2005-04-16 16:20:36 -06:00
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/*
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* proc/fs/generic.c --- generic routines for the proc-fs
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*
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* This file contains generic proc-fs routines for handling
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* directories and files.
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*
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* Copyright (C) 1991, 1992 Linus Torvalds.
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* Copyright (C) 1997 Theodore Ts'o
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*/
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#include <linux/errno.h>
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#include <linux/time.h>
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#include <linux/proc_fs.h>
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#include <linux/stat.h>
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#include <linux/module.h>
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#include <linux/mount.h>
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#include <linux/init.h>
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#include <linux/idr.h>
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#include <linux/namei.h>
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#include <linux/bitops.h>
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2006-03-26 02:36:55 -07:00
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#include <linux/spinlock.h>
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Fix rmmod/read/write races in /proc entries
Fix following races:
===========================================
1. Write via ->write_proc sleeps in copy_from_user(). Module disappears
meanwhile. Or, more generically, system call done on /proc file, method
supplied by module is called, module dissapeares meanwhile.
pde = create_proc_entry()
if (!pde)
return -ENOMEM;
pde->write_proc = ...
open
write
copy_from_user
pde = create_proc_entry();
if (!pde) {
remove_proc_entry();
return -ENOMEM;
/* module unloaded */
}
*boom*
==========================================
2. bogo-revoke aka proc_kill_inodes()
remove_proc_entry vfs_read
proc_kill_inodes [check ->f_op validness]
[check ->f_op->read validness]
[verify_area, security permissions checks]
->f_op = NULL;
if (file->f_op->read)
/* ->f_op dereference, boom */
NOTE, NOTE, NOTE: file_operations are proxied for regular files only. Let's
see how this scheme behaves, then extend if needed for directories.
Directories creators in /proc only set ->owner for them, so proxying for
directories may be unneeded.
NOTE, NOTE, NOTE: methods being proxied are ->llseek, ->read, ->write,
->poll, ->unlocked_ioctl, ->ioctl, ->compat_ioctl, ->open, ->release.
If your in-tree module uses something else, yell on me. Full audit pending.
[akpm@linux-foundation.org: build fix]
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 00:39:00 -06:00
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#include <linux/completion.h>
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2005-04-16 16:20:36 -06:00
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#include <asm/uaccess.h>
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2006-01-08 02:04:16 -07:00
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#include "internal.h"
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2006-03-26 02:36:55 -07:00
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DEFINE_SPINLOCK(proc_subdir_lock);
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2007-02-14 01:34:12 -07:00
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static int proc_match(int len, const char *name, struct proc_dir_entry *de)
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2005-04-16 16:20:36 -06:00
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{
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if (de->namelen != len)
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return 0;
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return !memcmp(name, de->name, len);
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}
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/* buffer size is one page but our output routines use some slack for overruns */
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#define PROC_BLOCK_SIZE (PAGE_SIZE - 1024)
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static ssize_t
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proc_file_read(struct file *file, char __user *buf, size_t nbytes,
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loff_t *ppos)
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{
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2006-12-08 03:36:36 -07:00
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struct inode * inode = file->f_path.dentry->d_inode;
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2005-04-16 16:20:36 -06:00
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char *page;
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ssize_t retval=0;
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int eof=0;
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ssize_t n, count;
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char *start;
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struct proc_dir_entry * dp;
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2005-12-30 09:39:10 -07:00
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unsigned long long pos;
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/*
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* Gaah, please just use "seq_file" instead. The legacy /proc
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* interfaces cut loff_t down to off_t for reads, and ignore
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* the offset entirely for writes..
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*/
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pos = *ppos;
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if (pos > MAX_NON_LFS)
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return 0;
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if (nbytes > MAX_NON_LFS - pos)
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nbytes = MAX_NON_LFS - pos;
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2005-04-16 16:20:36 -06:00
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dp = PDE(inode);
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2007-10-16 02:25:52 -06:00
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if (!(page = (char*) __get_free_page(GFP_TEMPORARY)))
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2005-04-16 16:20:36 -06:00
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return -ENOMEM;
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while ((nbytes > 0) && !eof) {
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count = min_t(size_t, PROC_BLOCK_SIZE, nbytes);
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start = NULL;
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2008-04-29 02:01:58 -06:00
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if (dp->read_proc) {
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2005-04-16 16:20:36 -06:00
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/*
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* How to be a proc read function
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* ------------------------------
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* Prototype:
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* int f(char *buffer, char **start, off_t offset,
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* int count, int *peof, void *dat)
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*
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* Assume that the buffer is "count" bytes in size.
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*
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* If you know you have supplied all the data you
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* have, set *peof.
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*
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* You have three ways to return data:
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* 0) Leave *start = NULL. (This is the default.)
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* Put the data of the requested offset at that
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* offset within the buffer. Return the number (n)
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* of bytes there are from the beginning of the
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* buffer up to the last byte of data. If the
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* number of supplied bytes (= n - offset) is
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* greater than zero and you didn't signal eof
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* and the reader is prepared to take more data
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* you will be called again with the requested
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* offset advanced by the number of bytes
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* absorbed. This interface is useful for files
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* no larger than the buffer.
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* 1) Set *start = an unsigned long value less than
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* the buffer address but greater than zero.
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* Put the data of the requested offset at the
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* beginning of the buffer. Return the number of
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* bytes of data placed there. If this number is
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* greater than zero and you didn't signal eof
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* and the reader is prepared to take more data
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* you will be called again with the requested
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* offset advanced by *start. This interface is
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* useful when you have a large file consisting
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* of a series of blocks which you want to count
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* and return as wholes.
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* (Hack by Paul.Russell@rustcorp.com.au)
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* 2) Set *start = an address within the buffer.
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* Put the data of the requested offset at *start.
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* Return the number of bytes of data placed there.
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* If this number is greater than zero and you
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* didn't signal eof and the reader is prepared to
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* take more data you will be called again with the
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* requested offset advanced by the number of bytes
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* absorbed.
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*/
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n = dp->read_proc(page, &start, *ppos,
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count, &eof, dp->data);
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} else
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break;
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if (n == 0) /* end of file */
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break;
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if (n < 0) { /* error */
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if (retval == 0)
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retval = n;
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break;
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}
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if (start == NULL) {
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if (n > PAGE_SIZE) {
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printk(KERN_ERR
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"proc_file_read: Apparent buffer overflow!\n");
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n = PAGE_SIZE;
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}
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n -= *ppos;
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if (n <= 0)
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break;
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if (n > count)
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n = count;
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start = page + *ppos;
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} else if (start < page) {
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if (n > PAGE_SIZE) {
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printk(KERN_ERR
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"proc_file_read: Apparent buffer overflow!\n");
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n = PAGE_SIZE;
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}
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if (n > count) {
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/*
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* Don't reduce n because doing so might
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* cut off part of a data block.
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*/
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printk(KERN_WARNING
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"proc_file_read: Read count exceeded\n");
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}
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} else /* start >= page */ {
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unsigned long startoff = (unsigned long)(start - page);
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if (n > (PAGE_SIZE - startoff)) {
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printk(KERN_ERR
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"proc_file_read: Apparent buffer overflow!\n");
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n = PAGE_SIZE - startoff;
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}
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if (n > count)
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n = count;
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}
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n -= copy_to_user(buf, start < page ? page : start, n);
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if (n == 0) {
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if (retval == 0)
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retval = -EFAULT;
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break;
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}
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*ppos += start < page ? (unsigned long)start : n;
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nbytes -= n;
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buf += n;
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retval += n;
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}
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free_page((unsigned long) page);
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return retval;
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}
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static ssize_t
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proc_file_write(struct file *file, const char __user *buffer,
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size_t count, loff_t *ppos)
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{
|
2006-12-08 03:36:36 -07:00
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struct inode *inode = file->f_path.dentry->d_inode;
|
2005-04-16 16:20:36 -06:00
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struct proc_dir_entry * dp;
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dp = PDE(inode);
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if (!dp->write_proc)
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return -EIO;
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/* FIXME: does this routine need ppos? probably... */
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return dp->write_proc(file, buffer, count, dp->data);
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}
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static loff_t
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proc_file_lseek(struct file *file, loff_t offset, int orig)
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{
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2005-12-30 09:39:10 -07:00
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loff_t retval = -EINVAL;
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switch (orig) {
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case 1:
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offset += file->f_pos;
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/* fallthrough */
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case 0:
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if (offset < 0 || offset > MAX_NON_LFS)
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break;
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file->f_pos = retval = offset;
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}
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return retval;
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2005-04-16 16:20:36 -06:00
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}
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2008-02-08 05:18:27 -07:00
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static const struct file_operations proc_file_operations = {
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.llseek = proc_file_lseek,
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.read = proc_file_read,
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.write = proc_file_write,
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};
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2005-04-16 16:20:36 -06:00
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static int proc_notify_change(struct dentry *dentry, struct iattr *iattr)
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{
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struct inode *inode = dentry->d_inode;
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struct proc_dir_entry *de = PDE(inode);
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int error;
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error = inode_change_ok(inode, iattr);
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if (error)
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goto out;
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error = inode_setattr(inode, iattr);
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if (error)
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goto out;
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de->uid = inode->i_uid;
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de->gid = inode->i_gid;
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de->mode = inode->i_mode;
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out:
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return error;
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}
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2005-09-06 16:17:18 -06:00
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static int proc_getattr(struct vfsmount *mnt, struct dentry *dentry,
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struct kstat *stat)
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{
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struct inode *inode = dentry->d_inode;
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struct proc_dir_entry *de = PROC_I(inode)->pde;
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if (de && de->nlink)
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inode->i_nlink = de->nlink;
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generic_fillattr(inode, stat);
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return 0;
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}
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2007-02-12 01:55:40 -07:00
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static const struct inode_operations proc_file_inode_operations = {
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2005-04-16 16:20:36 -06:00
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.setattr = proc_notify_change,
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};
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/*
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* This function parses a name such as "tty/driver/serial", and
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* returns the struct proc_dir_entry for "/proc/tty/driver", and
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* returns "serial" in residual.
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*/
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static int xlate_proc_name(const char *name,
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struct proc_dir_entry **ret, const char **residual)
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{
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const char *cp = name, *next;
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struct proc_dir_entry *de;
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int len;
|
2006-03-26 02:36:55 -07:00
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int rtn = 0;
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2005-04-16 16:20:36 -06:00
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proc: less special case in xlate code
If valid "parent" is passed to proc_create/remove_proc_entry(), then name of
PDE should consist of only one path component, otherwise creation or or
removal will fail. However, if NULL is passed as parent then create/remove
accept full path as a argument. This is arbitrary restriction -- all
infrastructure is in place.
So, patch allows the following to succeed:
create_proc_entry("foo/bar", 0, pde_baz);
remove_proc_entry("baz/foo/bar", &proc_root);
Also makes the following to behave identically:
create_proc_entry("foo/bar", 0, NULL);
create_proc_entry("foo/bar", 0, &proc_root);
Discrepancy noticed by Den Lunev (IIRC).
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 02:01:40 -06:00
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de = *ret;
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if (!de)
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de = &proc_root;
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2006-03-26 02:36:55 -07:00
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spin_lock(&proc_subdir_lock);
|
2005-04-16 16:20:36 -06:00
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while (1) {
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next = strchr(cp, '/');
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if (!next)
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break;
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len = next - cp;
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for (de = de->subdir; de ; de = de->next) {
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if (proc_match(len, cp, de))
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break;
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}
|
2006-03-26 02:36:55 -07:00
|
|
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if (!de) {
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rtn = -ENOENT;
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goto out;
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|
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}
|
2005-04-16 16:20:36 -06:00
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cp += len + 1;
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}
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*residual = cp;
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*ret = de;
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2006-03-26 02:36:55 -07:00
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out:
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spin_unlock(&proc_subdir_lock);
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return rtn;
|
2005-04-16 16:20:36 -06:00
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}
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|
2008-07-26 01:21:37 -06:00
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|
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static DEFINE_IDA(proc_inum_ida);
|
2005-04-16 16:20:36 -06:00
|
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static DEFINE_SPINLOCK(proc_inum_lock); /* protects the above */
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2008-07-26 01:18:28 -06:00
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|
#define PROC_DYNAMIC_FIRST 0xF0000000U
|
2005-04-16 16:20:36 -06:00
|
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|
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/*
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|
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* Return an inode number between PROC_DYNAMIC_FIRST and
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|
|
* 0xffffffff, or zero on failure.
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|
|
|
*/
|
|
|
|
static unsigned int get_inode_number(void)
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|
|
|
{
|
2008-07-26 01:18:28 -06:00
|
|
|
unsigned int i;
|
2005-04-16 16:20:36 -06:00
|
|
|
int error;
|
|
|
|
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|
|
retry:
|
2008-07-26 01:21:37 -06:00
|
|
|
if (ida_pre_get(&proc_inum_ida, GFP_KERNEL) == 0)
|
2005-04-16 16:20:36 -06:00
|
|
|
return 0;
|
|
|
|
|
|
|
|
spin_lock(&proc_inum_lock);
|
2008-07-26 01:21:37 -06:00
|
|
|
error = ida_get_new(&proc_inum_ida, &i);
|
2005-04-16 16:20:36 -06:00
|
|
|
spin_unlock(&proc_inum_lock);
|
|
|
|
if (error == -EAGAIN)
|
|
|
|
goto retry;
|
|
|
|
else if (error)
|
|
|
|
return 0;
|
|
|
|
|
2008-07-26 01:18:28 -06:00
|
|
|
if (i > UINT_MAX - PROC_DYNAMIC_FIRST) {
|
|
|
|
spin_lock(&proc_inum_lock);
|
2008-07-26 01:21:37 -06:00
|
|
|
ida_remove(&proc_inum_ida, i);
|
2008-07-26 01:18:28 -06:00
|
|
|
spin_unlock(&proc_inum_lock);
|
2008-08-01 21:30:48 -06:00
|
|
|
return 0;
|
2008-07-26 01:18:28 -06:00
|
|
|
}
|
|
|
|
return PROC_DYNAMIC_FIRST + i;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
static void release_inode_number(unsigned int inum)
|
|
|
|
{
|
|
|
|
spin_lock(&proc_inum_lock);
|
2008-07-26 01:21:37 -06:00
|
|
|
ida_remove(&proc_inum_ida, inum - PROC_DYNAMIC_FIRST);
|
2005-04-16 16:20:36 -06:00
|
|
|
spin_unlock(&proc_inum_lock);
|
|
|
|
}
|
|
|
|
|
[PATCH] Fix up symlink function pointers
This fixes up the symlink functions for the calling convention change:
* afs, autofs4, befs, devfs, freevxfs, jffs2, jfs, ncpfs, procfs,
smbfs, sysvfs, ufs, xfs - prototype change for ->follow_link()
* befs, smbfs, xfs - same for ->put_link()
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-19 17:17:39 -06:00
|
|
|
static void *proc_follow_link(struct dentry *dentry, struct nameidata *nd)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
|
|
|
nd_set_link(nd, PDE(dentry->d_inode)->data);
|
[PATCH] Fix up symlink function pointers
This fixes up the symlink functions for the calling convention change:
* afs, autofs4, befs, devfs, freevxfs, jffs2, jfs, ncpfs, procfs,
smbfs, sysvfs, ufs, xfs - prototype change for ->follow_link()
* befs, smbfs, xfs - same for ->put_link()
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-19 17:17:39 -06:00
|
|
|
return NULL;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
2007-02-12 01:55:40 -07:00
|
|
|
static const struct inode_operations proc_link_inode_operations = {
|
2005-04-16 16:20:36 -06:00
|
|
|
.readlink = generic_readlink,
|
|
|
|
.follow_link = proc_follow_link,
|
|
|
|
};
|
|
|
|
|
|
|
|
/*
|
|
|
|
* As some entries in /proc are volatile, we want to
|
|
|
|
* get rid of unused dentries. This could be made
|
|
|
|
* smarter: we could keep a "volatile" flag in the
|
|
|
|
* inode to indicate which ones to keep.
|
|
|
|
*/
|
|
|
|
static int proc_delete_dentry(struct dentry * dentry)
|
|
|
|
{
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
|
|
|
|
static struct dentry_operations proc_dentry_operations =
|
|
|
|
{
|
|
|
|
.d_delete = proc_delete_dentry,
|
|
|
|
};
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Don't create negative dentries here, return -ENOENT by hand
|
|
|
|
* instead.
|
|
|
|
*/
|
[NET]: Make /proc/net a symlink on /proc/self/net (v3)
Current /proc/net is done with so called "shadows", but current
implementation is broken and has little chances to get fixed.
The problem is that dentries subtree of /proc/net directory has
fancy revalidation rules to make processes living in different
net namespaces see different entries in /proc/net subtree, but
currently, tasks see in the /proc/net subdir the contents of any
other namespace, depending on who opened the file first.
The proposed fix is to turn /proc/net into a symlink, which points
to /proc/self/net, which in turn shows what previously was in
/proc/net - the network-related info, from the net namespace the
appropriate task lives in.
# ls -l /proc/net
lrwxrwxrwx 1 root root 8 Mar 5 15:17 /proc/net -> self/net
In other words - this behaves like /proc/mounts, but unlike
"mounts", "net" is not a file, but a directory.
Changes from v2:
* Fixed discrepancy of /proc/net nlink count and selinux labeling
screwup pointed out by Stephen.
To get the correct nlink count the ->getattr callback for /proc/net
is overridden to read one from the net->proc_net entry.
To make selinux still work the net->proc_net entry is initialized
properly, i.e. with the "net" name and the proc_net parent.
Selinux fixes are
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Changes from v1:
* Fixed a task_struct leak in get_proc_task_net, pointed out by Paul.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-03-07 12:08:40 -07:00
|
|
|
struct dentry *proc_lookup_de(struct proc_dir_entry *de, struct inode *dir,
|
|
|
|
struct dentry *dentry)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
|
|
|
struct inode *inode = NULL;
|
|
|
|
int error = -ENOENT;
|
|
|
|
|
2006-03-26 02:36:55 -07:00
|
|
|
spin_lock(&proc_subdir_lock);
|
2008-04-29 02:01:41 -06:00
|
|
|
for (de = de->subdir; de ; de = de->next) {
|
|
|
|
if (de->namelen != dentry->d_name.len)
|
|
|
|
continue;
|
|
|
|
if (!memcmp(dentry->d_name.name, de->name, de->namelen)) {
|
|
|
|
unsigned int ino;
|
|
|
|
|
|
|
|
ino = de->low_ino;
|
|
|
|
de_get(de);
|
|
|
|
spin_unlock(&proc_subdir_lock);
|
|
|
|
error = -EINVAL;
|
|
|
|
inode = proc_get_inode(dir->i_sb, ino, de);
|
|
|
|
goto out_unlock;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
}
|
2006-03-26 02:36:55 -07:00
|
|
|
spin_unlock(&proc_subdir_lock);
|
2008-02-08 05:18:27 -07:00
|
|
|
out_unlock:
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
if (inode) {
|
|
|
|
dentry->d_op = &proc_dentry_operations;
|
|
|
|
d_add(dentry, inode);
|
|
|
|
return NULL;
|
|
|
|
}
|
2008-04-29 02:01:41 -06:00
|
|
|
if (de)
|
|
|
|
de_put(de);
|
2005-04-16 16:20:36 -06:00
|
|
|
return ERR_PTR(error);
|
|
|
|
}
|
|
|
|
|
[NET]: Make /proc/net a symlink on /proc/self/net (v3)
Current /proc/net is done with so called "shadows", but current
implementation is broken and has little chances to get fixed.
The problem is that dentries subtree of /proc/net directory has
fancy revalidation rules to make processes living in different
net namespaces see different entries in /proc/net subtree, but
currently, tasks see in the /proc/net subdir the contents of any
other namespace, depending on who opened the file first.
The proposed fix is to turn /proc/net into a symlink, which points
to /proc/self/net, which in turn shows what previously was in
/proc/net - the network-related info, from the net namespace the
appropriate task lives in.
# ls -l /proc/net
lrwxrwxrwx 1 root root 8 Mar 5 15:17 /proc/net -> self/net
In other words - this behaves like /proc/mounts, but unlike
"mounts", "net" is not a file, but a directory.
Changes from v2:
* Fixed discrepancy of /proc/net nlink count and selinux labeling
screwup pointed out by Stephen.
To get the correct nlink count the ->getattr callback for /proc/net
is overridden to read one from the net->proc_net entry.
To make selinux still work the net->proc_net entry is initialized
properly, i.e. with the "net" name and the proc_net parent.
Selinux fixes are
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Changes from v1:
* Fixed a task_struct leak in get_proc_task_net, pointed out by Paul.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-03-07 12:08:40 -07:00
|
|
|
struct dentry *proc_lookup(struct inode *dir, struct dentry *dentry,
|
|
|
|
struct nameidata *nd)
|
|
|
|
{
|
|
|
|
return proc_lookup_de(PDE(dir), dir, dentry);
|
|
|
|
}
|
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
/*
|
|
|
|
* This returns non-zero if at EOF, so that the /proc
|
|
|
|
* root directory can use this and check if it should
|
|
|
|
* continue with the <pid> entries..
|
|
|
|
*
|
|
|
|
* Note that the VFS-layer doesn't care about the return
|
|
|
|
* value of the readdir() call, as long as it's non-negative
|
|
|
|
* for success..
|
|
|
|
*/
|
[NET]: Make /proc/net a symlink on /proc/self/net (v3)
Current /proc/net is done with so called "shadows", but current
implementation is broken and has little chances to get fixed.
The problem is that dentries subtree of /proc/net directory has
fancy revalidation rules to make processes living in different
net namespaces see different entries in /proc/net subtree, but
currently, tasks see in the /proc/net subdir the contents of any
other namespace, depending on who opened the file first.
The proposed fix is to turn /proc/net into a symlink, which points
to /proc/self/net, which in turn shows what previously was in
/proc/net - the network-related info, from the net namespace the
appropriate task lives in.
# ls -l /proc/net
lrwxrwxrwx 1 root root 8 Mar 5 15:17 /proc/net -> self/net
In other words - this behaves like /proc/mounts, but unlike
"mounts", "net" is not a file, but a directory.
Changes from v2:
* Fixed discrepancy of /proc/net nlink count and selinux labeling
screwup pointed out by Stephen.
To get the correct nlink count the ->getattr callback for /proc/net
is overridden to read one from the net->proc_net entry.
To make selinux still work the net->proc_net entry is initialized
properly, i.e. with the "net" name and the proc_net parent.
Selinux fixes are
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Changes from v1:
* Fixed a task_struct leak in get_proc_task_net, pointed out by Paul.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-03-07 12:08:40 -07:00
|
|
|
int proc_readdir_de(struct proc_dir_entry *de, struct file *filp, void *dirent,
|
|
|
|
filldir_t filldir)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
|
|
|
unsigned int ino;
|
|
|
|
int i;
|
2006-12-08 03:36:36 -07:00
|
|
|
struct inode *inode = filp->f_path.dentry->d_inode;
|
2005-04-16 16:20:36 -06:00
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
ino = inode->i_ino;
|
|
|
|
i = filp->f_pos;
|
|
|
|
switch (i) {
|
|
|
|
case 0:
|
|
|
|
if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
|
|
|
|
goto out;
|
|
|
|
i++;
|
|
|
|
filp->f_pos++;
|
|
|
|
/* fall through */
|
|
|
|
case 1:
|
|
|
|
if (filldir(dirent, "..", 2, i,
|
2006-12-08 03:36:36 -07:00
|
|
|
parent_ino(filp->f_path.dentry),
|
2005-04-16 16:20:36 -06:00
|
|
|
DT_DIR) < 0)
|
|
|
|
goto out;
|
|
|
|
i++;
|
|
|
|
filp->f_pos++;
|
|
|
|
/* fall through */
|
|
|
|
default:
|
2006-03-26 02:36:55 -07:00
|
|
|
spin_lock(&proc_subdir_lock);
|
2005-04-16 16:20:36 -06:00
|
|
|
de = de->subdir;
|
|
|
|
i -= 2;
|
|
|
|
for (;;) {
|
|
|
|
if (!de) {
|
|
|
|
ret = 1;
|
2006-03-26 02:36:55 -07:00
|
|
|
spin_unlock(&proc_subdir_lock);
|
2005-04-16 16:20:36 -06:00
|
|
|
goto out;
|
|
|
|
}
|
|
|
|
if (!i)
|
|
|
|
break;
|
|
|
|
de = de->next;
|
|
|
|
i--;
|
|
|
|
}
|
|
|
|
|
|
|
|
do {
|
2007-05-08 01:25:47 -06:00
|
|
|
struct proc_dir_entry *next;
|
|
|
|
|
2006-03-26 02:36:55 -07:00
|
|
|
/* filldir passes info to user space */
|
2007-05-08 01:25:47 -06:00
|
|
|
de_get(de);
|
2006-03-26 02:36:55 -07:00
|
|
|
spin_unlock(&proc_subdir_lock);
|
2005-04-16 16:20:36 -06:00
|
|
|
if (filldir(dirent, de->name, de->namelen, filp->f_pos,
|
2007-05-08 01:25:47 -06:00
|
|
|
de->low_ino, de->mode >> 12) < 0) {
|
|
|
|
de_put(de);
|
2005-04-16 16:20:36 -06:00
|
|
|
goto out;
|
2007-05-08 01:25:47 -06:00
|
|
|
}
|
2006-03-26 02:36:55 -07:00
|
|
|
spin_lock(&proc_subdir_lock);
|
2005-04-16 16:20:36 -06:00
|
|
|
filp->f_pos++;
|
2007-05-08 01:25:47 -06:00
|
|
|
next = de->next;
|
|
|
|
de_put(de);
|
|
|
|
de = next;
|
2005-04-16 16:20:36 -06:00
|
|
|
} while (de);
|
2006-03-26 02:36:55 -07:00
|
|
|
spin_unlock(&proc_subdir_lock);
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
ret = 1;
|
proc: stop using BKL
There are four BKL users in proc: de_put(), proc_lookup_de(),
proc_readdir_de(), proc_root_readdir(),
1) de_put()
-----------
de_put() is classic atomic_dec_and_test() refcount wrapper -- no BKL
needed. BKL doesn't matter to possible refcount leak as well.
2) proc_lookup_de()
-------------------
Walking PDE list is protected by proc_subdir_lock(), proc_get_inode() is
potentially blocking, all callers of proc_lookup_de() eventually end up
from ->lookup hooks which is protected by directory's ->i_mutex -- BKL
doesn't protect anything.
3) proc_readdir_de()
--------------------
"." and ".." part doesn't need BKL, walking PDE list is under
proc_subdir_lock, calling filldir callback is potentially blocking
because it writes to luserspace. All proc_readdir_de() callers
eventually come from ->readdir hook which is under directory's
->i_mutex -- BKL doesn't protect anything.
4) proc_root_readdir_de()
-------------------------
proc_root_readdir_de is ->readdir hook, see (3).
Since readdir hooks doesn't use BKL anymore, switch to
generic_file_llseek, since it also takes directory's i_mutex.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2008-10-27 13:48:36 -06:00
|
|
|
out:
|
2005-04-16 16:20:36 -06:00
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
[NET]: Make /proc/net a symlink on /proc/self/net (v3)
Current /proc/net is done with so called "shadows", but current
implementation is broken and has little chances to get fixed.
The problem is that dentries subtree of /proc/net directory has
fancy revalidation rules to make processes living in different
net namespaces see different entries in /proc/net subtree, but
currently, tasks see in the /proc/net subdir the contents of any
other namespace, depending on who opened the file first.
The proposed fix is to turn /proc/net into a symlink, which points
to /proc/self/net, which in turn shows what previously was in
/proc/net - the network-related info, from the net namespace the
appropriate task lives in.
# ls -l /proc/net
lrwxrwxrwx 1 root root 8 Mar 5 15:17 /proc/net -> self/net
In other words - this behaves like /proc/mounts, but unlike
"mounts", "net" is not a file, but a directory.
Changes from v2:
* Fixed discrepancy of /proc/net nlink count and selinux labeling
screwup pointed out by Stephen.
To get the correct nlink count the ->getattr callback for /proc/net
is overridden to read one from the net->proc_net entry.
To make selinux still work the net->proc_net entry is initialized
properly, i.e. with the "net" name and the proc_net parent.
Selinux fixes are
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Changes from v1:
* Fixed a task_struct leak in get_proc_task_net, pointed out by Paul.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-03-07 12:08:40 -07:00
|
|
|
int proc_readdir(struct file *filp, void *dirent, filldir_t filldir)
|
|
|
|
{
|
|
|
|
struct inode *inode = filp->f_path.dentry->d_inode;
|
|
|
|
|
|
|
|
return proc_readdir_de(PDE(inode), filp, dirent, filldir);
|
|
|
|
}
|
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
/*
|
|
|
|
* These are the generic /proc directory operations. They
|
|
|
|
* use the in-memory "struct proc_dir_entry" tree to parse
|
|
|
|
* the /proc directory.
|
|
|
|
*/
|
2007-02-12 01:55:34 -07:00
|
|
|
static const struct file_operations proc_dir_operations = {
|
proc: stop using BKL
There are four BKL users in proc: de_put(), proc_lookup_de(),
proc_readdir_de(), proc_root_readdir(),
1) de_put()
-----------
de_put() is classic atomic_dec_and_test() refcount wrapper -- no BKL
needed. BKL doesn't matter to possible refcount leak as well.
2) proc_lookup_de()
-------------------
Walking PDE list is protected by proc_subdir_lock(), proc_get_inode() is
potentially blocking, all callers of proc_lookup_de() eventually end up
from ->lookup hooks which is protected by directory's ->i_mutex -- BKL
doesn't protect anything.
3) proc_readdir_de()
--------------------
"." and ".." part doesn't need BKL, walking PDE list is under
proc_subdir_lock, calling filldir callback is potentially blocking
because it writes to luserspace. All proc_readdir_de() callers
eventually come from ->readdir hook which is under directory's
->i_mutex -- BKL doesn't protect anything.
4) proc_root_readdir_de()
-------------------------
proc_root_readdir_de is ->readdir hook, see (3).
Since readdir hooks doesn't use BKL anymore, switch to
generic_file_llseek, since it also takes directory's i_mutex.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2008-10-27 13:48:36 -06:00
|
|
|
.llseek = generic_file_llseek,
|
2005-04-16 16:20:36 -06:00
|
|
|
.read = generic_read_dir,
|
|
|
|
.readdir = proc_readdir,
|
|
|
|
};
|
|
|
|
|
|
|
|
/*
|
|
|
|
* proc directories can do almost nothing..
|
|
|
|
*/
|
2007-02-12 01:55:40 -07:00
|
|
|
static const struct inode_operations proc_dir_inode_operations = {
|
2005-04-16 16:20:36 -06:00
|
|
|
.lookup = proc_lookup,
|
2005-09-06 16:17:18 -06:00
|
|
|
.getattr = proc_getattr,
|
2005-04-16 16:20:36 -06:00
|
|
|
.setattr = proc_notify_change,
|
|
|
|
};
|
|
|
|
|
|
|
|
static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp)
|
|
|
|
{
|
|
|
|
unsigned int i;
|
2008-02-08 05:18:29 -07:00
|
|
|
struct proc_dir_entry *tmp;
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
i = get_inode_number();
|
|
|
|
if (i == 0)
|
|
|
|
return -EAGAIN;
|
|
|
|
dp->low_ino = i;
|
2006-03-26 02:36:55 -07:00
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
if (S_ISDIR(dp->mode)) {
|
|
|
|
if (dp->proc_iops == NULL) {
|
|
|
|
dp->proc_fops = &proc_dir_operations;
|
|
|
|
dp->proc_iops = &proc_dir_inode_operations;
|
|
|
|
}
|
|
|
|
dir->nlink++;
|
|
|
|
} else if (S_ISLNK(dp->mode)) {
|
|
|
|
if (dp->proc_iops == NULL)
|
|
|
|
dp->proc_iops = &proc_link_inode_operations;
|
|
|
|
} else if (S_ISREG(dp->mode)) {
|
|
|
|
if (dp->proc_fops == NULL)
|
|
|
|
dp->proc_fops = &proc_file_operations;
|
|
|
|
if (dp->proc_iops == NULL)
|
|
|
|
dp->proc_iops = &proc_file_inode_operations;
|
|
|
|
}
|
2007-07-16 00:40:09 -06:00
|
|
|
|
|
|
|
spin_lock(&proc_subdir_lock);
|
2008-02-08 05:18:29 -07:00
|
|
|
|
|
|
|
for (tmp = dir->subdir; tmp; tmp = tmp->next)
|
|
|
|
if (strcmp(tmp->name, dp->name) == 0) {
|
2008-09-13 20:51:30 -06:00
|
|
|
WARN(1, KERN_WARNING "proc_dir_entry '%s/%s' already registered\n",
|
2008-09-13 03:33:06 -06:00
|
|
|
dir->name, dp->name);
|
2008-02-08 05:18:29 -07:00
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
2007-07-16 00:40:09 -06:00
|
|
|
dp->next = dir->subdir;
|
|
|
|
dp->parent = dir;
|
|
|
|
dir->subdir = dp;
|
|
|
|
spin_unlock(&proc_subdir_lock);
|
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
proc: fix ->open'less usage due to ->proc_fops flip
Typical PDE creation code looks like:
pde = create_proc_entry("foo", 0, NULL);
if (pde)
pde->proc_fops = &foo_proc_fops;
Notice that PDE is first created, only then ->proc_fops is set up to
final value. This is a problem because right after creation
a) PDE is fully visible in /proc , and
b) ->proc_fops are proc_file_operations which do not have ->open callback. So, it's
possible to ->read without ->open (see one class of oopses below).
The fix is new API called proc_create() which makes sure ->proc_fops are
set up before gluing PDE to main tree. Typical new code looks like:
pde = proc_create("foo", 0, NULL, &foo_proc_fops);
if (!pde)
return -ENOMEM;
Fix most networking users for a start.
In the long run, create_proc_entry() for regular files will go.
BUG: unable to handle kernel NULL pointer dereference at virtual address 00000024
printing eip: c1188c1b *pdpt = 000000002929e001 *pde = 0000000000000000
Oops: 0002 [#1] PREEMPT SMP DEBUG_PAGEALLOC
last sysfs file: /sys/block/sda/sda1/dev
Modules linked in: foo af_packet ipv6 cpufreq_ondemand loop serio_raw psmouse k8temp hwmon sr_mod cdrom
Pid: 24679, comm: cat Not tainted (2.6.24-rc3-mm1 #2)
EIP: 0060:[<c1188c1b>] EFLAGS: 00210002 CPU: 0
EIP is at mutex_lock_nested+0x75/0x25d
EAX: 000006fe EBX: fffffffb ECX: 00001000 EDX: e9340570
ESI: 00000020 EDI: 00200246 EBP: e9340570 ESP: e8ea1ef8
DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process cat (pid: 24679, ti=E8EA1000 task=E9340570 task.ti=E8EA1000)
Stack: 00000000 c106f7ce e8ee05b4 00000000 00000001 458003d0 f6fb6f20 fffffffb
00000000 c106f7aa 00001000 c106f7ce 08ae9000 f6db53f0 00000020 00200246
00000000 00000002 00000000 00200246 00200246 e8ee05a0 fffffffb e8ee0550
Call Trace:
[<c106f7ce>] seq_read+0x24/0x28a
[<c106f7aa>] seq_read+0x0/0x28a
[<c106f7ce>] seq_read+0x24/0x28a
[<c106f7aa>] seq_read+0x0/0x28a
[<c10818b8>] proc_reg_read+0x60/0x73
[<c1081858>] proc_reg_read+0x0/0x73
[<c105a34f>] vfs_read+0x6c/0x8b
[<c105a6f3>] sys_read+0x3c/0x63
[<c10025f2>] sysenter_past_esp+0x5f/0xa5
[<c10697a7>] destroy_inode+0x24/0x33
=======================
INFO: lockdep is turned off.
Code: 75 21 68 e1 1a 19 c1 68 87 00 00 00 68 b8 e8 1f c1 68 25 73 1f c1 e8 84 06 e9 ff e8 52 b8 e7 ff 83 c4 10 9c 5f fa e8 28 89 ea ff <f0> fe 4e 04 79 0a f3 90 80 7e 04 00 7e f8 eb f0 39 76 34 74 33
EIP: [<c1188c1b>] mutex_lock_nested+0x75/0x25d SS:ESP 0068:e8ea1ef8
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 05:18:37 -07:00
|
|
|
static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent,
|
2005-04-16 16:20:36 -06:00
|
|
|
const char *name,
|
|
|
|
mode_t mode,
|
|
|
|
nlink_t nlink)
|
|
|
|
{
|
|
|
|
struct proc_dir_entry *ent = NULL;
|
|
|
|
const char *fn = name;
|
|
|
|
int len;
|
|
|
|
|
|
|
|
/* make sure name is valid */
|
|
|
|
if (!name || !strlen(name)) goto out;
|
|
|
|
|
proc: less special case in xlate code
If valid "parent" is passed to proc_create/remove_proc_entry(), then name of
PDE should consist of only one path component, otherwise creation or or
removal will fail. However, if NULL is passed as parent then create/remove
accept full path as a argument. This is arbitrary restriction -- all
infrastructure is in place.
So, patch allows the following to succeed:
create_proc_entry("foo/bar", 0, pde_baz);
remove_proc_entry("baz/foo/bar", &proc_root);
Also makes the following to behave identically:
create_proc_entry("foo/bar", 0, NULL);
create_proc_entry("foo/bar", 0, &proc_root);
Discrepancy noticed by Den Lunev (IIRC).
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 02:01:40 -06:00
|
|
|
if (xlate_proc_name(name, parent, &fn) != 0)
|
2005-04-16 16:20:36 -06:00
|
|
|
goto out;
|
|
|
|
|
|
|
|
/* At this point there must not be any '/' characters beyond *fn */
|
|
|
|
if (strchr(fn, '/'))
|
|
|
|
goto out;
|
|
|
|
|
|
|
|
len = strlen(fn);
|
|
|
|
|
|
|
|
ent = kmalloc(sizeof(struct proc_dir_entry) + len + 1, GFP_KERNEL);
|
|
|
|
if (!ent) goto out;
|
|
|
|
|
|
|
|
memset(ent, 0, sizeof(struct proc_dir_entry));
|
|
|
|
memcpy(((char *) ent) + sizeof(struct proc_dir_entry), fn, len + 1);
|
|
|
|
ent->name = ((char *) ent) + sizeof(*ent);
|
|
|
|
ent->namelen = len;
|
|
|
|
ent->mode = mode;
|
|
|
|
ent->nlink = nlink;
|
proc: fix proc_dir_entry refcounting
Creating PDEs with refcount 0 and "deleted" flag has problems (see below).
Switch to usual scheme:
* PDE is created with refcount 1
* every de_get does +1
* every de_put() and remove_proc_entry() do -1
* once refcount reaches 0, PDE is freed.
This elegantly fixes at least two following races (both observed) without
introducing new locks, without abusing old locks, without spreading
lock_kernel():
1) PDE leak
remove_proc_entry de_put
----------------- ------
[refcnt = 1]
if (atomic_read(&de->count) == 0)
if (atomic_dec_and_test(&de->count))
if (de->deleted)
/* also not taken! */
free_proc_entry(de);
else
de->deleted = 1;
[refcount=0, deleted=1]
2) use after free
remove_proc_entry de_put
----------------- ------
[refcnt = 1]
if (atomic_dec_and_test(&de->count))
if (atomic_read(&de->count) == 0)
free_proc_entry(de);
/* boom! */
if (de->deleted)
free_proc_entry(de);
BUG: unable to handle kernel paging request at virtual address 6b6b6b6b
printing eip: c10acdda *pdpt = 00000000338f8001 *pde = 0000000000000000
Oops: 0000 [#1] PREEMPT SMP
Modules linked in: af_packet ipv6 cpufreq_ondemand loop serio_raw psmouse k8temp hwmon sr_mod cdrom
Pid: 23161, comm: cat Not tainted (2.6.24-rc2-8c0863403f109a43d7000b4646da4818220d501f #4)
EIP: 0060:[<c10acdda>] EFLAGS: 00210097 CPU: 1
EIP is at strnlen+0x6/0x18
EAX: 6b6b6b6b EBX: 6b6b6b6b ECX: 6b6b6b6b EDX: fffffffe
ESI: c128fa3b EDI: f380bf34 EBP: ffffffff ESP: f380be44
DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process cat (pid: 23161, ti=f380b000 task=f38f2570 task.ti=f380b000)
Stack: c10ac4f0 00000278 c12ce000 f43cd2a8 00000163 00000000 7da86067 00000400
c128fa20 00896b18 f38325a8 c128fe20 ffffffff 00000000 c11f291e 00000400
f75be300 c128fa20 f769c9a0 c10ac779 f380bf34 f7bfee70 c1018e6b f380bf34
Call Trace:
[<c10ac4f0>] vsnprintf+0x2ad/0x49b
[<c10ac779>] vscnprintf+0x14/0x1f
[<c1018e6b>] vprintk+0xc5/0x2f9
[<c10379f1>] handle_fasteoi_irq+0x0/0xab
[<c1004f44>] do_IRQ+0x9f/0xb7
[<c117db3b>] preempt_schedule_irq+0x3f/0x5b
[<c100264e>] need_resched+0x1f/0x21
[<c10190ba>] printk+0x1b/0x1f
[<c107c8ad>] de_put+0x3d/0x50
[<c107c8f8>] proc_delete_inode+0x38/0x41
[<c107c8c0>] proc_delete_inode+0x0/0x41
[<c1066298>] generic_delete_inode+0x5e/0xc6
[<c1065aa9>] iput+0x60/0x62
[<c1063c8e>] d_kill+0x2d/0x46
[<c1063fa9>] dput+0xdc/0xe4
[<c10571a1>] __fput+0xb0/0xcd
[<c1054e49>] filp_close+0x48/0x4f
[<c1055ee9>] sys_close+0x67/0xa5
[<c10026b6>] sysenter_past_esp+0x5f/0x85
=======================
Code: c9 74 0c f2 ae 74 05 bf 01 00 00 00 4f 89 fa 5f 89 d0 c3 85 c9 57 89 c7 89 d0 74 05 f2 ae 75 01 4f 89 f8 5f c3 89 c1 89 c8 eb 06 <80> 38 00 74 07 40 4a 83 fa ff 75 f4 29 c8 c3 90 90 90 57 83 c9
EIP: [<c10acdda>] strnlen+0x6/0x18 SS:ESP 0068:f380be44
Also, remove broken usage of ->deleted from reiserfs: if sget() succeeds,
module is already pinned and remove_proc_entry() can't happen => nobody
can mark PDE deleted.
Dummy proc root in netns code is not marked with refcount 1. AFAICS, we
never get it, it's just for proper /proc/net removal. I double checked
CLONE_NETNS continues to work.
Patch survives many hours of modprobe/rmmod/cat loops without new bugs
which can be attributed to refcounting.
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
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>
2007-12-05 00:45:28 -07:00
|
|
|
atomic_set(&ent->count, 1);
|
Fix rmmod/read/write races in /proc entries
Fix following races:
===========================================
1. Write via ->write_proc sleeps in copy_from_user(). Module disappears
meanwhile. Or, more generically, system call done on /proc file, method
supplied by module is called, module dissapeares meanwhile.
pde = create_proc_entry()
if (!pde)
return -ENOMEM;
pde->write_proc = ...
open
write
copy_from_user
pde = create_proc_entry();
if (!pde) {
remove_proc_entry();
return -ENOMEM;
/* module unloaded */
}
*boom*
==========================================
2. bogo-revoke aka proc_kill_inodes()
remove_proc_entry vfs_read
proc_kill_inodes [check ->f_op validness]
[check ->f_op->read validness]
[verify_area, security permissions checks]
->f_op = NULL;
if (file->f_op->read)
/* ->f_op dereference, boom */
NOTE, NOTE, NOTE: file_operations are proxied for regular files only. Let's
see how this scheme behaves, then extend if needed for directories.
Directories creators in /proc only set ->owner for them, so proxying for
directories may be unneeded.
NOTE, NOTE, NOTE: methods being proxied are ->llseek, ->read, ->write,
->poll, ->unlocked_ioctl, ->ioctl, ->compat_ioctl, ->open, ->release.
If your in-tree module uses something else, yell on me. Full audit pending.
[akpm@linux-foundation.org: build fix]
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 00:39:00 -06:00
|
|
|
ent->pde_users = 0;
|
|
|
|
spin_lock_init(&ent->pde_unload_lock);
|
|
|
|
ent->pde_unload_completion = NULL;
|
2008-07-25 02:48:29 -06:00
|
|
|
INIT_LIST_HEAD(&ent->pde_openers);
|
2005-04-16 16:20:36 -06:00
|
|
|
out:
|
|
|
|
return ent;
|
|
|
|
}
|
|
|
|
|
|
|
|
struct proc_dir_entry *proc_symlink(const char *name,
|
|
|
|
struct proc_dir_entry *parent, const char *dest)
|
|
|
|
{
|
|
|
|
struct proc_dir_entry *ent;
|
|
|
|
|
proc: fix ->open'less usage due to ->proc_fops flip
Typical PDE creation code looks like:
pde = create_proc_entry("foo", 0, NULL);
if (pde)
pde->proc_fops = &foo_proc_fops;
Notice that PDE is first created, only then ->proc_fops is set up to
final value. This is a problem because right after creation
a) PDE is fully visible in /proc , and
b) ->proc_fops are proc_file_operations which do not have ->open callback. So, it's
possible to ->read without ->open (see one class of oopses below).
The fix is new API called proc_create() which makes sure ->proc_fops are
set up before gluing PDE to main tree. Typical new code looks like:
pde = proc_create("foo", 0, NULL, &foo_proc_fops);
if (!pde)
return -ENOMEM;
Fix most networking users for a start.
In the long run, create_proc_entry() for regular files will go.
BUG: unable to handle kernel NULL pointer dereference at virtual address 00000024
printing eip: c1188c1b *pdpt = 000000002929e001 *pde = 0000000000000000
Oops: 0002 [#1] PREEMPT SMP DEBUG_PAGEALLOC
last sysfs file: /sys/block/sda/sda1/dev
Modules linked in: foo af_packet ipv6 cpufreq_ondemand loop serio_raw psmouse k8temp hwmon sr_mod cdrom
Pid: 24679, comm: cat Not tainted (2.6.24-rc3-mm1 #2)
EIP: 0060:[<c1188c1b>] EFLAGS: 00210002 CPU: 0
EIP is at mutex_lock_nested+0x75/0x25d
EAX: 000006fe EBX: fffffffb ECX: 00001000 EDX: e9340570
ESI: 00000020 EDI: 00200246 EBP: e9340570 ESP: e8ea1ef8
DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process cat (pid: 24679, ti=E8EA1000 task=E9340570 task.ti=E8EA1000)
Stack: 00000000 c106f7ce e8ee05b4 00000000 00000001 458003d0 f6fb6f20 fffffffb
00000000 c106f7aa 00001000 c106f7ce 08ae9000 f6db53f0 00000020 00200246
00000000 00000002 00000000 00200246 00200246 e8ee05a0 fffffffb e8ee0550
Call Trace:
[<c106f7ce>] seq_read+0x24/0x28a
[<c106f7aa>] seq_read+0x0/0x28a
[<c106f7ce>] seq_read+0x24/0x28a
[<c106f7aa>] seq_read+0x0/0x28a
[<c10818b8>] proc_reg_read+0x60/0x73
[<c1081858>] proc_reg_read+0x0/0x73
[<c105a34f>] vfs_read+0x6c/0x8b
[<c105a6f3>] sys_read+0x3c/0x63
[<c10025f2>] sysenter_past_esp+0x5f/0xa5
[<c10697a7>] destroy_inode+0x24/0x33
=======================
INFO: lockdep is turned off.
Code: 75 21 68 e1 1a 19 c1 68 87 00 00 00 68 b8 e8 1f c1 68 25 73 1f c1 e8 84 06 e9 ff e8 52 b8 e7 ff 83 c4 10 9c 5f fa e8 28 89 ea ff <f0> fe 4e 04 79 0a f3 90 80 7e 04 00 7e f8 eb f0 39 76 34 74 33
EIP: [<c1188c1b>] mutex_lock_nested+0x75/0x25d SS:ESP 0068:e8ea1ef8
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 05:18:37 -07:00
|
|
|
ent = __proc_create(&parent, name,
|
2005-04-16 16:20:36 -06:00
|
|
|
(S_IFLNK | S_IRUGO | S_IWUGO | S_IXUGO),1);
|
|
|
|
|
|
|
|
if (ent) {
|
|
|
|
ent->data = kmalloc((ent->size=strlen(dest))+1, GFP_KERNEL);
|
|
|
|
if (ent->data) {
|
|
|
|
strcpy((char*)ent->data,dest);
|
|
|
|
if (proc_register(parent, ent) < 0) {
|
|
|
|
kfree(ent->data);
|
|
|
|
kfree(ent);
|
|
|
|
ent = NULL;
|
|
|
|
}
|
|
|
|
} else {
|
|
|
|
kfree(ent);
|
|
|
|
ent = NULL;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
return ent;
|
|
|
|
}
|
|
|
|
|
|
|
|
struct proc_dir_entry *proc_mkdir_mode(const char *name, mode_t mode,
|
|
|
|
struct proc_dir_entry *parent)
|
|
|
|
{
|
|
|
|
struct proc_dir_entry *ent;
|
|
|
|
|
proc: fix ->open'less usage due to ->proc_fops flip
Typical PDE creation code looks like:
pde = create_proc_entry("foo", 0, NULL);
if (pde)
pde->proc_fops = &foo_proc_fops;
Notice that PDE is first created, only then ->proc_fops is set up to
final value. This is a problem because right after creation
a) PDE is fully visible in /proc , and
b) ->proc_fops are proc_file_operations which do not have ->open callback. So, it's
possible to ->read without ->open (see one class of oopses below).
The fix is new API called proc_create() which makes sure ->proc_fops are
set up before gluing PDE to main tree. Typical new code looks like:
pde = proc_create("foo", 0, NULL, &foo_proc_fops);
if (!pde)
return -ENOMEM;
Fix most networking users for a start.
In the long run, create_proc_entry() for regular files will go.
BUG: unable to handle kernel NULL pointer dereference at virtual address 00000024
printing eip: c1188c1b *pdpt = 000000002929e001 *pde = 0000000000000000
Oops: 0002 [#1] PREEMPT SMP DEBUG_PAGEALLOC
last sysfs file: /sys/block/sda/sda1/dev
Modules linked in: foo af_packet ipv6 cpufreq_ondemand loop serio_raw psmouse k8temp hwmon sr_mod cdrom
Pid: 24679, comm: cat Not tainted (2.6.24-rc3-mm1 #2)
EIP: 0060:[<c1188c1b>] EFLAGS: 00210002 CPU: 0
EIP is at mutex_lock_nested+0x75/0x25d
EAX: 000006fe EBX: fffffffb ECX: 00001000 EDX: e9340570
ESI: 00000020 EDI: 00200246 EBP: e9340570 ESP: e8ea1ef8
DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process cat (pid: 24679, ti=E8EA1000 task=E9340570 task.ti=E8EA1000)
Stack: 00000000 c106f7ce e8ee05b4 00000000 00000001 458003d0 f6fb6f20 fffffffb
00000000 c106f7aa 00001000 c106f7ce 08ae9000 f6db53f0 00000020 00200246
00000000 00000002 00000000 00200246 00200246 e8ee05a0 fffffffb e8ee0550
Call Trace:
[<c106f7ce>] seq_read+0x24/0x28a
[<c106f7aa>] seq_read+0x0/0x28a
[<c106f7ce>] seq_read+0x24/0x28a
[<c106f7aa>] seq_read+0x0/0x28a
[<c10818b8>] proc_reg_read+0x60/0x73
[<c1081858>] proc_reg_read+0x0/0x73
[<c105a34f>] vfs_read+0x6c/0x8b
[<c105a6f3>] sys_read+0x3c/0x63
[<c10025f2>] sysenter_past_esp+0x5f/0xa5
[<c10697a7>] destroy_inode+0x24/0x33
=======================
INFO: lockdep is turned off.
Code: 75 21 68 e1 1a 19 c1 68 87 00 00 00 68 b8 e8 1f c1 68 25 73 1f c1 e8 84 06 e9 ff e8 52 b8 e7 ff 83 c4 10 9c 5f fa e8 28 89 ea ff <f0> fe 4e 04 79 0a f3 90 80 7e 04 00 7e f8 eb f0 39 76 34 74 33
EIP: [<c1188c1b>] mutex_lock_nested+0x75/0x25d SS:ESP 0068:e8ea1ef8
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 05:18:37 -07:00
|
|
|
ent = __proc_create(&parent, name, S_IFDIR | mode, 2);
|
2005-04-16 16:20:36 -06:00
|
|
|
if (ent) {
|
|
|
|
if (proc_register(parent, ent) < 0) {
|
|
|
|
kfree(ent);
|
|
|
|
ent = NULL;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
return ent;
|
|
|
|
}
|
|
|
|
|
2008-05-02 05:12:41 -06:00
|
|
|
struct proc_dir_entry *proc_net_mkdir(struct net *net, const char *name,
|
|
|
|
struct proc_dir_entry *parent)
|
|
|
|
{
|
|
|
|
struct proc_dir_entry *ent;
|
|
|
|
|
|
|
|
ent = __proc_create(&parent, name, S_IFDIR | S_IRUGO | S_IXUGO, 2);
|
|
|
|
if (ent) {
|
|
|
|
ent->data = net;
|
|
|
|
if (proc_register(parent, ent) < 0) {
|
|
|
|
kfree(ent);
|
|
|
|
ent = NULL;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
return ent;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(proc_net_mkdir);
|
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
struct proc_dir_entry *proc_mkdir(const char *name,
|
|
|
|
struct proc_dir_entry *parent)
|
|
|
|
{
|
|
|
|
return proc_mkdir_mode(name, S_IRUGO | S_IXUGO, parent);
|
|
|
|
}
|
|
|
|
|
|
|
|
struct proc_dir_entry *create_proc_entry(const char *name, mode_t mode,
|
|
|
|
struct proc_dir_entry *parent)
|
|
|
|
{
|
|
|
|
struct proc_dir_entry *ent;
|
|
|
|
nlink_t nlink;
|
|
|
|
|
|
|
|
if (S_ISDIR(mode)) {
|
|
|
|
if ((mode & S_IALLUGO) == 0)
|
|
|
|
mode |= S_IRUGO | S_IXUGO;
|
|
|
|
nlink = 2;
|
|
|
|
} else {
|
|
|
|
if ((mode & S_IFMT) == 0)
|
|
|
|
mode |= S_IFREG;
|
|
|
|
if ((mode & S_IALLUGO) == 0)
|
|
|
|
mode |= S_IRUGO;
|
|
|
|
nlink = 1;
|
|
|
|
}
|
|
|
|
|
proc: fix ->open'less usage due to ->proc_fops flip
Typical PDE creation code looks like:
pde = create_proc_entry("foo", 0, NULL);
if (pde)
pde->proc_fops = &foo_proc_fops;
Notice that PDE is first created, only then ->proc_fops is set up to
final value. This is a problem because right after creation
a) PDE is fully visible in /proc , and
b) ->proc_fops are proc_file_operations which do not have ->open callback. So, it's
possible to ->read without ->open (see one class of oopses below).
The fix is new API called proc_create() which makes sure ->proc_fops are
set up before gluing PDE to main tree. Typical new code looks like:
pde = proc_create("foo", 0, NULL, &foo_proc_fops);
if (!pde)
return -ENOMEM;
Fix most networking users for a start.
In the long run, create_proc_entry() for regular files will go.
BUG: unable to handle kernel NULL pointer dereference at virtual address 00000024
printing eip: c1188c1b *pdpt = 000000002929e001 *pde = 0000000000000000
Oops: 0002 [#1] PREEMPT SMP DEBUG_PAGEALLOC
last sysfs file: /sys/block/sda/sda1/dev
Modules linked in: foo af_packet ipv6 cpufreq_ondemand loop serio_raw psmouse k8temp hwmon sr_mod cdrom
Pid: 24679, comm: cat Not tainted (2.6.24-rc3-mm1 #2)
EIP: 0060:[<c1188c1b>] EFLAGS: 00210002 CPU: 0
EIP is at mutex_lock_nested+0x75/0x25d
EAX: 000006fe EBX: fffffffb ECX: 00001000 EDX: e9340570
ESI: 00000020 EDI: 00200246 EBP: e9340570 ESP: e8ea1ef8
DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process cat (pid: 24679, ti=E8EA1000 task=E9340570 task.ti=E8EA1000)
Stack: 00000000 c106f7ce e8ee05b4 00000000 00000001 458003d0 f6fb6f20 fffffffb
00000000 c106f7aa 00001000 c106f7ce 08ae9000 f6db53f0 00000020 00200246
00000000 00000002 00000000 00200246 00200246 e8ee05a0 fffffffb e8ee0550
Call Trace:
[<c106f7ce>] seq_read+0x24/0x28a
[<c106f7aa>] seq_read+0x0/0x28a
[<c106f7ce>] seq_read+0x24/0x28a
[<c106f7aa>] seq_read+0x0/0x28a
[<c10818b8>] proc_reg_read+0x60/0x73
[<c1081858>] proc_reg_read+0x0/0x73
[<c105a34f>] vfs_read+0x6c/0x8b
[<c105a6f3>] sys_read+0x3c/0x63
[<c10025f2>] sysenter_past_esp+0x5f/0xa5
[<c10697a7>] destroy_inode+0x24/0x33
=======================
INFO: lockdep is turned off.
Code: 75 21 68 e1 1a 19 c1 68 87 00 00 00 68 b8 e8 1f c1 68 25 73 1f c1 e8 84 06 e9 ff e8 52 b8 e7 ff 83 c4 10 9c 5f fa e8 28 89 ea ff <f0> fe 4e 04 79 0a f3 90 80 7e 04 00 7e f8 eb f0 39 76 34 74 33
EIP: [<c1188c1b>] mutex_lock_nested+0x75/0x25d SS:ESP 0068:e8ea1ef8
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 05:18:37 -07:00
|
|
|
ent = __proc_create(&parent, name, mode, nlink);
|
2005-04-16 16:20:36 -06:00
|
|
|
if (ent) {
|
|
|
|
if (proc_register(parent, ent) < 0) {
|
|
|
|
kfree(ent);
|
|
|
|
ent = NULL;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
return ent;
|
|
|
|
}
|
|
|
|
|
proc: introduce proc_create_data to setup de->data
This set of patches fixes an proc ->open'less usage due to ->proc_fops flip in
the most part of the kernel code. The original OOPS is described in the
commit 2d3a4e3666325a9709cc8ea2e88151394e8f20fc:
Typical PDE creation code looks like:
pde = create_proc_entry("foo", 0, NULL);
if (pde)
pde->proc_fops = &foo_proc_fops;
Notice that PDE is first created, only then ->proc_fops is set up to
final value. This is a problem because right after creation
a) PDE is fully visible in /proc , and
b) ->proc_fops are proc_file_operations which do not have ->open callback. So, it's
possible to ->read without ->open (see one class of oopses below).
The fix is new API called proc_create() which makes sure ->proc_fops are
set up before gluing PDE to main tree. Typical new code looks like:
pde = proc_create("foo", 0, NULL, &foo_proc_fops);
if (!pde)
return -ENOMEM;
Fix most networking users for a start.
In the long run, create_proc_entry() for regular files will go.
In addition to this, proc_create_data is introduced to fix reading from
proc without PDE->data. The race is basically the same as above.
create_proc_entries is replaced in the entire kernel code as new method
is also simply better.
This patch:
The problem is the same as for de->proc_fops. Right now PDE becomes visible
without data set. So, the entry could be looked up without data. This, in
most cases, will simply OOPS.
proc_create_data call is created to address this issue. proc_create now
becomes a wrapper around it.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Chris Mason <chris.mason@oracle.com>
Acked-by: David Howells <dhowells@redhat.com>
Cc: Dmitry Torokhov <dtor@mail.ru>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Jaroslav Kysela <perex@suse.cz>
Cc: Jeff Garzik <jgarzik@pobox.com>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Karsten Keil <kkeil@suse.de>
Cc: Kyle McMartin <kyle@parisc-linux.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Cc: Neil Brown <neilb@suse.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Osterlund <petero2@telia.com>
Cc: Pierre Peiffer <peifferp@gmail.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 02:02:00 -06:00
|
|
|
struct proc_dir_entry *proc_create_data(const char *name, mode_t mode,
|
|
|
|
struct proc_dir_entry *parent,
|
|
|
|
const struct file_operations *proc_fops,
|
|
|
|
void *data)
|
proc: fix ->open'less usage due to ->proc_fops flip
Typical PDE creation code looks like:
pde = create_proc_entry("foo", 0, NULL);
if (pde)
pde->proc_fops = &foo_proc_fops;
Notice that PDE is first created, only then ->proc_fops is set up to
final value. This is a problem because right after creation
a) PDE is fully visible in /proc , and
b) ->proc_fops are proc_file_operations which do not have ->open callback. So, it's
possible to ->read without ->open (see one class of oopses below).
The fix is new API called proc_create() which makes sure ->proc_fops are
set up before gluing PDE to main tree. Typical new code looks like:
pde = proc_create("foo", 0, NULL, &foo_proc_fops);
if (!pde)
return -ENOMEM;
Fix most networking users for a start.
In the long run, create_proc_entry() for regular files will go.
BUG: unable to handle kernel NULL pointer dereference at virtual address 00000024
printing eip: c1188c1b *pdpt = 000000002929e001 *pde = 0000000000000000
Oops: 0002 [#1] PREEMPT SMP DEBUG_PAGEALLOC
last sysfs file: /sys/block/sda/sda1/dev
Modules linked in: foo af_packet ipv6 cpufreq_ondemand loop serio_raw psmouse k8temp hwmon sr_mod cdrom
Pid: 24679, comm: cat Not tainted (2.6.24-rc3-mm1 #2)
EIP: 0060:[<c1188c1b>] EFLAGS: 00210002 CPU: 0
EIP is at mutex_lock_nested+0x75/0x25d
EAX: 000006fe EBX: fffffffb ECX: 00001000 EDX: e9340570
ESI: 00000020 EDI: 00200246 EBP: e9340570 ESP: e8ea1ef8
DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process cat (pid: 24679, ti=E8EA1000 task=E9340570 task.ti=E8EA1000)
Stack: 00000000 c106f7ce e8ee05b4 00000000 00000001 458003d0 f6fb6f20 fffffffb
00000000 c106f7aa 00001000 c106f7ce 08ae9000 f6db53f0 00000020 00200246
00000000 00000002 00000000 00200246 00200246 e8ee05a0 fffffffb e8ee0550
Call Trace:
[<c106f7ce>] seq_read+0x24/0x28a
[<c106f7aa>] seq_read+0x0/0x28a
[<c106f7ce>] seq_read+0x24/0x28a
[<c106f7aa>] seq_read+0x0/0x28a
[<c10818b8>] proc_reg_read+0x60/0x73
[<c1081858>] proc_reg_read+0x0/0x73
[<c105a34f>] vfs_read+0x6c/0x8b
[<c105a6f3>] sys_read+0x3c/0x63
[<c10025f2>] sysenter_past_esp+0x5f/0xa5
[<c10697a7>] destroy_inode+0x24/0x33
=======================
INFO: lockdep is turned off.
Code: 75 21 68 e1 1a 19 c1 68 87 00 00 00 68 b8 e8 1f c1 68 25 73 1f c1 e8 84 06 e9 ff e8 52 b8 e7 ff 83 c4 10 9c 5f fa e8 28 89 ea ff <f0> fe 4e 04 79 0a f3 90 80 7e 04 00 7e f8 eb f0 39 76 34 74 33
EIP: [<c1188c1b>] mutex_lock_nested+0x75/0x25d SS:ESP 0068:e8ea1ef8
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 05:18:37 -07:00
|
|
|
{
|
|
|
|
struct proc_dir_entry *pde;
|
|
|
|
nlink_t nlink;
|
|
|
|
|
|
|
|
if (S_ISDIR(mode)) {
|
|
|
|
if ((mode & S_IALLUGO) == 0)
|
|
|
|
mode |= S_IRUGO | S_IXUGO;
|
|
|
|
nlink = 2;
|
|
|
|
} else {
|
|
|
|
if ((mode & S_IFMT) == 0)
|
|
|
|
mode |= S_IFREG;
|
|
|
|
if ((mode & S_IALLUGO) == 0)
|
|
|
|
mode |= S_IRUGO;
|
|
|
|
nlink = 1;
|
|
|
|
}
|
|
|
|
|
|
|
|
pde = __proc_create(&parent, name, mode, nlink);
|
|
|
|
if (!pde)
|
|
|
|
goto out;
|
|
|
|
pde->proc_fops = proc_fops;
|
proc: introduce proc_create_data to setup de->data
This set of patches fixes an proc ->open'less usage due to ->proc_fops flip in
the most part of the kernel code. The original OOPS is described in the
commit 2d3a4e3666325a9709cc8ea2e88151394e8f20fc:
Typical PDE creation code looks like:
pde = create_proc_entry("foo", 0, NULL);
if (pde)
pde->proc_fops = &foo_proc_fops;
Notice that PDE is first created, only then ->proc_fops is set up to
final value. This is a problem because right after creation
a) PDE is fully visible in /proc , and
b) ->proc_fops are proc_file_operations which do not have ->open callback. So, it's
possible to ->read without ->open (see one class of oopses below).
The fix is new API called proc_create() which makes sure ->proc_fops are
set up before gluing PDE to main tree. Typical new code looks like:
pde = proc_create("foo", 0, NULL, &foo_proc_fops);
if (!pde)
return -ENOMEM;
Fix most networking users for a start.
In the long run, create_proc_entry() for regular files will go.
In addition to this, proc_create_data is introduced to fix reading from
proc without PDE->data. The race is basically the same as above.
create_proc_entries is replaced in the entire kernel code as new method
is also simply better.
This patch:
The problem is the same as for de->proc_fops. Right now PDE becomes visible
without data set. So, the entry could be looked up without data. This, in
most cases, will simply OOPS.
proc_create_data call is created to address this issue. proc_create now
becomes a wrapper around it.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Chris Mason <chris.mason@oracle.com>
Acked-by: David Howells <dhowells@redhat.com>
Cc: Dmitry Torokhov <dtor@mail.ru>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Jaroslav Kysela <perex@suse.cz>
Cc: Jeff Garzik <jgarzik@pobox.com>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Karsten Keil <kkeil@suse.de>
Cc: Kyle McMartin <kyle@parisc-linux.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Cc: Neil Brown <neilb@suse.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Osterlund <petero2@telia.com>
Cc: Pierre Peiffer <peifferp@gmail.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 02:02:00 -06:00
|
|
|
pde->data = data;
|
proc: fix ->open'less usage due to ->proc_fops flip
Typical PDE creation code looks like:
pde = create_proc_entry("foo", 0, NULL);
if (pde)
pde->proc_fops = &foo_proc_fops;
Notice that PDE is first created, only then ->proc_fops is set up to
final value. This is a problem because right after creation
a) PDE is fully visible in /proc , and
b) ->proc_fops are proc_file_operations which do not have ->open callback. So, it's
possible to ->read without ->open (see one class of oopses below).
The fix is new API called proc_create() which makes sure ->proc_fops are
set up before gluing PDE to main tree. Typical new code looks like:
pde = proc_create("foo", 0, NULL, &foo_proc_fops);
if (!pde)
return -ENOMEM;
Fix most networking users for a start.
In the long run, create_proc_entry() for regular files will go.
BUG: unable to handle kernel NULL pointer dereference at virtual address 00000024
printing eip: c1188c1b *pdpt = 000000002929e001 *pde = 0000000000000000
Oops: 0002 [#1] PREEMPT SMP DEBUG_PAGEALLOC
last sysfs file: /sys/block/sda/sda1/dev
Modules linked in: foo af_packet ipv6 cpufreq_ondemand loop serio_raw psmouse k8temp hwmon sr_mod cdrom
Pid: 24679, comm: cat Not tainted (2.6.24-rc3-mm1 #2)
EIP: 0060:[<c1188c1b>] EFLAGS: 00210002 CPU: 0
EIP is at mutex_lock_nested+0x75/0x25d
EAX: 000006fe EBX: fffffffb ECX: 00001000 EDX: e9340570
ESI: 00000020 EDI: 00200246 EBP: e9340570 ESP: e8ea1ef8
DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process cat (pid: 24679, ti=E8EA1000 task=E9340570 task.ti=E8EA1000)
Stack: 00000000 c106f7ce e8ee05b4 00000000 00000001 458003d0 f6fb6f20 fffffffb
00000000 c106f7aa 00001000 c106f7ce 08ae9000 f6db53f0 00000020 00200246
00000000 00000002 00000000 00200246 00200246 e8ee05a0 fffffffb e8ee0550
Call Trace:
[<c106f7ce>] seq_read+0x24/0x28a
[<c106f7aa>] seq_read+0x0/0x28a
[<c106f7ce>] seq_read+0x24/0x28a
[<c106f7aa>] seq_read+0x0/0x28a
[<c10818b8>] proc_reg_read+0x60/0x73
[<c1081858>] proc_reg_read+0x0/0x73
[<c105a34f>] vfs_read+0x6c/0x8b
[<c105a6f3>] sys_read+0x3c/0x63
[<c10025f2>] sysenter_past_esp+0x5f/0xa5
[<c10697a7>] destroy_inode+0x24/0x33
=======================
INFO: lockdep is turned off.
Code: 75 21 68 e1 1a 19 c1 68 87 00 00 00 68 b8 e8 1f c1 68 25 73 1f c1 e8 84 06 e9 ff e8 52 b8 e7 ff 83 c4 10 9c 5f fa e8 28 89 ea ff <f0> fe 4e 04 79 0a f3 90 80 7e 04 00 7e f8 eb f0 39 76 34 74 33
EIP: [<c1188c1b>] mutex_lock_nested+0x75/0x25d SS:ESP 0068:e8ea1ef8
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 05:18:37 -07:00
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if (proc_register(parent, pde) < 0)
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goto out_free;
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return pde;
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out_free:
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kfree(pde);
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out:
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return NULL;
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}
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2005-04-16 16:20:36 -06:00
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void free_proc_entry(struct proc_dir_entry *de)
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{
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unsigned int ino = de->low_ino;
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if (ino < PROC_DYNAMIC_FIRST)
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return;
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release_inode_number(ino);
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2008-02-08 05:18:28 -07:00
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if (S_ISLNK(de->mode))
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2005-04-16 16:20:36 -06:00
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kfree(de->data);
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kfree(de);
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}
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/*
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* Remove a /proc entry and free it if it's not currently in use.
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*/
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void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
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{
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struct proc_dir_entry **p;
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2008-04-29 02:01:39 -06:00
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struct proc_dir_entry *de = NULL;
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2005-04-16 16:20:36 -06:00
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const char *fn = name;
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int len;
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proc: less special case in xlate code
If valid "parent" is passed to proc_create/remove_proc_entry(), then name of
PDE should consist of only one path component, otherwise creation or or
removal will fail. However, if NULL is passed as parent then create/remove
accept full path as a argument. This is arbitrary restriction -- all
infrastructure is in place.
So, patch allows the following to succeed:
create_proc_entry("foo/bar", 0, pde_baz);
remove_proc_entry("baz/foo/bar", &proc_root);
Also makes the following to behave identically:
create_proc_entry("foo/bar", 0, NULL);
create_proc_entry("foo/bar", 0, &proc_root);
Discrepancy noticed by Den Lunev (IIRC).
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 02:01:40 -06:00
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if (xlate_proc_name(name, &parent, &fn) != 0)
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2008-04-29 02:01:39 -06:00
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return;
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2005-04-16 16:20:36 -06:00
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len = strlen(fn);
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2006-03-26 02:36:55 -07:00
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spin_lock(&proc_subdir_lock);
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2005-04-16 16:20:36 -06:00
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for (p = &parent->subdir; *p; p=&(*p)->next ) {
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2008-04-29 02:01:39 -06:00
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if (proc_match(len, fn, *p)) {
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de = *p;
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*p = de->next;
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de->next = NULL;
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break;
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}
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}
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spin_unlock(&proc_subdir_lock);
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if (!de)
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return;
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Fix rmmod/read/write races in /proc entries
Fix following races:
===========================================
1. Write via ->write_proc sleeps in copy_from_user(). Module disappears
meanwhile. Or, more generically, system call done on /proc file, method
supplied by module is called, module dissapeares meanwhile.
pde = create_proc_entry()
if (!pde)
return -ENOMEM;
pde->write_proc = ...
open
write
copy_from_user
pde = create_proc_entry();
if (!pde) {
remove_proc_entry();
return -ENOMEM;
/* module unloaded */
}
*boom*
==========================================
2. bogo-revoke aka proc_kill_inodes()
remove_proc_entry vfs_read
proc_kill_inodes [check ->f_op validness]
[check ->f_op->read validness]
[verify_area, security permissions checks]
->f_op = NULL;
if (file->f_op->read)
/* ->f_op dereference, boom */
NOTE, NOTE, NOTE: file_operations are proxied for regular files only. Let's
see how this scheme behaves, then extend if needed for directories.
Directories creators in /proc only set ->owner for them, so proxying for
directories may be unneeded.
NOTE, NOTE, NOTE: methods being proxied are ->llseek, ->read, ->write,
->poll, ->unlocked_ioctl, ->ioctl, ->compat_ioctl, ->open, ->release.
If your in-tree module uses something else, yell on me. Full audit pending.
[akpm@linux-foundation.org: build fix]
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 00:39:00 -06:00
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2008-04-29 02:01:39 -06:00
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spin_lock(&de->pde_unload_lock);
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/*
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* Stop accepting new callers into module. If you're
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* dynamically allocating ->proc_fops, save a pointer somewhere.
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*/
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de->proc_fops = NULL;
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/* Wait until all existing callers into module are done. */
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if (de->pde_users > 0) {
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DECLARE_COMPLETION_ONSTACK(c);
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if (!de->pde_unload_completion)
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de->pde_unload_completion = &c;
|
Fix rmmod/read/write races in /proc entries
Fix following races:
===========================================
1. Write via ->write_proc sleeps in copy_from_user(). Module disappears
meanwhile. Or, more generically, system call done on /proc file, method
supplied by module is called, module dissapeares meanwhile.
pde = create_proc_entry()
if (!pde)
return -ENOMEM;
pde->write_proc = ...
open
write
copy_from_user
pde = create_proc_entry();
if (!pde) {
remove_proc_entry();
return -ENOMEM;
/* module unloaded */
}
*boom*
==========================================
2. bogo-revoke aka proc_kill_inodes()
remove_proc_entry vfs_read
proc_kill_inodes [check ->f_op validness]
[check ->f_op->read validness]
[verify_area, security permissions checks]
->f_op = NULL;
if (file->f_op->read)
/* ->f_op dereference, boom */
NOTE, NOTE, NOTE: file_operations are proxied for regular files only. Let's
see how this scheme behaves, then extend if needed for directories.
Directories creators in /proc only set ->owner for them, so proxying for
directories may be unneeded.
NOTE, NOTE, NOTE: methods being proxied are ->llseek, ->read, ->write,
->poll, ->unlocked_ioctl, ->ioctl, ->compat_ioctl, ->open, ->release.
If your in-tree module uses something else, yell on me. Full audit pending.
[akpm@linux-foundation.org: build fix]
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 00:39:00 -06:00
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spin_unlock(&de->pde_unload_lock);
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2008-04-29 02:01:39 -06:00
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wait_for_completion(de->pde_unload_completion);
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goto continue_removing;
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}
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spin_unlock(&de->pde_unload_lock);
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Fix rmmod/read/write races in /proc entries
Fix following races:
===========================================
1. Write via ->write_proc sleeps in copy_from_user(). Module disappears
meanwhile. Or, more generically, system call done on /proc file, method
supplied by module is called, module dissapeares meanwhile.
pde = create_proc_entry()
if (!pde)
return -ENOMEM;
pde->write_proc = ...
open
write
copy_from_user
pde = create_proc_entry();
if (!pde) {
remove_proc_entry();
return -ENOMEM;
/* module unloaded */
}
*boom*
==========================================
2. bogo-revoke aka proc_kill_inodes()
remove_proc_entry vfs_read
proc_kill_inodes [check ->f_op validness]
[check ->f_op->read validness]
[verify_area, security permissions checks]
->f_op = NULL;
if (file->f_op->read)
/* ->f_op dereference, boom */
NOTE, NOTE, NOTE: file_operations are proxied for regular files only. Let's
see how this scheme behaves, then extend if needed for directories.
Directories creators in /proc only set ->owner for them, so proxying for
directories may be unneeded.
NOTE, NOTE, NOTE: methods being proxied are ->llseek, ->read, ->write,
->poll, ->unlocked_ioctl, ->ioctl, ->compat_ioctl, ->open, ->release.
If your in-tree module uses something else, yell on me. Full audit pending.
[akpm@linux-foundation.org: build fix]
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 00:39:00 -06:00
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continue_removing:
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2008-07-25 02:48:29 -06:00
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spin_lock(&de->pde_unload_lock);
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while (!list_empty(&de->pde_openers)) {
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struct pde_opener *pdeo;
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pdeo = list_first_entry(&de->pde_openers, struct pde_opener, lh);
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list_del(&pdeo->lh);
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spin_unlock(&de->pde_unload_lock);
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pdeo->release(pdeo->inode, pdeo->file);
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kfree(pdeo);
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spin_lock(&de->pde_unload_lock);
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}
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spin_unlock(&de->pde_unload_lock);
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2008-04-29 02:01:39 -06:00
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if (S_ISDIR(de->mode))
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parent->nlink--;
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de->nlink = 0;
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2008-07-25 20:45:41 -06:00
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WARN(de->subdir, KERN_WARNING "%s: removing non-empty directory "
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2008-04-29 02:01:39 -06:00
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"'%s/%s', leaking at least '%s'\n", __func__,
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de->parent->name, de->name, de->subdir->name);
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if (atomic_dec_and_test(&de->count))
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free_proc_entry(de);
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|