linux-stable/arch/powerpc/kernel/proc_ppc64.c
Denis V. Lunev 667471386d powerpc: use non-racy method for proc entries creation
Use proc_create()/proc_create_data() to make sure that ->proc_fops and ->data
be setup before gluing PDE to main tree.

Add correct ->owner to proc_fops to fix reading/module unloading race.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:22 -07:00

122 lines
3.1 KiB
C

/*
* Copyright (C) 2001 Mike Corrigan & Dave Engebretsen IBM Corporation
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/proc_fs.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <asm/machdep.h>
#include <asm/vdso_datapage.h>
#include <asm/rtas.h>
#include <asm/uaccess.h>
#include <asm/prom.h>
static loff_t page_map_seek( struct file *file, loff_t off, int whence);
static ssize_t page_map_read( struct file *file, char __user *buf, size_t nbytes,
loff_t *ppos);
static int page_map_mmap( struct file *file, struct vm_area_struct *vma );
static const struct file_operations page_map_fops = {
.llseek = page_map_seek,
.read = page_map_read,
.mmap = page_map_mmap
};
/*
* Create the ppc64 and ppc64/rtas directories early. This allows us to
* assume that they have been previously created in drivers.
*/
static int __init proc_ppc64_create(void)
{
struct proc_dir_entry *root;
root = proc_mkdir("ppc64", NULL);
if (!root)
return 1;
if (!of_find_node_by_path("/rtas"))
return 0;
if (!proc_mkdir("rtas", root))
return 1;
if (!proc_symlink("rtas", NULL, "ppc64/rtas"))
return 1;
return 0;
}
core_initcall(proc_ppc64_create);
static int __init proc_ppc64_init(void)
{
struct proc_dir_entry *pde;
pde = proc_create_data("ppc64/systemcfg", S_IFREG|S_IRUGO, NULL,
&page_map_fops, vdso_data);
if (!pde)
return 1;
pde->size = PAGE_SIZE;
return 0;
}
__initcall(proc_ppc64_init);
static loff_t page_map_seek( struct file *file, loff_t off, int whence)
{
loff_t new;
struct proc_dir_entry *dp = PDE(file->f_path.dentry->d_inode);
switch(whence) {
case 0:
new = off;
break;
case 1:
new = file->f_pos + off;
break;
case 2:
new = dp->size + off;
break;
default:
return -EINVAL;
}
if ( new < 0 || new > dp->size )
return -EINVAL;
return (file->f_pos = new);
}
static ssize_t page_map_read( struct file *file, char __user *buf, size_t nbytes,
loff_t *ppos)
{
struct proc_dir_entry *dp = PDE(file->f_path.dentry->d_inode);
return simple_read_from_buffer(buf, nbytes, ppos, dp->data, dp->size);
}
static int page_map_mmap( struct file *file, struct vm_area_struct *vma )
{
struct proc_dir_entry *dp = PDE(file->f_path.dentry->d_inode);
if ((vma->vm_end - vma->vm_start) > dp->size)
return -EINVAL;
remap_pfn_range(vma, vma->vm_start, __pa(dp->data) >> PAGE_SHIFT,
dp->size, vma->vm_page_prot);
return 0;
}