-/* Copyright (c) 2008-2015. The SimGrid Team.
- * All rights reserved. */
+/* Copyright (c) 2008-2020. The SimGrid Team. All rights reserved. */
/* This program is free software; you can redistribute it and/or modify it
* under the terms of the license (GNU LGPL) which comes with this package. */
-#include <cassert>
+#include "src/mc/ModelChecker.hpp"
+#include "src/mc/Session.hpp"
+#include "src/mc/Transition.hpp"
+#include "src/mc/checker/Checker.hpp"
+#include "src/mc/mc_config.hpp"
+#include "src/mc/mc_exit.hpp"
+#include "src/mc/mc_private.hpp"
+#include "src/mc/remote/RemoteSimulation.hpp"
+#include "xbt/automaton.hpp"
+#include "xbt/system_error.hpp"
-#include "simgrid/sg_config.h" // sg_cfg_get_boolean
+#include <sys/ptrace.h>
+#include <sys/wait.h>
-#include "ModelChecker.hpp"
-#include "PageStore.hpp"
+XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_ModelChecker, mc, "ModelChecker");
-::simgrid::mc::ModelChecker* mc_model_checker = NULL;
+::simgrid::mc::ModelChecker* mc_model_checker = nullptr;
+
+using simgrid::mc::remote;
+
+#ifdef __linux__
+# define WAITPID_CHECKED_FLAGS __WALL
+#else
+# define WAITPID_CHECKED_FLAGS 0
+#endif
namespace simgrid {
namespace mc {
-ModelChecker::ModelChecker(pid_t pid, int socket) :
- hostnames_(xbt_dict_new()),
- page_store_(500),
- process_(pid, socket),
- parent_snapshot_(nullptr)
+ModelChecker::ModelChecker(std::unique_ptr<RemoteSimulation> remote_simulation, int sockfd)
+ : checker_side_(sockfd), remote_simulation_(std::move(remote_simulation))
+{
+}
+
+void ModelChecker::start()
+{
+ checker_side_.start([](evutil_socket_t sig, short events, void* arg) {
+ auto mc = static_cast<simgrid::mc::ModelChecker*>(arg);
+ if (events == EV_READ) {
+ char buffer[MC_MESSAGE_LENGTH];
+ ssize_t size = mc->checker_side_.get_channel().receive(buffer, sizeof(buffer), false);
+ if (size == -1 && errno != EAGAIN)
+ throw simgrid::xbt::errno_error();
+
+ if (not mc->handle_message(buffer, size))
+ mc->checker_side_.break_loop();
+ } else if (events == EV_SIGNAL) {
+ if (sig == SIGCHLD)
+ mc->handle_waitpid();
+ } else {
+ xbt_die("Unexpected event");
+ }
+ });
+
+ XBT_DEBUG("Waiting for the model-checked process");
+ int status;
+
+ // The model-checked process SIGSTOP itself to signal it's ready:
+ const pid_t pid = remote_simulation_->pid();
+
+ pid_t res = waitpid(pid, &status, WAITPID_CHECKED_FLAGS);
+ if (res < 0 || not WIFSTOPPED(status) || WSTOPSIG(status) != SIGSTOP)
+ xbt_die("Could not wait model-checked process");
+
+ remote_simulation_->init();
+
+ if (not _sg_mc_dot_output_file.get().empty())
+ MC_init_dot_output();
+
+ setup_ignore();
+
+#ifdef __linux__
+ ptrace(PTRACE_SETOPTIONS, pid, nullptr, PTRACE_O_TRACEEXIT);
+ ptrace(PTRACE_CONT, pid, 0, 0);
+#elif defined BSD
+ ptrace(PT_CONTINUE, pid, (caddr_t)1, 0);
+#else
+# error "no ptrace equivalent coded for this platform"
+#endif
+}
+
+static const std::pair<const char*, const char*> ignored_local_variables[] = {
+ std::pair<const char*, const char*>{ "e", "*" },
+ std::pair<const char*, const char*>{ "_log_ev", "*" },
+
+ /* Ignore local variable about time used for tracing */
+ std::pair<const char*, const char*>{ "start_time", "*" },
+};
+
+void ModelChecker::setup_ignore()
+{
+ const RemoteSimulation& process = this->get_remote_simulation();
+ for (std::pair<const char*, const char*> const& var :
+ ignored_local_variables)
+ process.ignore_local_variable(var.first, var.second);
+
+ /* Static variable used for tracing */
+ process.ignore_global_variable("counter");
+}
+
+void ModelChecker::shutdown()
+{
+ XBT_DEBUG("Shutting down model-checker");
+
+ RemoteSimulation* process = &this->get_remote_simulation();
+ if (process->running()) {
+ XBT_DEBUG("Killing process");
+ kill(process->pid(), SIGKILL);
+ process->terminate();
+ }
+}
+
+void ModelChecker::resume(RemoteSimulation& process)
+{
+ int res = checker_side_.get_channel().send(MC_MESSAGE_CONTINUE);
+ if (res)
+ throw xbt::errno_error();
+ process.clear_cache();
+}
+
+static void MC_report_crash(int status)
{
- // TODO, avoid direct dependency on sg_cfg
- process_.privatized(sg_cfg_get_boolean("smpi/privatize_global_variables"));
+ XBT_INFO("**************************");
+ XBT_INFO("** CRASH IN THE PROGRAM **");
+ XBT_INFO("**************************");
+ if (WIFSIGNALED(status))
+ XBT_INFO("From signal: %s", strsignal(WTERMSIG(status)));
+ else if (WIFEXITED(status))
+ XBT_INFO("From exit: %i", WEXITSTATUS(status));
+ if (not xbt_log_no_loc)
+ XBT_INFO("%s core dump was generated by the system.", WCOREDUMP(status) ? "A" : "No");
+ XBT_INFO("Counter-example execution trace:");
+ for (auto const& s : mc_model_checker->getChecker()->get_textual_trace())
+ XBT_INFO(" %s", s.c_str());
+ dumpRecordPath();
+ session->log_state();
+ if (xbt_log_no_loc) {
+ XBT_INFO("Stack trace not displayed because you passed --log=no_loc");
+ } else {
+ XBT_INFO("Stack trace:");
+ mc_model_checker->get_remote_simulation().dump_stack();
+ }
+}
+
+static void MC_report_assertion_error()
+{
+ XBT_INFO("**************************");
+ XBT_INFO("*** PROPERTY NOT VALID ***");
+ XBT_INFO("**************************");
+ XBT_INFO("Counter-example execution trace:");
+ for (auto const& s : mc_model_checker->getChecker()->get_textual_trace())
+ XBT_INFO(" %s", s.c_str());
+ dumpRecordPath();
+ session->log_state();
+}
+
+bool ModelChecker::handle_message(const char* buffer, ssize_t size)
+{
+ s_mc_message_t base_message;
+ xbt_assert(size >= (ssize_t)sizeof(base_message), "Broken message");
+ memcpy(&base_message, buffer, sizeof(base_message));
+
+ switch(base_message.type) {
+ case MC_MESSAGE_IGNORE_HEAP:
+ {
+ s_mc_message_ignore_heap_t message;
+ xbt_assert(size == sizeof(message), "Broken message");
+ memcpy(&message, buffer, sizeof(message));
+
+ IgnoredHeapRegion region;
+ region.block = message.block;
+ region.fragment = message.fragment;
+ region.address = message.address;
+ region.size = message.size;
+ get_remote_simulation().ignore_heap(region);
+ break;
+ }
+
+ case MC_MESSAGE_UNIGNORE_HEAP:
+ {
+ s_mc_message_ignore_memory_t message;
+ xbt_assert(size == sizeof(message), "Broken message");
+ memcpy(&message, buffer, sizeof(message));
+ get_remote_simulation().unignore_heap((void*)(std::uintptr_t)message.addr, message.size);
+ break;
+ }
+
+ case MC_MESSAGE_IGNORE_MEMORY:
+ {
+ s_mc_message_ignore_memory_t message;
+ xbt_assert(size == sizeof(message), "Broken message");
+ memcpy(&message, buffer, sizeof(message));
+ this->get_remote_simulation().ignore_region(message.addr, message.size);
+ break;
+ }
+
+ case MC_MESSAGE_STACK_REGION:
+ {
+ s_mc_message_stack_region_t message;
+ xbt_assert(size == sizeof(message), "Broken message");
+ memcpy(&message, buffer, sizeof(message));
+ this->get_remote_simulation().stack_areas().push_back(message.stack_region);
+ }
+ break;
+
+ case MC_MESSAGE_REGISTER_SYMBOL:
+ {
+ s_mc_message_register_symbol_t message;
+ xbt_assert(size == sizeof(message), "Broken message");
+ memcpy(&message, buffer, sizeof(message));
+ xbt_assert(not message.callback, "Support for client-side function proposition is not implemented.");
+ XBT_DEBUG("Received symbol: %s", message.name);
+
+ if (property_automaton == nullptr)
+ property_automaton = xbt_automaton_new();
+
+ RemoteSimulation* process = &this->get_remote_simulation();
+ RemotePtr<int> address = remote((int*)message.data);
+ xbt::add_proposition(property_automaton, message.name, [process, address]() { return process->read(address); });
+
+ break;
+ }
+
+ case MC_MESSAGE_WAITING:
+ return false;
+
+ case MC_MESSAGE_ASSERTION_FAILED:
+ MC_report_assertion_error();
+ this->exit(SIMGRID_MC_EXIT_SAFETY);
+
+ default:
+ xbt_die("Unexpected message from model-checked application");
+ }
+ return true;
}
-ModelChecker::~ModelChecker()
+/** Terminate the model-checker application */
+void ModelChecker::exit(int status)
{
- xbt_dict_free(&this->hostnames_);
+ // TODO, terminate the model checker politely instead of exiting rudely
+ if (get_remote_simulation().running())
+ kill(get_remote_simulation().pid(), SIGKILL);
+ ::exit(status);
}
-const char* ModelChecker::get_host_name(const char* hostname)
+void ModelChecker::handle_waitpid()
{
- // Lookup the host name in the dictionary (or create it):
- xbt_dictelm_t elt = xbt_dict_get_elm_or_null(this->hostnames_, hostname);
- if (!elt) {
- xbt_dict_set(this->hostnames_, hostname, NULL, NULL);
- elt = xbt_dict_get_elm_or_null(this->hostnames_, hostname);
- assert(elt);
+ XBT_DEBUG("Check for wait event");
+ int status;
+ pid_t pid;
+ while ((pid = waitpid(-1, &status, WNOHANG)) != 0) {
+ if (pid == -1) {
+ if (errno == ECHILD) {
+ // No more children:
+ xbt_assert(not this->get_remote_simulation().running(), "Inconsistent state");
+ break;
+ } else {
+ XBT_ERROR("Could not wait for pid");
+ throw simgrid::xbt::errno_error();
+ }
+ }
+
+ if (pid == this->get_remote_simulation().pid()) {
+ // From PTRACE_O_TRACEEXIT:
+#ifdef __linux__
+ if (status>>8 == (SIGTRAP | (PTRACE_EVENT_EXIT<<8))) {
+ xbt_assert(ptrace(PTRACE_GETEVENTMSG, remote_simulation_->pid(), 0, &status) != -1,
+ "Could not get exit status");
+ if (WIFSIGNALED(status)) {
+ MC_report_crash(status);
+ mc_model_checker->exit(SIMGRID_MC_EXIT_PROGRAM_CRASH);
+ }
+ }
+#endif
+
+ // We don't care about signals, just reinject them:
+ if (WIFSTOPPED(status)) {
+ XBT_DEBUG("Stopped with signal %i", (int) WSTOPSIG(status));
+ errno = 0;
+#ifdef __linux__
+ ptrace(PTRACE_CONT, remote_simulation_->pid(), 0, WSTOPSIG(status));
+#elif defined BSD
+ ptrace(PT_CONTINUE, remote_simulation_->pid(), (caddr_t)1, WSTOPSIG(status));
+#endif
+ xbt_assert(errno == 0, "Could not PTRACE_CONT");
+ }
+
+ else if (WIFSIGNALED(status)) {
+ MC_report_crash(status);
+ mc_model_checker->exit(SIMGRID_MC_EXIT_PROGRAM_CRASH);
+ } else if (WIFEXITED(status)) {
+ XBT_DEBUG("Child process is over");
+ this->get_remote_simulation().terminate();
+ }
+ }
}
- return elt->key;
}
+void ModelChecker::wait_for_requests()
+{
+ this->resume(get_remote_simulation());
+ if (this->get_remote_simulation().running())
+ checker_side_.dispatch();
}
+
+void ModelChecker::handle_simcall(Transition const& transition)
+{
+ s_mc_message_simcall_handle_t m;
+ memset(&m, 0, sizeof(m));
+ m.type = MC_MESSAGE_SIMCALL_HANDLE;
+ m.pid = transition.pid_;
+ m.value = transition.argument_;
+ checker_side_.get_channel().send(m);
+ this->remote_simulation_->clear_cache();
+ if (this->remote_simulation_->running())
+ checker_side_.dispatch();
}
+
+bool ModelChecker::checkDeadlock()
+{
+ int res = checker_side_.get_channel().send(MC_MESSAGE_DEADLOCK_CHECK);
+ xbt_assert(res == 0, "Could not check deadlock state");
+ s_mc_message_int_t message;
+ ssize_t s = checker_side_.get_channel().receive(message);
+ xbt_assert(s != -1, "Could not receive message");
+ xbt_assert(s == sizeof(message) && message.type == MC_MESSAGE_DEADLOCK_CHECK_REPLY,
+ "Received unexpected message %s (%i, size=%i) "
+ "expected MC_MESSAGE_DEADLOCK_CHECK_REPLY (%i, size=%i)",
+ MC_message_type_name(message.type), (int)message.type, (int)s, (int)MC_MESSAGE_DEADLOCK_CHECK_REPLY,
+ (int)sizeof(message));
+ return message.value != 0;
+}
+
+} // namespace mc
+} // namespace simgrid
