Add a preempt count base offset to compare against the current
preempt level count. It prepares to pull up the might_sleep
check from cond_resched() to cond_resched_lock() and
cond_resched_bh().

For these two helpers, we need to respectively ensure that once
we'll unlock the given spinlock / reenable local softirqs, we
will reach a sleepable state.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
[ Move and rename preempt_count_equals() ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1247725694-6082-4-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Cover the off case for __might_sleep(), so that we avoid
#ifdefs in files that make use of it. Especially, this prepares
for the __might_sleep() pull up on cond_resched().
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1247725694-6082-3-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Remove the outdated comment from __cond_resched() related to
the now removed Big Kernel Semaphore.
Reported-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1247725694-6082-2-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

The schedule() function is a loop that reschedules the current
task while the TIF_NEED_RESCHED flag is set:

void schedule(void)
{
need_resched:
	/* schedule code */
	if (need_resched())
		goto need_resched;
}

And cond_resched() repeat this loop:

do {
	add_preempt_count(PREEMPT_ACTIVE);
	schedule();
	sub_preempt_count(PREEMPT_ACTIVE);
} while(need_resched());

This loop is needless because schedule() already did the check
and nothing can set TIF_NEED_RESCHED between schedule() exit
and the loop check in need_resched().

Then remove this needless loop.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1247725694-6082-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Merge reason: branch had an old upstream base (-rc1-ish), but also
              merge to avoid a conflict.
Signed-off-by: Ingo Molnar <mingo@elte.hu>

* 'drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6:
  drm: Move a dereference below a NULL test
  fb/intelfb: conflict with DRM_I915 and hide by default
  drm/ttm: fix misplaced parentheses
  drm/via: Fix vblank IRQ on VIA hardware.
  drm: drm_gem, check kzalloc retval
  drm: drm_debugfs, check kmalloc retval
  drm/radeon: add some missing pci ids

* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/fyu/linux-2.6:
  Revert "Neither asm/types.h nor linux/types.h is required for arch/ia64/include/asm/fpu.h"
  Add dma_debug_init() for ia64
  Fix ia64 compilation IS_ERR and PTE_ERR errors.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
  x86/pci: insert ioapic resource before assigning unassigned resources

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  ALSA: riptide -  proper handling of pci_register_driver for joystick
  sound: usb-audio: add workaround for Blue Microphones devices
  ALSA: hda_intel: more strict alc880_parse_auto_config dig_nid checking
  ASoC: Fix NULL pointer dereference in __pxa2xx_pcm_hw_free

* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  virtio_net: Sync header with qemu
  virtio-pci: correctly unregister root device on error
  virtio_blk: ioctl return value fix
  virtio_blk: don't bounce highmem requests
  lguest: restrict CPUID to avoid perf counter wrmsr
  lguest: remove unnecessary forward struct declaration
  lguest: fix journey

Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  tracing/function: Fix the return value of ftrace_trace_onoff_callback()

Whoops.. fortunately not many people use this yet.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

asm/fpu.h uses the __IA64_UL macro which is declared in asm/types.h, so
this include is really required. Without it, GNU libc fails to build.

This reverts commit 2678c07b.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Acked-by: Fenghua Yu <fenghua.yu@intel.com>

The commit 99162195 was supposed to
add CONFIG_DMA_API_DEBUG support to IA64 however I forgot to add
dma_debug_init().
Signed-off-by: fujita <fujita@tulip.osrg.net>
Acked-by: Fenghua Yu <fenghua.yu@intel.com>

When building ia64 kernel with CONFIG_XEN_SYS_HYPERVISOR, compiler reports
errors:

drivers/xen/sys-hypervisor.c: In function ‘uuid_show’:
drivers/xen/sys-hypervisor.c:125: error: implicit declaration of function ‘IS_ERR’
drivers/xen/sys-hypervisor.c:126: error: implicit declaration of function ‘PTR_ERR’

This patch fixes the errors.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Acked-by: Isaku Yamahata <yamahata@valinux.co.jp>

Qemu added support for a few extra RX modes that Linux doesn't
currently make use of.  Sync the headers to maintain consistency.
Signed-off-by: Alex Williamson <alex.williamson@hp.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

If pci_register_driver() fails we're incorrectly unregistering the root
device with device_unregister() rather than root_device_unregister().
Reported-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Block driver ioctl methods must return ENOTTY and not -ENOIOCTLCMD if
they expect the block layer to handle generic ioctls.

This triggered a BLKROSET failure in xfsqa #200.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

By default a block driver bounces highmem requests, but virtio-blk is
perfectly fine with any request that fit into it's 64 bit addressing scheme,
mapped in the kernel virtual space or not.

Besides improving performance on highmem systems this also makes the
reproducible oops in __bounce_end_io go away (but hiding the real cause).
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Avoid the following:
[    0.012093] WARNING: at arch/x86/kernel/apic/apic.c:249 native_apic_write_dummy+0x2f/0x40()

Rather than chase each new cpuid-detected feature, just lie about the highest
valid CPUID so this code is never run.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

While fixing lg.h to drop the fwd declaration, I noticed
there's another one ;)
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

fix: "make Guest" was complaining about duplicated G:032
Signed-off-by: Matias Zabaljauregui <zabaljauregui@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

ftrace_trace_onoff_callback() will return an error even if we do the
right operation, for example:

 # echo _spin_*:traceon:10 > set_ftrace_filter
 -bash: echo: write error: Invalid argument
 # cat set_ftrace_filter
 #### all functions enabled ####
 _spin_trylock_bh:traceon:count=10
 _spin_unlock_irq:traceon:count=10
 _spin_unlock_bh:traceon:count=10
 _spin_lock_irq:traceon:count=10
 _spin_unlock:traceon:count=10
 _spin_trylock:traceon:count=10
 _spin_unlock_irqrestore:traceon:count=10
 _spin_lock_irqsave:traceon:count=10
 _spin_lock_bh:traceon:count=10
 _spin_lock:traceon:count=10

We want to set _spin_*:traceon:10 to set_ftrace_filter, it complains
with "Invalid argument", but the operation is successful.

This is because ftrace_process_regex() returns the number of functions that
matched the pattern. If the number is not 0, this value is returned
by ftrace_regex_write() whereas we want to return the number of bytes
virtually written.
Also the file offset pointer is not updated in this case.

If the number of matched functions is lower than the number of bytes written
by the user, this results to a reprocessing of the string given by the user with
a lower size, leading to a malformed ftrace regex and then a -EINVAL returned.

So, this patch fixes it by returning 0 if no error occured.
The fix also applies on 2.6.30
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: stable@kernel.org
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>

Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/peterz/linux-2.6-sched

* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/peterz/linux-2.6-sched:
  sched: Fix bug in SCHED_IDLE interaction with group scheduling
  sched: Fix rt_rq->pushable_tasks initialization in init_rt_rq()
  sched: Reset sched stats on fork()
  sched_rt: Fix overload bug on rt group scheduling
  sched: Documentation/sched-rt-group: Fix style issues & bump version

Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  timer stats: fix quick check optimization

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc: Fix another bug in move of altivec code to vector.S
  powerpc: Fix booke user_disable_single_step()

If a tty in N_TTY mode with echo enabled manages to get itself into a state
where
	- echo characters are pending
	- FASYNC is enabled
	- tty_write_wakeup is called from either
		- a device write path (pty)
		- an IRQ (serial)

then it either deadlocks or explodes taking a mutex in the IRQ path.

On the serial side it is almost impossible to reproduce because you have to
go from a full serial port to a near empty one with echo characters
pending. The pty case happens to have become possible to trigger using
emacs and ptys, the pty changes having created a scenario which shows up
this bug.

The code path is

	n_tty:process_echoes() (takes mutex)
	tty_io:tty_put_char()
	pty:pty_write  (or serial paths)
	tty_wakeup     (from pty_write or serial IRQ)
	n_tty_write_wakeup()
	process_echoes()
	*KABOOM*
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Don't forget to drop a tty refererence on fail paths in
receive_data().
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Bootmem is not used for the vt screen buffer anymore as slab is now
available at the time the console is initialized.

Get rid of the now superfluous distinction between slab and bootmem,
it's always slab.

This also fixes a kmalloc leak which Catalin described thusly:

Commit a5f4f52e ("vt: use kzalloc() instead of the bootmem allocator")
replaced the alloc_bootmem() with kzalloc() but didn't set vc_kmalloced to
1 and the memory block is later leaked.  The corresponding kmemleak trace:

unreferenced object 0xdf828000 (size 8192):
  comm "swapper", pid 0, jiffies 4294937296
  backtrace:
    [<c006d473>] __save_stack_trace+0x17/0x1c
    [<c000d869>] log_early+0x55/0x84
    [<c01cfa4b>] kmemleak_alloc+0x33/0x3c
    [<c006c013>] __kmalloc+0xd7/0xe4
    [<c00108c7>] con_init+0xbf/0x1b8
    [<c0010149>] console_init+0x11/0x20
    [<c0008797>] start_kernel+0x137/0x1e4
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Tested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

dcb314@hotmail.com notes that this memset has its args reversed.

It's unneeded anyway, so remove it.

Addresses http://bugzilla.kernel.org/show_bug.cgi?id=13587Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

msm_serial_driver is registered using platform_driver_probe which takes
care for the probe function itself.  So don't pass it in the driver
struct, too.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

We can get a situation where a hangup occurs during or after a close. In
that case the ldisc gets disposed of by the close and the hangup then
explodes.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Turning on this flag could prevent the compiler from optimising away
some "useless" checks for null pointers.  Such bugs can sometimes become
exploitable at compile time because of the -O2 optimisation.

See http://gcc.gnu.org/onlinedocs/gcc-4.1.2/gcc/Optimize-Options.html

An example that clearly shows this 'problem' is commit 6bf67672.

 static void __devexit agnx_pci_remove(struct pci_dev *pdev)
 {
     struct ieee80211_hw *dev = pci_get_drvdata(pdev);
-    struct agnx_priv *priv = dev->priv;
+    struct agnx_priv *priv;
     AGNX_TRACE;

     if (!dev)
         return;
+    priv = dev->priv;

By reverting this patch, and compile it with and without
-fno-delete-null-pointer-checks flag, we can see that the check for dev
is compiled away.

    call    printk  #
-   testq   %r12, %r12  # dev
-   je  .L94    #,
    movq    %r12, %rdi  # dev,

Clearly the 'fix' is to stop using dev before it is tested, but building
with -fno-delete-null-pointer-checks flag at least makes it harder to
abuse.
Signed-off-by: Eugene Teo <eugeneteo@kernel.sg>
Acked-by: Eric Paris <eparis@redhat.com>
Acked-by: Wang Cong <amwang@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This reverts commit a6540f73, as
requested by Alan:

  "... as it was wrong, the pty code is now fixed and the fact this
   isn't reverted is breaking pptp setups."
Requested-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* fix/usb-audio:
  sound: usb-audio: add workaround for Blue Microphones devices

* fix/misc:
  ALSA: riptide -  proper handling of pci_register_driver for joystick

* fix/hda:
  ALSA: hda_intel: more strict alc880_parse_auto_config dig_nid checking

* fix/asoc:
  ASoC: Fix NULL pointer dereference in __pxa2xx_pcm_hw_free

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  ahci: add device ID for 82801JI sata controller
  drivers/ata: Move a dereference below a NULL test
  libata: implement and use HORKAGE_NOSETXFER, take#2
  libata: fix follow-up SRST failure path

We need to check returning error for pci_register_driver(&joystick_driver)

On failure, we should unregister formerly registered audio drivers

This also fixed the compiler warning :

  CC [M]  sound/pci/riptide/riptide.o
 sound/pci/riptide/riptide.c: In function ‘alsa_card_riptide_init’:
 sound/pci/riptide/riptide.c:2200: warning: ignoring return value of ‘__pci_register_driver’, declared with attribute warn_unused_result
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>