1 /* Copyright (c) 2008-2019. 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. */
6 #include "src/mc/ModelChecker.hpp"
7 #include "src/mc/Session.hpp"
8 #include "src/mc/Transition.hpp"
9 #include "src/mc/checker/Checker.hpp"
10 #include "src/mc/mc_config.hpp"
11 #include "src/mc/mc_exit.hpp"
12 #include "src/mc/mc_private.hpp"
13 #include "src/mc/remote/RemoteClient.hpp"
14 #include "xbt/automaton.hpp"
15 #include "xbt/system_error.hpp"
17 #include <sys/ptrace.h>
20 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_ModelChecker, mc, "ModelChecker");
22 ::simgrid::mc::ModelChecker* mc_model_checker = nullptr;
24 using simgrid::mc::remote;
27 # define WAITPID_CHECKED_FLAGS __WALL
29 # define WAITPID_CHECKED_FLAGS 0
35 ModelChecker::ModelChecker(std::unique_ptr<RemoteClient> process)
37 , socket_event_(nullptr)
38 , signal_event_(nullptr)
40 , process_(std::move(process))
45 ModelChecker::~ModelChecker() {
46 if (socket_event_ != nullptr)
47 event_free(socket_event_);
48 if (signal_event_ != nullptr)
49 event_free(signal_event_);
51 event_base_free(base_);
54 void ModelChecker::start()
56 base_ = event_base_new();
57 event_callback_fn event_callback = [](evutil_socket_t fd, short events, void *arg)
59 ((ModelChecker *)arg)->handle_events(fd, events);
61 socket_event_ = event_new(base_, process_->get_channel().get_socket(), EV_READ | EV_PERSIST, event_callback, this);
62 event_add(socket_event_, NULL);
63 signal_event_ = event_new(base_,
66 event_callback, this);
67 event_add(signal_event_, NULL);
69 XBT_DEBUG("Waiting for the model-checked process");
72 // The model-checked process SIGSTOP itself to signal it's ready:
73 const pid_t pid = process_->pid();
75 pid_t res = waitpid(pid, &status, WAITPID_CHECKED_FLAGS);
76 if (res < 0 || not WIFSTOPPED(status) || WSTOPSIG(status) != SIGSTOP)
77 xbt_die("Could not wait model-checked process");
81 if (not _sg_mc_dot_output_file.get().empty())
87 ptrace(PTRACE_SETOPTIONS, pid, nullptr, PTRACE_O_TRACEEXIT);
88 ptrace(PTRACE_CONT, pid, 0, 0);
90 ptrace(PT_CONTINUE, pid, (caddr_t)1, 0);
92 # error "no ptrace equivalent coded for this platform"
96 static const std::pair<const char*, const char*> ignored_local_variables[] = {
97 std::pair<const char*, const char*>{ "e", "*" },
98 std::pair<const char*, const char*>{ "_log_ev", "*" },
100 /* Ignore local variable about time used for tracing */
101 std::pair<const char*, const char*>{ "start_time", "*" },
104 void ModelChecker::setup_ignore()
106 RemoteClient& process = this->process();
107 for (std::pair<const char*, const char*> const& var :
108 ignored_local_variables)
109 process.ignore_local_variable(var.first, var.second);
111 /* Static variable used for tracing */
112 process.ignore_global_variable("counter");
115 void ModelChecker::shutdown()
117 XBT_DEBUG("Shuting down model-checker");
119 simgrid::mc::RemoteClient* process = &this->process();
120 if (process->running()) {
121 XBT_DEBUG("Killing process");
122 kill(process->pid(), SIGKILL);
123 process->terminate();
127 void ModelChecker::resume(simgrid::mc::RemoteClient& process)
129 int res = process.get_channel().send(MC_MESSAGE_CONTINUE);
131 throw simgrid::xbt::errno_error();
132 process.clear_cache();
135 static void MC_report_crash(int status)
137 XBT_INFO("**************************");
138 XBT_INFO("** CRASH IN THE PROGRAM **");
139 XBT_INFO("**************************");
140 if (WIFSIGNALED(status))
141 XBT_INFO("From signal: %s", strsignal(WTERMSIG(status)));
142 else if (WIFEXITED(status))
143 XBT_INFO("From exit: %i", WEXITSTATUS(status));
144 if (WCOREDUMP(status))
145 XBT_INFO("A core dump was generated by the system.");
147 XBT_INFO("No core dump was generated by the system.");
148 XBT_INFO("Counter-example execution trace:");
149 for (auto const& s : mc_model_checker->getChecker()->get_textual_trace())
150 XBT_INFO(" %s", s.c_str());
151 simgrid::mc::dumpRecordPath();
152 simgrid::mc::session->log_state();
153 if (xbt_log_no_loc) {
154 XBT_INFO("Stack trace not displayed because you passed --log=no_loc");
156 XBT_INFO("Stack trace:");
157 mc_model_checker->process().dump_stack();
161 static void MC_report_assertion_error()
163 XBT_INFO("**************************");
164 XBT_INFO("*** PROPERTY NOT VALID ***");
165 XBT_INFO("**************************");
166 XBT_INFO("Counter-example execution trace:");
167 for (auto const& s : mc_model_checker->getChecker()->get_textual_trace())
168 XBT_INFO(" %s", s.c_str());
169 simgrid::mc::dumpRecordPath();
170 simgrid::mc::session->log_state();
173 bool ModelChecker::handle_message(char* buffer, ssize_t size)
175 s_mc_message_t base_message;
176 if (size < (ssize_t) sizeof(base_message))
177 xbt_die("Broken message");
178 memcpy(&base_message, buffer, sizeof(base_message));
180 switch(base_message.type) {
182 case MC_MESSAGE_IGNORE_HEAP:
184 s_mc_message_ignore_heap_t message;
185 if (size != sizeof(message))
186 xbt_die("Broken messsage");
187 memcpy(&message, buffer, sizeof(message));
189 IgnoredHeapRegion region;
190 region.block = message.block;
191 region.fragment = message.fragment;
192 region.address = message.address;
193 region.size = message.size;
194 process().ignore_heap(region);
198 case MC_MESSAGE_UNIGNORE_HEAP:
200 s_mc_message_ignore_memory_t message;
201 if (size != sizeof(message))
202 xbt_die("Broken messsage");
203 memcpy(&message, buffer, sizeof(message));
204 process().unignore_heap((void*)(std::uintptr_t)message.addr, message.size);
208 case MC_MESSAGE_IGNORE_MEMORY:
210 s_mc_message_ignore_memory_t message;
211 if (size != sizeof(message))
212 xbt_die("Broken messsage");
213 memcpy(&message, buffer, sizeof(message));
214 this->process().ignore_region(message.addr, message.size);
218 case MC_MESSAGE_STACK_REGION:
220 s_mc_message_stack_region_t message;
221 if (size != sizeof(message))
222 xbt_die("Broken messsage");
223 memcpy(&message, buffer, sizeof(message));
224 this->process().stack_areas().push_back(message.stack_region);
228 case MC_MESSAGE_REGISTER_SYMBOL:
230 s_mc_message_register_symbol_t message;
231 if (size != sizeof(message))
232 xbt_die("Broken message");
233 memcpy(&message, buffer, sizeof(message));
234 if (message.callback)
235 xbt_die("Support for client-side function proposition is not implemented.");
236 XBT_DEBUG("Received symbol: %s", message.name);
238 if (simgrid::mc::property_automaton == nullptr)
239 simgrid::mc::property_automaton = xbt_automaton_new();
241 simgrid::mc::RemoteClient* process = &this->process();
242 simgrid::mc::RemotePtr<int> address = simgrid::mc::remote((int*)message.data);
243 simgrid::xbt::add_proposition(simgrid::mc::property_automaton, message.name,
244 [process, address]() { return process->read(address); });
249 case MC_MESSAGE_WAITING:
252 case MC_MESSAGE_ASSERTION_FAILED:
253 MC_report_assertion_error();
254 this->exit(SIMGRID_MC_EXIT_SAFETY);
257 xbt_die("Unexpected message from model-checked application");
263 /** Terminate the model-checker application */
264 void ModelChecker::exit(int status)
266 // TODO, terminate the model checker politely instead of exiting rudely
267 if (process().running())
268 kill(process().pid(), SIGKILL);
272 void ModelChecker::handle_events(int fd, short events)
274 if (events == EV_READ) {
275 char buffer[MC_MESSAGE_LENGTH];
276 ssize_t size = process_->get_channel().receive(buffer, sizeof(buffer), false);
277 if (size == -1 && errno != EAGAIN)
278 throw simgrid::xbt::errno_error();
279 if (not handle_message(buffer, size)) {
280 event_base_loopbreak(base_);
283 else if (events == EV_SIGNAL) {
287 xbt_die("Unexpected event");
291 void ModelChecker::loop()
293 if (this->process().running())
294 event_base_dispatch(base_);
297 void ModelChecker::handle_waitpid()
299 XBT_DEBUG("Check for wait event");
302 while ((pid = waitpid(-1, &status, WNOHANG)) != 0) {
304 if (errno == ECHILD) {
306 if (this->process().running())
307 xbt_die("Inconsistent state");
311 XBT_ERROR("Could not wait for pid");
312 throw simgrid::xbt::errno_error();
316 if (pid == this->process().pid()) {
318 // From PTRACE_O_TRACEEXIT:
320 if (status>>8 == (SIGTRAP | (PTRACE_EVENT_EXIT<<8))) {
321 if (ptrace(PTRACE_GETEVENTMSG, this->process().pid(), 0, &status) == -1)
322 xbt_die("Could not get exit status");
323 if (WIFSIGNALED(status)) {
324 MC_report_crash(status);
325 mc_model_checker->exit(SIMGRID_MC_EXIT_PROGRAM_CRASH);
330 // We don't care about signals, just reinject them:
331 if (WIFSTOPPED(status)) {
332 XBT_DEBUG("Stopped with signal %i", (int) WSTOPSIG(status));
335 ptrace(PTRACE_CONT, this->process().pid(), 0, WSTOPSIG(status));
337 ptrace(PT_CONTINUE, this->process().pid(), (caddr_t)1, WSTOPSIG(status));
340 xbt_die("Could not PTRACE_CONT");
343 else if (WIFEXITED(status) || WIFSIGNALED(status)) {
344 XBT_DEBUG("Child process is over");
345 this->process().terminate();
351 void ModelChecker::on_signal(int signo)
353 if (signo == SIGCHLD)
354 this->handle_waitpid();
357 void ModelChecker::wait_for_requests()
359 this->resume(process());
360 if (this->process().running())
361 event_base_dispatch(base_);
364 void ModelChecker::handle_simcall(Transition const& transition)
366 s_mc_message_simcall_handle_t m;
367 memset(&m, 0, sizeof(m));
368 m.type = MC_MESSAGE_SIMCALL_HANDLE;
369 m.pid = transition.pid;
370 m.value = transition.argument;
371 this->process_->get_channel().send(m);
372 this->process_->clear_cache();
373 if (this->process_->running())
374 event_base_dispatch(base_);
377 bool ModelChecker::checkDeadlock()
380 if ((res = this->process().get_channel().send(MC_MESSAGE_DEADLOCK_CHECK)))
381 xbt_die("Could not check deadlock state");
382 s_mc_message_int_t message;
383 ssize_t s = mc_model_checker->process().get_channel().receive(message);
385 xbt_die("Could not receive message");
386 if (s != sizeof(message) || message.type != MC_MESSAGE_DEADLOCK_CHECK_REPLY)
387 xbt_die("Received unexpected message %s (%i, size=%i) "
388 "expected MC_MESSAGE_DEADLOCK_CHECK_REPLY (%i, size=%i)",
389 MC_message_type_name(message.type), (int) message.type, (int) s,
390 (int) MC_MESSAGE_DEADLOCK_CHECK_REPLY, (int) sizeof(message)
392 return message.value != 0;