source: vbox/trunk/src/VBox/Runtime/r3/posix/allocex-r3-posix.cpp@ 46729

/* $Id: allocex-r3-posix.cpp 46729 2013-06-21 16:58:49Z vboxsync $ */
/** @file
 * IPRT - Memory Allocation, Extended Alloc and Free Functions for Ring-3, posix.
 */

/*
 * Copyright (C) 2006-2013 Oracle Corporation
 *
 * This file is part of VirtualBox Open Source Edition (OSE), as
 * available from http://www.215389.xyz. 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                                                               *
*******************************************************************************/
#define RTMEM_NO_WRAP_TO_EF_APIS
#include <iprt/mem.h>
#include "internal/iprt.h"

#include <iprt/assert.h>
#include <iprt/string.h>
#include "internal/magics.h"

#include <sys/mman.h>


/*******************************************************************************
*   Structures and Typedefs                                                    *
*******************************************************************************/
/**
 * Heading for extended memory allocations in ring-3.
 */
typedef struct RTMEMHDRR3
{
    /** Magic (RTMEMHDR_MAGIC). */
    uint32_t    u32Magic;
    /** Block flags (RTMEMALLOCEX_FLAGS_*). */
    uint32_t    fFlags;
    /** The actual size of the block, header not included. */
    uint32_t    cb;
    /** The requested allocation size. */
    uint32_t    cbReq;
} RTMEMHDRR3;
/** Pointer to a ring-3 extended memory header. */
typedef RTMEMHDRR3 *PRTMEMHDRR3;


/**
 * Allocates memory with upper boundrary.
 *
 * @returns Pointer to mmap allocation.
 * @param   cbAlloc             Number of bytes to alloacate.
 * @param   fFlags              Allocation flags.
 */
static void *rtMemAllocExAllocLow(size_t cbAlloc, uint32_t fFlags)
{
    int   fProt = PROT_READ | PROT_WRITE | (fFlags & RTMEMALLOCEX_FLAGS_EXEC ? PROT_EXEC : 0);
    void *pv    = NULL;
    if (fFlags & RTMEMALLOCEX_FLAGS_16BIT_REACH)
    {
        AssertReturn(cbAlloc < _64K, NULL);

        /*
         * Try with every possible address hint since the possible range is very limited.
         */
        uintptr_t uAddr     = fFlags & RTMEMALLOCEX_FLAGS_16BIT_REACH ? 0x1000  : _1M;
        uintptr_t uAddrLast = _64K - uAddr - cbAlloc;
        while (uAddr <= uAddrLast)
        {
            pv = mmap((void *)uAddr, cbAlloc, fProt, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
            if (pv && (uintptr_t)pv <= uAddrLast)
                break;
            if (pv)
            {
                munmap(pv, cbAlloc);
                pv = NULL;
            }
            uAddr += _4K;
        }
    }
    else
    {
#if ARCH_BITS == 32
        pv = mmap(NULL, cbAlloc, fProt, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);

#elif defined(RT_OS_LINUX)
# ifdef MAP_32BIT
        pv = mmap(NULL, cbAlloc, fProt, MAP_PRIVATE | MAP_ANONYMOUS | MAP_32BIT, -1, 0);
        if (pv)
            return pv;
# endif

        /** @todo On linux, we need an accurate hint. Since I don't need this branch of
         *        the code right now, I won't bother starting to parse
         *        /proc/curproc/mmap right now... */
        pv = NULL;
#else
        pv = NULL;
#endif
    }
    return pv;
}


RTDECL(int) RTMemAllocExTag(size_t cb, size_t cbAlignment, uint32_t fFlags, const char *pszTag, void **ppv) RT_NO_THROW
{
    /*
     * Validate and adjust input.
     */
    AssertMsgReturn(!(fFlags & ~RTMEMALLOCEX_FLAGS_VALID_MASK), ("%#x\n", fFlags), VERR_INVALID_PARAMETER);
    AssertReturn(cb > 0, VERR_INVALID_PARAMETER);
    AssertReturn(RT_IS_POWER_OF_TWO(cbAlignment), VERR_INVALID_PARAMETER);
    AssertMsgReturn(cbAlignment <= sizeof(void *), ("%zu (%#x)\n", cbAlignment, cbAlignment), VERR_UNSUPPORTED_ALIGNMENT);

    if (fFlags & RTMEMALLOCEX_FLAGS_ANY_CTX)
        return VERR_NOT_SUPPORTED;

    /*
     * Align the request.
     */
    size_t cbAligned = cb;
    if (cbAlignment)
        cbAligned = RT_ALIGN_Z(cb, cbAlignment);
    else
        cbAligned = RT_ALIGN_Z(cb, sizeof(uint64_t));
    AssertMsgReturn(cbAligned >= cb && cbAligned <= ~(size_t)0, ("cbAligned=%#zx cb=%#zx", cbAligned, cb),
                    VERR_INVALID_PARAMETER);

    /*
     * Allocate the requested memory.
     */
    void *pv;
    if (fFlags & (RTMEMALLOCEX_FLAGS_16BIT_REACH | RTMEMALLOCEX_FLAGS_32BIT_REACH))
        pv = rtMemAllocExAllocLow(cbAligned + sizeof(RTMEMHDRR3), fFlags);
    else if (fFlags & RTMEMALLOCEX_FLAGS_EXEC)
    {
        pv = RTMemExecAlloc(cbAligned + sizeof(RTMEMHDRR3));
        if ((fFlags & RTMEMALLOCEX_FLAGS_ZEROED) && pv)
            RT_BZERO(pv, cbAligned + sizeof(RTMEMHDRR3));
    }
    else if (fFlags & RTMEMALLOCEX_FLAGS_ZEROED)
        pv = RTMemAllocZ(cbAligned + sizeof(RTMEMHDRR3));
    else
        pv = RTMemAlloc(cbAligned + sizeof(RTMEMHDRR3));
    if (!pv)
        return VERR_NO_MEMORY;

    /*
     * Fill in the header and return.
     */
    PRTMEMHDRR3 pHdr = (PRTMEMHDRR3)pv;
    pHdr->u32Magic  = RTMEMHDR_MAGIC;
    pHdr->fFlags    = fFlags;
    pHdr->cb        = cbAligned;
    pHdr->cbReq     = cb;

    *ppv = pHdr + 1;
    return VINF_SUCCESS;
}
RT_EXPORT_SYMBOL(RTMemAllocExTag);


RTDECL(void) RTMemFreeEx(void *pv, size_t cb) RT_NO_THROW
{
    if (!pv)
        return;
    AssertPtr(pv);

    PRTMEMHDRR3 pHdr = (PRTMEMHDRR3)pv - 1;
    AssertMsg(pHdr->u32Magic == RTMEMHDR_MAGIC, ("pHdr->u32Magic=%RX32 pv=%p cb=%#x\n", pHdr->u32Magic, pv, cb));
    pHdr->u32Magic = RTMEMHDR_MAGIC_DEAD;
    Assert(pHdr->cbReq == cb);

    if (pHdr->fFlags & (RTMEMALLOCEX_FLAGS_16BIT_REACH | RTMEMALLOCEX_FLAGS_32BIT_REACH))
        munmap(pHdr, pHdr->cb + sizeof(*pHdr));
    else if (pHdr->fFlags & RTMEMALLOCEX_FLAGS_EXEC)
        RTMemExecFree(pHdr, pHdr->cb + sizeof(*pHdr));
    else
        RTMemFree(pHdr);
}
RT_EXPORT_SYMBOL(RTMemFreeEx);