windows-user-space-emulator/src/windows-emulator/debugging/gdb_stub.cpp

#include "../std_include.hpp"
#include "gdb_stub.hpp"

#include <utils/finally.hpp>

extern "C"
{
#include <gdbstub.h>
}

namespace
{
    gdb_action_t map_gdb_action(const gdb_action action)
    {
        switch (action)
        {
        case gdb_action::none:
            return ACT_NONE;
        case gdb_action::resume:
            return ACT_RESUME;
        case gdb_action::shutdown:
            return ACT_SHUTDOWN;
        }

        throw std::runtime_error("Bad action");
    }

    breakpoint_type map_breakpoint_type(const bp_type_t type)
    {
        switch (type)
        {
        case BP_SOFTWARE:
            return breakpoint_type::software;
        case BP_HARDWARE_EXEC:
            return breakpoint_type::hardware_exec;
        case BP_HARDWARE_WRITE:
            return breakpoint_type::hardware_write;
        case BP_HARDWARE_READ:
            return breakpoint_type::hardware_read;
        case BP_HARDWARE_READ_WRITE:
            return breakpoint_type::hardware_read_write;
        }

        throw std::runtime_error("Bad breakpoint type");
    }

    gdb_stub_handler& get_handler(void* args)
    {
        return *static_cast<gdb_stub_handler*>(args);
    }

    gdb_action_t cont(void* args)
    {
        return map_gdb_action(get_handler(args).cont());
    }

    gdb_action_t stepi(void* args)
    {
        return map_gdb_action(get_handler(args).stepi());
    }

    int read_reg(void* args, const int regno, size_t* value)
    {
        return get_handler(args).read_reg(regno, value) ? 0 : 1;
    }

    int write_reg(void* args, const int regno, const size_t value)
    {
        return get_handler(args).write_reg(regno, value) ? 0 : 1;
    }

    int read_mem(void* args, const size_t addr, const size_t len, void* val)
    {
        return get_handler(args).read_mem(addr, len, val) ? 0 : 1;
    }

    int write_mem(void* args, const size_t addr, const size_t len, void* val)
    {
        return get_handler(args).write_mem(addr, len, val) ? 0 : 1;
    }

    bool set_bp(void* args, const size_t addr, const bp_type_t type, const size_t size)
    {
        return get_handler(args).set_bp(map_breakpoint_type(type), addr, size);
    }

    bool del_bp(void* args, const size_t addr, const bp_type_t type, const size_t size)
    {
        return get_handler(args).del_bp(map_breakpoint_type(type), addr, size);
    }

    void on_interrupt(void* args)
    {
        get_handler(args).on_interrupt();
    }

    target_ops get_target_ops()
    {
        target_ops ops{};

        ops.cont = cont;
        ops.stepi = stepi;
        ops.read_reg = read_reg;
        ops.write_reg = write_reg;
        ops.read_mem = read_mem;
        ops.write_mem = write_mem;
        ops.set_bp = set_bp;
        ops.del_bp = del_bp;
        ops.on_interrupt = on_interrupt;

        return ops;
    }
}

bool run_gdb_stub(gdb_stub_handler& handler, std::string target_description, const size_t register_count,
                  std::string bind_address)
{
    const arch_info_t info{
        target_description.data(),
        static_cast<int>(register_count),
        sizeof(uint64_t),
    };

    auto ops = get_target_ops();

    gdbstub_t stub{};

    if (!gdbstub_init(&stub, &ops, info, bind_address.data()))
    {
        return false;
    }

    const auto _ = utils::finally([&] { gdbstub_close(&stub); });

    return gdbstub_run(&stub, &handler);
}