen("pipe:")) == 0 || strncmp(link, "socket:", std::strlen("socket:")) == 0)
518 // If dot_output enabled, do not handle the corresponding file
519 if (dot_output != nullptr) {
520 std::string link_basename = simgrid::xbt::Path(link).get_base_name();
521 if (link_basename == _sg_mc_dot_output_file.get())
525 // This is probably a shared memory used by lttng-ust:
526 if(strncmp("/dev/shm/ust-shm-tmp-", link, std::strlen("/dev/shm/ust-shm-tmp-"))==0)
529 // Add an entry for this FD in the snapshot:
531 fd.filename = std::string(link);
532 fd.number = fd_value;
533 fd.flags = fcntl(fd_value, F_GETFL) | fcntl(fd_value, F_GETFD) ;
534 fd.current_position = lseek(fd_value, 0, SEEK_CUR);
535 fds.push_back(std::move(fd));
542 std::shared_ptr<simgrid::mc::Snapshot> take_snapshot(int num_state)
544 XBT_DEBUG("Taking snapshot %i", num_state);
546 simgrid::mc::RemoteClient* mc_process = &mc_model_checker->process();
548 std::shared_ptr<simgrid::mc::Snapshot> snapshot = std::make_shared<simgrid::mc::Snapshot>(mc_process, num_state);
550 for (auto const& p : mc_model_checker->process().actors())
551 snapshot->enabled_processes.insert(p.copy.getBuffer()->pid_);
553 snapshot_handle_ignore(snapshot.get());
555 if (_sg_mc_snapshot_fds)
556 snapshot->current_fds = get_current_fds(mc_model_checker->process().pid());
558 /* Save the std heap and the writable mapped pages of libsimgrid and binary */
559 get_memory_regions(mc_process, snapshot.get());
561 snapshot->to_ignore = mc_model_checker->process().ignored_heap();
563 if (_sg_mc_max_visited_states > 0 || not _sg_mc_property_file.get().empty()) {
564 snapshot->stacks = take_snapshot_stacks(snapshot.get());
566 snapshot->hash = simgrid::mc::hash(*snapshot);
572 snapshot_ignore_restore(snapshot.get());
577 void restore_snapshot_regions(simgrid::mc::Snapshot* snapshot)
579 for (std::unique_ptr<s_mc_mem_region_t> const& region : snapshot->snapshot_regions) {
580 // For privatized, variables we decided it was not necessary to take the snapshot:
582 restore(region.get());
586 if(snapshot->privatization_index >= 0) {
587 // Fix the privatization mmap:
588 s_mc_message_restore_t message{MC_MESSAGE_RESTORE, snapshot->privatization_index};
589 mc_model_checker->process().getChannel().send(message);
595 void restore_snapshot_fds(simgrid::mc::Snapshot* snapshot)
597 xbt_die("FD snapshot not implemented in client/server mode.");
599 for (auto const& fd : snapshot->current_fds) {
601 int new_fd = open(fd.filename.c_str(), fd.flags);
603 xbt_die("Could not reopen the file %s fo restoring the file descriptor", fd.filename.c_str());
604 if (new_fd != fd.number) {
605 dup2(new_fd, fd.number);
608 lseek(fd.number, fd.current_position, SEEK_SET);
612 void restore_snapshot(std::shared_ptr<simgrid::mc::Snapshot> snapshot)
614 XBT_DEBUG("Restore snapshot %i", snapshot->num_state);
615 restore_snapshot_regions(snapshot.get());
616 if (_sg_mc_snapshot_fds)
617 restore_snapshot_fds(snapshot.get());
618 snapshot_ignore_restore(snapshot.get());
619 mc_model_checker->process().clear_cache();