1 /* Copyright (c) 2007-2023. The SimGrid Team. All rights reserved. */
3 /* This program is free software; you can redistribute it and/or modify it
4 * under the terms of the license (GNU LGPL) which comes with this package. */
6 #include "src/mc/remote/CheckerSide.hpp"
7 #include "src/mc/explo/Exploration.hpp"
8 #include "src/mc/explo/LivenessChecker.hpp"
9 #include "src/mc/sosp/RemoteProcessMemory.hpp"
10 #include "xbt/system_error.hpp"
13 #include <sys/ptrace.h>
16 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_checkerside, mc, "MC communication with the application");
18 namespace simgrid::mc {
19 CheckerSide::CheckerSide(int sockfd, std::unique_ptr<RemoteProcessMemory> memory)
20 : remote_memory_(std::move(memory)), channel_(sockfd)
22 auto* base = event_base_new();
25 auto* socket_event = event_new(
26 base, get_channel().get_socket(), EV_READ | EV_PERSIST,
27 [](evutil_socket_t sig, short events, void* arg) {
28 auto checker = static_cast<simgrid::mc::CheckerSide*>(arg);
29 if (events == EV_READ) {
30 std::array<char, MC_MESSAGE_LENGTH> buffer;
31 ssize_t size = recv(checker->get_channel().get_socket(), buffer.data(), buffer.size(), MSG_DONTWAIT);
33 XBT_ERROR("Channel::receive failure: %s", strerror(errno));
35 throw simgrid::xbt::errno_error();
38 if (not checker->handle_message(buffer.data(), size))
39 checker->break_loop();
41 xbt_die("Unexpected event");
45 event_add(socket_event, nullptr);
46 socket_event_.reset(socket_event);
48 auto* signal_event = event_new(
49 base, SIGCHLD, EV_SIGNAL | EV_PERSIST,
50 [](evutil_socket_t sig, short events, void* arg) {
51 auto checker = static_cast<simgrid::mc::CheckerSide*>(arg);
52 if (events == EV_SIGNAL) {
54 checker->handle_waitpid();
56 xbt_die("Unexpected signal: %d", sig);
58 xbt_die("Unexpected event");
62 event_add(signal_event, nullptr);
63 signal_event_.reset(signal_event);
66 void CheckerSide::dispatch_events() const
68 event_base_dispatch(base_.get());
71 void CheckerSide::break_loop() const
73 event_base_loopbreak(base_.get());
76 bool CheckerSide::handle_message(const char* buffer, ssize_t size)
78 s_mc_message_t base_message;
79 xbt_assert(size >= (ssize_t)sizeof(base_message), "Broken message");
80 memcpy(&base_message, buffer, sizeof(base_message));
82 switch (base_message.type) {
83 case MessageType::INITIAL_ADDRESSES: {
84 s_mc_message_initial_addresses_t message;
85 xbt_assert(size == sizeof(message), "Broken message. Got %d bytes instead of %d.", (int)size,
86 (int)sizeof(message));
87 memcpy(&message, buffer, sizeof(message));
89 get_remote_memory().init(message.mmalloc_default_mdp);
93 case MessageType::IGNORE_HEAP: {
94 s_mc_message_ignore_heap_t message;
95 xbt_assert(size == sizeof(message), "Broken message");
96 memcpy(&message, buffer, sizeof(message));
98 IgnoredHeapRegion region;
99 region.block = message.block;
100 region.fragment = message.fragment;
101 region.address = message.address;
102 region.size = message.size;
103 get_remote_memory().ignore_heap(region);
107 case MessageType::UNIGNORE_HEAP: {
108 s_mc_message_ignore_memory_t message;
109 xbt_assert(size == sizeof(message), "Broken message");
110 memcpy(&message, buffer, sizeof(message));
111 get_remote_memory().unignore_heap((void*)(std::uintptr_t)message.addr, message.size);
115 case MessageType::IGNORE_MEMORY: {
116 s_mc_message_ignore_memory_t message;
117 xbt_assert(size == sizeof(message), "Broken message");
118 memcpy(&message, buffer, sizeof(message));
119 get_remote_memory().ignore_region(message.addr, message.size);
123 case MessageType::STACK_REGION: {
124 s_mc_message_stack_region_t message;
125 xbt_assert(size == sizeof(message), "Broken message");
126 memcpy(&message, buffer, sizeof(message));
127 get_remote_memory().stack_areas().push_back(message.stack_region);
130 case MessageType::REGISTER_SYMBOL: {
131 s_mc_message_register_symbol_t message;
132 xbt_assert(size == sizeof(message), "Broken message");
133 memcpy(&message, buffer, sizeof(message));
134 xbt_assert(not message.callback, "Support for client-side function proposition is not implemented.");
135 XBT_DEBUG("Received symbol: %s", message.name.data());
137 LivenessChecker::automaton_register_symbol(get_remote_memory(), message.name.data(), remote((int*)message.data));
141 case MessageType::WAITING:
144 case MessageType::ASSERTION_FAILED:
145 Exploration::get_instance()->report_assertion_failure();
149 xbt_die("Unexpected message from model-checked application");
154 void CheckerSide::handle_waitpid()
156 XBT_DEBUG("Check for wait event");
159 while ((pid = waitpid(-1, &status, WNOHANG)) != 0) {
161 if (errno == ECHILD) { // No more children:
162 xbt_assert(not get_remote_memory().running(), "Inconsistent state");
165 XBT_ERROR("Could not wait for pid");
166 throw simgrid::xbt::errno_error();
170 if (pid == get_remote_memory().pid()) {
171 // From PTRACE_O_TRACEEXIT:
173 if (status >> 8 == (SIGTRAP | (PTRACE_EVENT_EXIT << 8))) {
174 unsigned long eventmsg;
175 xbt_assert(ptrace(PTRACE_GETEVENTMSG, pid, 0, &eventmsg) != -1, "Could not get exit status");
176 status = static_cast<int>(eventmsg);
177 if (WIFSIGNALED(status))
178 Exploration::get_instance()->report_crash(status);
182 // We don't care about non-lethal signals, just reinject them:
183 if (WIFSTOPPED(status)) {
184 XBT_DEBUG("Stopped with signal %i", (int)WSTOPSIG(status));
187 ptrace(PTRACE_CONT, pid, 0, WSTOPSIG(status));
189 ptrace(PT_CONTINUE, pid, (caddr_t)1, WSTOPSIG(status));
191 xbt_assert(errno == 0, "Could not PTRACE_CONT");
194 else if (WIFSIGNALED(status)) {
195 Exploration::get_instance()->report_crash(status);
196 } else if (WIFEXITED(status)) {
197 XBT_DEBUG("Child process is over");
198 get_remote_memory().terminate();
204 } // namespace simgrid::mc