forked from OSchip/llvm-project
121 lines
3.6 KiB
C++
121 lines
3.6 KiB
C++
//===- Win32/Memory.cpp - Win32 Memory Implementation -----------*- C++ -*-===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file provides the Win32 specific implementation of various Memory
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// management utilities
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//
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//===----------------------------------------------------------------------===//
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#include "Windows.h"
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#include "llvm/Support/DataTypes.h"
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#include "llvm/Support/Process.h"
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namespace llvm {
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using namespace sys;
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//===----------------------------------------------------------------------===//
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//=== WARNING: Implementation here must contain only Win32 specific code
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//=== and must not be UNIX code
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//===----------------------------------------------------------------------===//
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MemoryBlock Memory::AllocateRWX(size_t NumBytes,
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const MemoryBlock *NearBlock,
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std::string *ErrMsg) {
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if (NumBytes == 0) return MemoryBlock();
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static const size_t pageSize = Process::GetPageSize();
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size_t NumPages = (NumBytes+pageSize-1)/pageSize;
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PVOID start = NearBlock ? static_cast<unsigned char *>(NearBlock->base()) +
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NearBlock->size() : NULL;
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void *pa = VirtualAlloc(start, NumPages*pageSize, MEM_RESERVE | MEM_COMMIT,
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PAGE_EXECUTE_READWRITE);
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if (pa == NULL) {
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if (NearBlock) {
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// Try again without the NearBlock hint
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return AllocateRWX(NumBytes, NULL, ErrMsg);
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}
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MakeErrMsg(ErrMsg, "Can't allocate RWX Memory: ");
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return MemoryBlock();
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}
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MemoryBlock result;
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result.Address = pa;
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result.Size = NumPages*pageSize;
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return result;
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}
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bool Memory::ReleaseRWX(MemoryBlock &M, std::string *ErrMsg) {
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if (M.Address == 0 || M.Size == 0) return false;
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if (!VirtualFree(M.Address, 0, MEM_RELEASE))
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return MakeErrMsg(ErrMsg, "Can't release RWX Memory: ");
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return false;
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}
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static DWORD getProtection(const void *addr) {
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MEMORY_BASIC_INFORMATION info;
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if (sizeof(info) == ::VirtualQuery(addr, &info, sizeof(info))) {
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return info.Protect;
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}
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return 0;
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}
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bool Memory::setWritable(MemoryBlock &M, std::string *ErrMsg) {
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if (!setRangeWritable(M.Address, M.Size)) {
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return MakeErrMsg(ErrMsg, "Cannot set memory to writeable: ");
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}
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return true;
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}
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bool Memory::setExecutable(MemoryBlock &M, std::string *ErrMsg) {
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if (!setRangeExecutable(M.Address, M.Size)) {
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return MakeErrMsg(ErrMsg, "Cannot set memory to executable: ");
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}
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return true;
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}
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bool Memory::setRangeWritable(const void *Addr, size_t Size) {
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DWORD prot = getProtection(Addr);
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if (!prot)
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return false;
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if (prot == PAGE_EXECUTE || prot == PAGE_EXECUTE_READ) {
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prot = PAGE_EXECUTE_READWRITE;
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} else if (prot == PAGE_NOACCESS || prot == PAGE_READONLY) {
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prot = PAGE_READWRITE;
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}
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DWORD oldProt;
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sys::Memory::InvalidateInstructionCache(Addr, Size);
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return ::VirtualProtect(const_cast<LPVOID>(Addr), Size, prot, &oldProt)
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== TRUE;
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}
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bool Memory::setRangeExecutable(const void *Addr, size_t Size) {
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DWORD prot = getProtection(Addr);
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if (!prot)
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return false;
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if (prot == PAGE_NOACCESS) {
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prot = PAGE_EXECUTE;
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} else if (prot == PAGE_READONLY) {
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prot = PAGE_EXECUTE_READ;
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} else if (prot == PAGE_READWRITE) {
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prot = PAGE_EXECUTE_READWRITE;
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}
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DWORD oldProt;
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sys::Memory::InvalidateInstructionCache(Addr, Size);
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return ::VirtualProtect(const_cast<LPVOID>(Addr), Size, prot, &oldProt)
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== TRUE;
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}
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}
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