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. */
10 #include <sys/types.h>
12 #include <sys/socket.h>
13 #include <sys/signalfd.h>
14 #include <sys/ptrace.h>
17 #include <system_error>
20 #include <xbt/automaton.h>
21 #include <xbt/automaton.hpp>
23 #include "simgrid/sg_config.h"
25 #include "src/mc/ModelChecker.hpp"
26 #include "src/mc/PageStore.hpp"
27 #include "src/mc/ModelChecker.hpp"
28 #include "src/mc/mc_protocol.h"
29 #include "src/mc/mc_private.h"
30 #include "src/mc/mc_ignore.h"
31 #include "src/mc/mc_exit.h"
32 #include "src/mc/mc_liveness.h"
36 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_ModelChecker, mc, "ModelChecker");
40 ::simgrid::mc::ModelChecker* mc_model_checker = nullptr;
42 using simgrid::mc::remote;
44 // Hardcoded index for now:
45 #define SOCKET_FD_INDEX 0
46 #define SIGNAL_FD_INDEX 1
51 ModelChecker::ModelChecker(pid_t pid, int socket) :
52 pid_(pid), socket_(socket),
53 hostnames_(xbt_dict_new()),
55 parent_snapshot_(nullptr)
59 ModelChecker::~ModelChecker()
61 xbt_dict_free(&this->hostnames_);
64 const char* ModelChecker::get_host_name(const char* hostname)
66 // Lookup the host name in the dictionary (or create it):
67 xbt_dictelm_t elt = xbt_dict_get_elm_or_null(this->hostnames_, hostname);
69 xbt_dict_set(this->hostnames_, hostname, nullptr, nullptr);
70 elt = xbt_dict_get_elm_or_null(this->hostnames_, hostname);
76 void ModelChecker::start()
78 // Block SIGCHLD (this will be handled with accept/signalfd):
81 sigaddset(&set, SIGCHLD);
82 if (sigprocmask(SIG_BLOCK, &set, nullptr) == -1)
83 throw std::system_error(errno, std::system_category());
86 sigfillset(&full_set);
88 // Prepare data for poll:
90 struct pollfd* socket_pollfd = &fds_[SOCKET_FD_INDEX];
91 socket_pollfd->fd = socket_;
92 socket_pollfd->events = POLLIN;
93 socket_pollfd->revents = 0;
95 int signal_fd = signalfd(-1, &set, 0);
97 throw std::system_error(errno, std::system_category());
99 struct pollfd* signalfd_pollfd = &fds_[SIGNAL_FD_INDEX];
100 signalfd_pollfd->fd = signal_fd;
101 signalfd_pollfd->events = POLLIN;
102 signalfd_pollfd->revents = 0;
104 XBT_DEBUG("Waiting for the model-checked process");
107 // The model-checked process SIGSTOP itself to signal it's ready:
108 pid_t res = waitpid(pid_, &status, __WALL);
109 if (res < 0 || !WIFSTOPPED(status) || WSTOPSIG(status) != SIGSTOP)
110 xbt_die("Could not wait model-checked process");
112 assert(process_ == nullptr);
113 process_ = std::unique_ptr<Process>(new Process(pid_, socket_));
114 // TODO, avoid direct dependency on sg_cfg
115 process_->privatized(sg_cfg_get_boolean("smpi/privatize_global_variables"));
117 /* Initialize statistics */
118 mc_stats = xbt_new0(s_mc_stats_t, 1);
119 mc_stats->state_size = 1;
121 if ((_sg_mc_dot_output_file != nullptr) && (_sg_mc_dot_output_file[0] != '\0'))
122 MC_init_dot_output();
125 //parmap = xbt_parmap_mc_new(xbt_os_get_numcores(), XBT_PARMAP_DEFAULT);
129 ptrace(PTRACE_SETOPTIONS, pid_, nullptr, PTRACE_O_TRACEEXIT);
130 ptrace(PTRACE_CONT, pid_, 0, 0);
133 static const std::pair<const char*, const char*> ignored_local_variables[] = {
134 std::pair<const char*, const char*>{ "e", "*" },
135 std::pair<const char*, const char*>{ "__ex_cleanup", "*" },
136 std::pair<const char*, const char*>{ "__ex_mctx_en", "*" },
137 std::pair<const char*, const char*>{ "__ex_mctx_me", "*" },
138 std::pair<const char*, const char*>{ "__xbt_ex_ctx_ptr", "*" },
139 std::pair<const char*, const char*>{ "_log_ev", "*" },
140 std::pair<const char*, const char*>{ "_throw_ctx", "*" },
141 std::pair<const char*, const char*>{ "ctx", "*" },
143 std::pair<const char*, const char*>{ "self", "simcall_BODY_mc_snapshot" },
144 std::pair<const char*, const char*>{ "next_context", "smx_ctx_sysv_suspend_serial" },
145 std::pair<const char*, const char*>{ "i", "smx_ctx_sysv_suspend_serial" },
147 /* Ignore local variable about time used for tracing */
148 std::pair<const char*, const char*>{ "start_time", "*" },
151 void ModelChecker::setup_ignore()
153 Process& process = this->process();
154 for (std::pair<const char*, const char*> const& var :
155 ignored_local_variables)
156 process.ignore_local_variable(var.first, var.second);
158 /* Static variable used for tracing */
159 process.ignore_global_variable("counter");
162 process.ignore_global_variable("smx_total_comms");
165 void ModelChecker::shutdown()
167 XBT_DEBUG("Shuting down model-checker");
169 simgrid::mc::Process* process = &this->process();
170 if (process->running()) {
171 XBT_DEBUG("Killing process");
172 kill(process->pid(), SIGTERM);
173 process->terminate();
177 void ModelChecker::resume(simgrid::mc::Process& process)
179 int res = process.send_message(MC_MESSAGE_CONTINUE);
181 throw std::system_error(res, std::system_category());
182 process.cache_flags = (mc_process_cache_flags_t) 0;
186 void throw_socket_error(int fd)
189 socklen_t errlen = sizeof(error);
190 if (getsockopt(fd, SOL_SOCKET, SO_ERROR, (void *)&error, &errlen) == -1)
192 throw std::system_error(error, std::system_category());
195 bool ModelChecker::handle_message(char* buffer, ssize_t size)
197 s_mc_message_t base_message;
198 if (size < (ssize_t) sizeof(base_message))
199 xbt_die("Broken message");
200 memcpy(&base_message, buffer, sizeof(base_message));
202 switch(base_message.type) {
204 case MC_MESSAGE_IGNORE_HEAP:
206 s_mc_ignore_heap_message_t message;
207 if (size != sizeof(message))
208 xbt_die("Broken messsage");
209 memcpy(&message, buffer, sizeof(message));
211 IgnoredHeapRegion region;
212 region.block = message.block;
213 region.fragment = message.fragment;
214 region.address = message.address;
215 region.size = message.size;
216 process().ignore_heap(region);
220 case MC_MESSAGE_UNIGNORE_HEAP:
222 s_mc_ignore_memory_message_t message;
223 if (size != sizeof(message))
224 xbt_die("Broken messsage");
225 memcpy(&message, buffer, sizeof(message));
226 process().unignore_heap(
227 (void *)(std::uintptr_t) message.addr, message.size);
231 case MC_MESSAGE_IGNORE_MEMORY:
233 s_mc_ignore_memory_message_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_stack_region_message_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_register_symbol_message_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 (_mc_property_automaton == nullptr)
262 _mc_property_automaton = xbt_automaton_new();
264 simgrid::mc::Process* process = &this->process();
265 simgrid::mc::remote_ptr<int> address
266 = simgrid::mc::remote((int*) message.data);
267 simgrid::xbt::add_proposition(_mc_property_automaton,
269 [process, address]() { return process->read(address); }
275 case MC_MESSAGE_WAITING:
278 case MC_MESSAGE_ASSERTION_FAILED:
279 MC_report_assertion_error();
280 ::exit(SIMGRID_MC_EXIT_SAFETY);
284 xbt_die("Unexpected message from model-checked application");
290 bool ModelChecker::handle_events()
292 char buffer[MC_MESSAGE_LENGTH];
293 struct pollfd* socket_pollfd = &fds_[SOCKET_FD_INDEX];
294 struct pollfd* signalfd_pollfd = &fds_[SIGNAL_FD_INDEX];
296 while(poll(fds_, 2, -1) == -1) {
301 throw std::system_error(errno, std::system_category());
305 if (socket_pollfd->revents) {
306 if (socket_pollfd->revents & POLLIN) {
307 ssize_t size = MC_receive_message(socket_pollfd->fd, buffer, sizeof(buffer), MSG_DONTWAIT);
308 if (size == -1 && errno != EAGAIN)
309 throw std::system_error(errno, std::system_category());
310 return handle_message(buffer, size);
312 if (socket_pollfd->revents & POLLERR) {
313 throw_socket_error(socket_pollfd->fd);
315 if (socket_pollfd->revents & POLLHUP)
316 xbt_die("Socket hang up?");
319 if (signalfd_pollfd->revents) {
320 if (signalfd_pollfd->revents & POLLIN) {
321 this->handle_signals();
324 if (signalfd_pollfd->revents & POLLERR) {
325 throw_socket_error(signalfd_pollfd->fd);
327 if (signalfd_pollfd->revents & POLLHUP)
328 xbt_die("Signalfd hang up?");
334 void ModelChecker::loop()
336 while (this->process().running())
337 this->handle_events();
340 void ModelChecker::handle_signals()
342 struct signalfd_siginfo info;
343 struct pollfd* signalfd_pollfd = &fds_[SIGNAL_FD_INDEX];
345 ssize_t size = read(signalfd_pollfd->fd, &info, sizeof(info));
350 throw std::system_error(errno, std::system_category());
351 } else if (size != sizeof(info))
352 return throw std::runtime_error(
353 "Bad communication with model-checked application");
357 this->on_signal(&info);
360 void ModelChecker::handle_waitpid()
362 XBT_DEBUG("Check for wait event");
365 while ((pid = waitpid(-1, &status, WNOHANG)) != 0) {
367 if (errno == ECHILD) {
369 if (this->process().running())
370 xbt_die("Inconsistent state");
374 XBT_ERROR("Could not wait for pid");
375 throw std::system_error(errno, std::system_category());
379 if (pid == this->process().pid()) {
381 // From PTRACE_O_TRACEEXIT:
382 if (status>>8 == (SIGTRAP | (PTRACE_EVENT_EXIT<<8))) {
383 if (ptrace(PTRACE_GETEVENTMSG, pid_, 0, &status) == -1)
384 xbt_die("Could not get exit status");
385 if (WIFSIGNALED(status)) {
386 MC_report_crash(status);
387 ::exit(SIMGRID_MC_EXIT_PROGRAM_CRASH);
391 // We don't care about signals, just reinject them:
392 if (WIFSTOPPED(status)) {
393 XBT_DEBUG("Stopped with signal %i", (int) WSTOPSIG(status));
394 if (ptrace(PTRACE_CONT, pid_, 0, WSTOPSIG(status)) == -1)
395 xbt_die("Could not PTRACE_CONT");
398 else if (WIFEXITED(status) || WIFSIGNALED(status)) {
399 XBT_DEBUG("Child process is over");
400 this->process().terminate();
406 void ModelChecker::on_signal(const struct signalfd_siginfo* info)
408 switch(info->ssi_signo) {
410 this->handle_waitpid();
417 void ModelChecker::wait_client(simgrid::mc::Process& process)
419 this->resume(process);
420 while (this->process().running()) {
421 if (!this->handle_events())
426 void ModelChecker::simcall_handle(simgrid::mc::Process& process, unsigned long pid, int value)
428 s_mc_simcall_handle_message m;
429 memset(&m, 0, sizeof(m));
430 m.type = MC_MESSAGE_SIMCALL_HANDLE;
433 process.send_message(m);
434 process.cache_flags = (mc_process_cache_flags_t) 0;
435 while (process.running()) {
436 if (!this->handle_events())