linux-toradex.git/include/linux/proc_fs.h, branch v2.6.23.14

Remove unused struct proc_dir_entry::set

2007-08-11T22:47:40+00:00

After /proc/sys rewrite it was left unused.

Signed-off-by: Alexey Dobriyan 
Cc: "Eric W. Biederman" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Fix rmmod/read/write races in /proc entries

2007-07-16T16:05:39+00:00

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 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Fix race between proc_get_inode() and remove_proc_entry()

2007-05-08T18:15:01+00:00

proc_lookup				remove_proc_entry
===========				=================

lock_kernel();
spin_lock(&proc_subdir_lock);
[find PDE with refcount 0]
spin_unlock(&proc_subdir_lock);
					spin_lock(&proc_subdir_lock);
					[find PDE with refcount 0]
					[check refcount and free PDE]
					spin_unlock(&proc_subdir_lock);
proc_get_inode:
	de_get(de); /* boom */

Signed-off-by: Alexey Dobriyan 
Cc: "Eric W. Biederman" 
Cc: Oleg Nesterov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

smaps: add clear_refs file to clear reference

2007-05-07T19:12:52+00:00

Adds /proc/pid/clear_refs.  When any non-zero number is written to this file,
pte_mkold() and ClearPageReferenced() is called for each pte and its
corresponding page, respectively, in that task's VMAs.  This file is only
writable by the user who owns the task.

It is now possible to measure _approximately_ how much memory a task is using
by clearing the reference bits with

	echo 1 > /proc/pid/clear_refs

and checking the reference count for each VMA from the /proc/pid/smaps output
at a measured time interval.  For example, to observe the approximate change
in memory footprint for a task, write a script that clears the references
(echo 1 > /proc/pid/clear_refs), sleeps, and then greps for Pgs_Referenced and
extracts the size in kB.  Add the sizes for each VMA together for the total
referenced footprint.  Moments later, repeat the process and observe the
difference.

For example, using an efficient Mozilla:

	accumulated time		referenced memory
	----------------		-----------------
		 0 s				 408 kB
		 1 s				 408 kB
		 2 s				 556 kB
		 3 s				1028 kB
		 4 s				 872 kB
		 5 s				1956 kB
		 6 s				 416 kB
		 7 s				1560 kB
		 8 s				2336 kB
		 9 s				1044 kB
		10 s				 416 kB

This is a valuable tool to get an approximate measurement of the memory
footprint for a task.

Cc: Hugh Dickins 
Cc: Paul Mundt 
Cc: Christoph Lameter 
Signed-off-by: David Rientjes 
[akpm@linux-foundation.org: build fixes]
[mpm@selenic.com: rename for_each_pmd]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] sysctl: reimplement the sysctl proc support

2007-02-14T16:10:00+00:00

With this change the sysctl inodes can be cached and nothing needs to be done
when removing a sysctl table.

For a cost of 2K code we will save about 4K of static tables (when we remove
de from ctl_table) and 70K in proc_dir_entries that we will not allocate, or
about half that on a 32bit arch.

The speed feels about the same, even though we can now cache the sysctl
dentries :(

We get the core advantage that we don't need to have a 1 to 1 mapping between
ctl table entries and proc files.  Making it possible to have /proc/sys vary
depending on the namespace you are in.  The currently merged namespaces don't
have an issue here but the network namespace under /proc/sys/net needs to have
different directories depending on which network adapters are visible.  By
simply being a cache different directories being visible depending on who you
are is trivial to implement.

[akpm@osdl.org: fix uninitialised var]
[akpm@osdl.org: fix ARM build]
[bunk@stusta.de: make things static]
Signed-off-by: Eric W. Biederman 
Cc: Russell King 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] mark struct inode_operations const 3

2007-02-12T17:48:46+00:00

Many struct inode_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.

Signed-off-by: Arjan van de Ven 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] proc: modify proc_pident_lookup to be completely table driven

2006-10-02T14:57:13+00:00

Currently proc_pident_lookup gets the names and types from a table and then
has a huge switch statement to get the inode and file operations it needs.
That is silly and is becoming increasingly hard to maintain so I just put all
of the information in the table.

Signed-off-by: Eric W. Biederman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] NOMMU: Implement /proc/pid/maps for NOMMU

2006-09-27T15:26:14+00:00

Implement /proc/pid/maps for NOMMU by reading the vm_area_list attached to
current->mm->context.vmlist.

Signed-off-by: David Howells 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Move several *_SUPER_MAGIC symbols to include/linux/magic.h.

2006-09-24T15:13:19+00:00

Signed-off-by: Jeff Garzik

[PATCH] proc: Use struct pid not struct task_ref

2006-06-26T16:58:26+00:00

Incrementally update my proc-dont-lock-task_structs-indefinitely patches so
that they work with struct pid instead of struct task_ref.

Mostly this is a straight 1-1 substitution.

Signed-off-by: Eric W. Biederman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds