-/* Copyright (c) 2008-2015. The SimGrid Team.
- * All rights reserved. */
+/* Copyright (c) 2008-2021. 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/RemoteProcess.hpp"
+#include "xbt/automaton.hpp"
+#include "xbt/system_error.hpp"
-#include "ModelChecker.hpp"
-#include "PageStore.hpp"
+#include <array>
+#include <csignal>
+#include <sys/ptrace.h>
+#include <sys/wait.h>
-::simgrid::mc::ModelChecker* mc_model_checker = NULL;
+XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_ModelChecker, mc, "ModelChecker");
+
+::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<RemoteProcess> remote_simulation, int sockfd)
+ : checker_side_(sockfd), remote_process_(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) {
+ std::array<char, MC_MESSAGE_LENGTH> buffer;
+ ssize_t size = mc->checker_side_.get_channel().receive(buffer.data(), buffer.size(), false);
+ if (size == -1 && errno != EAGAIN)
+ throw simgrid::xbt::errno_error();
+
+ if (not mc->handle_message(buffer.data(), size))
+ mc->checker_side_.break_loop();
+ } else if (events == EV_SIGNAL) {
+ if (sig == SIGCHLD)
+ mc->handle_waitpid();
+ } else {
+ xbt_die("Unexpected event");
+ }
+ },
+ this);
+
+ 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_process_->pid();
+
+ xbt_assert(waitpid(pid, &status, WAITPID_CHECKED_FLAGS) == pid && WIFSTOPPED(status) && WSTOPSIG(status) == SIGSTOP,
+ "Could not wait model-checked process");
+
+ 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 constexpr auto ignored_local_variables = {
+ std::make_pair("e", "*"),
+ std::make_pair("_log_ev", "*"),
+
+ /* Ignore local variable about time used for tracing */
+ std::make_pair("start_time", "*"),
+};
+
+void ModelChecker::setup_ignore()
+{
+ const RemoteProcess& process = this->get_remote_process();
+ for (auto 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");
+
+ RemoteProcess& process = get_remote_process();
+ if (process.running()) {
+ XBT_DEBUG("Killing process");
+ finalize_app(true);
+ kill(process.pid(), SIGKILL);
+ process.terminate();
+ }
+}
+
+void ModelChecker::resume()
+{
+ int res = checker_side_.get_channel().send(MessageType::CONTINUE);
+ if (res)
+ throw xbt::errno_error();
+ remote_process_->clear_cache();
+}
+
+static void MC_report_crash(int status)
+{
+ 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_singleton->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_process().dump_stack();
+ }
+}
+
+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 MessageType::INITIAL_ADDRESSES: {
+ s_mc_message_initial_addresses_t message;
+ xbt_assert(size == sizeof(message), "Broken message. Got %d bytes instead of %d.", (int)size, (int)sizeof(message));
+ memcpy(&message, buffer, sizeof(message));
+
+ get_remote_process().init(message.mmalloc_default_mdp, message.maxpid, message.actors, message.dead_actors);
+ break;
+ }
+
+ case MessageType::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_process().ignore_heap(region);
+ break;
+ }
+
+ case MessageType::UNIGNORE_HEAP: {
+ s_mc_message_ignore_memory_t message;
+ xbt_assert(size == sizeof(message), "Broken message");
+ memcpy(&message, buffer, sizeof(message));
+ get_remote_process().unignore_heap((void*)(std::uintptr_t)message.addr, message.size);
+ break;
+ }
+
+ case MessageType::IGNORE_MEMORY: {
+ s_mc_message_ignore_memory_t message;
+ xbt_assert(size == sizeof(message), "Broken message");
+ memcpy(&message, buffer, sizeof(message));
+ this->get_remote_process().ignore_region(message.addr, message.size);
+ break;
+ }
+
+ case MessageType::STACK_REGION: {
+ s_mc_message_stack_region_t message;
+ xbt_assert(size == sizeof(message), "Broken message");
+ memcpy(&message, buffer, sizeof(message));
+ this->get_remote_process().stack_areas().push_back(message.stack_region);
+ } break;
+
+ case MessageType::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.data());
+
+ if (property_automaton == nullptr)
+ property_automaton = xbt_automaton_new();
+
+ const RemoteProcess* process = &this->get_remote_process();
+ RemotePtr<int> address = remote((int*)message.data);
+ xbt::add_proposition(property_automaton, message.name.data(),
+ [process, address]() { return process->read(address); });
+
+ break;
+ }
+
+ case MessageType::WAITING:
+ return false;
+
+ case MessageType::ASSERTION_FAILED:
+ XBT_INFO("**************************");
+ XBT_INFO("*** PROPERTY NOT VALID ***");
+ XBT_INFO("**************************");
+ XBT_INFO("Counter-example execution trace:");
+ for (auto const& s : getChecker()->get_textual_trace())
+ XBT_INFO(" %s", s.c_str());
+ dumpRecordPath();
+ session_singleton->log_state();
+
+ 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_);
+ shutdown();
+ ::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_process().running(), "Inconsistent state");
+ break;
+ } else {
+ XBT_ERROR("Could not wait for pid");
+ throw simgrid::xbt::errno_error();
+ }
+ }
+
+ if (pid == this->get_remote_process().pid()) {
+ // From PTRACE_O_TRACEEXIT:
+#ifdef __linux__
+ if (status>>8 == (SIGTRAP | (PTRACE_EVENT_EXIT<<8))) {
+ xbt_assert(ptrace(PTRACE_GETEVENTMSG, remote_process_->pid(), 0, &status) != -1, "Could not get exit status");
+ if (WIFSIGNALED(status)) {
+ MC_report_crash(status);
+ this->get_remote_process().terminate();
+ this->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_process_->pid(), 0, WSTOPSIG(status));
+#elif defined BSD
+ ptrace(PT_CONTINUE, remote_process_->pid(), (caddr_t)1, WSTOPSIG(status));
+#endif
+ xbt_assert(errno == 0, "Could not PTRACE_CONT");
+ }
+
+ else if (WIFSIGNALED(status)) {
+ MC_report_crash(status);
+ this->get_remote_process().terminate();
+ this->exit(SIMGRID_MC_EXIT_PROGRAM_CRASH);
+ } else if (WIFEXITED(status)) {
+ XBT_DEBUG("Child process is over");
+ this->get_remote_process().terminate();
+ }
+ }
}
- return elt->key;
}
+void ModelChecker::wait_for_requests()
+{
+ this->resume();
+ if (this->get_remote_process().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 = MessageType::SIMCALL_HANDLE;
+ m.aid_ = transition.aid_;
+ m.times_considered_ = transition.times_considered_;
+ checker_side_.get_channel().send(m);
+ this->remote_process_->clear_cache();
+ if (this->remote_process_->running())
+ checker_side_.dispatch();
}
+bool ModelChecker::simcall_is_visible(aid_t aid)
+{
+ xbt_assert(mc_model_checker != nullptr, "This should be called from the checker side");
+
+ s_mc_message_simcall_is_visible_t m;
+ memset(&m, 0, sizeof(m));
+ m.type = MessageType::SIMCALL_IS_VISIBLE;
+ m.aid = aid;
+ checker_side_.get_channel().send(m);
+
+ s_mc_message_simcall_is_visible_answer_t answer;
+ ssize_t s = checker_side_.get_channel().receive(answer);
+ xbt_assert(s != -1, "Could not receive message");
+ xbt_assert(s == sizeof(answer) && answer.type == MessageType::SIMCALL_IS_VISIBLE_ANSWER,
+ "Received unexpected message %s (%i, size=%i) "
+ "expected MessageType::SIMCALL_IS_VISIBLE_ANSWER (%i, size=%i)",
+ to_c_str(answer.type), (int)answer.type, (int)s, (int)MessageType::SIMCALL_IS_VISIBLE_ANSWER,
+ (int)sizeof(answer));
+
+ XBT_DEBUG("is_visible(%ld) is returning %s", aid, answer.value ? "true" : "false");
+
+ this->remote_process_->clear_cache();
+ return answer.value;
}
+
+std::string ModelChecker::simcall_to_string(MessageType type, aid_t aid, int times_considered)
+{
+ xbt_assert(mc_model_checker != nullptr, "This should be called from the checker side");
+
+ s_mc_message_simcall_to_string_t m;
+ memset(&m, 0, sizeof(m));
+ m.type = type;
+ m.aid = aid;
+ m.time_considered = times_considered;
+ checker_side_.get_channel().send(m);
+
+ s_mc_message_simcall_to_string_answer_t answer;
+ ssize_t s = checker_side_.get_channel().receive(answer);
+ xbt_assert(s != -1, "Could not receive message");
+ xbt_assert(s == sizeof(answer) && answer.type == MessageType::SIMCALL_TO_STRING_ANSWER,
+ "Received unexpected message %s (%i, size=%i) "
+ "expected MessageType::SIMCALL_TO_STRING_ANSWER (%i, size=%i)",
+ to_c_str(answer.type), (int)answer.type, (int)s, (int)MessageType::SIMCALL_TO_STRING_ANSWER,
+ (int)sizeof(answer));
+
+ return std::string(answer.value);
+}
+
+std::string ModelChecker::simcall_to_string(aid_t aid, int times_considered)
+{
+ std::string answer = simcall_to_string(MessageType::SIMCALL_TO_STRING, aid, times_considered);
+ XBT_DEBUG("to_string(%ld) is returning %s", aid, answer.c_str());
+ return answer;
+}
+
+std::string ModelChecker::simcall_dot_label(aid_t aid, int times_considered)
+{
+ std::string answer = simcall_to_string(MessageType::SIMCALL_DOT_LABEL, aid, times_considered);
+ XBT_DEBUG("dot_label(%ld) is returning %s", aid, answer.c_str());
+ return answer;
+}
+
+void ModelChecker::finalize_app(bool terminate_asap)
+{
+ s_mc_message_int_t m;
+ memset(&m, 0, sizeof m);
+ m.type = MessageType::FINALIZE;
+ m.value = terminate_asap;
+ xbt_assert(checker_side_.get_channel().send(m) == 0, "Could not ask the app to finalize on need");
+
+ s_mc_message_t answer;
+ xbt_assert(checker_side_.get_channel().receive(answer) != -1, "Could not receive answer to FINALIZE");
+}
+
+bool ModelChecker::checkDeadlock()
+{
+ xbt_assert(checker_side_.get_channel().send(MessageType::DEADLOCK_CHECK) == 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 == MessageType::DEADLOCK_CHECK_REPLY,
+ "Received unexpected message %s (%i, size=%i) "
+ "expected MessageType::DEADLOCK_CHECK_REPLY (%i, size=%i)",
+ to_c_str(message.type), (int)message.type, (int)s, (int)MessageType::DEADLOCK_CHECK_REPLY,
+ (int)sizeof(message));
+ return message.value != 0;
+}
+
+} // namespace mc
+} // namespace simgrid
