llvm-6502/lib/System/Interix/Memory.cpp
Reid Spencer 111a348435 Use the /dev/zero device as the device on which the pages are mapped.
Patch contributed by Henrik Bach. Thanks Henrik!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16397 91177308-0d34-0410-b5e6-96231b3b80d8
2004-09-18 19:34:09 +00:00

61 lines
1.9 KiB
C++

//===- Interix/Memory.cpp - Interix Memory Implementation -------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by Reid Spencer and is distributed under the
// University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file provides the Interix specific implementation of various Memory
// management utilities
//
//===----------------------------------------------------------------------===//
// Include the generic unix implementation
#include "../Unix/Memory.cpp"
#include "llvm/System/Process.h"
#include <fcntl.h>
#include <sys/mman.h>
namespace llvm {
using namespace sys;
//===----------------------------------------------------------------------===//
//=== WARNING: Implementation here must contain only Interix specific code
//=== and must not be generic UNIX code (see ../Unix/Memory.cpp)
//===----------------------------------------------------------------------===//
MemoryBlock Memory::AllocateRWX(unsigned NumBytes) {
if (NumBytes == 0) return MemoryBlock();
static const long pageSize = Process::GetPageSize();
unsigned NumPages = (NumBytes+pageSize-1)/pageSize;
int fd = open("/dev/zero", O_RDWR);
if (fd == -1) {
throw std::string("Can't open /dev/zero device: ") + strerror(errno);
}
void *pa = mmap(0, pageSize*NumPages, PROT_READ|PROT_WRITE|PROT_EXEC,
MAP_SHARED, fd, 0);
if (pa == (void*)-1) {
throw std::string("Can't allocate RWX Memory: ") + strerror(errno);
}
MemoryBlock result;
result.Address = pa;
result.Size = NumPages*pageSize;
return result;
}
void Memory::ReleaseRWX(MemoryBlock& M) {
if (M.Address == 0 || M.Size == 0) return;
if (0 != munmap(M.Address, M.Size)) {
throw std::string("Can't release RWX Memory: ") + strerror(errno);
}
}
}
// vim: sw=2 smartindent smarttab tw=80 autoindent expandtab