1 /* Copyright (c) 2008-2015. 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. */
11 #include <sys/socket.h>
12 #include <sys/ptrace.h>
15 #include <system_error>
17 #include "xbt/automaton.h"
18 #include "xbt/automaton.hpp"
20 #include "xbt/system_error.hpp"
22 #include "simgrid/sg_config.h"
24 #include "src/mc/ModelChecker.hpp"
25 #include "src/mc/ModelChecker.hpp"
26 #include "src/mc/PageStore.hpp"
27 #include "src/mc/Transition.hpp"
28 #include "src/mc/checker/Checker.hpp"
29 #include "src/mc/mc_exit.h"
30 #include "src/mc/mc_private.h"
31 #include "src/mc/mc_record.h"
32 #include "src/mc/remote/mc_protocol.h"
34 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_ModelChecker, mc, "ModelChecker");
36 ::simgrid::mc::ModelChecker* mc_model_checker = nullptr;
38 using simgrid::mc::remote;
41 # define WAITPID_CHECKED_FLAGS __WALL
43 # define WAITPID_CHECKED_FLAGS 0
49 ModelChecker::ModelChecker(std::unique_ptr<Process> process) :
51 socket_event_(nullptr),
52 signal_event_(nullptr),
54 process_(std::move(process)),
55 parent_snapshot_(nullptr)
60 ModelChecker::~ModelChecker() {
61 if (socket_event_ != nullptr)
62 event_free(socket_event_);
63 if (signal_event_ != nullptr)
64 event_free(signal_event_);
66 event_base_free(base_);
69 void ModelChecker::start()
71 const pid_t pid = process_->pid();
73 base_ = event_base_new();
74 event_callback_fn event_callback = [](evutil_socket_t fd, short events, void *arg)
76 ((ModelChecker *)arg)->handle_events(fd, events);
78 socket_event_ = event_new(base_,
79 process_->getChannel().getSocket(),
81 event_callback, this);
82 event_add(socket_event_, NULL);
83 signal_event_ = event_new(base_,
86 event_callback, this);
87 event_add(signal_event_, NULL);
89 XBT_DEBUG("Waiting for the model-checked process");
92 // The model-checked process SIGSTOP itself to signal it's ready:
93 pid_t res = waitpid(pid, &status, WAITPID_CHECKED_FLAGS);
94 if (res < 0 || not WIFSTOPPED(status) || WSTOPSIG(status) != SIGSTOP)
95 xbt_die("Could not wait model-checked process");
99 if ((_sg_mc_dot_output_file != nullptr) && (_sg_mc_dot_output_file[0] != '\0'))
100 MC_init_dot_output();
105 ptrace(PTRACE_SETOPTIONS, pid, nullptr, PTRACE_O_TRACEEXIT);
106 ptrace(PTRACE_CONT, pid, 0, 0);
108 ptrace(PT_CONTINUE, pid, (caddr_t)1, 0);
110 # error "no ptrace equivalent coded for this platform"
114 static const std::pair<const char*, const char*> ignored_local_variables[] = {
115 std::pair<const char*, const char*>{ "e", "*" },
116 std::pair<const char*, const char*>{ "__ex_cleanup", "*" },
117 std::pair<const char*, const char*>{ "__ex_mctx_en", "*" },
118 std::pair<const char*, const char*>{ "__ex_mctx_me", "*" },
119 std::pair<const char*, const char*>{ "__xbt_ex_ctx_ptr", "*" },
120 std::pair<const char*, const char*>{ "_log_ev", "*" },
121 std::pair<const char*, const char*>{ "_throw_ctx", "*" },
122 std::pair<const char*, const char*>{ "ctx", "*" },
124 std::pair<const char*, const char*>{ "self", "simcall_BODY_mc_snapshot" },
125 std::pair<const char*, const char*>{ "next_context", "smx_ctx_sysv_suspend_serial" },
126 std::pair<const char*, const char*>{ "i", "smx_ctx_sysv_suspend_serial" },
128 /* Ignore local variable about time used for tracing */
129 std::pair<const char*, const char*>{ "start_time", "*" },
132 void ModelChecker::setup_ignore()
134 Process& process = this->process();
135 for (std::pair<const char*, const char*> const& var :
136 ignored_local_variables)
137 process.ignore_local_variable(var.first, var.second);
139 /* Static variable used for tracing */
140 process.ignore_global_variable("counter");
143 void ModelChecker::shutdown()
145 XBT_DEBUG("Shuting down model-checker");
147 simgrid::mc::Process* process = &this->process();
148 if (process->running()) {
149 XBT_DEBUG("Killing process");
150 kill(process->pid(), SIGTERM);
151 process->terminate();
155 void ModelChecker::resume(simgrid::mc::Process& process)
157 int res = process.getChannel().send(MC_MESSAGE_CONTINUE);
159 throw simgrid::xbt::errno_error();
160 process.clear_cache();
163 static void MC_report_crash(int status)
165 XBT_INFO("**************************");
166 XBT_INFO("** CRASH IN THE PROGRAM **");
167 XBT_INFO("**************************");
168 if (WIFSIGNALED(status))
169 XBT_INFO("From signal: %s", strsignal(WTERMSIG(status)));
170 else if (WIFEXITED(status))
171 XBT_INFO("From exit: %i", WEXITSTATUS(status));
172 if (WCOREDUMP(status))
173 XBT_INFO("A core dump was generated by the system.");
175 XBT_INFO("No core dump was generated by the system.");
176 XBT_INFO("Counter-example execution trace:");
177 simgrid::mc::dumpRecordPath();
178 for (auto& s : mc_model_checker->getChecker()->getTextualTrace())
179 XBT_INFO("%s", s.c_str());
180 simgrid::mc::session->logState();
181 XBT_INFO("Stack trace:");
182 mc_model_checker->process().dumpStack();
185 static void MC_report_assertion_error()
187 XBT_INFO("**************************");
188 XBT_INFO("*** PROPERTY NOT VALID ***");
189 XBT_INFO("**************************");
190 XBT_INFO("Counter-example execution trace:");
191 simgrid::mc::dumpRecordPath();
192 for (auto& s : mc_model_checker->getChecker()->getTextualTrace())
193 XBT_INFO("%s", s.c_str());
194 simgrid::mc::session->logState();
197 bool ModelChecker::handle_message(char* buffer, ssize_t size)
199 s_mc_message_t base_message;
200 if (size < (ssize_t) sizeof(base_message))
201 xbt_die("Broken message");
202 memcpy(&base_message, buffer, sizeof(base_message));
204 switch(base_message.type) {
206 case MC_MESSAGE_IGNORE_HEAP:
208 s_mc_ignore_heap_message_t message;
209 if (size != sizeof(message))
210 xbt_die("Broken messsage");
211 memcpy(&message, buffer, sizeof(message));
213 IgnoredHeapRegion region;
214 region.block = message.block;
215 region.fragment = message.fragment;
216 region.address = message.address;
217 region.size = message.size;
218 process().ignore_heap(region);
222 case MC_MESSAGE_UNIGNORE_HEAP:
224 s_mc_ignore_memory_message_t message;
225 if (size != sizeof(message))
226 xbt_die("Broken messsage");
227 memcpy(&message, buffer, sizeof(message));
228 process().unignore_heap(
229 (void *)(std::uintptr_t) message.addr, message.size);
233 case MC_MESSAGE_IGNORE_MEMORY:
235 s_mc_ignore_memory_message_t message;
236 if (size != sizeof(message))
237 xbt_die("Broken messsage");
238 memcpy(&message, buffer, sizeof(message));
239 this->process().ignore_region(message.addr, message.size);
243 case MC_MESSAGE_STACK_REGION:
245 s_mc_stack_region_message_t message;
246 if (size != sizeof(message))
247 xbt_die("Broken messsage");
248 memcpy(&message, buffer, sizeof(message));
249 this->process().stack_areas().push_back(message.stack_region);
253 case MC_MESSAGE_REGISTER_SYMBOL:
255 s_mc_register_symbol_message_t message;
256 if (size != sizeof(message))
257 xbt_die("Broken message");
258 memcpy(&message, buffer, sizeof(message));
259 if (message.callback)
260 xbt_die("Support for client-side function proposition is not implemented.");
261 XBT_DEBUG("Received symbol: %s", message.name);
263 if (simgrid::mc::property_automaton == nullptr)
264 simgrid::mc::property_automaton = xbt_automaton_new();
266 simgrid::mc::Process* process = &this->process();
267 simgrid::mc::RemotePtr<int> address
268 = simgrid::mc::remote((int*) message.data);
269 simgrid::xbt::add_proposition(simgrid::mc::property_automaton,
271 [process, address]() { return process->read(address); }
277 case MC_MESSAGE_WAITING:
280 case MC_MESSAGE_ASSERTION_FAILED:
281 MC_report_assertion_error();
282 this->exit(SIMGRID_MC_EXIT_SAFETY);
286 xbt_die("Unexpected message from model-checked application");
292 /** Terminate the model-checker application */
293 void ModelChecker::exit(int status)
295 // TODO, terminate the model checker politely instead of exiting rudely
296 if (process().running())
297 kill(process().pid(), SIGKILL);
301 void ModelChecker::handle_events(int fd, short events)
303 if (events == EV_READ) {
304 char buffer[MC_MESSAGE_LENGTH];
305 ssize_t size = process_->getChannel().receive(buffer, sizeof(buffer), false);
306 if (size == -1 && errno != EAGAIN)
307 throw simgrid::xbt::errno_error();
308 if (not handle_message(buffer, size)) {
309 event_base_loopbreak(base_);
312 else if (events == EV_SIGNAL) {
316 xbt_die("Unexpected event");
320 void ModelChecker::loop()
322 if (this->process().running())
323 event_base_dispatch(base_);
326 void ModelChecker::handle_waitpid()
328 XBT_DEBUG("Check for wait event");
331 while ((pid = waitpid(-1, &status, WNOHANG)) != 0) {
333 if (errno == ECHILD) {
335 if (this->process().running())
336 xbt_die("Inconsistent state");
340 XBT_ERROR("Could not wait for pid");
341 throw simgrid::xbt::errno_error();
345 if (pid == this->process().pid()) {
347 // From PTRACE_O_TRACEEXIT:
349 if (status>>8 == (SIGTRAP | (PTRACE_EVENT_EXIT<<8))) {
350 if (ptrace(PTRACE_GETEVENTMSG, this->process().pid(), 0, &status) == -1)
351 xbt_die("Could not get exit status");
352 if (WIFSIGNALED(status)) {
353 MC_report_crash(status);
354 mc_model_checker->exit(SIMGRID_MC_EXIT_PROGRAM_CRASH);
359 // We don't care about signals, just reinject them:
360 if (WIFSTOPPED(status)) {
361 XBT_DEBUG("Stopped with signal %i", (int) WSTOPSIG(status));
364 ptrace(PTRACE_CONT, this->process().pid(), 0, WSTOPSIG(status));
366 ptrace(PT_CONTINUE, this->process().pid(), (caddr_t)1, WSTOPSIG(status));
369 xbt_die("Could not PTRACE_CONT");
372 else if (WIFEXITED(status) || WIFSIGNALED(status)) {
373 XBT_DEBUG("Child process is over");
374 this->process().terminate();
380 void ModelChecker::on_signal(int signo)
384 this->handle_waitpid();
391 void ModelChecker::wait_client(simgrid::mc::Process& process)
393 this->resume(process);
394 if (this->process().running())
395 event_base_dispatch(base_);
398 void ModelChecker::handle_simcall(Transition const& transition)
400 s_mc_simcall_handle_message m;
401 memset(&m, 0, sizeof(m));
402 m.type = MC_MESSAGE_SIMCALL_HANDLE;
403 m.pid = transition.pid;
404 m.value = transition.argument;
405 this->process_->getChannel().send(m);
406 this->process_->clear_cache();
407 if (this->process_->running())
408 event_base_dispatch(base_);
411 bool ModelChecker::checkDeadlock()
414 if ((res = this->process().getChannel().send(MC_MESSAGE_DEADLOCK_CHECK)))
415 xbt_die("Could not check deadlock state");
416 s_mc_int_message_t message;
417 ssize_t s = mc_model_checker->process().getChannel().receive(message);
419 xbt_die("Could not receive message");
420 if (s != sizeof(message) || message.type != MC_MESSAGE_DEADLOCK_CHECK_REPLY)
421 xbt_die("Received unexpected message %s (%i, size=%i) "
422 "expected MC_MESSAGE_DEADLOCK_CHECK_REPLY (%i, size=%i)",
423 MC_message_type_name(message.type), (int) message.type, (int) s,
424 (int) MC_MESSAGE_DEADLOCK_CHECK_REPLY, (int) sizeof(message)
426 return message.value != 0;