source/Plugins/Process/Linux/NativeRegisterContextLinux.cpp

//===-- NativeRegisterContextLinux.cpp --------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "NativeRegisterContextLinux.h"

#include "lldb/Core/RegisterValue.h"
#include "lldb/Host/common/NativeProcessProtocol.h"
#include "lldb/Host/common/NativeThreadProtocol.h"
#include "lldb/Host/linux/Ptrace.h"

#include "Plugins/Process/POSIX/ProcessPOSIXLog.h"

using namespace lldb_private;
using namespace lldb_private::process_linux;

NativeRegisterContextLinux::NativeRegisterContextLinux(NativeThreadProtocol &native_thread,
                                                       uint32_t concrete_frame_idx,
                                                       RegisterInfoInterface *reg_info_interface_p) :
    NativeRegisterContextRegisterInfo(native_thread, concrete_frame_idx, reg_info_interface_p)
{}

lldb::ByteOrder
NativeRegisterContextLinux::GetByteOrder() const
{
    // Get the target process whose privileged thread was used for the register read.
    lldb::ByteOrder byte_order = lldb::eByteOrderInvalid;

    NativeProcessProtocolSP process_sp (m_thread.GetProcess ());
    if (!process_sp)
        return byte_order;

    if (!process_sp->GetByteOrder (byte_order))
    {
        // FIXME log here
    }

    return byte_order;
}

Error
NativeRegisterContextLinux::ReadRegisterRaw(uint32_t reg_index, RegisterValue &reg_value)
{
    const RegisterInfo *const reg_info = GetRegisterInfoAtIndex(reg_index);
    if (!reg_info)
        return Error("register %" PRIu32 " not found", reg_index);

    NativeProcessProtocolSP process_sp(m_thread.GetProcess());
    if (!process_sp)
        return Error("NativeProcessProtocol is NULL");

    NativeProcessLinux* process_p = static_cast<NativeProcessLinux*>(process_sp.get());
    return process_p->DoOperation([&] {
        return DoReadRegisterValue(reg_info->byte_offset, reg_info->name, reg_info->byte_size, reg_value);
    });
}

Error
NativeRegisterContextLinux::WriteRegisterRaw(uint32_t reg_index, const RegisterValue &reg_value)
{
    uint32_t reg_to_write = reg_index;
    RegisterValue value_to_write = reg_value;

    // Check if this is a subregister of a full register.
    const RegisterInfo *reg_info = GetRegisterInfoAtIndex(reg_index);
    if (reg_info->invalidate_regs && (reg_info->invalidate_regs[0] != LLDB_INVALID_REGNUM))
    {
        Error error;

        RegisterValue full_value;
        uint32_t full_reg = reg_info->invalidate_regs[0];
        const RegisterInfo *full_reg_info = GetRegisterInfoAtIndex(full_reg);

        // Read the full register.
        error = ReadRegister(full_reg_info, full_value);
        if (error.Fail ())
            return error;

        lldb::ByteOrder byte_order = GetByteOrder();
        uint8_t dst[RegisterValue::kMaxRegisterByteSize];

        // Get the bytes for the full register.
        const uint32_t dest_size = full_value.GetAsMemoryData (full_reg_info,
                                                               dst,
                                                               sizeof(dst),
                                                               byte_order,
                                                               error);
        if (error.Success() && dest_size)
        {
            uint8_t src[RegisterValue::kMaxRegisterByteSize];

            // Get the bytes for the source data.
            const uint32_t src_size = reg_value.GetAsMemoryData (reg_info, src, sizeof(src), byte_order, error);
            if (error.Success() && src_size && (src_size < dest_size))
            {
                // Copy the src bytes to the destination.
                memcpy (dst + (reg_info->byte_offset & 0x1), src, src_size);
                // Set this full register as the value to write.
                value_to_write.SetBytes(dst, full_value.GetByteSize(), byte_order);
                value_to_write.SetType(full_reg_info);
                reg_to_write = full_reg;
            }
        }
    }

    NativeProcessProtocolSP process_sp (m_thread.GetProcess ());
    if (!process_sp)
        return Error("NativeProcessProtocol is NULL");

    const RegisterInfo *const register_to_write_info_p = GetRegisterInfoAtIndex (reg_to_write);
    assert (register_to_write_info_p && "register to write does not have valid RegisterInfo");
    if (!register_to_write_info_p)
        return Error("NativeRegisterContextLinux::%s failed to get RegisterInfo for write register index %" PRIu32, __FUNCTION__, reg_to_write);

    NativeProcessLinux* process_p = static_cast<NativeProcessLinux*> (process_sp.get ());
    return process_p->DoOperation([&] {
        return DoWriteRegisterValue(reg_info->byte_offset, reg_info->name, reg_value);
    });
}

Error
NativeRegisterContextLinux::ReadGPR()
{
    NativeProcessProtocolSP process_sp (m_thread.GetProcess ());
    if (!process_sp)
        return Error("NativeProcessProtocol is NULL");

    void* buf = GetGPRBuffer();
    if (!buf)
        return Error("GPR buffer is NULL");
    size_t buf_size = GetGPRSize();

    NativeProcessLinux* process_p = static_cast<NativeProcessLinux*>(process_sp.get());
    return process_p->DoOperation([&] { return DoReadGPR(buf, buf_size); });
}

Error
NativeRegisterContextLinux::WriteGPR()
{
    NativeProcessProtocolSP process_sp (m_thread.GetProcess ());
    if (!process_sp)
        return Error("NativeProcessProtocol is NULL");

    void* buf = GetGPRBuffer();
    if (!buf)
        return Error("GPR buffer is NULL");
    size_t buf_size = GetGPRSize();

    NativeProcessLinux* process_p = static_cast<NativeProcessLinux*>(process_sp.get());
    return process_p->DoOperation([&] { return DoWriteGPR(buf, buf_size); });
}

Error
NativeRegisterContextLinux::ReadFPR()
{
    NativeProcessProtocolSP process_sp (m_thread.GetProcess ());
    if (!process_sp)
        return Error("NativeProcessProtocol is NULL");

    void* buf = GetFPRBuffer();
    if (!buf)
        return Error("FPR buffer is NULL");
    size_t buf_size = GetFPRSize();

    NativeProcessLinux* process_p = static_cast<NativeProcessLinux*>(process_sp.get());
    return process_p->DoOperation([&] { return DoReadFPR(buf, buf_size); });
}

Error
NativeRegisterContextLinux::WriteFPR()
{
    NativeProcessProtocolSP process_sp (m_thread.GetProcess ());
    if (!process_sp)
        return Error("NativeProcessProtocol is NULL");

    void* buf = GetFPRBuffer();
    if (!buf)
        return Error("FPR buffer is NULL");
    size_t buf_size = GetFPRSize();

    NativeProcessLinux* process_p = static_cast<NativeProcessLinux*>(process_sp.get());
    return process_p->DoOperation([&] { return DoWriteFPR(buf, buf_size); });
}

Error
NativeRegisterContextLinux::ReadRegisterSet(void *buf, size_t buf_size, unsigned int regset)
{
    NativeProcessProtocolSP process_sp (m_thread.GetProcess());
    if (!process_sp)
        return Error("NativeProcessProtocol is NULL");
    NativeProcessLinux* process_p = static_cast<NativeProcessLinux*>(process_sp.get());

    return process_p->DoOperation([&] {
        return NativeProcessLinux::PtraceWrapper(PTRACE_GETREGSET, m_thread.GetID(),
                static_cast<void *>(&regset), buf, buf_size);
    });
}

Error
NativeRegisterContextLinux::WriteRegisterSet(void *buf, size_t buf_size, unsigned int regset)
{
    NativeProcessProtocolSP process_sp (m_thread.GetProcess());
    if (!process_sp)
        return Error("NativeProcessProtocol is NULL");
    NativeProcessLinux* process_p = static_cast<NativeProcessLinux*>(process_sp.get());

    return process_p->DoOperation([&] {
        return NativeProcessLinux::PtraceWrapper(PTRACE_SETREGSET, m_thread.GetID(),
                static_cast<void *>(&regset), buf, buf_size);
    });
}

Error
NativeRegisterContextLinux::DoReadRegisterValue(uint32_t offset,
                                                const char* reg_name,
                                                uint32_t size,
                                                RegisterValue &value)
{
    Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_REGISTERS));

    long data;
    Error error = NativeProcessLinux::PtraceWrapper(
            PTRACE_PEEKUSER, m_thread.GetID(), reinterpret_cast<void *>(offset), nullptr, 0, &data);

    if (error.Success())
        // First cast to an unsigned of the same size to avoid sign extension.
        value.SetUInt64(static_cast<unsigned long>(data));

    if (log)
        log->Printf ("NativeRegisterContextLinux::%s() reg %s: 0x%lx", __FUNCTION__, reg_name, data);

    return error;
}

Error
NativeRegisterContextLinux::DoWriteRegisterValue(uint32_t offset,
                                                 const char* reg_name,
                                                 const RegisterValue &value)
{
    Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_REGISTERS));

    void* buf = reinterpret_cast<void *>(value.GetAsUInt64());

    if (log)
        log->Printf ("NativeRegisterContextLinux::%s() reg %s: %p", __FUNCTION__, reg_name, buf);

    return NativeProcessLinux::PtraceWrapper(
            PTRACE_POKEUSER, m_thread.GetID(), reinterpret_cast<void *>(offset), buf);
}

Error
NativeRegisterContextLinux::DoReadGPR(void *buf, size_t buf_size)
{
    return NativeProcessLinux::PtraceWrapper(PTRACE_GETREGS, m_thread.GetID(), nullptr, buf, buf_size);
}

Error
NativeRegisterContextLinux::DoWriteGPR(void *buf, size_t buf_size)
{
    return NativeProcessLinux::PtraceWrapper(PTRACE_SETREGS, m_thread.GetID(), nullptr, buf, buf_size);
}

Error
NativeRegisterContextLinux::DoReadFPR(void *buf, size_t buf_size)
{
    return NativeProcessLinux::PtraceWrapper(PTRACE_GETFPREGS, m_thread.GetID(), nullptr, buf, buf_size);
}

Error
NativeRegisterContextLinux::DoWriteFPR(void *buf, size_t buf_size)
{
    return NativeProcessLinux::PtraceWrapper(PTRACE_SETFPREGS, m_thread.GetID(), nullptr, buf, buf_size);
}