#include <algorithm>
#include <array>
-#include <boost/tokenizer.hpp>
#include <memory>
#include <numeric>
#include <string>
-#include <fcntl.h>
-#ifdef __linux__
-#include <sys/personality.h>
-#include <sys/prctl.h>
-#endif
#include <sys/ptrace.h>
#include <sys/wait.h>
-#ifdef __linux__
-#define WAITPID_CHECKED_FLAGS __WALL
-#else
-#define WAITPID_CHECKED_FLAGS 0
-#endif
-
XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_Session, mc, "Model-checker session");
XBT_LOG_EXTERNAL_CATEGORY(mc_global);
-static simgrid::config::Flag<std::string> _sg_mc_setenv{
- "model-check/setenv", "Extra environment variables to pass to the child process (ex: 'AZE=aze;QWE=qwe').", "",
- [](std::string_view value) {
- xbt_assert(value.empty() || value.find('=', 0) != std::string_view::npos,
- "The 'model-check/setenv' parameter must be like 'AZE=aze', but it does not contain an equal sign.");
- }};
-
namespace simgrid::mc {
-XBT_ATTRIB_NORETURN static void run_child_process(int socket, const std::vector<char*>& args)
-{
- /* On startup, simix_global_init() calls simgrid::mc::Client::initialize(), which checks whether the MC_ENV_SOCKET_FD
- * env variable is set. If so, MC mode is assumed, and the client is setup from its side
- */
-
-#ifdef __linux__
- // Make sure we do not outlive our parent
- sigset_t mask;
- sigemptyset(&mask);
- xbt_assert(sigprocmask(SIG_SETMASK, &mask, nullptr) >= 0, "Could not unblock signals");
- xbt_assert(prctl(PR_SET_PDEATHSIG, SIGHUP) == 0, "Could not PR_SET_PDEATHSIG");
-
- // Make sure that the application process layout is not randomized, so that the info we gather is stable over re-execs
- if (personality(ADDR_NO_RANDOMIZE) == -1) {
- XBT_ERROR("Could not set the NO_RANDOMIZE personality");
- throw xbt::errno_error();
- }
-#endif
-
- // Remove CLOEXEC to pass the socket to the application
- int fdflags = fcntl(socket, F_GETFD, 0);
- xbt_assert(fdflags != -1 && fcntl(socket, F_SETFD, fdflags & ~FD_CLOEXEC) != -1,
- "Could not remove CLOEXEC for socket");
-
- setenv(MC_ENV_SOCKET_FD, std::to_string(socket).c_str(), 1);
-
- /* Setup the tokenizer that parses the cfg:model-check/setenv parameter */
- using Tokenizer = boost::tokenizer<boost::char_separator<char>>;
- boost::char_separator<char> semicol_sep(";");
- boost::char_separator<char> equal_sep("=");
- Tokenizer token_vars(_sg_mc_setenv.get(), semicol_sep); /* Iterate over all FOO=foo parts */
- for (const auto& token : token_vars) {
- std::vector<std::string> kv;
- Tokenizer token_kv(token, equal_sep);
- for (const auto& t : token_kv) /* Iterate over 'FOO' and then 'foo' in that 'FOO=foo' */
- kv.push_back(t);
- xbt_assert(kv.size() == 2, "Parse error on 'model-check/setenv' value %s. Does it contain an equal sign?",
- token.c_str());
- XBT_INFO("setenv '%s'='%s'", kv[0].c_str(), kv[1].c_str());
- setenv(kv[0].c_str(), kv[1].c_str(), 1);
- }
-
- /* And now, exec the child process */
- int i = 1;
- while (args[i] != nullptr && args[i][0] == '-')
- i++;
-
- xbt_assert(args[i] != nullptr,
- "Unable to find a binary to exec on the command line. Did you only pass config flags?");
-
- execvp(args[i], args.data() + i);
- XBT_CRITICAL("The model-checked process failed to exec(%s): %s.\n"
- " Make sure that your binary exists on disk and is executable.",
- args[i], strerror(errno));
- if (strchr(args[i], '=') != nullptr)
- XBT_CRITICAL("If you want to pass environment variables to the application, please use --cfg=model-check/setenv:%s",
- args[i]);
-
- xbt_die("Aborting now.");
-}
-
RemoteApp::RemoteApp(const std::vector<char*>& args)
{
- // Create an AF_LOCAL socketpair used for exchanging messages
- // between the model-checker process (ourselves) and the model-checked
- // process:
- int sockets[2];
- xbt_assert(socketpair(AF_LOCAL, SOCK_SEQPACKET | SOCK_CLOEXEC, 0, sockets) != -1, "Could not create socketpair");
-
- pid_t pid = fork();
- xbt_assert(pid >= 0, "Could not fork model-checked process");
-
- if (pid == 0) { // Child
- ::close(sockets[1]);
- run_child_process(sockets[0], args);
- DIE_IMPOSSIBLE;
- }
-
- // Parent (model-checker):
- ::close(sockets[0]);
- checker_side_ = std::make_unique<simgrid::mc::CheckerSide>(sockets[1], pid);
-
- start();
+ checker_side_ = std::make_unique<simgrid::mc::CheckerSide>(args);
/* Take the initial snapshot */
- wait_for_requests();
initial_snapshot_ = std::make_shared<simgrid::mc::Snapshot>(0, page_store_, checker_side_->get_remote_memory());
}
initial_snapshot_ = nullptr;
shutdown();
}
-void RemoteApp::start()
-{
- 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 = checker_side_->get_pid();
-
- 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);
-#elif defined BSD
- ptrace(PT_CONTINUE, pid, (caddr_t)1, 0);
-#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);
-}
+
void RemoteApp::restore_initial_state() const
{
this->initial_snapshot_->restore(checker_side_->get_remote_memory());
void RemoteApp::wait_for_requests()
{
- /* Resume the application */
- if (checker_side_->get_channel().send(MessageType::CONTINUE) != 0)
- throw xbt::errno_error();
- checker_side_->clear_memory_cache();
-
- if (checker_side_->running())
- checker_side_->dispatch_events();
+ checker_side_->wait_for_requests();
}
void RemoteApp::shutdown()
~RemoteApp();
- void start();
void restore_initial_state() const;
void wait_for_requests();
template <class M> static constexpr bool messageType() { return std::is_class_v<M> && std::is_trivial_v<M>; }
public:
+ Channel() = default;
explicit Channel(int sock) : socket_(sock) {}
~Channel();
}
int get_socket() const { return socket_; }
+ void reset_socket(int socket) { socket_ = socket; }
};
} // namespace simgrid::mc
#include "src/mc/sosp/RemoteProcessMemory.hpp"
#include "xbt/system_error.hpp"
+#ifdef __linux__
+#include <sys/personality.h>
+#include <sys/prctl.h>
+#endif
+
+#include <boost/tokenizer.hpp>
#include <csignal>
+#include <fcntl.h>
#include <sys/ptrace.h>
#include <sys/wait.h>
+#ifdef __linux__
+#define WAITPID_CHECKED_FLAGS __WALL
+#else
+#define WAITPID_CHECKED_FLAGS 0
+#endif
+
XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_checkerside, mc, "MC communication with the application");
+static simgrid::config::Flag<std::string> _sg_mc_setenv{
+ "model-check/setenv", "Extra environment variables to pass to the child process (ex: 'AZE=aze;QWE=qwe').", "",
+ [](std::string_view value) {
+ xbt_assert(value.empty() || value.find('=', 0) != std::string_view::npos,
+ "The 'model-check/setenv' parameter must be like 'AZE=aze', but it does not contain an equal sign.");
+ }};
+
namespace simgrid::mc {
-CheckerSide::CheckerSide(int sockfd, pid_t pid) : channel_(sockfd), running_(true), pid_(pid)
+
+XBT_ATTRIB_NORETURN static void run_child_process(int socket, const std::vector<char*>& args)
+{
+ /* On startup, simix_global_init() calls simgrid::mc::Client::initialize(), which checks whether the MC_ENV_SOCKET_FD
+ * env variable is set. If so, MC mode is assumed, and the client is setup from its side
+ */
+
+#ifdef __linux__
+ // Make sure we do not outlive our parent
+ sigset_t mask;
+ sigemptyset(&mask);
+ xbt_assert(sigprocmask(SIG_SETMASK, &mask, nullptr) >= 0, "Could not unblock signals");
+ xbt_assert(prctl(PR_SET_PDEATHSIG, SIGHUP) == 0, "Could not PR_SET_PDEATHSIG");
+
+ // Make sure that the application process layout is not randomized, so that the info we gather is stable over re-execs
+ if (personality(ADDR_NO_RANDOMIZE) == -1) {
+ XBT_ERROR("Could not set the NO_RANDOMIZE personality");
+ throw xbt::errno_error();
+ }
+#endif
+
+ // Remove CLOEXEC to pass the socket to the application
+ int fdflags = fcntl(socket, F_GETFD, 0);
+ xbt_assert(fdflags != -1 && fcntl(socket, F_SETFD, fdflags & ~FD_CLOEXEC) != -1,
+ "Could not remove CLOEXEC for socket");
+
+ setenv(MC_ENV_SOCKET_FD, std::to_string(socket).c_str(), 1);
+
+ /* Setup the tokenizer that parses the cfg:model-check/setenv parameter */
+ using Tokenizer = boost::tokenizer<boost::char_separator<char>>;
+ boost::char_separator<char> semicol_sep(";");
+ boost::char_separator<char> equal_sep("=");
+ Tokenizer token_vars(_sg_mc_setenv.get(), semicol_sep); /* Iterate over all FOO=foo parts */
+ for (const auto& token : token_vars) {
+ std::vector<std::string> kv;
+ Tokenizer token_kv(token, equal_sep);
+ for (const auto& t : token_kv) /* Iterate over 'FOO' and then 'foo' in that 'FOO=foo' */
+ kv.push_back(t);
+ xbt_assert(kv.size() == 2, "Parse error on 'model-check/setenv' value %s. Does it contain an equal sign?",
+ token.c_str());
+ XBT_INFO("setenv '%s'='%s'", kv[0].c_str(), kv[1].c_str());
+ setenv(kv[0].c_str(), kv[1].c_str(), 1);
+ }
+
+ /* And now, exec the child process */
+ int i = 1;
+ while (args[i] != nullptr && args[i][0] == '-')
+ i++;
+
+ xbt_assert(args[i] != nullptr,
+ "Unable to find a binary to exec on the command line. Did you only pass config flags?");
+
+ execvp(args[i], args.data() + i);
+ XBT_CRITICAL("The model-checked process failed to exec(%s): %s.\n"
+ " Make sure that your binary exists on disk and is executable.",
+ args[i], strerror(errno));
+ if (strchr(args[i], '=') != nullptr)
+ XBT_CRITICAL("If you want to pass environment variables to the application, please use --cfg=model-check/setenv:%s",
+ args[i]);
+
+ xbt_die("Aborting now.");
+}
+
+static void wait_application_process(pid_t pid)
+{
+ XBT_DEBUG("Waiting for the model-checked process");
+ int status;
+
+ // The model-checked process SIGSTOP itself to signal it's ready:
+ 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);
+#elif defined BSD
+ ptrace(PT_CONTINUE, pid, (caddr_t)1, 0);
+#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);
+}
+
+void CheckerSide::setup_events()
{
auto* base = event_base_new();
base_.reset(base);
signal_event_.reset(signal_event);
}
+CheckerSide::CheckerSide(const std::vector<char*>& args) : 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");
+
+ pid_ = fork();
+ xbt_assert(pid_ >= 0, "Could not fork model-checked process");
+
+ if (pid_ == 0) { // Child
+ ::close(sockets[1]);
+ run_child_process(sockets[0], args);
+ DIE_IMPOSSIBLE;
+ }
+
+ // Parent (model-checker):
+ ::close(sockets[0]);
+ channel_.reset_socket(sockets[1]);
+
+ setup_events();
+ wait_application_process(pid_);
+
+ wait_for_requests();
+}
+
void CheckerSide::dispatch_events() const
{
event_base_dispatch(base_.get());
return true;
}
+void CheckerSide::wait_for_requests()
+{
+ /* Resume the application */
+ if (get_channel().send(MessageType::CONTINUE) != 0)
+ throw xbt::errno_error();
+ clear_memory_cache();
+
+ if (running())
+ dispatch_events();
+}
+
void CheckerSide::clear_memory_cache()
{
if (remote_memory_)
bool running_ = false;
pid_t pid_;
+ void setup_events(); // Part of the initialization
+
public:
- explicit CheckerSide(int sockfd, pid_t pid);
+ explicit CheckerSide(const std::vector<char*>& args);
// No copy:
CheckerSide(CheckerSide const&) = delete;
bool handle_message(const char* buffer, ssize_t size);
void dispatch_events() const;
void break_loop() const;
+ void wait_for_requests();
/* Interacting with the application process */
pid_t get_pid() const { return pid_; }
