hrtimers: Special-case zero length sleeps

sleep(0) is a common construct used by applications that want to trigger
the scheduler.  sched_yield() might make more sense, but only appeared in
POSIX.1-2001 and so plenty of example code still uses the sleep(0) form.

This wouldn't normally be a problem, but it means that event-driven
applications that are merely trying to avoid starving other processes may
actually end up sleeping due to having large timer_slack values.  Special-
casing this seems reasonable.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drm: avoid switching to text console if there is no panic timeout

Add a check for panic_timeout in the drm_fb_helper_panic() notifier: if
we're going to reboot immediately, the user will not be able to see the
messages anyway, and messing with the video mode may display artifacts,
and certainly get into several layers of complexity (including mutexes and
memory allocations) which we shall be much safer to avoid.

[msb@chromium.org: edited commit message and modified to short-circuit panic_timeout < 0 instead of testing panic_timeout >= 0]
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Cc: Dave Airlie <airlied@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Stéphane Marchesin <marcheu@chromium.org>
Cc: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/gpu/vga/vgaarb.c: add missing kfree

kbuf is a buffer that is local to this function, so all of the error paths
leaving the function should release it.

Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

devtmpfsd: fix task state handling

- Set the state to TASK_INTERRUPTIBLE using __set_current_state()
  instead of set_current_state() as the spin_unlock is an implicit memory
  barrier.

- After return from schedule(), there is no need to set the current
  state to TASK_RUNNING - a call to schedule() always returns in
  TASK_RUNNING state.

Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/edac/mpc85xx_edac.c: fix memory controller compatible for edac

compatible in dts has been changed, so the driver needs to be updated
accordingly.

Signed-off-by: Shaohui Xie <Shaohui.Xie@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

audit: always follow va_copy() with va_end()

A call to va_copy() should always be followed by a call to va_end() in the
same function.  In kernel/autit.c::audit_log_vformat() this is not always
done.  This patch makes sure va_end() is always called.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

arm, exec: remove redundant set_fs(USER_DS)

The address limit is already set in flush_old_exec() so this
set_fs(USER_DS) is redundant.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

arch/arm/mach-ux500/mbox-db5500.c: world-writable sysfs fifo file

Don't allow everybody to use a modem.

Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

x86/paravirt: PTE updates in k(un)map_atomic need to be synchronous, regardless of lazy_mmu mode

Fix an outstanding issue that has been reported since 2.6.37.  Under a
heavy loaded machine processing "fork()" calls could crash with:

BUG: unable to handle kernel paging request at f573fc8c
IP: [<c01abc54>] swap_count_continued+0x104/0x180
*pdpt = 000000002a3b9027 *pde = 0000000001bed067 *pte = 0000000000000000
Oops: 0000 [#1] SMP
Modules linked in:
Pid: 1638, comm: apache2 Not tainted 3.0.4-linode37 #1
EIP: 0061:[<c01abc54>] EFLAGS: 00210246 CPU: 3
EIP is at swap_count_continued+0x104/0x180
.. snip..
Call Trace:
 [<c01ac222>] ? __swap_duplicate+0xc2/0x160
 [<c01040f7>] ? pte_mfn_to_pfn+0x87/0xe0
 [<c01ac2e4>] ? swap_duplicate+0x14/0x40
 [<c01a0a6b>] ? copy_pte_range+0x45b/0x500
 [<c01a0ca5>] ? copy_page_range+0x195/0x200
 [<c01328c6>] ? dup_mmap+0x1c6/0x2c0
 [<c0132cf8>] ? dup_mm+0xa8/0x130
 [<c013376a>] ? copy_process+0x98a/0xb30
 [<c013395f>] ? do_fork+0x4f/0x280
 [<c01573b3>] ? getnstimeofday+0x43/0x100
 [<c010f770>] ? sys_clone+0x30/0x40
 [<c06c048d>] ? ptregs_clone+0x15/0x48
 [<c06bfb71>] ? syscall_call+0x7/0xb

The problem is that in copy_page_range() we turn lazy mode on, and then in
swap_entry_free() we call swap_count_continued() which ends up in:

         map = kmap_atomic(page, KM_USER0) + offset;

and then later we touch *map.

Since we are running in batched mode (lazy) we don't actually set up the
PTE mappings and the kmap_atomic is not done synchronously and ends up
trying to dereference a page that has not been set.

Looking at kmap_atomic_prot_pfn(), it uses 'arch_flush_lazy_mmu_mode' and
doing the same in kmap_atomic_prot() and __kunmap_atomic() makes the problem
go away.

Interestingly, commit b8bcfe997e4615 ("x86/paravirt: remove lazy mode in
interrupts") removed part of this to fix an interrupt issue - but it went
to far and did not consider this scenario.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

x86-reduce-clock-calibration-time-during-slave-cpu-startup-fix

fix CONFIG_SMP=n build

arch/x86/kernel/tsc.c: In function 'calibrate_delay_is_known':
arch/x86/kernel/tsc.c:1012: error: 'struct cpuinfo_x86' has no member named 'phys_proc_id'
arch/x86/kernel/tsc.c:1012: error: 'struct cpuinfo_x86' has no member named 'phys_proc_id'
arch/x86/kernel/tsc.c:1006: warning: unused variable 'cpu'

Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

x86: reduce clock calibration time during slave cpu startup

Reduce the startup time for slave cpus.

Adds hooks for an arch-specific function for clock calibration.  These
hooks are used on x86.  If a newly started cpu has the same phys_proc_id
as a core already active, uses the TSC for the delay loop and has a
CONSTANT_TSC, use the already-calculated value of loops_per_jiffy.

This patch reduces the time required to start slave cpus on a 4096 cpu
system from: 465 sec OLD 62 sec NEW

This reduces boot time on a 4096p system by almost 7 minutes.  Nice...

Signed-off-by: Jack Steiner <steiner@sgi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

x86: tlb flush avoid superflous leave_mm()

If just one page VA tlb is required to be flushed and current task is in
lazy TLB state, doing leave_mm() is superfluous because it flushes the
whole TLB.  This can reduce some TLB miss.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

arch/x86/mm/pageattr.c: quiet sparse noise; local functions should be static

Local functions should be marked static.  This quiets the following
sparse noise:

warning: symbol '_set_memory_array' was not declared. Should it be static?

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

arch/x86/kernel/ptrace.c: quiet sparse noise

ptrace_set_debugreg() is only used in this file and should be static.
This quiets the following sparse warning:

warning: symbol 'ptrace_set_debugreg' was not declared. Should it be static?

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

arch/x86/kernel/e820.c: quiet sparse noise about plain integer as NULL pointer

The last parameter to sort() is a pointer to the function used to swap
items.  This parameter should be NULL, not 0, when not used.  This quiets
the following sparse warning:

warning: Using plain integer as NULL pointer

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/power/intel_mid_battery.c: fix build

Seems that nobody's even trying any more.

Cc: Nithish Mahalingam <nithish.mahalingam@intel.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Anton Vorontsov <cbouatmailru@gmail.com>
Cc: Major Lee <major_lee@wistron.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mrst: battery fixes

When DCDC input line over current detecting, PMIC will change charging
current automatically.  Logging event is enough.

Signed-off-by: Major Lee <major_lee@wistron.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

x86: rtc: don't register a platform RTC device for Intel MID platforms

Intel MID x86 platforms have a memory mapped virtual RTC instead.  No MID
platform have the default ports (and accessing them may do weird stuff)

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

arch/x86/kernel/e820.c: eliminate bubble sort from sanitize_e820_map

Replace the bubble sort in sanitize_e820_map() with a call to the generic
kernel sort function to avoid pathological performance with large maps.

On large (thousands of entries) E820 maps, the previous code took minutes
to run; with this change it's now milliseconds.

Signed-off-by: Mike Ditto <mditto@google.com>
Cc: Stefan Assmann <sassmann@kpanic.de>
Cc: Nancy Yuen <yuenn@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

x86: fix mmap random address range

On x86_32 casting the unsigned int result of get_random_int() to long may
result in a negative value.  On x86_32 the range of mmap_rnd() therefore
was -255 to 255.  The 32bit mode on x86_64 used 0 to 255 as intended.

The bug was introduced by 675a081 ("x86: unify mmap_{32|64}.c") in January
2008.

Signed-off-by: Ludwig Nussel <ludwig.nussel@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Harvey Harrison <harvey.harrison@gmail.com>
Cc: <stable@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

arch/x86/platform/iris/iris.c: register a platform device and a platform driver

This makes the iris driver use the platform API, so it is properly exposed
in /sys.

[akpm@linux-foundation.org: remove commented-out code, add missing space to printk, clean up code layout]
Signed-off-by: Shérab <Sebastien.Hinderer@ens-lyon.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

acerhdf: add support for Aspire 1410 BIOS v1.3314

Add support for Aspire 1410 BIOS v1.3314.  Fixes the following error:

acerhdf: unknown (unsupported) BIOS version Acer/Aspire 1410/v1.3314,
please report, aborting!

Signed-off-by: Clay Carpenter <claycarpenter@gmail.com>
Signed-off-by: Peter Feuerer <peter@piie.net>
Cc: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

net/netfilter/nf_conntrack_netlink.c: fix Oops on container destroy

Problem:

A repeatable Oops can be caused if a container with networking
unshared is destroyed when it has nf_conntrack entries yet to expire.

A copy of the oops follows below. A perl program generating the oops
repeatably is attached inline below.

Analysis:

The oops is called from cleanup_net when the namespace is
destroyed. conntrack iterates through outstanding events and calls
death_by_timeout on each of them, which in turn produces a call to
ctnetlink_conntrack_event. This calls nf_netlink_has_listeners, which
oopses because net->nfnl is NULL.

The perl program generates the container through fork() then
clone(NS_NEWNET). I does not explicitly set up netlink
explicitly set up netlink, but I presume it was set up else net->nfnl
would have been NULL earlier (i.e. when an earlier connection
timed out). This would thus suggest that net->nfnl is made NULL
during the destruction of the container, which I think is done by
nfnetlink_net_exit_batch.

I can see that the various subsystems are deinitialised in the opposite
order to which the relevant register_pernet_subsys calls are called,
and both nf_conntrack and nfnetlink_net_ops register their relevant
subsystems. If nfnetlink_net_ops registered later than nfconntrack,
then its exit routine would have been called first, which would cause
the oops described. I am not sure there is anything to prevent this
happening in a container environment.

Whilst there's perhaps a more complex problem revolving around ordering
of subsystem deinit, it seems to me that missing a netlink event on a
container that is dying is not a disaster. An early check for net->nfnl
being non-NULL in ctnetlink_conntrack_event appears to fix this. There
may remain a potential race condition if it becomes NULL immediately
after being checked (I am not sure any lock is held at this point or
how synchronisation for subsystem deinitialization works).

Patch:

The patch attached should apply on everything from 2.6.26 (if not before)
onwards; it appears to be a problem on all kernels. This was taken against
Ubuntu-3.0.0-11.17 which is very close to 3.0.4. I have torture-tested it
with the above perl script for 15 minutes or so; the perl script hung the
machine within 20 seconds without this patch.

Applicability:

If this is the right solution, it should be applied to all stable kernels
as well as head. Apart from the minor overhead of checking one variable
against NULL, it can never 'do the wrong thing', because if net->nfnl
is NULL, an oops will inevitably result. Therefore, checking is a reasonable
thing to do unless it can be proven than net->nfnl will never be NULL.

Check net->nfnl for NULL in ctnetlink_conntrack_event to avoid Oops on
container destroy

Signed-off-by: Alex Bligh <alex@alex.org.uk>
Cc: Patrick McHardy <kaber@trash.net>
Cc: David Miller <davem@davemloft.net>
Cc: <stable@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Merge remote-tracking branch 'kvmtool/master'

Conflicts:
include/net/9p/9p.h
scripts/kconfig/Makefile

Merge remote-tracking branch 'pinctrl/for-next'

Merge remote-tracking branch 'tmem/tmem'

Conflicts:
mm/swapfile.c

Merge remote-tracking branch 'usb/usb-next'

Merge remote-tracking branch 'regmap/for-next'

Merge remote-tracking branch 'namespace/master'

Merge remote-tracking branch 'sysctl/master'

Merge remote-tracking branch 'percpu/for-next'

Merge remote-tracking branch 'xen-two/linux-next'

Merge remote-tracking branch 'xen/upstream/xen'

Conflicts:
arch/x86/xen/Kconfig

Merge remote-tracking branch 'kmemleak/kmemleak'

Merge remote-tracking branch 'tip/auto-latest'

Conflicts:
MAINTAINERS

Merge remote-tracking branch 'fsnotify/for-next'

Merge remote-tracking branch 'pm/linux-next'

Merge remote-tracking branch 'trivial/for-next'

Merge remote-tracking branch 'osd/linux-next'

Merge remote-tracking branch 'cputime/cputime'

Merge remote-tracking branch 'iommu/next'

Merge remote-tracking branch 'watchdog/linux-next'

Merge remote-tracking branch 'regulator/for-next'

Merge remote-tracking branch 'fbdev/fbdev-next'

Merge remote-tracking branch 'md/for-next'

Merge remote-tracking branch 'slab/for-next'

Merge remote-tracking branch 'kgdb/kgdb-next'

Merge remote-tracking branch 'mmc/mmc-next'

Merge remote-tracking branch 'battery/master'

Merge remote-tracking branch 'block/for-next'

Merge remote-tracking branch 'input/next'

Conflicts:
drivers/input/keyboard/Kconfig
drivers/input/keyboard/samsung-keypad.c

Merge branch 'quilt/rr'

Merge remote-tracking branch 'cpufreq/next'

Merge remote-tracking branch 'sound-asoc/for-next'

Merge remote-tracking branch 'sound/for-next'

Merge remote-tracking branch 'crypto/master'

Merge remote-tracking branch 'l2-mtd/master'

Merge remote-tracking branch 'bluetooth/master'

Merge remote-tracking branch 'wireless-next/master'

Conflicts:
drivers/net/wireless/libertas/cfg.c
include/net/bluetooth/bluetooth.h

Merge remote-tracking branch 'net-next/master'

Merge remote-tracking branch 'slave-dma/next'

Conflicts:
drivers/dma/pl330.c

Merge remote-tracking branch 'target-merge/for-next-merge'

Merge remote-tracking branch 'ibft/master'

Merge remote-tracking branch 'swiotlb/master'

Conflicts:
drivers/xen/swiotlb-xen.c

Merge remote-tracking branch 'infiniband/for-next'

Merge remote-tracking branch 'libata/NEXT'

Merge remote-tracking branch 'kconfig/for-next'

Merge remote-tracking branch 'kbuild/for-next'

Merge remote-tracking branch 'v4l-dvb/master'

Merge remote-tracking branch 'bjdooks-i2c/next-i2c'

Conflicts:
drivers/i2c/busses/i2c-designware-platdrv.c

Merge branch 'quilt/i2c'

Merge remote-tracking branch 'hid/for-next'

Merge remote-tracking branch 'pci/linux-next'

Merge remote-tracking branch 'xfs/master'

Merge remote-tracking branch 'ocfs2/linux-next'

Conflicts:
fs/ocfs2/xattr.c

Merge commit 'refs/next/20111115/nfsd'

Merge remote-tracking branch 'nfs/linux-next'

Merge remote-tracking branch 'logfs/master'

Conflicts:
fs/logfs/file.c

Merge remote-tracking branch 'gfs2/master'

Merge remote-tracking branch 'cifs/master'

Merge remote-tracking branch 'xtensa/master'

Merge remote-tracking branch 'unicore32/unicore32'

Merge remote-tracking branch 's390/features'

Merge remote-tracking branch '52xx-and-virtex/powerpc/next'

Merge remote-tracking branch 'parisc/for-next'

Merge remote-tracking branch 'mips/mips-for-linux-next'

Merge remote-tracking branch 'm68knommu/for-next'

Conflicts:
arch/m68k/Kconfig.debug

Merge remote-tracking branch 'm68k/for-next'

Merge remote-tracking branch 'ia64/next'

Merge remote-tracking branch 'cris/for-next'

Merge remote-tracking branch 'c6x/for-linux-next'

Merge remote-tracking branch 'tegra/for-next'

Merge remote-tracking branch 's5p/for-next'

Merge remote-tracking branch 'i.MX/for-next'

Conflicts:
arch/arm/mach-mx5/clock-mx51-mx53.c
arch/arm/mach-mx5/devices-imx53.h
arch/arm/mach-mx5/mm.c
arch/arm/plat-mxc/include/mach/hardware.h

Merge remote-tracking branch 'at91/at91-next'

Merge remote-tracking branch 'arm-lpae/for-next'

Conflicts:
arch/arm/include/asm/pgalloc.h
arch/arm/include/asm/pgtable.h
arch/arm/include/asm/tlb.h

Merge remote-tracking branch 'arm/for-next'

Merge remote-tracking branch 'ide/master'

Merge remote-tracking branch 'input-current/for-linus'

Merge remote-tracking branch 'char-misc.current/char-misc-linus'