kernel_optimize_test/include
Denis V. Lunev 59b7435149 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 08:06:20 -07:00
..
acpi
asm-alpha alpha: teach the compiler that BUG doesn't return 2008-04-28 08:58:27 -07:00
asm-arm mm: introduce pte_special pte bit 2008-04-28 08:58:23 -07:00
asm-avr32 mm: introduce pte_special pte bit 2008-04-28 08:58:23 -07:00
asm-blackfin
asm-cris cris: add constfy to pgd_offset() 2008-04-28 08:58:28 -07:00
asm-frv mm: introduce pte_special pte bit 2008-04-28 08:58:23 -07:00
asm-generic gpiochip_reserve() 2008-04-28 08:58:34 -07:00
asm-h8300
asm-ia64 dma/ia64: update ia64 machvecs, swiotlb.c 2008-04-29 08:06:12 -07:00
asm-m32r mm: introduce pte_special pte bit 2008-04-28 08:58:23 -07:00
asm-m68k mm: introduce pte_special pte bit 2008-04-28 08:58:23 -07:00
asm-m68knommu
asm-mips Merge branch 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus 2008-04-28 10:51:43 -07:00
asm-mn10300 mm: introduce pte_special pte bit 2008-04-28 08:58:23 -07:00
asm-parisc mm: introduce pte_special pte bit 2008-04-28 08:58:23 -07:00
asm-powerpc proper __do_softirq() prototype 2008-04-29 08:06:02 -07:00
asm-ppc mm: introduce pte_special pte bit 2008-04-28 08:58:23 -07:00
asm-s390 s390: implement pte special bit 2008-04-28 08:58:23 -07:00
asm-sh hugetlbfs: common code update for s390 2008-04-28 08:58:25 -07:00
asm-sparc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6 2008-04-28 09:45:57 -07:00
asm-sparc64 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6 2008-04-28 09:45:57 -07:00
asm-um mm: introduce pte_special pte bit 2008-04-28 08:58:23 -07:00
asm-v850
asm-x86 x86: olpc: add One Laptop Per Child architecture support 2008-04-29 08:06:07 -07:00
asm-xtensa mm: introduce pte_special pte bit 2008-04-28 08:58:23 -07:00
crypto
keys
linux proc: introduce proc_create_data to setup de->data 2008-04-29 08:06:20 -07:00
math-emu
media
mtd
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6 2008-04-28 09:44:11 -07:00
pcmcia
rdma IB: expand ib_umem_get() prototype 2008-04-29 08:06:12 -07:00
rxrpc
scsi
sound
video fbdev: platforming hecubafb and n411 2008-04-28 08:58:41 -07:00
xen xen: add balloon driver 2008-04-24 23:57:33 +02:00
Kbuild