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. */
10 #include <sys/socket.h>
11 #include <sys/ptrace.h>
14 #include <system_error>
16 #include "xbt/automaton.h"
17 #include "xbt/automaton.hpp"
19 #include "xbt/system_error.hpp"
21 #include "simgrid/sg_config.hpp"
23 #include "src/mc/ModelChecker.hpp"
24 #include "src/mc/Transition.hpp"
25 #include "src/mc/checker/Checker.hpp"
26 #include "src/mc/mc_exit.hpp"
27 #include "src/mc/mc_private.hpp"
28 #include "src/mc/mc_record.hpp"
29 #include "src/mc/remote/RemoteClient.hpp"
30 #include "src/mc/remote/mc_protocol.h"
31 #include "src/mc/sosp/PageStore.hpp"
33 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_ModelChecker, mc, "ModelChecker");
35 ::simgrid::mc::ModelChecker* mc_model_checker = nullptr;
37 using simgrid::mc::remote;
40 # define WAITPID_CHECKED_FLAGS __WALL
42 # define WAITPID_CHECKED_FLAGS 0
48 ModelChecker::ModelChecker(std::unique_ptr<RemoteClient> process)
50 , socket_event_(nullptr)
51 , signal_event_(nullptr)
53 , process_(std::move(process))
54 , parent_snapshot_(nullptr)
59 ModelChecker::~ModelChecker() {
60 if (socket_event_ != nullptr)
61 event_free(socket_event_);
62 if (signal_event_ != nullptr)
63 event_free(signal_event_);
65 event_base_free(base_);
68 void ModelChecker::start()
70 const pid_t pid = process_->pid();
72 base_ = event_base_new();
73 event_callback_fn event_callback = [](evutil_socket_t fd, short events, void *arg)
75 ((ModelChecker *)arg)->handle_events(fd, events);
77 socket_event_ = event_new(base_,
78 process_->getChannel().getSocket(),
80 event_callback, this);
81 event_add(socket_event_, NULL);
82 signal_event_ = event_new(base_,
85 event_callback, this);
86 event_add(signal_event_, NULL);
88 XBT_DEBUG("Waiting for the model-checked process");
91 // The model-checked process SIGSTOP itself to signal it's ready:
92 pid_t res = waitpid(pid, &status, WAITPID_CHECKED_FLAGS);
93 if (res < 0 || not WIFSTOPPED(status) || WSTOPSIG(status) != SIGSTOP)
94 xbt_die("Could not wait model-checked process");
98 if (not _sg_mc_dot_output_file.get().empty())
104 ptrace(PTRACE_SETOPTIONS, pid, nullptr, PTRACE_O_TRACEEXIT);
105 ptrace(PTRACE_CONT, pid, 0, 0);
107 ptrace(PT_CONTINUE, pid, (caddr_t)1, 0);
109 # error "no ptrace equivalent coded for this platform"
113 static const std::pair<const char*, const char*> ignored_local_variables[] = {
114 std::pair<const char*, const char*>{ "e", "*" },
115 std::pair<const char*, const char*>{ "__ex_cleanup", "*" },
116 std::pair<const char*, const char*>{ "__ex_mctx_en", "*" },
117 std::pair<const char*, const char*>{ "__ex_mctx_me", "*" },
118 std::pair<const char*, const char*>{ "__xbt_ex_ctx_ptr", "*" },
119 std::pair<const char*, const char*>{ "_log_ev", "*" },
120 std::pair<const char*, const char*>{ "_throw_ctx", "*" },
121 std::pair<const char*, const char*>{ "ctx", "*" },
123 std::pair<const char*, const char*>{ "self", "simcall_BODY_mc_snapshot" },
124 std::pair<const char*, const char*>{ "next_context", "smx_ctx_sysv_suspend_serial" },
125 std::pair<const char*, const char*>{ "i", "smx_ctx_sysv_suspend_serial" },
127 /* Ignore local variable about time used for tracing */
128 std::pair<const char*, const char*>{ "start_time", "*" },
131 void ModelChecker::setup_ignore()
133 RemoteClient& process = this->process();
134 for (std::pair<const char*, const char*> const& var :
135 ignored_local_variables)
136 process.ignore_local_variable(var.first, var.second);
138 /* Static variable used for tracing */
139 process.ignore_global_variable("counter");
142 void ModelChecker::shutdown()
144 XBT_DEBUG("Shuting down model-checker");
146 simgrid::mc::RemoteClient* process = &this->process();
147 if (process->running()) {
148 XBT_DEBUG("Killing process");
149 kill(process->pid(), SIGKILL);
150 process->terminate();
154 void ModelChecker::resume(simgrid::mc::RemoteClient& process)
156 int res = process.getChannel().send(MC_MESSAGE_CONTINUE);
158 throw simgrid::xbt::errno_error();
159 process.clear_cache();
162 static void MC_report_crash(int status)
164 XBT_INFO("**************************");
165 XBT_INFO("** CRASH IN THE PROGRAM **");
166 XBT_INFO("**************************");
167 if (WIFSIGNALED(status))
168 XBT_INFO("From signal: %s", strsignal(WTERMSIG(status)));
169 else if (WIFEXITED(status))
170 XBT_INFO("From exit: %i", WEXITSTATUS(status));
171 if (WCOREDUMP(status))
172 XBT_INFO("A core dump was generated by the system.");
174 XBT_INFO("No core dump was generated by the system.");
175 XBT_INFO("Counter-example execution trace:");
176 simgrid::mc::dumpRecordPath();
177 for (auto const& s : mc_model_checker->getChecker()->getTextualTrace())
178 XBT_INFO("%s", s.c_str());
179 simgrid::mc::session->logState();
180 XBT_INFO("Stack trace:");
181 mc_model_checker->process().dumpStack();
184 static void MC_report_assertion_error()
186 XBT_INFO("**************************");
187 XBT_INFO("*** PROPERTY NOT VALID ***");
188 XBT_INFO("**************************");
189 XBT_INFO("Counter-example execution trace:");
190 simgrid::mc::dumpRecordPath();
191 for (auto const& s : mc_model_checker->getChecker()->getTextualTrace())
192 XBT_INFO("%s", s.c_str());
193 simgrid::mc::session->logState();
196 bool ModelChecker::handle_message(char* buffer, ssize_t size)
198 s_mc_message_t base_message;
199 if (size < (ssize_t) sizeof(base_message))
200 xbt_die("Broken message");
201 memcpy(&base_message, buffer, sizeof(base_message));
203 switch(base_message.type) {
205 case MC_MESSAGE_IGNORE_HEAP:
207 s_mc_message_ignore_heap_t message;
208 if (size != sizeof(message))
209 xbt_die("Broken messsage");
210 memcpy(&message, buffer, sizeof(message));
212 IgnoredHeapRegion region;
213 region.block = message.block;
214 region.fragment = message.fragment;
215 region.address = message.address;
216 region.size = message.size;
217 process().ignore_heap(region);
221 case MC_MESSAGE_UNIGNORE_HEAP:
223 s_mc_message_ignore_memory_t message;
224 if (size != sizeof(message))
225 xbt_die("Broken messsage");
226 memcpy(&message, buffer, sizeof(message));
227 process().unignore_heap((void*)(std::uintptr_t)message.addr, message.size);
231 case MC_MESSAGE_IGNORE_MEMORY:
233 s_mc_message_ignore_memory_t message;
234 if (size != sizeof(message))
235 xbt_die("Broken messsage");
236 memcpy(&message, buffer, sizeof(message));
237 this->process().ignore_region(message.addr, message.size);
241 case MC_MESSAGE_STACK_REGION:
243 s_mc_message_stack_region_t message;
244 if (size != sizeof(message))
245 xbt_die("Broken messsage");
246 memcpy(&message, buffer, sizeof(message));
247 this->process().stack_areas().push_back(message.stack_region);
251 case MC_MESSAGE_REGISTER_SYMBOL:
253 s_mc_message_register_symbol_t message;
254 if (size != sizeof(message))
255 xbt_die("Broken message");
256 memcpy(&message, buffer, sizeof(message));
257 if (message.callback)
258 xbt_die("Support for client-side function proposition is not implemented.");
259 XBT_DEBUG("Received symbol: %s", message.name);
261 if (simgrid::mc::property_automaton == nullptr)
262 simgrid::mc::property_automaton = xbt_automaton_new();
264 simgrid::mc::RemoteClient* process = &this->process();
265 simgrid::mc::RemotePtr<int> address = simgrid::mc::remote((int*)message.data);
266 simgrid::xbt::add_proposition(simgrid::mc::property_automaton, message.name,
267 [process, address]() { return process->read(address); });
272 case MC_MESSAGE_WAITING:
275 case MC_MESSAGE_ASSERTION_FAILED:
276 MC_report_assertion_error();
277 this->exit(SIMGRID_MC_EXIT_SAFETY);
281 xbt_die("Unexpected message from model-checked application");
287 /** Terminate the model-checker application */
288 void ModelChecker::exit(int status)
290 // TODO, terminate the model checker politely instead of exiting rudely
291 if (process().running())
292 kill(process().pid(), SIGKILL);
296 void ModelChecker::handle_events(int fd, short events)
298 if (events == EV_READ) {
299 char buffer[MC_MESSAGE_LENGTH];
300 ssize_t size = process_->getChannel().receive(buffer, sizeof(buffer), false);
301 if (size == -1 && errno != EAGAIN)
302 throw simgrid::xbt::errno_error();
303 if (not handle_message(buffer, size)) {
304 event_base_loopbreak(base_);
307 else if (events == EV_SIGNAL) {
311 xbt_die("Unexpected event");
315 void ModelChecker::loop()
317 if (this->process().running())
318 event_base_dispatch(base_);
321 void ModelChecker::handle_waitpid()
323 XBT_DEBUG("Check for wait event");
326 while ((pid = waitpid(-1, &status, WNOHANG)) != 0) {
328 if (errno == ECHILD) {
330 if (this->process().running())
331 xbt_die("Inconsistent state");
335 XBT_ERROR("Could not wait for pid");
336 throw simgrid::xbt::errno_error();
340 if (pid == this->process().pid()) {
342 // From PTRACE_O_TRACEEXIT:
344 if (status>>8 == (SIGTRAP | (PTRACE_EVENT_EXIT<<8))) {
345 if (ptrace(PTRACE_GETEVENTMSG, this->process().pid(), 0, &status) == -1)
346 xbt_die("Could not get exit status");
347 if (WIFSIGNALED(status)) {
348 MC_report_crash(status);
349 mc_model_checker->exit(SIMGRID_MC_EXIT_PROGRAM_CRASH);
354 // We don't care about signals, just reinject them:
355 if (WIFSTOPPED(status)) {
356 XBT_DEBUG("Stopped with signal %i", (int) WSTOPSIG(status));
359 ptrace(PTRACE_CONT, this->process().pid(), 0, WSTOPSIG(status));
361 ptrace(PT_CONTINUE, this->process().pid(), (caddr_t)1, WSTOPSIG(status));
364 xbt_die("Could not PTRACE_CONT");
367 else if (WIFEXITED(status) || WIFSIGNALED(status)) {
368 XBT_DEBUG("Child process is over");
369 this->process().terminate();
375 void ModelChecker::on_signal(int signo)
377 if (signo == SIGCHLD)
378 this->handle_waitpid();
381 void ModelChecker::wait_for_requests()
383 this->resume(process());
384 if (this->process().running())
385 event_base_dispatch(base_);
388 void ModelChecker::handle_simcall(Transition const& transition)
390 s_mc_message_simcall_handle_t m;
391 memset(&m, 0, sizeof(m));
392 m.type = MC_MESSAGE_SIMCALL_HANDLE;
393 m.pid = transition.pid;
394 m.value = transition.argument;
395 this->process_->getChannel().send(m);
396 this->process_->clear_cache();
397 if (this->process_->running())
398 event_base_dispatch(base_);
401 bool ModelChecker::checkDeadlock()
404 if ((res = this->process().getChannel().send(MC_MESSAGE_DEADLOCK_CHECK)))
405 xbt_die("Could not check deadlock state");
406 s_mc_message_int_t message;
407 ssize_t s = mc_model_checker->process().getChannel().receive(message);
409 xbt_die("Could not receive message");
410 if (s != sizeof(message) || message.type != MC_MESSAGE_DEADLOCK_CHECK_REPLY)
411 xbt_die("Received unexpected message %s (%i, size=%i) "
412 "expected MC_MESSAGE_DEADLOCK_CHECK_REPLY (%i, size=%i)",
413 MC_message_type_name(message.type), (int) message.type, (int) s,
414 (int) MC_MESSAGE_DEADLOCK_CHECK_REPLY, (int) sizeof(message)
416 return message.value != 0;