Commit Graph

201418 Commits

Author SHA1 Message Date
Christoph Hellwig 33659ebbae block: remove wrappers for request type/flags
Remove all the trivial wrappers for the cmd_type and cmd_flags fields in
struct requests.  This allows much easier grepping for different request
types instead of unwinding through macros.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:17:56 +02:00
FUJITA Tomonori 7e005f7979 remove needless ISA_DMA_THRESHOLD
Architectures don't need to define ISA_DMA_THRESHOLD anymore.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: James Bottomley <James.Bottomley@suse.de>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:15:50 +02:00
FUJITA Tomonori bfe172310e block: kill ISA_DMA_THRESHOLD usage
block uses ISA_DMA_THRESHOLD for BLK_BOUNCE_ISA. Only SCSI uses
ISA_DMA_THRESHOLD for ancient drivers with non-zero
unchecked_isa_dma. Nowadays drivers (and subsystems) use dma_mask
properly instead of ISA_DMA_THRESHOLD.

Documentation/scsi/scsi_mid_low_api.txt says:

unchecked_isa_dma - 1=>only use bottom 16 MB of ram (ISA DMA addressing
                   restriction), 0=>can use full 32 bit (or better) DMA
                   address space

So block simply uses DMA_BIT_MASK(24) for BLK_BOUNCE_ISA for SCSI.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:15:49 +02:00
FUJITA Tomonori b375a612ad aha1532: remove ISA_DMA_THRESHOLD usage
We can safely remove ISA_DMA_THRESHOLD usage in aha1542. aha1542 uses
ISA_DMA_THRESHOLD to see if:

- the buffers in scatter/list are below 16MB.
- scsi_host is below 16MB.

Both checkings were added in the ancient times but aren't necessary
nowadays since we properly bounce the buffers and allocate scsi_host
below 16MB with non-zero unchecked_isa_dma.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:15:46 +02:00
Christoph Hellwig 41f2df6289 block: BARRIER request should imply SYNC
A barrier request should by defintion have priority in get_request
and let the queue be unplugged immediately as it's blocking all forward
progress due to the queue draining.

Most filesystems already get this implicitly by the way how submit_bh
treats the buffer_ordered flag, and gfs2 sets it explicitly.  But btrfs
and XFS are still forgetting to set the flag, as is blkdev_issue_flush
and some places in DM/MD.

For XFS on metadata heavy workloads this gives a consistent speedup
in the 2-3% range.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:15:44 +02:00
Stephen Hemminger 01b6b67eda floppy: use warning macros
Convert assertions to use WARN().  There are several error checks in the
code for things that should never happen.  Convert them to standard
warnings so kerneloops.org will see them.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:15:43 +02:00
Stephen Hemminger b862f26fe1 floppy: use wait_event_interruptible
Convert wait loops to use wait_event_ macros.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:15:41 +02:00
Stephen Hemminger 21af544804 floppy: fix signed/unsigned warnings
Ioctl cmd value is unsigned, so change normalize_ioctl

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:15:39 +02:00
Stephen Hemminger be1c0fbfb4 floppy: cmos attribute should be static
As reported by sparse, cmos attribute is local.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:15:37 +02:00
Stephen Hemminger 575cfc673e floppy: use atomic type for usage_count
The usage_count was being protected by a lock which was only there to
create an atomic counter.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:15:36 +02:00
Stephen Hemminger 41a55b4de3 floppy: silence warning during disk test
The first thing the floppy does is read block 0 to test geometry and to
test for disk presence.  If disk is not present this causes a console
warning message about failed I/O.  Set flag to silence.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:15:34 +02:00
Stephen Hemminger be7a12bb1a floppy: remove unnecessary inlines
These routines are all big enough that is better to let the compiler
decide to inline or not.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:15:32 +02:00
Stephen Hemminger 285203c8ff floppy: initialize debug jiffies offset
Set debug jiffies offset at initialization.  Avoids wierd values showing
up if debugging enabled.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:15:30 +02:00
Mike Miller f3bcb14332 cciss: change pad value from 32 to 0
Change the command padding on 32-bit systems to 0 since setting it to 32
has the identical effect.

Signed-off-by: Mike Miller <mike.miller@hp.com>
Cc: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:15:29 +02:00
Mike Miller b0dd5cad3a cciss: remove errant debug code
Remove a debug statement left behind by accident Ths debug statement got
left behind.  It was commented out after use but not deleted.

Signed-off-by: Mike Miller <mike.miller@hp.com>
Cc: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:15:27 +02:00
Mike Miller 29979a7122 cciss: move next_command function from ifdef
The definition of next_command also ended up in wrong place It ended up
inside an "#ifdef CONFIG_PROCFS".  Already caught by Randy Dunlap and a
couple others.  Tried to put it somewhere that made sense.

Signed-off-by: Mike Miller <mike.miller@hp.com>
Cc: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:15:25 +02:00
Mike Miller b14aa6dcd0 cciss: fix call to put_controller_in_performant_mode
call to put_controller_in_performant_mode was in the wrong place
The call inadvertently ended up in an error path.

Signed-off-by: Mike Miller <mike.miller@hp.com>
Cc: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:15:23 +02:00
Mike Miller 256aea3fd3 cciss: make sure we request the performant mode irq
Make sure we register the performant mode interrupt Another blunder.
Seemed to work because the call to put_controller_into_performant_mode was
never called.

Signed-off-by: Mike Miller <mike.miller@hp.com>
Cc: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:15:21 +02:00
Jens Axboe 956bcb7c1a block: add helpers for the trivial queue flag sysfs show/store entries
The code for nonrot, random, and io stats are completely identical.

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:13:50 +02:00
Jens Axboe e2e1a148bc block: add sysfs knob for turning off disk entropy contributions
There are two reasons for doing this:

- On SSD disks, the completion times aren't as random as they
  are for rotational drives. So it's questionable whether they
  should contribute to the random pool in the first place.

- Calling add_disk_randomness() has a lot of overhead.

This adds /sys/block/<dev>/queue/add_random that will allow you to
switch off on a per-device basis. The default setting is on, so there
should be no functional changes from this patch.

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:13:00 +02:00
Mike Miller 841fdffdd3 cciss: new controller support and bump driver version
Add support for new controllers due out next year.  HP must continue to
support new controllers in older distros.  All vendors require support be
upstream.  These controllers support only 16 commands in simple mode but
can support up to 1024 in performant mode.  See patch 5/6/ We have no
marketing names yet.

Signed-off-by: Mike Miller <mike.miller@hp.com>
Cc: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:12:51 +02:00
Mike Miller 5e216153c3 cciss: add performant mode support for Stars/Sirius
Add a mode of controller operation called Performant Mode.  Even though
cciss has been deprecated in favor of hpsa there are new controllers due
out next year that HP must support in older vendor distros.  Vendors
require all fixes/features be upstream.  These new controllers support
only 16 commands in simple mode but support up to 1024 in performant mode.
This requires us to add this support at this late date.

The performant mode transport minimizes host PCI accesses by performinf
many completions per read.  PCI writes are posted so the host can write
then immediately get off the bus not waiting for the writwe to complete to
the target.  In the context of performant mode the host read out to a
controller pulls all posted writes into host memory ensuring the reply
queue is coherent.

Signed-off-by: Mike Miller <mike.miller@hp.com>
Cc: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:12:51 +02:00
Mike Miller 1d1414419f cciss: make interrupt access methods return type bool
Change the return type of our interrupt access routines to bool from
unsigned long.  It makes more sense that way.

Signed-off-by: Mike Miller <mike.miller@hp.com>
Cc: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:12:51 +02:00
Mike Miller 2cf3af1c9e cciss: check for msi in interrupt_not_for_us
Check to see if h->msi[x]_vector is set.  We need this for a following
patch.  Without this check we process one interrupt then stop because in
msi[x] mode the interrupt pending bit is not set.  Not sure why we didn't
encounter this before.

Signed-off-by: Mike Miller <mike.miller@hp.com>
Cc: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:12:35 +02:00
Mike Miller 0c2b39087c cciss: clean up interrupt handler
Simplify the interrupt handler code to more closely match hpsa and to
hopefully make it easier to follow.

Signed-off-by: Mike Miller <mike.miller@hp.com>
Cc: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:12:33 +02:00
Mike Miller 664a717d3a cciss: enqueue and submit io
Clean up some code where we subit our io.  The same 5 lines appeared
several times.  Also helps for a following patch.

Signed-off-by: Mike Miller <mike.miller@hp.com>
Cc: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:12:32 +02:00
Linus Torvalds 9fe6206f40 Linux 2.6.35 2010-08-01 15:11:14 -07:00
Trond Myklebust 77a63f3d1e NFS: Fix a typo in include/linux/nfs_fs.h
nfs_commit_inode() needs to be defined irrespectively of whether or not
we are supporting NFSv3 and NFSv4.

Allow the compiler to optimise away code in the NFSv2-only case by
converting it into an inlined stub function.

Reported-and-tested-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-01 15:10:01 -07:00
Linus Torvalds a63ecd835f Merge master.kernel.org:/home/rmk/linux-2.6-arm
* master.kernel.org:/home/rmk/linux-2.6-arm:
  cyber2000fb: fix console in truecolor modes
  cyber2000fb: fix machine hang on module load
  SA1111: Eliminate use after free
  ARM: Fix Versatile/Realview/VExpress MMC card detection sense
  ARM: 6279/1: highmem: fix SMP preemption bug in kmap_high_l1_vipt
  ARM: Add barriers to io{read,write}{8,16,32} accessors as well
  ARM: 6273/1: Add barriers to the I/O accessors if ARM_DMA_MEM_BUFFERABLE
  ARM: 6272/1: Convert L2x0 to use the IO relaxed operations
  ARM: 6271/1: Introduce *_relaxed() I/O accessors
  ARM: 6275/1: ux500: don't use writeb() in uncompress.h
  ARM: 6270/1: clean files in arch/arm/boot/compressed/
  ARM: Fix csum_partial_copy_from_user()
2010-07-30 19:02:51 -07:00
Linus Torvalds fc71ff8a6c Merge branch 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6
* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6:
  NFS: Ensure that writepage respects the nonblock flag
  NFS: kswapd must not block in nfs_release_page
  nfs: include space for the NUL in root path
2010-07-30 19:02:21 -07:00
Linus Torvalds 1cf66e1616 Merge branch 'drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6
* 'drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6:
  drm/edid: Fix the HDTV hack sync adjustment
  drm/radeon/kms: fix radeon mid power profile reporting
2010-07-30 19:01:11 -07:00
Hugh Dickins de51257aa3 mm: fix ia64 crash when gcore reads gate area
Debian's ia64 autobuilders have been seeing kernel freeze or reboot
when running the gdb testsuite (Debian bug 588574): dannf bisected to
2.6.32 62eede62da "mm: ZERO_PAGE without
PTE_SPECIAL"; and reproduced it with gdb's gcore on a simple target.

I'd missed updating the gate_vma handling in __get_user_pages(): that
happens to use vm_normal_page() (nowadays failing on the zero page),
yet reported success even when it failed to get a page - boom when
access_process_vm() tried to copy that to its intermediate buffer.

Fix this, resisting cleanups: in particular, leave it for now reporting
success when not asked to get any pages - very probably safe to change,
but let's not risk it without testing exposure.

Why did ia64 crash with 16kB pages, but succeed with 64kB pages?
Because setup_gate() pads each 64kB of its gate area with zero pages.

Reported-by: Andreas Barth <aba@not.so.argh.org>
Bisected-by: dann frazier <dannf@debian.org>
Signed-off-by: Hugh Dickins <hughd@google.com>
Tested-by: dann frazier <dannf@dannf.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-07-30 18:56:09 -07:00
David Howells 51c20fcced CIFS: Remove __exit mark from cifs_exit_dns_resolver()
Remove the __exit mark from cifs_exit_dns_resolver() as it's called by the
module init routine in case of error, and so may have been discarded during
linkage.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-07-30 18:56:09 -07:00
Ondrej Zary e76df4d339 cyber2000fb: fix console in truecolor modes
Return value was not set to 0 in setcolreg() with truecolor modes. This causes
fb_set_cmap() to abort after first color, resulting in blank palette - and
blank console in 24bpp and 32bpp modes.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-07-30 23:29:33 +01:00
Ondrej Zary 00b4703f03 cyber2000fb: fix machine hang on module load
I was testing two CyberPro 2000 based PCI cards on x86 and the machine always
hanged completely when the cyber2000fb module was loaded. It seems that the
card hangs when some registers are accessed too quickly after writing RAMDAC
control register. With this patch, both card work.

Add delay after RAMDAC control register write to prevent hangs on module load.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-07-30 23:29:33 +01:00
Julia Lawall f2d2420bbf SA1111: Eliminate use after free
__sa1111_remove always frees its argument, so the subsequent reference to
sachip->saved_state represents a use after free.  __sa1111_remove does not
appear to use the saved_state field, so the patch simply frees it first.

A simplified version of the semantic patch that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
expression E,E2;
@@

__sa1111_remove(E)
...
(
  E = E2
|
* E
)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-07-30 23:19:30 +01:00
Russell King 74bc80931c ARM: Fix Versatile/Realview/VExpress MMC card detection sense
The MMC card detection sense has become really confused with negations
at various levels, leading to some platforms not detecting inserted
cards.  Fix this by converting everything to positive logic throughout,
thereby getting rid of these negations.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-07-30 23:16:32 +01:00
Gary King 831e8047eb ARM: 6279/1: highmem: fix SMP preemption bug in kmap_high_l1_vipt
smp_processor_id() must not be called from a preemptible context (this
is checked by CONFIG_DEBUG_PREEMPT).  kmap_high_l1_vipt() was doing so.
This lead to a problem where the wrong per_cpu kmap_high_l1_vipt_depth
could be incremented, causing a BUG_ON(*depth <= 0); in
kunmap_high_l1_vipt().

The solution is to move the call to smp_processor_id() after the call
to preempt_disable().

Originally by: Andrew Howe <ahowe@nvidia.com>

Signed-off-by: Gary King <gking@nvidia.com>
Acked-by: Nicolas Pitre <nico.as.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-07-30 23:16:07 +01:00
Trond Myklebust cfb506e1d3 NFS: Ensure that writepage respects the nonblock flag
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-07-30 15:38:56 -04:00
Trond Myklebust b608b283a9 NFS: kswapd must not block in nfs_release_page
See https://bugzilla.kernel.org/show_bug.cgi?id=16056

If other processes are blocked waiting for kswapd to free up some memory so
that they can make progress, then we cannot allow kswapd to block on those
processes.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org
2010-07-30 15:38:42 -04:00
Dan Carpenter 674b222292 nfs: include space for the NUL in root path
In root_nfs_name() it does the following:

        if (strlen(buf) + strlen(cp) > NFS_MAXPATHLEN) {
                printk(KERN_ERR "Root-NFS: Pathname for remote directory too long.\n");
                return -1;
        }
        sprintf(nfs_export_path, buf, cp);

In the original code if (strlen(buf) + strlen(cp) == NFS_MAXPATHLEN)
then the sprintf() would lead to an overflow.  Generally the rest of the
code assumes that the path can have NFS_MAXPATHLEN (1024) characters and
a NUL terminator so the fix is to add space to the nfs_export_path[]
buffer.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-07-30 15:33:39 -04:00
Linus Torvalds a2dccdb205 Merge branch 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6
* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6:
  [S390] etr: fix clock synchronization race
  [S390] Fix IRQ tracing in case of PER
2010-07-29 15:23:28 -07:00
Linus Torvalds 7d5fcdc38f Merge git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog
* git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog:
  watchdog: update MAINTAINERS entry
2010-07-29 15:21:44 -07:00
Linus Torvalds e271e872a8 Merge branch 'fix/hda' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6
* 'fix/hda' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  ALSA: hda - Add a PC-beep workaround for ASUS P5-V
  ALSA: hda - Assume PC-beep as default for Realtek
  ALSA: hda - Don't register beep input device when no beep is available
  ALSA: hda - Fix pin-detection of Nvidia HDMI
2010-07-29 15:21:07 -07:00
David Howells 8f92054e7c CRED: Fix __task_cred()'s lockdep check and banner comment
Fix __task_cred()'s lockdep check by removing the following validation
condition:

	lockdep_tasklist_lock_is_held()

as commit_creds() does not take the tasklist_lock, and nor do most of the
functions that call it, so this check is pointless and it can prevent
detection of the RCU lock not being held if the tasklist_lock is held.

Instead, add the following validation condition:

	task->exit_state >= 0

to permit the access if the target task is dead and therefore unable to change
its own credentials.

Fix __task_cred()'s comment to:

 (1) discard the bit that says that the caller must prevent the target task
     from being deleted.  That shouldn't need saying.

 (2) Add a comment indicating the result of __task_cred() should not be passed
     directly to get_cred(), but rather than get_task_cred() should be used
     instead.

Also put a note into the documentation to enforce this point there too.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-07-29 15:16:18 -07:00
David Howells de09a9771a CRED: Fix get_task_cred() and task_state() to not resurrect dead credentials
It's possible for get_task_cred() as it currently stands to 'corrupt' a set of
credentials by incrementing their usage count after their replacement by the
task being accessed.

What happens is that get_task_cred() can race with commit_creds():

	TASK_1			TASK_2			RCU_CLEANER
	-->get_task_cred(TASK_2)
	rcu_read_lock()
	__cred = __task_cred(TASK_2)
				-->commit_creds()
				old_cred = TASK_2->real_cred
				TASK_2->real_cred = ...
				put_cred(old_cred)
				  call_rcu(old_cred)
		[__cred->usage == 0]
	get_cred(__cred)
		[__cred->usage == 1]
	rcu_read_unlock()
							-->put_cred_rcu()
							[__cred->usage == 1]
							panic()

However, since a tasks credentials are generally not changed very often, we can
reasonably make use of a loop involving reading the creds pointer and using
atomic_inc_not_zero() to attempt to increment it if it hasn't already hit zero.

If successful, we can safely return the credentials in the knowledge that, even
if the task we're accessing has released them, they haven't gone to the RCU
cleanup code.

We then change task_state() in procfs to use get_task_cred() rather than
calling get_cred() on the result of __task_cred(), as that suffers from the
same problem.

Without this change, a BUG_ON in __put_cred() or in put_cred_rcu() can be
tripped when it is noticed that the usage count is not zero as it ought to be,
for example:

kernel BUG at kernel/cred.c:168!
invalid opcode: 0000 [#1] SMP
last sysfs file: /sys/kernel/mm/ksm/run
CPU 0
Pid: 2436, comm: master Not tainted 2.6.33.3-85.fc13.x86_64 #1 0HR330/OptiPlex
745
RIP: 0010:[<ffffffff81069881>]  [<ffffffff81069881>] __put_cred+0xc/0x45
RSP: 0018:ffff88019e7e9eb8  EFLAGS: 00010202
RAX: 0000000000000001 RBX: ffff880161514480 RCX: 00000000ffffffff
RDX: 00000000ffffffff RSI: ffff880140c690c0 RDI: ffff880140c690c0
RBP: ffff88019e7e9eb8 R08: 00000000000000d0 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000040 R12: ffff880140c690c0
R13: ffff88019e77aea0 R14: 00007fff336b0a5c R15: 0000000000000001
FS:  00007f12f50d97c0(0000) GS:ffff880007400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8f461bc000 CR3: 00000001b26ce000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process master (pid: 2436, threadinfo ffff88019e7e8000, task ffff88019e77aea0)
Stack:
 ffff88019e7e9ec8 ffffffff810698cd ffff88019e7e9ef8 ffffffff81069b45
<0> ffff880161514180 ffff880161514480 ffff880161514180 0000000000000000
<0> ffff88019e7e9f28 ffffffff8106aace 0000000000000001 0000000000000246
Call Trace:
 [<ffffffff810698cd>] put_cred+0x13/0x15
 [<ffffffff81069b45>] commit_creds+0x16b/0x175
 [<ffffffff8106aace>] set_current_groups+0x47/0x4e
 [<ffffffff8106ac89>] sys_setgroups+0xf6/0x105
 [<ffffffff81009b02>] system_call_fastpath+0x16/0x1b
Code: 48 8d 71 ff e8 7e 4e 15 00 85 c0 78 0b 8b 75 ec 48 89 df e8 ef 4a 15 00
48 83 c4 18 5b c9 c3 55 8b 07 8b 07 48 89 e5 85 c0 74 04 <0f> 0b eb fe 65 48 8b
04 25 00 cc 00 00 48 3b b8 58 04 00 00 75
RIP  [<ffffffff81069881>] __put_cred+0xc/0x45
 RSP <ffff88019e7e9eb8>
---[ end trace df391256a100ebdd ]---

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-07-29 15:16:17 -07:00
Wim Van Sebroeck 230a5cef48 watchdog: update MAINTAINERS entry
Add Mailing-list and website to watchdog MAINTAINERS entry.

Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2010-07-29 18:02:51 +00:00
Takashi Iwai dc1eae256c ALSA: hda - Add a PC-beep workaround for ASUS P5-V
ASUS P5-V provides a SSID that unexpectedly matches with the value
compilant with Realtek's specification.  Thus the driver interprets
it badly, resulting in non-working PC beep.

This patch adds a white-list for such a case; a white-list of known
devices with working PC beep.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2010-07-29 15:30:02 +02:00
Russell King b92b361213 ARM: Add barriers to io{read,write}{8,16,32} accessors as well
The ioread/iowrite accessors also need barriers as they're used in
place of readl/writel et.al. in portable drivers.  Create __iormb()
and __iowmb() which are conditionally defined to be barriers dependent
on ARM_DMA_MEM_BUFFERABLE, and always use these macros in the accessors.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-07-29 14:04:37 +01:00
Catalin Marinas 79f64dbf68 ARM: 6273/1: Add barriers to the I/O accessors if ARM_DMA_MEM_BUFFERABLE
When the coherent DMA buffers are mapped as Normal Non-cacheable
(ARM_DMA_MEM_BUFFERABLE enabled), buffer accesses are no longer ordered
with Device memory accesses causing failures in device drivers that do
not use the mandatory memory barriers before starting a DMA transfer.
LKML discussions led to the conclusion that such barriers have to be
added to the I/O accessors:

http://thread.gmane.org/gmane.linux.kernel/683509/focus=686153
http://thread.gmane.org/gmane.linux.ide/46414
http://thread.gmane.org/gmane.linux.kernel.cross-arch/5250

This patch introduces a wmb() barrier to the write*() I/O accessors to
handle the situations where Normal Non-cacheable writes are still in the
processor (or L2 cache controller) write buffer before a DMA transfer
command is issued. For the read*() accessors, a rmb() is introduced
after the I/O to avoid speculative loads where the driver polls for a
DMA transfer ready bit.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-07-29 14:04:37 +01:00