SUPLib-linux.cpp revision fbce7e4e7123ca200586ee9257a12d663e928841
/** @file
*
* VBox host drivers - Ring-0 support drivers - Linux host:
* Linux implementations for driver support library
*/
/*
* 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;
* 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 *
*******************************************************************************/
#include <errno.h>
#include <unistd.h>
#include <stdlib.h>
#include <malloc.h>
#include <string.h>
#include "SUPLibInternal.h"
#include "SUPDRVIOC.h"
/*******************************************************************************
* Defined Constants And Macros *
*******************************************************************************/
/** Unix Device name. */
#define DEVICE_NAME "/dev/vboxdrv"
/* define MADV_DONTFORK if it's missing from the system headers. */
#ifndef MADV_DONTFORK
# define MADV_DONTFORK 10
#endif
/*******************************************************************************
* Global Variables *
*******************************************************************************/
/** Handle to the open device. */
static int g_hDevice = -1;
/** Flags whether or not we've loaded the kernel module. */
static bool g_fLoadedModule = false;
/** Indicates whether madvise(,,MADV_DONTFORK) works. */
static bool g_fSysMadviseWorks = false;
/*******************************************************************************
* Internal Functions *
*******************************************************************************/
/**
* Initialize the OS specific part of the library.
* On Linux this involves:
* - loading the module.
* - open driver.
*
* @returns 0 on success.
* @returns current -1 on failure but this must be changed to proper error codes.
* @param cbReserved Ignored on linux.
*/
{
/*
* Check if already initialized.
*/
if (g_hDevice >= 0)
return 0;
/*
* Try open the device.
*/
if (g_hDevice < 0)
{
/*
* Try load the device.
*/
//todo suplibOsLoadKernelModule();
if (g_hDevice < 0)
{
switch (errno)
{
case ENXIO: /* see man 2 open, ENODEV is actually a kernel bug */
case ENODEV: return VERR_VM_DRIVER_LOAD_ERROR;
case EPERM:
case EACCES: return VERR_VM_DRIVER_NOT_ACCESSIBLE;
case ENOENT: return VERR_VM_DRIVER_NOT_INSTALLED;
default:
return VERR_VM_DRIVER_OPEN_ERROR;
}
}
}
/*
* Mark the file handle close on exec.
*/
{
g_hDevice = -1;
return RTErrConvertFromErrno(errno);
}
/*
* Check if madvise works.
*/
if (pv == MAP_FAILED)
return VERR_NO_MEMORY;
/*
* We're done.
*/
return 0;
}
int suplibOsTerm(void)
{
/*
* Check if we're initited at all.
*/
if (g_hDevice >= 0)
{
AssertFailed();
g_hDevice = -1;
}
/*
* If we started the service we might consider stopping it too.
*
* Since this won't work unless the the process starting it is the
* last user we might wanna skip this...
*/
if (g_fLoadedModule)
{
//todo kernel module unloading.
//suplibOsStopService();
//g_fStartedService = false;
}
return 0;
}
/**
* Installs anything required by the support library.
*
* @returns 0 on success.
* @returns error code on failure.
*/
int suplibOsInstall(void)
{
// nothing to do on Linux
return VERR_NOT_IMPLEMENTED;
}
/**
* Installs anything required by the support library.
*
* @returns 0 on success.
* @returns error code on failure.
*/
int suplibOsUninstall(void)
{
// nothing to do on Linux
return VERR_NOT_IMPLEMENTED;
}
/**
* Send a I/O Control request to the device.
*
* @returns 0 on success.
* @returns VBOX error code on failure.
* @param uFunction IO Control function.
* @param pvReq The request buffer.
* @param cbReq The size of the request buffer.
*/
{
/*
* Issue device iocontrol.
*/
return VINF_SUCCESS;
/* This is the reverse operation of the one found in SUPDrv-linux.c */
switch (errno)
{
case EACCES: return VERR_GENERAL_FAILURE;
case EINVAL: return VERR_INVALID_PARAMETER;
case EILSEQ: return VERR_INVALID_MAGIC;
case ENXIO: return VERR_INVALID_HANDLE;
case EFAULT: return VERR_INVALID_POINTER;
case ENOLCK: return VERR_LOCK_FAILED;
case EEXIST: return VERR_ALREADY_LOADED;
case EPERM: return VERR_PERMISSION_DENIED;
case ENOSYS: return VERR_VERSION_MISMATCH;
case 1000: return VERR_IDT_FAILED;
}
return RTErrConvertFromErrno(errno);
}
/**
* Allocate a number of zero-filled pages in user space.
*
* @returns VBox status code.
* @param cPages Number of pages to allocate.
* @param ppvPages Where to return the base pointer.
*/
{
char *pvPages = (char *)mmap(NULL, cbMmap, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if (pvPages == MAP_FAILED)
return VERR_NO_MEMORY;
if (g_fSysMadviseWorks)
{
/*
* It is not fatal if we fail here but a forked child (e.g. the ALSA sound server)
* could crash. Linux < 2.6.16 does not implement madvise(MADV_DONTFORK) but the
* kernel seems to split bigger VMAs and that is all that we want -- later we set the
* VM_DONTCOPY attribute in supdrvOSLockMemOne().
*/
}
else
{
/*
* madvise(MADV_DONTFORK) is not available (most probably Linux 2.4). Enclose any
* mmapped region by two unmapped pages to guarantee that there is exactly one VM
* area struct of the very same size as the mmap area.
*/
}
return VINF_SUCCESS;
}
/**
* Frees pages allocated by suplibOsPageAlloc().
*
* @returns VBox status code.
* @param pvPages Pointer to pages.
*/
{
return VINF_SUCCESS;
}