summaryrefslogtreecommitdiffstats
path: root/src/core/debugger/debugger.cpp
blob: 1a8e02e6a4dd1ac109142b92b948de3229d4c89a (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
// SPDX-FileCopyrightText: Copyright 2022 yuzu Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later

#include <algorithm>
#include <mutex>
#include <thread>

#include <boost/asio.hpp>
#include <boost/process/async_pipe.hpp>

#include "common/logging/log.h"
#include "common/thread.h"
#include "core/core.h"
#include "core/debugger/debugger.h"
#include "core/debugger/debugger_interface.h"
#include "core/debugger/gdbstub.h"
#include "core/hle/kernel/global_scheduler_context.h"
#include "core/hle/kernel/k_scheduler.h"

template <typename Readable, typename Buffer, typename Callback>
static void AsyncReceiveInto(Readable& r, Buffer& buffer, Callback&& c) {
    static_assert(std::is_trivial_v<Buffer>);
    auto boost_buffer{boost::asio::buffer(&buffer, sizeof(Buffer))};
    r.async_read_some(
        boost_buffer, [&, c](const boost::system::error_code& error, size_t bytes_read) {
            if (!error.failed()) {
                const u8* buffer_start = reinterpret_cast<const u8*>(&buffer);
                std::span<const u8> received_data{buffer_start, buffer_start + bytes_read};
                c(received_data);
                AsyncReceiveInto(r, buffer, c);
            }
        });
}

template <typename Callback>
static void AsyncAccept(boost::asio::ip::tcp::acceptor& acceptor, Callback&& c) {
    acceptor.async_accept([&, c](const boost::system::error_code& error, auto&& peer_socket) {
        if (!error.failed()) {
            c(peer_socket);
            AsyncAccept(acceptor, c);
        }
    });
}

template <typename Readable, typename Buffer>
static std::span<const u8> ReceiveInto(Readable& r, Buffer& buffer) {
    static_assert(std::is_trivial_v<Buffer>);
    auto boost_buffer{boost::asio::buffer(&buffer, sizeof(Buffer))};
    size_t bytes_read = r.read_some(boost_buffer);
    const u8* buffer_start = reinterpret_cast<const u8*>(&buffer);
    std::span<const u8> received_data{buffer_start, buffer_start + bytes_read};
    return received_data;
}

enum class SignalType {
    Stopped,
    Watchpoint,
    ShuttingDown,
};

struct SignalInfo {
    SignalType type;
    Kernel::KThread* thread;
    const Kernel::DebugWatchpoint* watchpoint;
};

namespace Core {

class DebuggerImpl : public DebuggerBackend {
public:
    explicit DebuggerImpl(Core::System& system_, u16 port) : system{system_} {
        InitializeServer(port);
    }

    ~DebuggerImpl() override {
        ShutdownServer();
    }

    bool SignalDebugger(SignalInfo signal_info) {
        std::scoped_lock lk{connection_lock};

        if (stopped || !state) {
            // Do not notify the debugger about another event.
            // It should be ignored.
            return false;
        }

        // Set up the state.
        stopped = true;
        state->info = signal_info;

        // Write a single byte into the pipe to wake up the debug interface.
        boost::asio::write(state->signal_pipe, boost::asio::buffer(&stopped, sizeof(stopped)));

        return true;
    }

    // These functions are callbacks from the frontend, and the lock will be held.
    // There is no need to relock it.

    std::span<const u8> ReadFromClient() override {
        return ReceiveInto(state->client_socket, state->client_data);
    }

    void WriteToClient(std::span<const u8> data) override {
        boost::asio::write(state->client_socket,
                           boost::asio::buffer(data.data(), data.size_bytes()));
    }

    void SetActiveThread(Kernel::KThread* thread) override {
        state->active_thread = thread;
    }

    Kernel::KThread* GetActiveThread() override {
        return state->active_thread;
    }

private:
    void InitializeServer(u16 port) {
        using boost::asio::ip::tcp;

        LOG_INFO(Debug_GDBStub, "Starting server on port {}...", port);

        // Run the connection thread.
        connection_thread = std::jthread([&, port](std::stop_token stop_token) {
            Common::SetCurrentThreadName("Debugger");

            try {
                // Initialize the listening socket and accept a new client.
                tcp::endpoint endpoint{boost::asio::ip::address_v4::any(), port};
                tcp::acceptor acceptor{io_context, endpoint};

                AsyncAccept(acceptor, [&](auto&& peer) { AcceptConnection(std::move(peer)); });

                while (!stop_token.stop_requested() && io_context.run()) {
                }
            } catch (const std::exception& ex) {
                LOG_CRITICAL(Debug_GDBStub, "Stopping server: {}", ex.what());
            }
        });
    }

    void AcceptConnection(boost::asio::ip::tcp::socket&& peer) {
        LOG_INFO(Debug_GDBStub, "Accepting new peer connection");

        std::scoped_lock lk{connection_lock};

        // Ensure everything is stopped.
        PauseEmulation();

        // Set up the new frontend.
        frontend = std::make_unique<GDBStub>(*this, system);

        // Set the new state. This will tear down any existing state.
        state = ConnectionState{
            .client_socket{std::move(peer)},
            .signal_pipe{io_context},
            .info{},
            .active_thread{},
            .client_data{},
            .pipe_data{},
        };

        // Set up the client signals for new data.
        AsyncReceiveInto(state->signal_pipe, state->pipe_data, [&](auto d) { PipeData(d); });
        AsyncReceiveInto(state->client_socket, state->client_data, [&](auto d) { ClientData(d); });

        // Set the active thread.
        UpdateActiveThread();

        // Set up the frontend.
        frontend->Connected();
    }

    void ShutdownServer() {
        connection_thread.request_stop();
        io_context.stop();
        connection_thread.join();
    }

    void PipeData(std::span<const u8> data) {
        std::scoped_lock lk{connection_lock};

        switch (state->info.type) {
        case SignalType::Stopped:
        case SignalType::Watchpoint:
            // Stop emulation.
            PauseEmulation();

            // Notify the client.
            state->active_thread = state->info.thread;
            UpdateActiveThread();

            if (state->info.type == SignalType::Watchpoint) {
                frontend->Watchpoint(state->active_thread, *state->info.watchpoint);
            } else {
                frontend->Stopped(state->active_thread);
            }

            break;
        case SignalType::ShuttingDown:
            frontend->ShuttingDown();

            // Wait for emulation to shut down gracefully now.
            state->signal_pipe.close();
            state->client_socket.shutdown(boost::asio::socket_base::shutdown_both);
            LOG_INFO(Debug_GDBStub, "Shut down server");

            break;
        }
    }

    void ClientData(std::span<const u8> data) {
        std::scoped_lock lk{connection_lock};

        const auto actions{frontend->ClientData(data)};
        for (const auto action : actions) {
            switch (action) {
            case DebuggerAction::Interrupt: {
                stopped = true;
                PauseEmulation();
                UpdateActiveThread();
                frontend->Stopped(state->active_thread);
                break;
            }
            case DebuggerAction::Continue:
                MarkResumed([&] { ResumeEmulation(); });
                break;
            case DebuggerAction::StepThreadUnlocked:
                MarkResumed([&] {
                    state->active_thread->SetStepState(Kernel::StepState::StepPending);
                    state->active_thread->Resume(Kernel::SuspendType::Debug);
                    ResumeEmulation(state->active_thread);
                });
                break;
            case DebuggerAction::StepThreadLocked: {
                MarkResumed([&] {
                    state->active_thread->SetStepState(Kernel::StepState::StepPending);
                    state->active_thread->Resume(Kernel::SuspendType::Debug);
                });
                break;
            }
            case DebuggerAction::ShutdownEmulation: {
                // Spawn another thread that will exit after shutdown,
                // to avoid a deadlock
                Core::System* system_ref{&system};
                std::thread t([system_ref] { system_ref->Exit(); });
                t.detach();
                break;
            }
            }
        }
    }

    void PauseEmulation() {
        Kernel::KScopedSchedulerLock sl{system.Kernel()};

        // Put all threads to sleep on next scheduler round.
        for (auto* thread : ThreadList()) {
            thread->RequestSuspend(Kernel::SuspendType::Debug);
        }
    }

    void ResumeEmulation(Kernel::KThread* except = nullptr) {
        // Wake up all threads.
        for (auto* thread : ThreadList()) {
            if (thread == except) {
                continue;
            }

            thread->SetStepState(Kernel::StepState::NotStepping);
            thread->Resume(Kernel::SuspendType::Debug);
        }
    }

    template <typename Callback>
    void MarkResumed(Callback&& cb) {
        Kernel::KScopedSchedulerLock sl{system.Kernel()};
        stopped = false;
        cb();
    }

    void UpdateActiveThread() {
        const auto& threads{ThreadList()};
        if (std::find(threads.begin(), threads.end(), state->active_thread) == threads.end()) {
            state->active_thread = threads[0];
        }
    }

    const std::vector<Kernel::KThread*>& ThreadList() {
        return system.GlobalSchedulerContext().GetThreadList();
    }

private:
    System& system;
    std::unique_ptr<DebuggerFrontend> frontend;

    boost::asio::io_context io_context;
    std::jthread connection_thread;
    std::mutex connection_lock;

    struct ConnectionState {
        boost::asio::ip::tcp::socket client_socket;
        boost::process::async_pipe signal_pipe;

        SignalInfo info;
        Kernel::KThread* active_thread;
        std::array<u8, 4096> client_data;
        bool pipe_data;
    };

    std::optional<ConnectionState> state{};
    bool stopped{};
};

Debugger::Debugger(Core::System& system, u16 port) {
    try {
        impl = std::make_unique<DebuggerImpl>(system, port);
    } catch (const std::exception& ex) {
        LOG_CRITICAL(Debug_GDBStub, "Failed to initialize debugger: {}", ex.what());
    }
}

Debugger::~Debugger() = default;

bool Debugger::NotifyThreadStopped(Kernel::KThread* thread) {
    return impl && impl->SignalDebugger(SignalInfo{SignalType::Stopped, thread, nullptr});
}

bool Debugger::NotifyThreadWatchpoint(Kernel::KThread* thread,
                                      const Kernel::DebugWatchpoint& watch) {
    return impl && impl->SignalDebugger(SignalInfo{SignalType::Watchpoint, thread, &watch});
}

void Debugger::NotifyShutdown() {
    if (impl) {
        impl->SignalDebugger(SignalInfo{SignalType::ShuttingDown, nullptr, nullptr});
    }
}

} // namespace Core