kernel_samsung_smdk4412/ipc, branch v2.6.21-rc2

[PATCH] shm: make sysv ipc shared memory use stacked files

2007-02-21T01:10:13+00:00

The current ipc shared memory code runs into several problems because it
does not quite use files like the rest of the kernel.  With the option of
backing ipc shared memory with either hugetlbfs or ordinary shared memory
the problems got worse.  With the added support for ipc namespaces things
behaved so unexpected that we now have several bad namespace reference
counting bugs when using what appears at first glance to be a reasonable
idiom.

So to attack these problems and hopefully make the code more maintainable
this patch simply uses the files provided by other parts of the kernel and
builds it's own files out of them.  The shm files are allocated in do_shmat
and freed when their reference count drops to zero with their last unmap.
The file and vm operations that we don't want to implement or we don't
implement completely we just delegate to the operations of our backing
file.

This means that we now get an accurate shm_nattch count for we have a
hugetlbfs inode for backing store, and the shm accounting of last attach
and last detach time work as well.

This means that getting a reference to the ipc namespace when we create the
file and dropping the referenece in the release method is now safe and
correct.

This means we no longer need a special case for clearing VM_MAYWRITE
as our file descriptor now only has write permissions when we have
requested write access when calling shmat.  Although VM_SHARED is now
cleared as well which I believe is harmless and is mostly likely a
minor bug fix.

By using the same set of operations for both the hugetlb case and regular
shared memory case shmdt is not simplified and made slightly more correct
as now the test "vma->vm_ops == &shm_vm_ops" is 100% accurate in spotting
all shared memory regions generated from sysvipc shared memory.

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

[PATCH] sysctl: remove insert_at_head from register_sysctl

2007-02-14T16:09:59+00:00

The semantic effect of insert_at_head is that it would allow new registered
sysctl entries to override existing sysctl entries of the same name.  Which is
pain for caching and the proc interface never implemented.

I have done an audit and discovered that none of the current users of
register_sysctl care as (excpet for directories) they do not register
duplicate sysctl entries.

So this patch simply removes the support for overriding existing entries in
the sys_sysctl interface since no one uses it or cares and it makes future
enhancments harder.

Signed-off-by: Eric W. Biederman 
Acked-by: Ralf Baechle 
Acked-by: Martin Schwidefsky 
Cc: Russell King 
Cc: David Howells 
Cc: "Luck, Tony" 
Cc: Ralf Baechle 
Cc: Paul Mackerras 
Cc: Martin Schwidefsky 
Cc: Andi Kleen 
Cc: Jens Axboe 
Cc: Corey Minyard 
Cc: Neil Brown 
Cc: "John W. Linville" 
Cc: James Bottomley 
Cc: Jan Kara 
Cc: Trond Myklebust 
Cc: Mark Fasheh 
Cc: David Chinner 
Cc: "David S. Miller" 
Cc: Patrick McHardy 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] sysctl: move SYSV IPC sysctls to their own file

2007-02-14T16:09:59+00:00

This is just a simple cleanup to keep kernel/sysctl.c from getting to crowded
with special cases, and by keeping all of the ipc logic to together it makes
the code a little more readable.

[gcoady.lk@gmail.com: build fix]
Signed-off-by: Eric W. Biederman 
Cc: Serge E. Hallyn 
Cc: Herbert Poetzl 
Cc: Kirill Korotaev 
Signed-off-by: Grant Coady 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] mark struct inode_operations const 2

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] mark struct file_operations const 7

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

Many struct file_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] ipc: save the ipc namespace while reading proc files

2007-02-12T17:48:29+00:00

The problem we were assuming that current->nsproxy->ipc_ns would never
change while someone has our file in /proc/sysvipc/ file open.  Given that
this can change with both unshare and by passing the file descriptor to
another process that assumption is occasionally wrong.

Therefore this patch causes /proc/sysvipc/* to cache the namespace and
increment it's count when we open the file and to decrement the count when
we close the file, ensuring consistent operation with no surprises.

Signed-off-by: Eric W. Biederman 
Cc: Serge E. Hallyn 
Cc: Herbert Poetzl 
Cc: Kirill Korotaev 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Numerous fixes to kernel-doc info in source files.

2007-02-11T18:51:32+00:00

A variety of (mostly) innocuous fixes to the embedded kernel-doc content in
source files, including:

  * make multi-line initial descriptions single line
  * denote some function names, constants and structs as such
  * change erroneous opening '/*' to '/**' in a few places
  * reword some text for clarity

Signed-off-by: Robert P. J. Day 
Cc: "Randy.Dunlap" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] correct sys_shmget allocation check

2007-01-23T19:18:50+00:00

As written, sys_shmget will return ENOSPC when one page is still
available for allocation. This patch corrects the test.

Signed-off-by: Guy Streeter 
Signed-off-by: Linus Torvalds 
--

[PATCH] getting rid of all casts of k[cmz]alloc() calls

2006-12-13T17:05:58+00:00

Run this:

	#!/bin/sh
	for f in $(grep -Erl "\([^\)]*\) *k[cmz]alloc" *) ; do
	  echo "De-casting $f..."
	  perl -pi -e "s/ ?= ?\([^\)]*\) *(k[cmz]alloc) *\(/ = \1\(/" $f
	done

And then go through and reinstate those cases where code is casting pointers
to non-pointers.

And then drop a few hunks which conflicted with outstanding work.

Cc: Russell King , Ian Molton 
Cc: Mikael Starvik 
Cc: Yoshinori Sato 
Cc: Roman Zippel 
Cc: Geert Uytterhoeven 
Cc: Ralf Baechle 
Cc: Paul Mackerras 
Cc: Kyle McMartin 
Cc: Benjamin Herrenschmidt 
Cc: Martin Schwidefsky 
Cc: "David S. Miller" 
Cc: Jeff Dike 
Cc: Greg KH 
Cc: Jens Axboe 
Cc: Paul Fulghum 
Cc: Alan Cox 
Cc: Karsten Keil 
Cc: Mauro Carvalho Chehab 
Cc: Jeff Garzik 
Cc: James Bottomley 
Cc: Ian Kent 
Cc: Steven French 
Cc: David Woodhouse 
Cc: Neil Brown 
Cc: Jaroslav Kysela 
Cc: Takashi Iwai 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] struct path: convert ipc

2006-12-08T16:28:46+00:00

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