#include "src/mc/remote/CheckerSide.hpp"
#include "src/mc/explo/Exploration.hpp"
+#include "xbt/config.hpp"
+#include "xbt/system_error.hpp"
+
+#if SIMGRID_HAVE_STATEFUL_MC
#include "src/mc/explo/LivenessChecker.hpp"
#include "src/mc/sosp/RemoteProcessMemory.hpp"
-#include "xbt/system_error.hpp"
+#endif
#ifdef __linux__
#include <sys/prctl.h>
errno);
}
-void CheckerSide::setup_events()
+void CheckerSide::setup_events(bool socket_only)
{
- if (base_ != nullptr)
- event_base_free(base_.get());
auto* base = event_base_new();
base_.reset(base);
this);
event_add(socket_event_, nullptr);
- signal_event_ = event_new(
- base, SIGCHLD, EV_SIGNAL | EV_PERSIST,
- [](evutil_socket_t sig, short events, void* arg) {
- auto checker = static_cast<simgrid::mc::CheckerSide*>(arg);
- if (events == EV_SIGNAL) {
- if (sig == SIGCHLD)
- checker->handle_waitpid();
- else
- xbt_die("Unexpected signal: %d", sig);
- } else {
- xbt_die("Unexpected event");
- }
- },
- this);
- event_add(signal_event_, nullptr);
+ if (socket_only) {
+ signal_event_ = nullptr;
+ } else {
+ signal_event_ = event_new(
+ base, SIGCHLD, EV_SIGNAL | EV_PERSIST,
+ [](evutil_socket_t sig, short events, void* arg) {
+ auto checker = static_cast<simgrid::mc::CheckerSide*>(arg);
+ if (events == EV_SIGNAL) {
+ if (sig == SIGCHLD)
+ checker->handle_waitpid();
+ else
+ xbt_die("Unexpected signal: %d", sig);
+ } else {
+ xbt_die("Unexpected event");
+ }
+ },
+ this);
+ event_add(signal_event_, nullptr);
+ }
}
+/* When this constructor is called, no other checkerside exists */
CheckerSide::CheckerSide(const std::vector<char*>& args, bool need_memory_info) : running_(true)
{
// Create an AF_LOCAL socketpair used for exchanging messages between the model-checker process (ancestor)
// and the application process (child)
int sockets[2];
- xbt_assert(socketpair(AF_LOCAL, SOCK_SEQPACKET | SOCK_CLOEXEC, 0, sockets) != -1, "Could not create socketpair");
+ xbt_assert(socketpair(AF_LOCAL, SOCK_SEQPACKET | SOCK_CLOEXEC, 0, sockets) != -1, "Could not create socketpair: %s",
+ strerror(errno));
pid_ = fork();
- xbt_assert(pid_ >= 0, "Could not fork model-checked process");
+ xbt_assert(pid_ >= 0, "Could not fork application process");
if (pid_ == 0) { // Child
::close(sockets[1]);
::close(sockets[0]);
channel_.reset_socket(sockets[1]);
- setup_events();
- if (need_memory_info)
+ setup_events(false); /* we need a signal handler too */
+ if (need_memory_info) {
+#if SIMGRID_HAVE_STATEFUL_MC
+ // setup ptrace and sync with the app
wait_application_process(pid_);
- // Request the initial memory on need
- if (need_memory_info) {
- channel_.send(MessageType::INITIAL_ADDRESSES);
- s_mc_message_initial_addresses_reply_t answer;
+ // Request the initial memory on need
+ channel_.send(MessageType::NEED_MEMINFO);
+ s_mc_message_need_meminfo_reply_t answer;
ssize_t answer_size = channel_.receive(answer);
xbt_assert(answer_size != -1, "Could not receive message");
- xbt_assert(answer.type == MessageType::INITIAL_ADDRESSES_REPLY,
- "The received message is not the INITIAL_ADDRESS_REPLY I was expecting but of type %s",
+ xbt_assert(answer.type == MessageType::NEED_MEMINFO_REPLY,
+ "The received message is not the NEED_MEMINFO_REPLY I was expecting but of type %s",
to_c_str(answer.type));
xbt_assert(answer_size == sizeof answer, "Broken message (size=%zd; expected %zu)", answer_size, sizeof answer);
/* We now have enough info to create the memory address space */
remote_memory_ = std::make_unique<simgrid::mc::RemoteProcessMemory>(pid_, answer.mmalloc_default_mdp);
+#else
+ xbt_die("Cannot introspect memory without MC support");
+#endif
}
wait_for_requests();
{
event_del(socket_event_);
event_free(socket_event_);
- event_del(signal_event_);
- event_free(signal_event_);
+ if (signal_event_ != nullptr) {
+ event_del(signal_event_);
+ event_free(signal_event_);
+ }
+}
+
+/* This constructor is called when cloning a checkerside to get its application to fork away */
+CheckerSide::CheckerSide(int socket, CheckerSide* child_checker)
+ : channel_(socket), running_(true), child_checker_(child_checker)
+{
+ setup_events(true); // We already have a signal handled in that case
+
+ s_mc_message_int_t answer;
+ ssize_t s = get_channel().receive(answer);
+ xbt_assert(s != -1, "Could not receive answer to FORK_REPLY");
+ xbt_assert(s == sizeof answer, "Broken message (size=%zd; expected %zu)", s, sizeof answer);
+ xbt_assert(answer.type == MessageType::FORK_REPLY,
+ "Received unexpected message %s (%i); expected MessageType::FORK_REPLY (%i)", to_c_str(answer.type),
+ (int)answer.type, (int)MessageType::FORK_REPLY);
+ pid_ = answer.value;
+
+ wait_for_requests();
+}
+
+std::unique_ptr<CheckerSide> CheckerSide::clone(int master_socket)
+{
+ s_mc_message_int_t m = {};
+ m.type = MessageType::FORK;
+ m.value = getpid();
+ xbt_assert(get_channel().send(m) == 0, "Could not ask the app to fork on need.");
+
+ int sock = accept(master_socket, nullptr /* I know who's connecting*/, nullptr);
+ xbt_assert(sock > 0, "Cannot accept the incomming connection of the forked app: %s.", strerror(errno));
+
+ return std::make_unique<CheckerSide>(sock, this);
}
void CheckerSide::finalize(bool terminate_asap)
switch (base_message.type) {
case MessageType::IGNORE_HEAP: {
+#if SIMGRID_HAVE_STATEFUL_MC
if (remote_memory_ != nullptr) {
s_mc_message_ignore_heap_t message;
xbt_assert(size == sizeof(message), "Broken message");
region.address = message.address;
region.size = message.size;
get_remote_memory()->ignore_heap(region);
- } else {
+ } else
+#endif
XBT_INFO("Ignoring a IGNORE_HEAP message because we don't need to introspect memory.");
- }
break;
}
case MessageType::UNIGNORE_HEAP: {
+#if SIMGRID_HAVE_STATEFUL_MC
if (remote_memory_ != nullptr) {
s_mc_message_ignore_memory_t message;
xbt_assert(size == sizeof(message), "Broken message");
memcpy(&message, buffer, sizeof(message));
get_remote_memory()->unignore_heap((void*)message.addr, message.size);
- } else {
+ } else
+#endif
XBT_INFO("Ignoring an UNIGNORE_HEAP message because we don't need to introspect memory.");
- }
break;
}
case MessageType::IGNORE_MEMORY: {
+#if SIMGRID_HAVE_STATEFUL_MC
if (remote_memory_ != nullptr) {
s_mc_message_ignore_memory_t message;
xbt_assert(size == sizeof(message), "Broken message");
memcpy(&message, buffer, sizeof(message));
get_remote_memory()->ignore_region(message.addr, message.size);
- } else {
+ } else
+#endif
XBT_INFO("Ignoring an IGNORE_MEMORY message because we don't need to introspect memory.");
- }
break;
}
case MessageType::STACK_REGION: {
+#if SIMGRID_HAVE_STATEFUL_MC
if (remote_memory_ != nullptr) {
s_mc_message_stack_region_t message;
xbt_assert(size == sizeof(message), "Broken message");
memcpy(&message, buffer, sizeof(message));
get_remote_memory()->stack_areas().push_back(message.stack_region);
- } else {
+ } else
+#endif
XBT_INFO("Ignoring an STACK_REGION message because we don't need to introspect memory.");
- }
break;
}
case MessageType::REGISTER_SYMBOL: {
+#if SIMGRID_HAVE_STATEFUL_MC
s_mc_message_register_symbol_t message;
xbt_assert(size == sizeof(message), "Broken message");
memcpy(&message, buffer, sizeof(message));
XBT_DEBUG("Received symbol: %s", message.name.data());
LivenessChecker::automaton_register_symbol(*get_remote_memory(), message.name.data(), remote((int*)message.data));
+#else
+ xbt_die("Please don't use liveness properties when MC is compiled out.");
+#endif
break;
}
break;
default:
- xbt_die("Unexpected message from model-checked application");
+ xbt_die("Unexpected message from the application");
}
return true;
}
void CheckerSide::wait_for_requests()
{
- /* Resume the application */
+ XBT_DEBUG("Resume the application");
if (get_channel().send(MessageType::CONTINUE) != 0)
throw xbt::errno_error();
clear_memory_cache();
void CheckerSide::clear_memory_cache()
{
+#if SIMGRID_HAVE_STATEFUL_MC
if (remote_memory_)
remote_memory_->clear_cache();
+#endif
}
-void CheckerSide::handle_waitpid()
+void CheckerSide::handle_dead_child(int status)
{
- 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->running(), "Inconsistent state");
- break;
- } else {
- xbt_die("Could not wait for pid: %s", strerror(errno));
- }
- }
-
- if (pid == get_pid()) {
- // From PTRACE_O_TRACEEXIT:
+ // From PTRACE_O_TRACEEXIT:
#ifdef __linux__
- if (status >> 8 == (SIGTRAP | (PTRACE_EVENT_EXIT << 8))) {
- unsigned long eventmsg;
- xbt_assert(ptrace(PTRACE_GETEVENTMSG, pid, 0, &eventmsg) != -1, "Could not get exit status");
- status = static_cast<int>(eventmsg);
- if (WIFSIGNALED(status)) {
- this->terminate();
- Exploration::get_instance()->report_crash(status);
- }
- }
+ if (status >> 8 == (SIGTRAP | (PTRACE_EVENT_EXIT << 8))) {
+ unsigned long eventmsg;
+ xbt_assert(ptrace(PTRACE_GETEVENTMSG, pid_, 0, &eventmsg) != -1, "Could not get exit status");
+ status = static_cast<int>(eventmsg);
+ if (WIFSIGNALED(status)) {
+ this->terminate();
+ Exploration::get_instance()->report_crash(status);
+ }
+ }
#endif
- // 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;
+ // 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, pid, 0, WSTOPSIG(status));
+ ptrace(PTRACE_CONT, pid_, 0, WSTOPSIG(status));
#elif defined BSD
- ptrace(PT_CONTINUE, pid, (caddr_t)1, WSTOPSIG(status));
+ ptrace(PT_CONTINUE, pid_, (caddr_t)1, WSTOPSIG(status));
#endif
- xbt_assert(errno == 0, "Could not PTRACE_CONT");
- }
+ xbt_assert(errno == 0, "Could not PTRACE_CONT: %s", strerror(errno));
+ }
- else if (WIFSIGNALED(status)) {
- this->terminate();
- Exploration::get_instance()->report_crash(status);
- } else if (WIFEXITED(status)) {
- XBT_DEBUG("Child process is over");
- this->terminate();
+ else if (WIFSIGNALED(status)) {
+ this->terminate();
+ Exploration::get_instance()->report_crash(status);
+ } else if (WIFEXITED(status)) {
+ XBT_DEBUG("Child process is over");
+ this->terminate();
+ }
+}
+
+void CheckerSide::handle_waitpid()
+{
+ XBT_DEBUG("Check for wait event");
+
+ if (child_checker_ == nullptr) { // Wait directly
+ 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->running(), "Inconsistent state");
+ break;
+ } else {
+ xbt_die("Could not wait for pid: %s", strerror(errno));
+ }
}
+
+ if (pid == get_pid())
+ handle_dead_child(status);
}
+
+ } else { // Ask our proxy to wait for us
+
+ s_mc_message_int_t request = {};
+ request.type = MessageType::WAIT_CHILD;
+ request.value = pid_;
+ xbt_assert(child_checker_->get_channel().send(request) == 0,
+ "Could not ask my child to waitpid its child for me: %s", strerror(errno));
+
+ s_mc_message_int_t answer;
+ ssize_t answer_size = child_checker_->get_channel().receive(answer);
+ xbt_assert(answer_size != -1, "Could not receive message");
+ xbt_assert(answer.type == MessageType::WAIT_CHILD_REPLY,
+ "The received message is not the WAIT_CHILD_REPLY I was expecting but of type %s",
+ to_c_str(answer.type));
+ xbt_assert(answer_size == sizeof answer, "Broken message (size=%zd; expected %zu)", answer_size, sizeof answer);
+ handle_dead_child(answer.value);
}
}
-
} // namespace simgrid::mc
