xref: /llvm-project-15.0.7/lldb/source/Expression/IRMemoryMap.cpp (revision 35005f76)

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

#include "lldb/Core/DataBufferHeap.h"
#include "lldb/Core/DataExtractor.h"
#include "lldb/Core/Error.h"
#include "lldb/Core/Log.h"
#include "lldb/Core/Scalar.h"
#include "lldb/Expression/IRMemoryMap.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/Target.h"

using namespace lldb_private;

IRMemoryMap::IRMemoryMap (lldb::ProcessSP process_sp) :
    m_process_wp(process_sp),
    m_target_wp(process_sp->GetTarget().shared_from_this())
{
}

IRMemoryMap::IRMemoryMap (lldb::TargetSP target_sp) :
    m_process_wp(),
    m_target_wp(target_sp)
{
}

IRMemoryMap::~IRMemoryMap ()
{
    lldb::ProcessSP process_sp = m_process_wp.lock();

    if (process_sp)
    {
        for (AllocationMap::value_type &allocation : m_allocations)
        {
            if (allocation.second.m_policy == eAllocationPolicyMirror ||
                allocation.second.m_policy == eAllocationPolicyHostOnly)
                process_sp->DeallocateMemory(allocation.second.m_process_alloc);

            if (lldb_private::Log *log = lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS))
            {
                log->Printf("IRMemoryMap::~IRMemoryMap deallocated [0x%llx..0x%llx)",
                            (uint64_t)allocation.second.m_process_start,
                            (uint64_t)allocation.second.m_process_start + (uint64_t)allocation.second.m_size);
            }
        }
    }
}

lldb::addr_t
IRMemoryMap::FindSpace (size_t size)
{
    // Yup, this is just plain O(n) insertion.  We'll use a range tree if we
    // start caring.

    lldb::addr_t remote_address = 0x1000; // skip first page of memory

    for (AllocationMap::value_type &allocation : m_allocations)
    {
        if (remote_address < allocation.second.m_process_start &&
            remote_address + size <= allocation.second.m_process_start)
            return remote_address;

        remote_address = allocation.second.m_process_start = allocation.second.m_size;
    }

    if (remote_address + size < remote_address)
        return LLDB_INVALID_ADDRESS; // massively unlikely

    return remote_address;
}

bool
IRMemoryMap::ContainsHostOnlyAllocations ()
{
    for (AllocationMap::value_type &allocation : m_allocations)
    {
        if (allocation.second.m_policy == eAllocationPolicyHostOnly)
            return true;
    }

    return false;
}

IRMemoryMap::AllocationMap::iterator
IRMemoryMap::FindAllocation (lldb::addr_t addr, size_t size)
{
    AllocationMap::iterator iter = m_allocations.lower_bound (addr);

    if (iter == m_allocations.end())
        return iter;

    if (iter->first > addr)
    {
        if (iter == m_allocations.begin())
            return m_allocations.end();
        iter--;
    }

    if (iter->first <= addr && iter->first + iter->second.m_size >= addr + size)
        return iter;

    return m_allocations.end();
}

lldb::ByteOrder
IRMemoryMap::GetByteOrder()
{
    lldb::ProcessSP process_sp = m_process_wp.lock();

    if (process_sp)
        return process_sp->GetByteOrder();

    lldb::TargetSP target_sp = m_target_wp.lock();

    if (target_sp)
        return target_sp->GetDefaultArchitecture().GetByteOrder();

    return lldb::eByteOrderInvalid;
}

uint32_t
IRMemoryMap::GetAddressByteSize()
{
    lldb::ProcessSP process_sp = m_process_wp.lock();

    if (process_sp)
        return process_sp->GetAddressByteSize();

    lldb::TargetSP target_sp = m_target_wp.lock();

    if (target_sp)
        return target_sp->GetDefaultArchitecture().GetAddressByteSize();

    return UINT32_MAX;
}

ExecutionContextScope *
IRMemoryMap::GetBestExecutionContextScope()
{
    lldb::ProcessSP process_sp = m_process_wp.lock();

    if (process_sp)
        return process_sp.get();

    lldb::TargetSP target_sp = m_target_wp.lock();

    if (target_sp)
        return target_sp.get();

    return NULL;
}

lldb::addr_t
IRMemoryMap::Malloc (size_t size, uint8_t alignment, uint32_t permissions, AllocationPolicy policy, Error &error)
{
    lldb::ProcessSP process_sp;
    lldb::addr_t    allocation_address  = LLDB_INVALID_ADDRESS;
    lldb::addr_t    aligned_address     = LLDB_INVALID_ADDRESS;

    size_t          allocation_size = (size ? size : 1) + alignment - 1;

    switch (policy)
    {
    default:
        error.SetErrorToGenericError();
        error.SetErrorString("Couldn't malloc: invalid allocation policy");
        return LLDB_INVALID_ADDRESS;
    case eAllocationPolicyHostOnly:
        allocation_address = FindSpace(allocation_size);
        if (allocation_address == LLDB_INVALID_ADDRESS)
        {
            error.SetErrorToGenericError();
            error.SetErrorString("Couldn't malloc: address space is full");
            return LLDB_INVALID_ADDRESS;
        }
        break;
    case eAllocationPolicyMirror:
        if (ContainsHostOnlyAllocations())
        {
            error.SetErrorToGenericError();
            error.SetErrorString("Couldn't malloc: host-only allocations are polluting the address space");
            return LLDB_INVALID_ADDRESS;
        }
        process_sp = m_process_wp.lock();
        if (process_sp)
        {
            allocation_address = process_sp->AllocateMemory(allocation_size, permissions, error);
            if (!error.Success())
                return LLDB_INVALID_ADDRESS;
        }
        else
        {
            allocation_address = FindSpace(allocation_size);
            if (allocation_address == LLDB_INVALID_ADDRESS)
            {
                error.SetErrorToGenericError();
                error.SetErrorString("Couldn't malloc: address space is full");
                return LLDB_INVALID_ADDRESS;
            }
        }
        break;
    case eAllocationPolicyProcessOnly:
        if (ContainsHostOnlyAllocations())
        {
            error.SetErrorToGenericError();
            error.SetErrorString("Couldn't malloc: host-only allocations are polluting the address space");
            return LLDB_INVALID_ADDRESS;
        }
        process_sp = m_process_wp.lock();
        if (process_sp)
        {
            allocation_address = process_sp->AllocateMemory(allocation_size, permissions, error);
            if (!error.Success())
                return LLDB_INVALID_ADDRESS;
        }
        else
        {
            error.SetErrorToGenericError();
            error.SetErrorString("Couldn't malloc: process doesn't exist, and this memory must be in the process");
            return LLDB_INVALID_ADDRESS;
        }
        break;
    }


    lldb::addr_t mask = alignment - 1;
    aligned_address = (allocation_address + mask) & (~mask);

    Allocation &allocation(m_allocations[aligned_address]);

    allocation.m_process_alloc = allocation_address;
    allocation.m_process_start = aligned_address;
    allocation.m_size = size;
    allocation.m_permissions = permissions;
    allocation.m_alignment = alignment;
    allocation.m_policy = policy;

    switch (policy)
    {
    default:
        assert (0 && "We cannot reach this!");
    case eAllocationPolicyHostOnly:
        allocation.m_data.reset(new DataBufferHeap(size, 0));
        break;
    case eAllocationPolicyProcessOnly:
        break;
    case eAllocationPolicyMirror:
        allocation.m_data.reset(new DataBufferHeap(size, 0));
        break;
    }

    if (lldb_private::Log *log = lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS))
    {
        const char * policy_string;

        switch (policy)
        {
        default:
            policy_string = "<invalid policy>";
            break;
        case eAllocationPolicyHostOnly:
            policy_string = "eAllocationPolicyHostOnly";
            break;
        case eAllocationPolicyProcessOnly:
            policy_string = "eAllocationPolicyProcessOnly";
            break;
        case eAllocationPolicyMirror:
            policy_string = "eAllocationPolicyMirror";
            break;
        }

        log->Printf("IRMemoryMap::Malloc (%llu, 0x%llx, 0x%llx, %s) -> 0x%llx",
                    (uint64_t)size,
                    (uint64_t)alignment,
                    (uint64_t)permissions,
                    policy_string,
                    aligned_address);
    }

    return aligned_address;
}

void
IRMemoryMap::Free (lldb::addr_t process_address, Error &error)
{
    AllocationMap::iterator iter = m_allocations.find(process_address);

    if (iter == m_allocations.end())
    {
        error.SetErrorToGenericError();
        error.SetErrorString("Couldn't free: allocation doesn't exist");
        return;
    }

    Allocation &allocation = iter->second;

    switch (allocation.m_policy)
    {
    default:
    case eAllocationPolicyHostOnly:
        break;
    case eAllocationPolicyMirror:
    case eAllocationPolicyProcessOnly:
        lldb::ProcessSP process_sp = m_process_wp.lock();
        if (process_sp)
            process_sp->DeallocateMemory(allocation.m_process_alloc);
    }

    if (lldb_private::Log *log = lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS))
    {
        log->Printf("IRMemoryMap::Free (0x%llx) freed [0x%llx..0x%llx)",
                    (uint64_t)process_address,
                    iter->second.m_process_start,
                    iter->second.m_process_start + iter->second.m_size);
    }

    m_allocations.erase(iter);
}

void
IRMemoryMap::WriteMemory (lldb::addr_t process_address, const uint8_t *bytes, size_t size, Error &error)
{
    AllocationMap::iterator iter = FindAllocation(process_address, size);

    if (iter == m_allocations.end())
    {
        error.SetErrorToGenericError();
        error.SetErrorString("Couldn't write: no allocation contains the target range");
        return;
    }

    Allocation &allocation = iter->second;

    uint64_t offset = process_address - allocation.m_process_start;

    lldb::ProcessSP process_sp;

    switch (allocation.m_policy)
    {
    default:
        error.SetErrorToGenericError();
        error.SetErrorString("Couldn't write: invalid allocation policy");
        return;
    case eAllocationPolicyHostOnly:
        if (!allocation.m_data)
        {
            error.SetErrorToGenericError();
            error.SetErrorString("Couldn't write: data buffer is empty");
            return;
        }
        ::memcpy (allocation.m_data->GetBytes() + offset, bytes, size);
        break;
    case eAllocationPolicyMirror:
        if (!allocation.m_data)
        {
            error.SetErrorToGenericError();
            error.SetErrorString("Couldn't write: data buffer is empty");
            return;
        }
        ::memcpy (allocation.m_data->GetBytes() + offset, bytes, size);
        process_sp = m_process_wp.lock();
        if (process_sp)
        {
            process_sp->WriteMemory(process_address, bytes, size, error);
            if (!error.Success())
                return;
        }
        break;
    case eAllocationPolicyProcessOnly:
        process_sp = m_process_wp.lock();
        if (process_sp)
        {
            process_sp->WriteMemory(process_address, bytes, size, error);
            if (!error.Success())
                return;
        }
        break;
    }

    if (lldb_private::Log *log = lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS))
    {
        log->Printf("IRMemoryMap::WriteMemory (0x%llx, 0x%llx, 0x%lld) went to [0x%llx..0x%llx)",
                    (uint64_t)process_address,
                    (uint64_t)bytes,
                    (uint64_t)size,
                    (uint64_t)allocation.m_process_start,
                    (uint64_t)allocation.m_process_start + (uint64_t)allocation.m_size);
    }
}

void
IRMemoryMap::WriteScalarToMemory (lldb::addr_t process_address, Scalar &scalar, size_t size, Error &error)
{
    if (size == UINT32_MAX)
        size = scalar.GetByteSize();

    if (size > 0)
    {
        uint8_t buf[32];
        const size_t mem_size = scalar.GetAsMemoryData (buf, size, GetByteOrder(), error);
        if (mem_size > 0)
        {
            return WriteMemory(process_address, buf, mem_size, error);
        }
        else
        {
            error.SetErrorToGenericError();
            error.SetErrorString ("Couldn't write scalar: failed to get scalar as memory data");
        }
    }
    else
    {
        error.SetErrorToGenericError();
        error.SetErrorString ("Couldn't write scalar: its size was zero");
    }
    return;
}

void
IRMemoryMap::ReadMemory (uint8_t *bytes, lldb::addr_t process_address, size_t size, Error &error)
{
    AllocationMap::iterator iter = FindAllocation(process_address, size);

    if (iter == m_allocations.end())
    {
        error.SetErrorToGenericError();
        error.SetErrorString("Couldn't read: no allocation contains the target range");
        return;
    }

    Allocation &allocation = iter->second;

    uint64_t offset = process_address - allocation.m_process_start;

    lldb::ProcessSP process_sp;

    switch (allocation.m_policy)
    {
    default:
        error.SetErrorToGenericError();
        error.SetErrorString("Couldn't read: invalid allocation policy");
        return;
    case eAllocationPolicyHostOnly:
        if (!allocation.m_data)
        {
            error.SetErrorToGenericError();
            error.SetErrorString("Couldn't read: data buffer is empty");
            return;
        }
        ::memcpy (bytes, allocation.m_data->GetBytes() + offset, size);
        break;
    case eAllocationPolicyMirror:
        process_sp = m_process_wp.lock();
        if (process_sp)
        {
            process_sp->ReadMemory(process_address, bytes, size, error);
            if (!error.Success())
                return;
        }
        else
        {
            if (!allocation.m_data)
            {
                error.SetErrorToGenericError();
                error.SetErrorString("Couldn't read: data buffer is empty");
                return;
            }
            ::memcpy (bytes, allocation.m_data->GetBytes() + offset, size);
        }
        break;
    case eAllocationPolicyProcessOnly:
        process_sp = m_process_wp.lock();
        if (process_sp)
        {
            process_sp->ReadMemory(process_address, bytes, size, error);
            if (!error.Success())
                return;
        }
        break;
    }

    if (lldb_private::Log *log = lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS))
    {
        log->Printf("IRMemoryMap::ReadMemory (0x%llx, 0x%llx, 0x%lld) came from [0x%llx..0x%llx)",
                    (uint64_t)process_address,
                    (uint64_t)bytes,
                    (uint64_t)size,
                    (uint64_t)allocation.m_process_start,
                    (uint64_t)allocation.m_process_start + (uint64_t)allocation.m_size);
    }
}

void
IRMemoryMap::ReadScalarFromMemory (Scalar &scalar, lldb::addr_t process_address, size_t size, Error &error)
{
    if (size > 0)
    {
        DataBufferHeap buf(size, 0);
        ReadMemory(buf.GetBytes(), process_address, size, error);

        if (!error.Success())
            return;

        DataExtractor extractor(buf.GetBytes(), buf.GetByteSize(), GetByteOrder(), GetAddressByteSize());

        lldb::offset_t offset = 0;

        switch (size)
        {
        default:
            error.SetErrorToGenericError();
            error.SetErrorStringWithFormat("Couldn't read scalar: unsupported size %lld", (unsigned long long)size);
            return;
        case 1: scalar = extractor.GetU8(&offset);  break;
        case 2: scalar = extractor.GetU16(&offset); break;
        case 4: scalar = extractor.GetU32(&offset); break;
        case 8: scalar = extractor.GetU64(&offset); break;
        }
    }
    else
    {
        error.SetErrorToGenericError();
        error.SetErrorString ("Couldn't write scalar: its size was zero");
    }
    return;
}