alloc-freebsd.cpp revision e64031e20c39650a7bc902a3e1aba613b9415dee
/* $Id$ */
/** @file
* IPRT - Memory Allocation, POSIX.
*/
/*
* Copyright (C) 2006-2007 Oracle Corporation
*
* 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 (GPL) 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.
*
* The contents of this file may alternatively be used under the terms
* of the Common Development and Distribution License Version 1.0
* (CDDL) only, as it comes in the "COPYING.CDDL" file of the
* VirtualBox OSE distribution, in which case the provisions of the
* CDDL are applicable instead of those of the GPL.
*
* You may elect to license modified versions of this file under the
* terms and conditions of either the GPL or the CDDL or both.
*/
/*******************************************************************************
* Header Files *
*******************************************************************************/
#include <iprt/alloc.h>
#include <iprt/assert.h>
#include <iprt/param.h>
#include <iprt/err.h>
#include <iprt/string.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/mman.h>
/**
* 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) RT_NO_THROW
{
/*
* 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, PAGE_SIZE);
void *pv = RTMemPageAlloc(cb);
if (pv)
{
/*
* Add PROT_EXEC flag to the page(s).
*/
memset(pv, 0xcc, cb);
int rc = mprotect(pv, cb, PROT_READ | PROT_WRITE | PROT_EXEC);
if (rc)
{
AssertMsgFailed(("mprotect(%p, %#x,,) -> rc=%d, errno=%d\n", pv, cb, rc, errno));
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) RT_NO_THROW
{
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) RT_NO_THROW
{
cb = RT_ALIGN_Z(cb, PAGE_SIZE);
void *pv = malloc(cb);
AssertReleaseMsgReturn(RT_ALIGN_P(pv, PAGE_SIZE) == pv,
("malloc(%zu) -> %p; expected page aligned!\n", cb, pv),
NULL);
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) RT_NO_THROW
{
cb = RT_ALIGN_Z(cb, PAGE_SIZE);
void *pv = RTMemPageAlloc(cb);
if (pv)
bzero(pv, RT_ALIGN_Z(cb, PAGE_SIZE));
return pv;
}
/**
* 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, size_t cb) RT_NO_THROW
{
if (pv)
free(pv);
}
/**
* 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) RT_NO_THROW
{
/*
* 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;
#if RTMEM_PROT_NONE == PROT_NONE \
&& RTMEM_PROT_READ == PROT_READ \
&& RTMEM_PROT_WRITE == PROT_WRITE \
&& RTMEM_PROT_EXEC == PROT_EXEC
fProt = fProtect;
#else
Assert(!RTMEM_PROT_NONE);
if (!fProtect)
fProt = PROT_NONE;
else
{
fProt = 0;
if (fProtect & RTMEM_PROT_READ)
fProt |= PROT_READ;
if (fProtect & RTMEM_PROT_WRITE)
fProt |= PROT_WRITE;
if (fProtect & RTMEM_PROT_EXEC)
fProt |= PROT_EXEC;
}
#endif
/*
* Align the request.
*/
cb += (uintptr_t)pv & PAGE_OFFSET_MASK;
pv = (void *)((uintptr_t)pv & ~PAGE_OFFSET_MASK);
/*
* Change the page attributes.
*/
int rc = mprotect(pv, cb, fProt);
if (!rc)
return rc;
return RTErrConvertFromErrno(errno);
}