alloc-win.cpp revision 7c3df511b65c587226c53ce0d72c3644bc803ef9
/* $Id$ */
/** @file
* innotek Portable Runtime - Memory Allocation, Win32.
*/
/*
* Copyright (C) 2006-2007 innotek GmbH
*
* This file is part of VirtualBox Open Source Edition (OSE), as
* available from http://www.virtualbox.org. This file is free software;
* you can redistribute it and/or modify it under the terms of the GNU
* General Public License as published by the Free Software Foundation,
* in version 2 as it comes in the "COPYING" file of the VirtualBox OSE
* distribution. VirtualBox OSE is distributed in the hope that it will
* be useful, but WITHOUT ANY WARRANTY of any kind.
*/
/*******************************************************************************
* Header Files *
*******************************************************************************/
#define LOG_GROUP RTLOGGROUP_MEM
#include <Windows.h>
#include <iprt/alloc.h>
#include <iprt/assert.h>
#include <iprt/param.h>
#include <iprt/string.h>
#include <iprt/err.h>
#ifndef USE_VIRTUAL_ALLOC
# include <malloc.h>
#endif
/**
* Allocates memory which may contain code.
*
* @returns Pointer to the allocated memory.
* @returns NULL on failure.
* @param cb Size in bytes of the memory block to allocate.
*/
RTDECL(void *) RTMemExecAlloc(size_t cb)
{
/*
* Allocate first.
*/
AssertMsg(cb, ("Allocating ZERO bytes is really not a good idea! Good luck with the next assertion!\n"));
cb = RT_ALIGN_Z(cb, 32);
void *pv = malloc(cb);
AssertMsg(pv, ("malloc(%d) failed!!!\n", cb));
if (pv)
{
/*
* Add PROT_EXEC flag to the page.
*
* This is in violation of the SuS where I think it saith that mprotect() shall
* only be used with mmap()'ed memory. Works on linux and OS/2 LIBC v0.6.
*/
memset(pv, 0xcc, cb);
void *pvProt = (void *)((uintptr_t)pv & ~PAGE_OFFSET_MASK);
size_t cbProt = ((uintptr_t)pv & PAGE_OFFSET_MASK) + cb;
cbProt = RT_ALIGN_Z(cbProt, PAGE_SIZE);
DWORD fFlags = 0;
if (!VirtualProtect(pvProt, cbProt, PAGE_EXECUTE_READWRITE, &fFlags))
{
AssertMsgFailed(("VirtualProtect(%p, %#x,,) -> lasterr=%d\n", pvProt, cbProt, GetLastError()));
free(pv);
pv = NULL;
}
}
return pv;
}
/**
* Free executable/read/write memory allocated by RTMemExecAlloc().
*
* @param pv Pointer to memory block.
*/
RTDECL(void) RTMemExecFree(void *pv)
{
if (pv)
free(pv);
}
/**
* Allocate page aligned memory.
*
* @returns Pointer to the allocated memory.
* @returns NULL if we're out of memory.
* @param cb Size of the memory block. Will be rounded up to page size.
*/
RTDECL(void *) RTMemPageAlloc(size_t cb)
{
#ifdef USE_VIRTUAL_ALLOC
void *pv = VirtualAlloc(NULL, RT_ALIGN_Z(cb, PAGE_SIZE), MEM_COMMIT, PAGE_READWRITE);
#else
void *pv = _aligned_malloc(cb, PAGE_SIZE);
#endif
AssertMsg(pv, ("cb=%d lasterr=%d\n", cb, GetLastError()));
return pv;
}
/**
* Allocate zero'ed page aligned memory.
*
* @returns Pointer to the allocated memory.
* @returns NULL if we're out of memory.
* @param cb Size of the memory block. Will be rounded up to page size.
*/
RTDECL(void *) RTMemPageAllocZ(size_t cb)
{
#ifdef USE_VIRTUAL_ALLOC
void *pv = VirtualAlloc(NULL, RT_ALIGN_Z(cb, PAGE_SIZE), MEM_COMMIT, PAGE_READWRITE);
#else
void *pv = _aligned_malloc(cb, PAGE_SIZE);
#endif
if (pv)
{
memset(pv, 0, RT_ALIGN_Z(cb, PAGE_SIZE));
return pv;
}
AssertMsgFailed(("cb=%d lasterr=%d\n", cb, GetLastError()));
return NULL;
}
/**
* Free a memory block allocated with RTMemPageAlloc() or RTMemPageAllocZ().
*
* @param pv Pointer to the block as it was returned by the allocation function.
* NULL will be ignored.
*/
RTDECL(void) RTMemPageFree(void *pv)
{
if (pv)
{
#ifdef USE_VIRTUAL_ALLOC
if (!VirtualFree(pv, 0, MEM_RELEASE))
AssertMsgFailed(("pv=%p lasterr=%d\n", pv, GetLastError()));
#else
_aligned_free(pv);
#endif
}
}
/**
* Change the page level protection of a memory region.
*
* @returns iprt status code.
* @param pv Start of the region. Will be rounded down to nearest page boundary.
* @param cb Size of the region. Will be rounded up to the nearest page boundary.
* @param fProtect The new protection, a combination of the RTMEM_PROT_* defines.
*/
RTDECL(int) RTMemProtect(void *pv, size_t cb, unsigned fProtect)
{
/*
* Validate input.
*/
if (cb == 0)
{
AssertMsgFailed(("!cb\n"));
return VERR_INVALID_PARAMETER;
}
if (fProtect & ~(RTMEM_PROT_NONE | RTMEM_PROT_READ | RTMEM_PROT_WRITE | RTMEM_PROT_EXEC))
{
AssertMsgFailed(("fProtect=%#x\n", fProtect));
return VERR_INVALID_PARAMETER;
}
/*
* Convert the flags.
*/
int fProt;
Assert(!RTMEM_PROT_NONE);
switch (fProtect & (RTMEM_PROT_NONE | RTMEM_PROT_READ | RTMEM_PROT_WRITE | RTMEM_PROT_EXEC))
{
case RTMEM_PROT_NONE:
fProt = PAGE_NOACCESS;
break;
case RTMEM_PROT_READ:
fProt = PAGE_READONLY;
break;
case RTMEM_PROT_READ | RTMEM_PROT_WRITE:
fProt = PAGE_READWRITE;
break;
case RTMEM_PROT_READ | RTMEM_PROT_WRITE | RTMEM_PROT_EXEC:
fProt = PAGE_EXECUTE_READWRITE;
break;
case RTMEM_PROT_READ | RTMEM_PROT_EXEC:
fProt = PAGE_EXECUTE_READWRITE;
break;
case RTMEM_PROT_WRITE:
fProt = PAGE_READWRITE;
break;
case RTMEM_PROT_WRITE | RTMEM_PROT_EXEC:
fProt = PAGE_EXECUTE_READWRITE;
break;
case RTMEM_PROT_EXEC:
fProt = PAGE_EXECUTE_READWRITE;
break;
/* If the compiler had any brains it would warn about this case. */
default:
AssertMsgFailed(("fProtect=%#x\n", fProtect));
return VERR_INTERNAL_ERROR;
}
/*
* Align the request.
*/
cb += (uintptr_t)pv & PAGE_OFFSET_MASK;
pv = (void *)((uintptr_t)pv & ~PAGE_OFFSET_MASK);
/*
* Change the page attributes.
*/
DWORD fFlags = 0;
if (VirtualProtect(pv, cb, fProt, &fFlags))
return VINF_SUCCESS;
return RTErrConvertFromWin32(GetLastError());
}