1 /* Copyright (c) 2008-2018. 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. */
18 #include "src/internal_config.h"
19 #include "src/mc/mc_private.hpp"
20 #include "src/smpi/include/private.hpp"
21 #include "xbt/file.hpp"
22 #include "xbt/mmalloc.h"
23 #include "xbt/module.h"
25 #include "src/xbt/mmalloc/mmprivate.h"
27 #include "src/simix/smx_private.hpp"
29 #include <libunwind.h>
32 #include "src/mc/mc_private.hpp"
35 #include "src/mc/mc_config.hpp"
36 #include "src/mc/mc_hash.hpp"
37 #include "src/mc/mc_mmu.hpp"
38 #include "src/mc/mc_smx.hpp"
39 #include "src/mc/mc_snapshot.hpp"
40 #include "src/mc/mc_unw.hpp"
41 #include "src/mc/remote/mc_protocol.h"
43 #include "src/mc/RegionSnapshot.hpp"
44 #include "src/mc/ObjectInformation.hpp"
45 #include "src/mc/Frame.hpp"
46 #include "src/mc/Variable.hpp"
48 using simgrid::mc::remote;
50 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_checkpoint, mc, "Logging specific to mc_checkpoint");
52 #define PROT_RWX (PROT_READ | PROT_WRITE | PROT_EXEC)
53 #define PROT_RW (PROT_READ | PROT_WRITE)
54 #define PROT_RX (PROT_READ | PROT_EXEC)
59 /************************************ Free functions **************************************/
60 /*****************************************************************************************/
62 /** @brief Restore a region from a snapshot
64 * @param region Target region
66 static void restore(mc_mem_region_t region)
68 switch(region->storage_type()) {
69 case simgrid::mc::StorageType::Flat:
70 mc_model_checker->process().write_bytes(region->flat_data().get(),
71 region->size(), region->permanent_address());
74 case simgrid::mc::StorageType::Chunked:
75 mc_region_restore_sparse(&mc_model_checker->process(), region);
78 case simgrid::mc::StorageType::Privatized:
79 for (auto& p : region->privatized_data())
83 default: // includes StorageType::NoData
84 xbt_die("Storage type not supported");
90 RegionSnapshot privatized_region(
91 RegionType region_type, void *start_addr, void* permanent_addr,
95 size_t process_count = MC_smpi_process_count();
97 // Read smpi_privatization_regions from MCed:
98 smpi_privatization_region_t remote_smpi_privatization_regions;
99 mc_model_checker->process().read_variable(
100 "smpi_privatization_regions",
101 &remote_smpi_privatization_regions, sizeof(remote_smpi_privatization_regions));
102 s_smpi_privatization_region_t privatization_regions[process_count];
103 mc_model_checker->process().read_bytes(
104 &privatization_regions, sizeof(privatization_regions),
105 remote(remote_smpi_privatization_regions));
107 std::vector<simgrid::mc::RegionSnapshot> data;
108 data.reserve(process_count);
109 for (size_t i = 0; i < process_count; i++)
110 data.push_back(simgrid::mc::region(region_type, start_addr,
111 privatization_regions[i].address, size));
113 simgrid::mc::RegionSnapshot region = simgrid::mc::RegionSnapshot(
114 region_type, start_addr, permanent_addr, size);
115 region.privatized_data(std::move(data));
121 void add_region(int index, simgrid::mc::Snapshot* snapshot,
122 simgrid::mc::RegionType type,
123 simgrid::mc::ObjectInformation* object_info,
124 void *start_addr, void* permanent_addr,
127 if (type == simgrid::mc::RegionType::Data)
128 xbt_assert(object_info, "Missing object info for object.");
129 else if (type == simgrid::mc::RegionType::Heap)
130 xbt_assert(not object_info, "Unexpected object info for heap region.");
132 simgrid::mc::RegionSnapshot region;
134 const bool privatization_aware = object_info
135 && mc_model_checker->process().privatized(*object_info);
136 if (privatization_aware && MC_smpi_process_count())
137 region = simgrid::mc::privatized_region(
138 type, start_addr, permanent_addr, size);
141 region = simgrid::mc::region(type, start_addr, permanent_addr, size);
143 region.object_info(object_info);
144 snapshot->snapshot_regions[index]
145 = std::unique_ptr<simgrid::mc::RegionSnapshot>(
146 new simgrid::mc::RegionSnapshot(std::move(region)));
149 static void get_memory_regions(simgrid::mc::RemoteClient* process, simgrid::mc::Snapshot* snapshot)
151 const size_t n = process->object_infos.size();
152 snapshot->snapshot_regions.resize(n + 1);
154 for (auto const& object_info : process->object_infos)
155 add_region(i++, snapshot, simgrid::mc::RegionType::Data,
157 object_info->start_rw, object_info->start_rw,
158 object_info->end_rw - object_info->start_rw);
160 xbt_mheap_t heap = process->get_heap();
161 void *start_heap = heap->base;
162 void *end_heap = heap->breakval;
164 add_region(n, snapshot, simgrid::mc::RegionType::Heap, nullptr,
165 start_heap, start_heap,
166 (char *) end_heap - (char *) start_heap);
167 snapshot->heap_bytes_used = mmalloc_get_bytes_used_remote(
169 process->get_malloc_info());
172 if (mc_model_checker->process().privatized() && MC_smpi_process_count())
173 // snapshot->privatization_index = smpi_loaded_page
174 mc_model_checker->process().read_variable(
175 "smpi_loaded_page", &snapshot->privatization_index,
176 sizeof(snapshot->privatization_index));
179 snapshot->privatization_index = simgrid::mc::ProcessIndexMissing;
182 /** \brief Fills the position of the segments (executable, read-only, read/write).
184 // TODO, use the ELF segment information for more robustness
185 void find_object_address(
186 std::vector<simgrid::xbt::VmMap> const& maps,
187 simgrid::mc::ObjectInformation* result)
189 std::string name = simgrid::xbt::Path(result->file_name).get_base_name();
191 for (size_t i = 0; i < maps.size(); ++i) {
192 simgrid::xbt::VmMap const& reg = maps[i];
193 if (maps[i].pathname.empty())
195 std::string map_basename = simgrid::xbt::Path(maps[i].pathname).get_base_name();
196 if (map_basename != name)
199 // This is the non-GNU_RELRO-part of the data segment:
200 if (reg.prot == PROT_RW) {
201 xbt_assert(not result->start_rw, "Multiple read-write segments for %s, not supported", maps[i].pathname.c_str());
202 result->start_rw = (char*) reg.start_addr;
203 result->end_rw = (char*) reg.end_addr;
205 // The next VMA might be end of the data segment:
206 if (i + 1 < maps.size()
207 && maps[i + 1].pathname.empty()
208 && maps[i + 1].prot == PROT_RW
209 && maps[i + 1].start_addr == reg.end_addr)
210 result->end_rw = (char*) maps[i + 1].end_addr;
213 // This is the text segment:
214 else if (reg.prot == PROT_RX) {
215 xbt_assert(not result->start_exec, "Multiple executable segments for %s, not supported",
216 maps[i].pathname.c_str());
217 result->start_exec = (char*) reg.start_addr;
218 result->end_exec = (char*) reg.end_addr;
220 // The next VMA might be end of the data segment:
221 if (i + 1 < maps.size()
222 && maps[i + 1].pathname.empty()
223 && maps[i + 1].prot == PROT_RW
224 && maps[i + 1].start_addr == reg.end_addr) {
225 result->start_rw = (char*) maps[i + 1].start_addr;
226 result->end_rw = (char*) maps[i + 1].end_addr;
230 // This is the GNU_RELRO-part of the data segment:
231 else if (reg.prot == PROT_READ) {
232 xbt_assert(not result->start_ro, "Multiple read only segments for %s, not supported", maps[i].pathname.c_str());
233 result->start_ro = (char*) reg.start_addr;
234 result->end_ro = (char*) reg.end_addr;
238 result->start = result->start_rw;
239 if ((const void*) result->start_ro < result->start)
240 result->start = result->start_ro;
241 if ((const void*) result->start_exec < result->start)
242 result->start = result->start_exec;
244 result->end = result->end_rw;
245 if (result->end_ro && (const void*) result->end_ro > result->end)
246 result->end = result->end_ro;
247 if (result->end_exec && (const void*) result->end_exec > result->end)
248 result->end = result->end_exec;
250 xbt_assert(result->start_exec || result->start_rw || result->start_ro);
253 /************************************* Take Snapshot ************************************/
254 /****************************************************************************************/
256 /** \brief Checks whether the variable is in scope for a given IP.
258 * A variable may be defined only from a given value of IP.
260 * \param var Variable description
261 * \param scope Scope description
262 * \param ip Instruction pointer
263 * \return true if the variable is valid
265 static bool valid_variable(simgrid::mc::Variable* var,
266 simgrid::mc::Frame* scope,
269 // The variable is not yet valid:
270 if (scope->range.begin() + var->start_scope > (std::uint64_t) ip)
276 static void fill_local_variables_values(mc_stack_frame_t stack_frame, simgrid::mc::Frame* scope, int process_index,
277 std::vector<s_local_variable_t>& result)
279 simgrid::mc::RemoteClient* process = &mc_model_checker->process();
281 if (not scope || not scope->range.contain(stack_frame->ip))
284 for (simgrid::mc::Variable& current_variable : scope->variables) {
286 if (not valid_variable(¤t_variable, scope, (void*)stack_frame->ip))
290 // FIXME, get rid of `region_type`
291 if ((long) stack_frame->ip > (long) process->libsimgrid_info->start_exec)
296 s_local_variable_t new_var;
297 new_var.subprogram = stack_frame->frame;
298 new_var.ip = stack_frame->ip;
299 new_var.name = current_variable.name;
300 new_var.type = current_variable.type;
301 new_var.region = region_type;
302 new_var.address = nullptr;
304 if (current_variable.address != nullptr)
305 new_var.address = current_variable.address;
306 else if (not current_variable.location_list.empty()) {
307 simgrid::dwarf::Location location =
308 simgrid::dwarf::resolve(
309 current_variable.location_list,
310 current_variable.object_info,
311 &(stack_frame->unw_cursor),
312 (void *) stack_frame->frame_base,
313 &mc_model_checker->process(), process_index);
315 if (not location.in_memory())
316 xbt_die("Cannot handle non-address variable");
317 new_var.address = location.address();
320 xbt_die("No address");
322 result.push_back(std::move(new_var));
325 // Recursive processing of nested scopes:
326 for (simgrid::mc::Frame& nested_scope : scope->scopes)
327 fill_local_variables_values(
328 stack_frame, &nested_scope, process_index, result);
331 static std::vector<s_local_variable_t> get_local_variables_values(std::vector<s_mc_stack_frame_t>& stack_frames,
334 std::vector<s_local_variable_t> variables;
335 for (s_mc_stack_frame_t& stack_frame : stack_frames)
336 fill_local_variables_values(&stack_frame, stack_frame.frame, process_index, variables);
340 static std::vector<s_mc_stack_frame_t> unwind_stack_frames(simgrid::mc::UnwindContext* stack_context)
342 simgrid::mc::RemoteClient* process = &mc_model_checker->process();
343 std::vector<s_mc_stack_frame_t> result;
345 unw_cursor_t c = stack_context->cursor();
347 // TODO, check condition check (unw_init_local==0 means end of frame)
351 s_mc_stack_frame_t stack_frame;
353 stack_frame.unw_cursor = c;
358 unw_get_reg(&c, UNW_REG_IP, &ip);
359 unw_get_reg(&c, UNW_REG_SP, &sp);
364 // TODO, use real addresses in frame_t instead of fixing it here
366 simgrid::mc::Frame* frame = process->find_function(remote(ip));
367 stack_frame.frame = frame;
370 stack_frame.frame_name = frame->name;
371 stack_frame.frame_base =
372 (unw_word_t) frame->frame_base(c);
374 stack_frame.frame_base = 0;
375 stack_frame.frame_name = std::string();
378 result.push_back(std::move(stack_frame));
380 /* Stop before context switch with maestro */
381 if (frame != nullptr &&
382 frame->name == "smx_ctx_sysv_wrapper")
385 int ret = unw_step(&c);
387 xbt_die("Unexpected end of stack.");
389 xbt_die("Error while unwinding stack");
392 if (result.empty()) {
393 XBT_INFO("unw_init_local failed");
400 static std::vector<s_mc_snapshot_stack_t> take_snapshot_stacks(simgrid::mc::Snapshot* snapshot)
402 std::vector<s_mc_snapshot_stack_t> res;
404 for (auto const& stack : mc_model_checker->process().stack_areas()) {
405 s_mc_snapshot_stack_t st;
407 // Read the context from remote process:
408 unw_context_t context;
409 mc_model_checker->process().read_bytes(
410 &context, sizeof(context), remote(stack.context));
412 st.context.initialize(&mc_model_checker->process(), &context);
414 st.stack_frames = unwind_stack_frames(&st.context);
415 st.local_variables = get_local_variables_values(st.stack_frames, stack.process_index);
416 st.process_index = stack.process_index;
418 unw_word_t sp = st.stack_frames[0].sp;
420 res.push_back(std::move(st));
423 (char*) stack.address + stack.size - (char*) sp;
424 snapshot->stack_sizes.push_back(stack_size);
431 static void snapshot_handle_ignore(simgrid::mc::Snapshot* snapshot)
433 xbt_assert(snapshot->process());
436 for (auto const& region : mc_model_checker->process().ignored_regions()) {
437 s_mc_snapshot_ignored_data_t ignored_data;
438 ignored_data.start = (void*)region.addr;
439 ignored_data.data.resize(region.size);
440 // TODO, we should do this once per privatization segment:
441 snapshot->process()->read_bytes(
442 ignored_data.data.data(), region.size, remote(region.addr),
443 simgrid::mc::ProcessIndexDisabled);
444 snapshot->ignored_data.push_back(std::move(ignored_data));
448 for (auto const& region : mc_model_checker->process().ignored_regions())
449 snapshot->process()->clear_bytes(remote(region.addr), region.size);
453 static void snapshot_ignore_restore(simgrid::mc::Snapshot* snapshot)
455 for (auto const& ignored_data : snapshot->ignored_data)
456 snapshot->process()->write_bytes(
457 ignored_data.data.data(), ignored_data.data.size(),
458 remote(ignored_data.start));
461 static std::vector<s_fd_infos_t> get_current_fds(pid_t pid)
463 const size_t fd_dir_path_size = 20;
464 char fd_dir_path[fd_dir_path_size];
465 int res = snprintf(fd_dir_path, fd_dir_path_size,
466 "/proc/%lli/fd", (long long int) pid);
467 xbt_assert(res >= 0);
468 if ((size_t) res > fd_dir_path_size)
469 xbt_die("Unexpected buffer is too small for fd_dir_path");
471 DIR* fd_dir = opendir(fd_dir_path);
472 if (fd_dir == nullptr)
473 xbt_die("Cannot open directory '/proc/self/fd'\n");
475 std::vector<s_fd_infos_t> fds;
477 struct dirent* fd_number;
478 while ((fd_number = readdir(fd_dir))) {
480 int fd_value = xbt_str_parse_int(fd_number->d_name, "Found a non-numerical FD: %s. Freaking out!");
485 const size_t source_size = 25;
487 int res = snprintf(source, source_size, "/proc/%lli/fd/%s",
488 (long long int) pid, fd_number->d_name);
489 xbt_assert(res >= 0);
490 if ((size_t) res > source_size)
491 xbt_die("Unexpected buffer is too small for fd %s", fd_number->d_name);
493 const size_t link_size = 200;
495 res = readlink(source, link, link_size);
498 xbt_die("Could not read link for %s", source);
500 xbt_die("Buffer to small for link of %s", source);
505 if(smpi_is_privatization_file(link))
509 // This is (probably) the DIR* we are reading:
510 // TODO, read all the file entries at once and close the DIR.*
511 if(strcmp(fd_dir_path, link) == 0)
514 // We don't handle them.
515 // It does not mean we should silently ignore them however.
516 if (strncmp(link, "pipe:", std::strlen("pipe:")) == 0 || strncmp(link, "socket:", std::strlen("socket:")) == 0)
519 // If dot_output enabled, do not handle the corresponding file
520 if (dot_output != nullptr) {
521 std::string link_basename = simgrid::xbt::Path(link).get_base_name();
522 if (link_basename == _sg_mc_dot_output_file.get())
526 // This is probably a shared memory used by lttng-ust:
527 if(strncmp("/dev/shm/ust-shm-tmp-", link, std::strlen("/dev/shm/ust-shm-tmp-"))==0)
530 // Add an entry for this FD in the snapshot:
532 fd.filename = std::string(link);
533 fd.number = fd_value;
534 fd.flags = fcntl(fd_value, F_GETFL) | fcntl(fd_value, F_GETFD) ;
535 fd.current_position = lseek(fd_value, 0, SEEK_CUR);
536 fds.push_back(std::move(fd));
543 std::shared_ptr<simgrid::mc::Snapshot> take_snapshot(int num_state)
545 XBT_DEBUG("Taking snapshot %i", num_state);
547 simgrid::mc::RemoteClient* mc_process = &mc_model_checker->process();
549 std::shared_ptr<simgrid::mc::Snapshot> snapshot = std::make_shared<simgrid::mc::Snapshot>(mc_process, num_state);
551 for (auto const& p : mc_model_checker->process().actors())
552 snapshot->enabled_processes.insert(p.copy.getBuffer()->pid);
554 snapshot_handle_ignore(snapshot.get());
556 if (_sg_mc_snapshot_fds)
557 snapshot->current_fds = get_current_fds(mc_model_checker->process().pid());
559 /* Save the std heap and the writable mapped pages of libsimgrid and binary */
560 get_memory_regions(mc_process, snapshot.get());
562 snapshot->to_ignore = mc_model_checker->process().ignored_heap();
564 if (_sg_mc_max_visited_states > 0 || not _sg_mc_property_file.get().empty()) {
565 snapshot->stacks = take_snapshot_stacks(snapshot.get());
567 snapshot->hash = simgrid::mc::hash(*snapshot);
573 snapshot_ignore_restore(snapshot.get());
578 void restore_snapshot_regions(simgrid::mc::Snapshot* snapshot)
580 for (std::unique_ptr<s_mc_mem_region_t> const& region : snapshot->snapshot_regions) {
581 // For privatized, variables we decided it was not necessary to take the snapshot:
583 restore(region.get());
587 if(snapshot->privatization_index >= 0) {
588 // Fix the privatization mmap:
589 s_mc_message_restore_t message{MC_MESSAGE_RESTORE, snapshot->privatization_index};
590 mc_model_checker->process().getChannel().send(message);
596 void restore_snapshot_fds(simgrid::mc::Snapshot* snapshot)
598 xbt_die("FD snapshot not implemented in client/server mode.");
600 for (auto const& fd : snapshot->current_fds) {
602 int new_fd = open(fd.filename.c_str(), fd.flags);
604 xbt_die("Could not reopen the file %s fo restoring the file descriptor", fd.filename.c_str());
605 if (new_fd != fd.number) {
606 dup2(new_fd, fd.number);
609 lseek(fd.number, fd.current_position, SEEK_SET);
613 void restore_snapshot(std::shared_ptr<simgrid::mc::Snapshot> snapshot)
615 XBT_DEBUG("Restore snapshot %i", snapshot->num_state);
616 restore_snapshot_regions(snapshot.get());
617 if (_sg_mc_snapshot_fds)
618 restore_snapshot_fds(snapshot.get());
619 snapshot_ignore_restore(snapshot.get());
620 mc_model_checker->process().clear_cache();
629 #define BOOST_TEST_MODULE checkpoint
630 #define BOOST_TEST_DYN_LINK
631 #include <boost/test/unit_test.hpp>
632 #include <stdio.h> // perror()
633 #include <errno.h> // perror()
634 #include <stdlib.h> // exit()
636 #include <functional>
637 #include <sys/mman.h>
643 void add_content(void*, int, size_t);
644 size_t make_hash(char*);
646 int add_region_BOOST()
649 RemoteClient* this_process = new RemoteClient(getpid(), -1);
650 /* read /proc/getpid()/maps into "this_process->memory_map", etc. */
651 this_process->init();
652 simgrid::mc::Snapshot* snapshot = new simgrid::mc::Snapshot(this_process, 0); // first ckpt
653 simgrid::mc::RegionType type = simgrid::mc::RegionType::Unknown;
654 std::size_t PAGESIZE = 4096;
655 std::size_t region_num = 10;
656 std::size_t size = PAGESIZE * region_num;
658 int prot = PROT_READ|PROT_WRITE;
659 int flags = MAP_PRIVATE|MAP_ANONYMOUS;
660 if (mmap(addr, size, prot, flags, -1, 0) == (void *)-1) {
664 size_t hashes[region_num];
666 for(int i=0; i<region_num; ++i) {
667 source = (char*)addr + i*PAGESIZE;
668 hashes[i] = add_content(source, i, PAGESIZE);
669 add_region(i, snaphot, type, NULL, source, source, size);
672 BOOST_TEST((snapshot->snapshot_regions).size == 10, "snapshot_regions size");
673 /* test retrieving regions from a snapshot*/
674 for (int i=0; i<region_num; ++) {
675 // TODO: hashes of even regions should be equal
676 // and hashes of odd regions should also be equal.
679 /* release memory before returning */
680 if (munmap(addr, size) == -1) {
684 return 1; // just for testing
687 BOOST_AUTO_TEST_SUITE(checkpoint)
688 BOOST_AUTO_TEST_CASE(add_region_test) {
689 BOOST_TEST(add_region_BOOST() == 1);
691 BOOST_AUTO_TEST_SUITE_END()
693 void add_content(void* addr, int index, size_t size) {
694 memset(addr, index%2+1, size);
695 memset(addr+size-1, 0, 1); // NULL-termination
698 st::hash<std::string> str_hash;
699 void make_hash(char* addr) {
700 return str_hash(string(addr));
703 #endif // SIMGRID_TEST