5 files changed, 151 insertions, 26 deletions

diff --git a/src/core/debugger/debugger.cpp b/src/core/debugger/debugger.cpp
index ab3940922..ac64d2f9d 100644
--- a/src/core/debugger/debugger.cpp
+++ b/src/core/debugger/debugger.cpp
@@ -44,12 +44,14 @@ static std::span<const u8> ReceiveInto(Readable& r, Buffer& buffer) {
 
 enum class SignalType {
     Stopped,
+    Watchpoint,
     ShuttingDown,
 };
 
 struct SignalInfo {
     SignalType type;
     Kernel::KThread* thread;
+    const Kernel::DebugWatchpoint* watchpoint;
 };
 
 namespace Core {
@@ -157,13 +159,19 @@ private:
     void PipeData(std::span<const u8> data) {
         switch (info.type) {
         case SignalType::Stopped:
+        case SignalType::Watchpoint:
             // Stop emulation.
             PauseEmulation();
 
             // Notify the client.
             active_thread = info.thread;
             UpdateActiveThread();
-            frontend->Stopped(active_thread);
+
+            if (info.type == SignalType::Watchpoint) {
+                frontend->Watchpoint(active_thread, *info.watchpoint);
+            } else {
+                frontend->Stopped(active_thread);
+            }
 
             break;
         case SignalType::ShuttingDown:
@@ -290,12 +298,17 @@ Debugger::Debugger(Core::System& system, u16 port) {
 Debugger::~Debugger() = default;
 
 bool Debugger::NotifyThreadStopped(Kernel::KThread* thread) {
-    return impl && impl->SignalDebugger(SignalInfo{SignalType::Stopped, 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});
+        impl->SignalDebugger(SignalInfo{SignalType::ShuttingDown, nullptr, nullptr});
     }
 }
 
diff --git a/src/core/debugger/debugger.h b/src/core/debugger/debugger.h
index f9738ca3d..b2f503376 100644
--- a/src/core/debugger/debugger.h
+++ b/src/core/debugger/debugger.h
@@ -9,7 +9,8 @@
 
 namespace Kernel {
 class KThread;
-}
+struct DebugWatchpoint;
+} // namespace Kernel
 
 namespace Core {
 class System;
@@ -40,6 +41,11 @@ public:
      */
     void NotifyShutdown();
 
+    /*
+     * Notify the debugger that the given thread has stopped due to hitting a watchpoint.
+     */
+    bool NotifyThreadWatchpoint(Kernel::KThread* thread, const Kernel::DebugWatchpoint& watch);
+
 private:
     std::unique_ptr<DebuggerImpl> impl;
 };
diff --git a/src/core/debugger/debugger_interface.h b/src/core/debugger/debugger_interface.h
index c0bb4ecaf..5b31edc43 100644
--- a/src/core/debugger/debugger_interface.h
+++ b/src/core/debugger/debugger_interface.h
@@ -11,7 +11,8 @@
 
 namespace Kernel {
 class KThread;
-}
+struct DebugWatchpoint;
+} // namespace Kernel
 
 namespace Core {
 
@@ -71,6 +72,11 @@ public:
      */
     virtual void ShuttingDown() = 0;
 
+    /*
+     * Called when emulation has stopped on a watchpoint.
+     */
+    virtual void Watchpoint(Kernel::KThread* thread, const Kernel::DebugWatchpoint& watch) = 0;
+
     /**
      * Called when new data is asynchronously received on the client socket.
      * A list of actions to perform is returned.
diff --git a/src/core/debugger/gdbstub.cpp b/src/core/debugger/gdbstub.cpp
index 52e76f659..f5e9a303d 100644
--- a/src/core/debugger/gdbstub.cpp
+++ b/src/core/debugger/gdbstub.cpp
@@ -112,6 +112,23 @@ void GDBStub::Stopped(Kernel::KThread* thread) {
     SendReply(arch->ThreadStatus(thread, GDB_STUB_SIGTRAP));
 }
 
+void GDBStub::Watchpoint(Kernel::KThread* thread, const Kernel::DebugWatchpoint& watch) {
+    const auto status{arch->ThreadStatus(thread, GDB_STUB_SIGTRAP)};
+
+    switch (watch.type) {
+    case Kernel::DebugWatchpointType::Read:
+        SendReply(fmt::format("{}rwatch:{:x};", status, watch.start_address));
+        break;
+    case Kernel::DebugWatchpointType::Write:
+        SendReply(fmt::format("{}watch:{:x};", status, watch.start_address));
+        break;
+    case Kernel::DebugWatchpointType::ReadOrWrite:
+    default:
+        SendReply(fmt::format("{}awatch:{:x};", status, watch.start_address));
+        break;
+    }
+}
+
 std::vector<DebuggerAction> GDBStub::ClientData(std::span<const u8> data) {
     std::vector<DebuggerAction> actions;
     current_command.insert(current_command.end(), data.begin(), data.end());
@@ -278,41 +295,121 @@ void GDBStub::ExecuteCommand(std::string_view packet, std::vector<DebuggerAction
     case 'c':
         actions.push_back(DebuggerAction::Continue);
         break;
-    case 'Z': {
-        const auto addr_sep{std::find(command.begin(), command.end(), ',') - command.begin() + 1};
-        const size_t addr{static_cast<size_t>(strtoll(command.data() + addr_sep, nullptr, 16))};
+    case 'Z':
+        HandleBreakpointInsert(command);
+        break;
+    case 'z':
+        HandleBreakpointRemove(command);
+        break;
+    default:
+        SendReply(GDB_STUB_REPLY_EMPTY);
+        break;
+    }
+}
 
-        if (system.Memory().IsValidVirtualAddress(addr)) {
-            replaced_instructions[addr] = system.Memory().Read32(addr);
-            system.Memory().Write32(addr, arch->BreakpointInstruction());
-            system.InvalidateCpuInstructionCacheRange(addr, sizeof(u32));
+enum class BreakpointType {
+    Software = 0,
+    Hardware = 1,
+    WriteWatch = 2,
+    ReadWatch = 3,
+    AccessWatch = 4,
+};
+
+void GDBStub::HandleBreakpointInsert(std::string_view command) {
+    const auto type{static_cast<BreakpointType>(strtoll(command.data(), nullptr, 16))};
+    const auto addr_sep{std::find(command.begin(), command.end(), ',') - command.begin() + 1};
+    const auto size_sep{std::find(command.begin() + addr_sep, command.end(), ',') -
+                        command.begin() + 1};
+    const size_t addr{static_cast<size_t>(strtoll(command.data() + addr_sep, nullptr, 16))};
+    const size_t size{static_cast<size_t>(strtoll(command.data() + size_sep, nullptr, 16))};
+
+    if (!system.Memory().IsValidVirtualAddressRange(addr, size)) {
+        SendReply(GDB_STUB_REPLY_ERR);
+        return;
+    }
 
-            SendReply(GDB_STUB_REPLY_OK);
-        } else {
-            SendReply(GDB_STUB_REPLY_ERR);
-        }
+    bool success{};
+
+    switch (type) {
+    case BreakpointType::Software:
+        replaced_instructions[addr] = system.Memory().Read32(addr);
+        system.Memory().Write32(addr, arch->BreakpointInstruction());
+        system.InvalidateCpuInstructionCacheRange(addr, sizeof(u32));
+        success = true;
+        break;
+    case BreakpointType::WriteWatch:
+        success = system.CurrentProcess()->InsertWatchpoint(system, addr, size,
+                                                            Kernel::DebugWatchpointType::Write);
         break;
+    case BreakpointType::ReadWatch:
+        success = system.CurrentProcess()->InsertWatchpoint(system, addr, size,
+                                                            Kernel::DebugWatchpointType::Read);
+        break;
+    case BreakpointType::AccessWatch:
+        success = system.CurrentProcess()->InsertWatchpoint(
+            system, addr, size, Kernel::DebugWatchpointType::ReadOrWrite);
+        break;
+    case BreakpointType::Hardware:
+    default:
+        SendReply(GDB_STUB_REPLY_EMPTY);
+        return;
+    }
+
+    if (success) {
+        SendReply(GDB_STUB_REPLY_OK);
+    } else {
+        SendReply(GDB_STUB_REPLY_ERR);
     }
-    case 'z': {
-        const auto addr_sep{std::find(command.begin(), command.end(), ',') - command.begin() + 1};
-        const size_t addr{static_cast<size_t>(strtoll(command.data() + addr_sep, nullptr, 16))};
+}
+
+void GDBStub::HandleBreakpointRemove(std::string_view command) {
+    const auto type{static_cast<BreakpointType>(strtoll(command.data(), nullptr, 16))};
+    const auto addr_sep{std::find(command.begin(), command.end(), ',') - command.begin() + 1};
+    const auto size_sep{std::find(command.begin() + addr_sep, command.end(), ',') -
+                        command.begin() + 1};
+    const size_t addr{static_cast<size_t>(strtoll(command.data() + addr_sep, nullptr, 16))};
+    const size_t size{static_cast<size_t>(strtoll(command.data() + size_sep, nullptr, 16))};
+
+    if (!system.Memory().IsValidVirtualAddressRange(addr, size)) {
+        SendReply(GDB_STUB_REPLY_ERR);
+        return;
+    }
+
+    bool success{};
 
+    switch (type) {
+    case BreakpointType::Software: {
         const auto orig_insn{replaced_instructions.find(addr)};
-        if (system.Memory().IsValidVirtualAddress(addr) &&
-            orig_insn != replaced_instructions.end()) {
+        if (orig_insn != replaced_instructions.end()) {
             system.Memory().Write32(addr, orig_insn->second);
             system.InvalidateCpuInstructionCacheRange(addr, sizeof(u32));
             replaced_instructions.erase(addr);
-
-            SendReply(GDB_STUB_REPLY_OK);
-        } else {
-            SendReply(GDB_STUB_REPLY_ERR);
+            success = true;
         }
         break;
     }
+    case BreakpointType::WriteWatch:
+        success = system.CurrentProcess()->RemoveWatchpoint(system, addr, size,
+                                                            Kernel::DebugWatchpointType::Write);
+        break;
+    case BreakpointType::ReadWatch:
+        success = system.CurrentProcess()->RemoveWatchpoint(system, addr, size,
+                                                            Kernel::DebugWatchpointType::Read);
+        break;
+    case BreakpointType::AccessWatch:
+        success = system.CurrentProcess()->RemoveWatchpoint(
+            system, addr, size, Kernel::DebugWatchpointType::ReadOrWrite);
+        break;
+    case BreakpointType::Hardware:
     default:
         SendReply(GDB_STUB_REPLY_EMPTY);
-        break;
+        return;
+    }
+
+    if (success) {
+        SendReply(GDB_STUB_REPLY_OK);
+    } else {
+        SendReply(GDB_STUB_REPLY_ERR);
     }
 }
 
diff --git a/src/core/debugger/gdbstub.h b/src/core/debugger/gdbstub.h
index ec934c77e..0b0f56e4b 100644
--- a/src/core/debugger/gdbstub.h
+++ b/src/core/debugger/gdbstub.h
@@ -24,6 +24,7 @@ public:
     void Connected() override;
     void Stopped(Kernel::KThread* thread) override;
     void ShuttingDown() override;
+    void Watchpoint(Kernel::KThread* thread, const Kernel::DebugWatchpoint& watch) override;
     std::vector<DebuggerAction> ClientData(std::span<const u8> data) override;
 
 private:
@@ -31,6 +32,8 @@ private:
     void ExecuteCommand(std::string_view packet, std::vector<DebuggerAction>& actions);
     void HandleVCont(std::string_view command, std::vector<DebuggerAction>& actions);
     void HandleQuery(std::string_view command);
+    void HandleBreakpointInsert(std::string_view command);
+    void HandleBreakpointRemove(std::string_view command);
     std::vector<char>::const_iterator CommandEnd() const;
     std::optional<std::string> DetachCommand();
     Kernel::KThread* GetThreadByID(u64 thread_id);