177 lines
4.2 KiB
C
177 lines
4.2 KiB
C
/*
|
|
* The Qubes OS Project, http://www.qubes-os.org
|
|
*
|
|
* Copyright (C) 2010 Rafal Wojtczuk <rafal@invisiblethingslab.com>
|
|
*
|
|
* This program 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; either version 2
|
|
* of the License, or (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
|
*
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/version.h>
|
|
#include <linux/proc_fs.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/sched.h>
|
|
#ifndef FOREIGN_FRAME_BIT
|
|
#include <xen/page.h>
|
|
#endif
|
|
#include <linux/highmem.h>
|
|
|
|
/* copy of /usr/include/u2mfn-kernel.h, to reduce requirements */
|
|
#include <linux/ioctl.h>
|
|
#define U2MFN_MAGIC 0xf5
|
|
#define U2MFN_GET_MFN_FOR_PAGE _IOW(U2MFN_MAGIC, 1, int)
|
|
#define U2MFN_GET_LAST_MFN _IO(U2MFN_MAGIC, 2)
|
|
|
|
|
|
#if LINUX_VERSION_CODE < KERNEL_VERSION(3,0,0)
|
|
static inline unsigned long virt_to_phys(volatile void *address)
|
|
{
|
|
return __pa((unsigned long) address);
|
|
}
|
|
#endif
|
|
|
|
#ifdef virt_to_mfn
|
|
#define VIRT_TO_MFN virt_to_mfn
|
|
#else
|
|
extern unsigned long *phys_to_machine_mapping;
|
|
static inline unsigned long VIRT_TO_MFN(void *addr)
|
|
{
|
|
return phys_to_machine_mapping[virt_to_phys(addr) >> PAGE_SHIFT] & ~FOREIGN_FRAME_BIT;
|
|
}
|
|
#endif
|
|
|
|
/// User virtual address to mfn translator
|
|
/**
|
|
\param cmd ignored
|
|
\param data the user-specified address
|
|
\return mfn corresponding to "data" argument, or -1 on error
|
|
*/
|
|
static long u2mfn_ioctl(struct file *f, unsigned int cmd,
|
|
unsigned long data)
|
|
{
|
|
struct page *user_page;
|
|
void *kaddr;
|
|
long ret;
|
|
|
|
if (_IOC_TYPE(cmd) != U2MFN_MAGIC) {
|
|
printk("Qubes u2mfn: wrong IOCTL magic");
|
|
return -ENOTTY;
|
|
}
|
|
|
|
switch (cmd) {
|
|
case U2MFN_GET_MFN_FOR_PAGE:
|
|
down_read(¤t->mm->mmap_sem);
|
|
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 6, 0)
|
|
ret = get_user_pages
|
|
(data, 1, 1, 0, &user_page, 0);
|
|
#else
|
|
ret = get_user_pages
|
|
(current, current->mm, data, 1, 1, 0, &user_page, 0);
|
|
#endif
|
|
up_read(¤t->mm->mmap_sem);
|
|
if (ret != 1) {
|
|
printk("U2MFN_GET_MFN_FOR_PAGE: get_user_pages failed, ret=0x%lx\n", ret);
|
|
return -1;
|
|
}
|
|
kaddr = kmap(user_page);
|
|
ret = VIRT_TO_MFN(kaddr);
|
|
kunmap(user_page);
|
|
put_page(user_page);
|
|
break;
|
|
|
|
case U2MFN_GET_LAST_MFN:
|
|
if (f->private_data)
|
|
ret = VIRT_TO_MFN(f->private_data);
|
|
else
|
|
ret = 0;
|
|
break;
|
|
|
|
default:
|
|
printk("Qubes u2mfn: wrong ioctl passed!\n");
|
|
return -ENOTTY;
|
|
}
|
|
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int u2mfn_mmap(struct file *f, struct vm_area_struct *vma)
|
|
{
|
|
int ret;
|
|
char *kbuf;
|
|
long length = vma->vm_end - vma->vm_start;
|
|
printk("u2mfn_mmap: entering, private=%p\n", f->private_data);
|
|
if (f->private_data)
|
|
return -EBUSY;
|
|
if (length != PAGE_SIZE)
|
|
return -EINVAL;
|
|
kbuf = (char *) __get_free_page(GFP_KERNEL);
|
|
if (!kbuf)
|
|
return -ENOMEM;
|
|
|
|
f->private_data = kbuf;
|
|
|
|
ret = remap_pfn_range(vma, vma->vm_start,
|
|
virt_to_phys(kbuf) >> PAGE_SHIFT,
|
|
length, vma->vm_page_prot);
|
|
|
|
printk("u2mfn_mmap: calling remap return %d\n", ret);
|
|
if (ret)
|
|
return ret;
|
|
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int u2mfn_release(struct inode *i, struct file *f)
|
|
{
|
|
printk("u2mfn_release, priv=%p\n", f->private_data);
|
|
if (f->private_data)
|
|
__free_page(f->private_data);
|
|
f->private_data = NULL;
|
|
return 0;
|
|
}
|
|
|
|
static struct file_operations u2mfn_fops = {
|
|
.unlocked_ioctl = u2mfn_ioctl,
|
|
.mmap = u2mfn_mmap,
|
|
.release = u2mfn_release
|
|
};
|
|
|
|
/// u2mfn module registration
|
|
/**
|
|
tries to register "/proc/u2mfn" pseudofile
|
|
*/
|
|
static int u2mfn_init(void)
|
|
{
|
|
struct proc_dir_entry *u2mfn_node =
|
|
proc_create_data("u2mfn", 0666, NULL,
|
|
&u2mfn_fops, 0);
|
|
if (!u2mfn_node)
|
|
return -1;
|
|
return 0;
|
|
}
|
|
|
|
static void u2mfn_exit(void)
|
|
{
|
|
remove_proc_entry("u2mfn", 0);
|
|
}
|
|
|
|
module_init(u2mfn_init);
|
|
module_exit(u2mfn_exit);
|
|
MODULE_LICENSE("GPL");
|