X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/d20f024dba9ff1e9c8822237caaf963b9e913889..8f980bafd078433bccc0f0117221753fdd8107c0:/src/mc/ModelChecker.cpp

diff --git a/src/mc/ModelChecker.cpp b/src/mc/ModelChecker.cpp
index 4c47db57f7..10f0ba30c6 100644
--- a/src/mc/ModelChecker.cpp
+++ b/src/mc/ModelChecker.cpp
@@ -1,106 +1,75 @@
-/* Copyright (c) 2008-2017. The SimGrid Team.
- * All rights reserved.                                                     */
+/* Copyright (c) 2008-2023. 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 <sys/types.h>
-#include <sys/wait.h>
-#include <sys/socket.h>
-#include <sys/ptrace.h>
-
-#include <memory>
-#include <system_error>
-
-#include "xbt/automaton.h"
-#include "xbt/automaton.hpp"
-#include "xbt/log.h"
-#include "xbt/system_error.hpp"
-
-#include "simgrid/sg_config.h"
-
 #include "src/mc/ModelChecker.hpp"
-#include "src/mc/ModelChecker.hpp"
-#include "src/mc/PageStore.hpp"
-#include "src/mc/Transition.hpp"
-#include "src/mc/checker/Checker.hpp"
+#include "src/mc/explo/Exploration.hpp"
+#include "src/mc/explo/LivenessChecker.hpp"
+#include "src/mc/mc_config.hpp"
 #include "src/mc/mc_exit.hpp"
 #include "src/mc/mc_private.hpp"
-#include "src/mc/mc_record.hpp"
-#include "src/mc/remote/mc_protocol.h"
+#include "src/mc/sosp/RemoteProcessMemory.hpp"
+#include "src/mc/transition/TransitionComm.hpp"
+#include "xbt/automaton.hpp"
+#include "xbt/system_error.hpp"
+
+#include <array>
+#include <csignal>
+#include <sys/ptrace.h>
+#include <sys/wait.h>
 
 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 {
+namespace simgrid::mc {
 
-ModelChecker::ModelChecker(std::unique_ptr<RemoteClient> process)
-    : base_(nullptr)
-    , socket_event_(nullptr)
-    , signal_event_(nullptr)
-    , page_store_(500)
-    , process_(std::move(process))
-    , parent_snapshot_(nullptr)
+ModelChecker::ModelChecker(std::unique_ptr<RemoteProcessMemory> remote_memory, int sockfd)
+    : checker_side_(sockfd), remote_process_memory_(std::move(remote_memory))
 {
-
-}
-
-ModelChecker::~ModelChecker() {
-  if (socket_event_ != nullptr)
-    event_free(socket_event_);
-  if (signal_event_ != nullptr)
-    event_free(signal_event_);
-  if (base_ != nullptr)
-    event_base_free(base_);
 }
 
 void ModelChecker::start()
 {
-  const pid_t pid = process_->pid();
-
-  base_ = event_base_new();
-  event_callback_fn event_callback = [](evutil_socket_t fd, short events, void *arg)
-  {
-    ((ModelChecker *)arg)->handle_events(fd, events);
-  };
-  socket_event_ = event_new(base_,
-                            process_->getChannel().getSocket(),
-                            EV_READ|EV_PERSIST,
-                            event_callback, this);
-  event_add(socket_event_, NULL);
-  signal_event_ = event_new(base_,
-                            SIGCHLD,
-                            EV_SIGNAL|EV_PERSIST,
-                            event_callback, this);
-  event_add(signal_event_, NULL);
+  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 signal: %d", sig);
+        } 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:
-  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");
-
-  process_->init();
+  const pid_t pid = remote_process_memory_->pid();
 
-  if ((_sg_mc_dot_output_file != nullptr) && (_sg_mc_dot_output_file[0] != '\0'))
-    MC_init_dot_output();
-
-  setup_ignore();
+  xbt_assert(waitpid(pid, &status, WAITPID_CHECKED_FLAGS) == pid && WIFSTOPPED(status) && WSTOPSIG(status) == SIGSTOP,
+             "Could not wait model-checked process");
 
+  errno = 0;
 #ifdef __linux__
   ptrace(PTRACE_SETOPTIONS, pid, nullptr, PTRACE_O_TRACEEXIT);
   ptrace(PTRACE_CONT, pid, 0, 0);
@@ -109,216 +78,91 @@ void ModelChecker::start()
 #else
 # error "no ptrace equivalent coded for this platform"
 #endif
+  xbt_assert(errno == 0,
+             "Ptrace does not seem to be usable in your setup (errno: %d). "
+             "If you run from within a docker, adding `--cap-add SYS_PTRACE` to the docker line may help. "
+             "If it does not help, please report this bug.",
+             errno);
 }
 
-static const std::pair<const char*, const char*> ignored_local_variables[] = {
-  std::pair<const char*, const char*>{  "e", "*" },
-  std::pair<const char*, const char*>{ "__ex_cleanup", "*" },
-  std::pair<const char*, const char*>{ "__ex_mctx_en", "*" },
-  std::pair<const char*, const char*>{ "__ex_mctx_me", "*" },
-  std::pair<const char*, const char*>{ "__xbt_ex_ctx_ptr", "*" },
-  std::pair<const char*, const char*>{ "_log_ev", "*" },
-  std::pair<const char*, const char*>{ "_throw_ctx", "*" },
-  std::pair<const char*, const char*>{ "ctx", "*" },
-
-  std::pair<const char*, const char*>{ "self", "simcall_BODY_mc_snapshot" },
-  std::pair<const char*, const char*>{ "next_context", "smx_ctx_sysv_suspend_serial" },
-  std::pair<const char*, const char*>{ "i", "smx_ctx_sysv_suspend_serial" },
-
-  /* Ignore local variable about time used for tracing */
-  std::pair<const char*, const char*>{ "start_time", "*" },
-};
-
-void ModelChecker::setup_ignore()
-{
-  RemoteClient& process = this->process();
-  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("Shuting down model-checker");
-
-  simgrid::mc::RemoteClient* process = &this->process();
-  if (process->running()) {
-    XBT_DEBUG("Killing process");
-    kill(process->pid(), SIGKILL);
-    process->terminate();
-  }
-}
-
-void ModelChecker::resume(simgrid::mc::RemoteClient& process)
-{
-  int res = process.getChannel().send(MC_MESSAGE_CONTINUE);
-  if (res)
-    throw simgrid::xbt::errno_error();
-  process.clear_cache();
-}
-
-static void MC_report_crash(int status)
+bool ModelChecker::handle_message(const char* buffer, ssize_t size)
 {
-  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 (WCOREDUMP(status))
-    XBT_INFO("A core dump was generated by the system.");
-  else
-    XBT_INFO("No core dump was generated by the system.");
-  XBT_INFO("Counter-example execution trace:");
-  simgrid::mc::dumpRecordPath();
-  for (auto const& s : mc_model_checker->getChecker()->getTextualTrace())
-    XBT_INFO("%s", s.c_str());
-  simgrid::mc::session->logState();
-  XBT_INFO("Stack trace:");
-  mc_model_checker->process().dumpStack();
-}
-
-static void MC_report_assertion_error()
-{
-  XBT_INFO("**************************");
-  XBT_INFO("*** PROPERTY NOT VALID ***");
-  XBT_INFO("**************************");
-  XBT_INFO("Counter-example execution trace:");
-  simgrid::mc::dumpRecordPath();
-  for (auto const& s : mc_model_checker->getChecker()->getTextualTrace())
-    XBT_INFO("%s", s.c_str());
-  simgrid::mc::session->logState();
-}
-
-bool ModelChecker::handle_message(char* buffer, ssize_t size)
-{
-  mc_message_t base_message;
-  if (size < (ssize_t) sizeof(base_message))
-    xbt_die("Broken message");
+  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));
 
-  case MC_MESSAGE_IGNORE_HEAP:
-    {
-    s_mc_message_ignore_heap_t message;
-    if (size != sizeof(message))
-      xbt_die("Broken messsage");
-    memcpy(&message, buffer, sizeof(message));
-
-    IgnoredHeapRegion region;
-    region.block    = message.block;
-    region.fragment = message.fragment;
-    region.address  = message.address;
-    region.size     = message.size;
-    process().ignore_heap(region);
-    break;
+      get_remote_process_memory().init(message.mmalloc_default_mdp);
+      break;
     }
 
-  case MC_MESSAGE_UNIGNORE_HEAP:
-    {
-    s_mc_message_ignore_memory_t message;
-    if (size != sizeof(message))
-      xbt_die("Broken messsage");
-    memcpy(&message, buffer, sizeof(message));
-    process().unignore_heap((void*)(std::uintptr_t)message.addr, message.size);
-    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_memory().ignore_heap(region);
+      break;
     }
 
-  case MC_MESSAGE_IGNORE_MEMORY:
-    {
-    s_mc_message_ignore_memory_t message;
-    if (size != sizeof(message))
-      xbt_die("Broken messsage");
-    memcpy(&message, buffer, sizeof(message));
-    this->process().ignore_region(message.addr, message.size);
-    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_memory().unignore_heap((void*)(std::uintptr_t)message.addr, message.size);
+      break;
     }
 
-  case MC_MESSAGE_STACK_REGION:
-    {
-    s_mc_message_stack_region_t message;
-    if (size != sizeof(message))
-      xbt_die("Broken messsage");
-    memcpy(&message, buffer, sizeof(message));
-    this->process().stack_areas().push_back(message.stack_region);
-    }
-    break;
-
-  case MC_MESSAGE_REGISTER_SYMBOL:
-    {
-    s_mc_message_register_symbol_t message;
-    if (size != sizeof(message))
-      xbt_die("Broken message");
-    memcpy(&message, buffer, sizeof(message));
-    if (message.callback)
-      xbt_die("Support for client-side function proposition is not implemented.");
-    XBT_DEBUG("Received symbol: %s", message.name);
-
-    if (simgrid::mc::property_automaton == nullptr)
-      simgrid::mc::property_automaton = xbt_automaton_new();
-
-    simgrid::mc::RemoteClient* process  = &this->process();
-    simgrid::mc::RemotePtr<int> address = simgrid::mc::remote((int*)message.data);
-    simgrid::xbt::add_proposition(simgrid::mc::property_automaton, message.name,
-                                  [process, address]() { return process->read(address); });
-
-    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_memory().ignore_region(message.addr, message.size);
+      break;
     }
 
-  case MC_MESSAGE_WAITING:
-    return false;
+    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_memory().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());
+
+      LivenessChecker::automaton_register_symbol(get_remote_process_memory(), message.name.data(),
+                                                 remote((int*)message.data));
+      break;
+    }
 
-  case MC_MESSAGE_ASSERTION_FAILED:
-    MC_report_assertion_error();
-    this->exit(SIMGRID_MC_EXIT_SAFETY);
-    break;
+    case MessageType::WAITING:
+      return false;
 
-  default:
-    xbt_die("Unexpected message from model-checked application");
+    case MessageType::ASSERTION_FAILED:
+      exploration_->report_assertion_failure();
+      break;
 
+    default:
+      xbt_die("Unexpected message from model-checked application");
   }
   return true;
 }
 
-/** Terminate the model-checker application */
-void ModelChecker::exit(int status)
-{
-  // TODO, terminate the model checker politely instead of exiting rudely
-  if (process().running())
-    kill(process().pid(), SIGKILL);
-  ::exit(status);
-}
-
-void ModelChecker::handle_events(int fd, short events)
-{
-  if (events == EV_READ) {
-    char buffer[MC_MESSAGE_LENGTH];
-    ssize_t size = process_->getChannel().receive(buffer, sizeof(buffer), false);
-    if (size == -1 && errno != EAGAIN)
-      throw simgrid::xbt::errno_error();
-    if (not handle_message(buffer, size)) {
-      event_base_loopbreak(base_);
-    }
-  }
-  else if (events == EV_SIGNAL) {
-    on_signal(fd);
-  }
-  else {
-    xbt_die("Unexpected event");
-  }
-}
-
-void ModelChecker::loop()
-{
-  if (this->process().running())
-    event_base_dispatch(base_);
-}
-
 void ModelChecker::handle_waitpid()
 {
   XBT_DEBUG("Check for wait event");
@@ -328,99 +172,74 @@ void ModelChecker::handle_waitpid()
     if (pid == -1) {
       if (errno == ECHILD) {
         // No more children:
-        if (this->process().running())
-          xbt_die("Inconsistent state");
-        else
-          break;
+        xbt_assert(not this->get_remote_process_memory().running(), "Inconsistent state");
+        break;
       } else {
         XBT_ERROR("Could not wait for pid");
         throw simgrid::xbt::errno_error();
       }
     }
 
-    if (pid == this->process().pid()) {
-
+    if (pid == this->get_remote_process_memory().pid()) {
       // From PTRACE_O_TRACEEXIT:
 #ifdef __linux__
       if (status>>8 == (SIGTRAP | (PTRACE_EVENT_EXIT<<8))) {
-        if (ptrace(PTRACE_GETEVENTMSG, this->process().pid(), 0, &status) == -1)
-          xbt_die("Could not get exit status");
-        if (WIFSIGNALED(status)) {
-          MC_report_crash(status);
-          mc_model_checker->exit(SIMGRID_MC_EXIT_PROGRAM_CRASH);
-        }
+        unsigned long eventmsg;
+        xbt_assert(ptrace(PTRACE_GETEVENTMSG, get_remote_process_memory().pid(), 0, &eventmsg) != -1,
+                   "Could not get exit status");
+        status = static_cast<int>(eventmsg);
+        if (WIFSIGNALED(status))
+          exploration_->report_crash(status);
       }
 #endif
 
-      // We don't care about signals, just reinject them:
+      // We don't care about non-lethal signals, just reinject them:
       if (WIFSTOPPED(status)) {
         XBT_DEBUG("Stopped with signal %i", (int) WSTOPSIG(status));
         errno = 0;
 #ifdef __linux__
-        ptrace(PTRACE_CONT, this->process().pid(), 0, WSTOPSIG(status));
+        ptrace(PTRACE_CONT, get_remote_process_memory().pid(), 0, WSTOPSIG(status));
 #elif defined BSD
-        ptrace(PT_CONTINUE, this->process().pid(), (caddr_t)1, WSTOPSIG(status));
+        ptrace(PT_CONTINUE, get_remote_process_memory().pid(), (caddr_t)1, WSTOPSIG(status));
 #endif
-        if (errno != 0)
-          xbt_die("Could not PTRACE_CONT");
+        xbt_assert(errno == 0, "Could not PTRACE_CONT");
       }
 
-      else if (WIFEXITED(status) || WIFSIGNALED(status)) {
+      else if (WIFSIGNALED(status)) {
+        exploration_->report_crash(status);
+      } else if (WIFEXITED(status)) {
         XBT_DEBUG("Child process is over");
-        this->process().terminate();
+        this->get_remote_process_memory().terminate();
       }
     }
   }
 }
 
-void ModelChecker::on_signal(int signo)
+Transition* ModelChecker::handle_simcall(aid_t aid, int times_considered, bool new_transition)
 {
-  switch(signo) {
-  case SIGCHLD:
-    this->handle_waitpid();
-    break;
-  default:
-    break;
-  }
-}
+  s_mc_message_simcall_execute_t m = {};
+  m.type              = MessageType::SIMCALL_EXECUTE;
+  m.aid_              = aid;
+  m.times_considered_ = times_considered;
+  checker_side_.get_channel().send(m);
 
-void ModelChecker::wait_for_requests()
-{
-  this->resume(process());
-  if (this->process().running())
-    event_base_dispatch(base_);
-}
+  this->remote_process_memory_->clear_cache();
+  if (this->remote_process_memory_->running())
+    checker_side_.dispatch(); // The app may send messages while processing the transition
 
-void ModelChecker::handle_simcall(Transition const& transition)
-{
-  s_mc_message_simcall_handle m;
-  memset(&m, 0, sizeof(m));
-  m.type  = MC_MESSAGE_SIMCALL_HANDLE;
-  m.pid   = transition.pid;
-  m.value = transition.argument;
-  this->process_->getChannel().send(m);
-  this->process_->clear_cache();
-  if (this->process_->running())
-    event_base_dispatch(base_);
-}
+  s_mc_message_simcall_execute_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, "Broken message (size=%zd; expected %zu)", s, sizeof answer);
+  xbt_assert(answer.type == MessageType::SIMCALL_EXECUTE_ANSWER,
+             "Received unexpected message %s (%i); expected MessageType::SIMCALL_EXECUTE_ANSWER (%i)",
+             to_c_str(answer.type), (int)answer.type, (int)MessageType::SIMCALL_EXECUTE_ANSWER);
 
-bool ModelChecker::checkDeadlock()
-{
-  int res;
-  if ((res = this->process().getChannel().send(MC_MESSAGE_DEADLOCK_CHECK)))
-    xbt_die("Could not check deadlock state");
-  mc_message_int_t message;
-  ssize_t s = mc_model_checker->process().getChannel().receive(message);
-  if (s == -1)
-    xbt_die("Could not receive message");
-  if (s != sizeof(message) || message.type != MC_MESSAGE_DEADLOCK_CHECK_REPLY)
-    xbt_die("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;
+  if (new_transition) {
+    std::stringstream stream(answer.buffer.data());
+    return deserialize_transition(aid, times_considered, stream);
+  } else
+    return nullptr;
 }
 
-}
-}
+} // namespace simgrid::mc