diff options
| author | 2016-09-03 22:46:54 +0000 | |
|---|---|---|
| committer | 2016-09-03 22:46:54 +0000 | |
| commit | b5500b9ca0102f1ccaf32f0e77e96d0739aded9b (patch) | |
| tree | e1b7ebb5a0231f9e6d8d3f6f719582cebd64dc98 /gnu/llvm/lib/Support/Windows/Memory.inc | |
| parent | clarify purpose of src/gnu/ directory. (diff) | |
| download | wireguard-openbsd-b5500b9ca0102f1ccaf32f0e77e96d0739aded9b.tar.xz wireguard-openbsd-b5500b9ca0102f1ccaf32f0e77e96d0739aded9b.zip | |
Use the space freed up by sparc and zaurus to import LLVM.
ok hackroom@
Diffstat (limited to 'gnu/llvm/lib/Support/Windows/Memory.inc')
| -rw-r--r-- | gnu/llvm/lib/Support/Windows/Memory.inc | 244 |
1 files changed, 244 insertions, 0 deletions
diff --git a/gnu/llvm/lib/Support/Windows/Memory.inc b/gnu/llvm/lib/Support/Windows/Memory.inc new file mode 100644 index 00000000000..7eab9ff3afd --- /dev/null +++ b/gnu/llvm/lib/Support/Windows/Memory.inc @@ -0,0 +1,244 @@ +//===- Win32/Memory.cpp - Win32 Memory Implementation -----------*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file provides the Win32 specific implementation of various Memory +// management utilities +// +//===----------------------------------------------------------------------===// + +#include "llvm/Support/DataTypes.h" +#include "llvm/Support/ErrorHandling.h" +#include "llvm/Support/Process.h" +#include "llvm/Support/WindowsError.h" + +// The Windows.h header must be the last one included. +#include "WindowsSupport.h" + +namespace { + +DWORD getWindowsProtectionFlags(unsigned Flags) { + switch (Flags) { + // Contrary to what you might expect, the Windows page protection flags + // are not a bitwise combination of RWX values + case llvm::sys::Memory::MF_READ: + return PAGE_READONLY; + case llvm::sys::Memory::MF_WRITE: + // Note: PAGE_WRITE is not supported by VirtualProtect + return PAGE_READWRITE; + case llvm::sys::Memory::MF_READ|llvm::sys::Memory::MF_WRITE: + return PAGE_READWRITE; + case llvm::sys::Memory::MF_READ|llvm::sys::Memory::MF_EXEC: + return PAGE_EXECUTE_READ; + case llvm::sys::Memory::MF_READ | + llvm::sys::Memory::MF_WRITE | + llvm::sys::Memory::MF_EXEC: + return PAGE_EXECUTE_READWRITE; + case llvm::sys::Memory::MF_EXEC: + return PAGE_EXECUTE; + default: + llvm_unreachable("Illegal memory protection flag specified!"); + } + // Provide a default return value as required by some compilers. + return PAGE_NOACCESS; +} + +size_t getAllocationGranularity() { + SYSTEM_INFO Info; + ::GetSystemInfo(&Info); + if (Info.dwPageSize > Info.dwAllocationGranularity) + return Info.dwPageSize; + else + return Info.dwAllocationGranularity; +} + +} // namespace + +namespace llvm { +namespace sys { + +//===----------------------------------------------------------------------===// +//=== WARNING: Implementation here must contain only Win32 specific code +//=== and must not be UNIX code +//===----------------------------------------------------------------------===// + +MemoryBlock Memory::allocateMappedMemory(size_t NumBytes, + const MemoryBlock *const NearBlock, + unsigned Flags, + std::error_code &EC) { + EC = std::error_code(); + if (NumBytes == 0) + return MemoryBlock(); + + // While we'd be happy to allocate single pages, the Windows allocation + // granularity may be larger than a single page (in practice, it is 64K) + // so mapping less than that will create an unreachable fragment of memory. + // Avoid using one-time initialization of static locals here, since they + // aren't thread safe with MSVC. + static volatile size_t GranularityCached; + size_t Granularity = GranularityCached; + if (Granularity == 0) { + Granularity = getAllocationGranularity(); + GranularityCached = Granularity; + } + + const size_t NumBlocks = (NumBytes+Granularity-1)/Granularity; + + uintptr_t Start = NearBlock ? reinterpret_cast<uintptr_t>(NearBlock->base()) + + NearBlock->size() + : 0; + + // If the requested address is not aligned to the allocation granularity, + // round up to get beyond NearBlock. VirtualAlloc would have rounded down. + if (Start && Start % Granularity != 0) + Start += Granularity - Start % Granularity; + + DWORD Protect = getWindowsProtectionFlags(Flags); + + void *PA = ::VirtualAlloc(reinterpret_cast<void*>(Start), + NumBlocks*Granularity, + MEM_RESERVE | MEM_COMMIT, Protect); + if (PA == NULL) { + if (NearBlock) { + // Try again without the NearBlock hint + return allocateMappedMemory(NumBytes, NULL, Flags, EC); + } + EC = mapWindowsError(::GetLastError()); + return MemoryBlock(); + } + + MemoryBlock Result; + Result.Address = PA; + Result.Size = NumBlocks*Granularity; + + if (Flags & MF_EXEC) + Memory::InvalidateInstructionCache(Result.Address, Result.Size); + + return Result; +} + + std::error_code Memory::releaseMappedMemory(MemoryBlock &M) { + if (M.Address == 0 || M.Size == 0) + return std::error_code(); + + if (!VirtualFree(M.Address, 0, MEM_RELEASE)) + return mapWindowsError(::GetLastError()); + + M.Address = 0; + M.Size = 0; + + return std::error_code(); +} + + std::error_code Memory::protectMappedMemory(const MemoryBlock &M, + unsigned Flags) { + if (M.Address == 0 || M.Size == 0) + return std::error_code(); + + DWORD Protect = getWindowsProtectionFlags(Flags); + + DWORD OldFlags; + if (!VirtualProtect(M.Address, M.Size, Protect, &OldFlags)) + return mapWindowsError(::GetLastError()); + + if (Flags & MF_EXEC) + Memory::InvalidateInstructionCache(M.Address, M.Size); + + return std::error_code(); +} + +/// InvalidateInstructionCache - Before the JIT can run a block of code +/// that has been emitted it must invalidate the instruction cache on some +/// platforms. +void Memory::InvalidateInstructionCache( + const void *Addr, size_t Len) { + FlushInstructionCache(GetCurrentProcess(), Addr, Len); +} + + +MemoryBlock Memory::AllocateRWX(size_t NumBytes, + const MemoryBlock *NearBlock, + std::string *ErrMsg) { + MemoryBlock MB; + std::error_code EC; + MB = allocateMappedMemory(NumBytes, NearBlock, + MF_READ|MF_WRITE|MF_EXEC, EC); + if (EC != std::error_code() && ErrMsg) { + MakeErrMsg(ErrMsg, EC.message()); + } + return MB; +} + +bool Memory::ReleaseRWX(MemoryBlock &M, std::string *ErrMsg) { + std::error_code EC = releaseMappedMemory(M); + if (EC == std::error_code()) + return false; + MakeErrMsg(ErrMsg, EC.message()); + return true; +} + +static DWORD getProtection(const void *addr) { + MEMORY_BASIC_INFORMATION info; + if (sizeof(info) == ::VirtualQuery(addr, &info, sizeof(info))) { + return info.Protect; + } + return 0; +} + +bool Memory::setWritable(MemoryBlock &M, std::string *ErrMsg) { + if (!setRangeWritable(M.Address, M.Size)) { + return MakeErrMsg(ErrMsg, "Cannot set memory to writeable"); + } + return true; +} + +bool Memory::setExecutable(MemoryBlock &M, std::string *ErrMsg) { + if (!setRangeExecutable(M.Address, M.Size)) { + return MakeErrMsg(ErrMsg, "Cannot set memory to executable"); + } + return true; +} + +bool Memory::setRangeWritable(const void *Addr, size_t Size) { + DWORD prot = getProtection(Addr); + if (!prot) + return false; + + if (prot == PAGE_EXECUTE || prot == PAGE_EXECUTE_READ) { + prot = PAGE_EXECUTE_READWRITE; + } else if (prot == PAGE_NOACCESS || prot == PAGE_READONLY) { + prot = PAGE_READWRITE; + } + + DWORD oldProt; + Memory::InvalidateInstructionCache(Addr, Size); + return ::VirtualProtect(const_cast<LPVOID>(Addr), Size, prot, &oldProt) + == TRUE; +} + +bool Memory::setRangeExecutable(const void *Addr, size_t Size) { + DWORD prot = getProtection(Addr); + if (!prot) + return false; + + if (prot == PAGE_NOACCESS) { + prot = PAGE_EXECUTE; + } else if (prot == PAGE_READONLY) { + prot = PAGE_EXECUTE_READ; + } else if (prot == PAGE_READWRITE) { + prot = PAGE_EXECUTE_READWRITE; + } + + DWORD oldProt; + Memory::InvalidateInstructionCache(Addr, Size); + return ::VirtualProtect(const_cast<LPVOID>(Addr), Size, prot, &oldProt) + == TRUE; +} + +} // namespace sys +} // namespace llvm |
