compat_exit_robust_list() computes a pointer to the
futex entry in userspace as follows:

	(void __user *)entry + futex_offset

'entry' is a 'struct robust_list __user *', and
'futex_offset' is a 'compat_long_t' (typically a 's32').

Things explode if the 32-bit sign bit is set in futex_offset.

Type promotion sign extends futex_offset to a 64-bit value before
adding it to 'entry'.

This triggered a problem on sparc64 running 32-bit applications which
would lock up a cpu looping forever in the fault handling for the
userspace load in handle_futex_death().

Compat userspace runs with address masking (wherein the cpu zeros out
the top 32-bits of every effective address given to a memory operation
instruction) so the sparc64 fault handler accounts for this by
zero'ing out the top 32-bits of the fault address too.

Since the kernel properly uses the compat_uptr interfaces, kernel side
accesses to compat userspace work too since they will only use
addresses with the top 32-bit clear.

Because of this compat futex layer bug we get into the following loop
when executing the get_user() load near the top of handle_futex_death():

1) load from address '0xfffffffff7f16bd8', FAULT
2) fault handler clears upper 32-bits, processes fault
   for address '0xf7f16bd8' which succeeds
3) goto #1

I want to thank Bernd Zeimetz, Josip Rodin, and Fabio Massimo Di Nitto
for their tireless efforts helping me track down this bug.
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
  [IA64] IOSAPIC bogus error cleanup
  [IA64] Update printing of feature set bits
  [IA64] Fix IOSAPIC delivery mode setting
  [IA64] XPC heartbeat timer function must run on CPU 0
  [IA64] Clean up /proc/interrupts output
  [IA64] Disable/re-enable CPE interrupts on Altix
  [IA64] Clean-up McKinley Errata message
  [IA64] Add gate.lds to list of files ignored by Git
  [IA64] Fix section mismatch in contig.c version of per_cpu_init()
  [IA64] Wrong args to memset in efi_gettimeofday()
  [IA64] Remove duplicate includes from ia32priv.h
  [IA64] fix number of bytes zeroed by sys_fw_init() in arch/ia64/hp/sim/boot/fw-emu.c
  [IA64] Fix perfmon sysctl directory modes

* git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched:
  sched: proper prototype for kernel/sched.c:migration_init()
  sched: avoid large irq-latencies in smp-balancing
  sched: fix copy_namespace() <-> sched_fork() dependency in do_fork
  sched: clean up the wakeup preempt check, #2
  sched: clean up the wakeup preempt check
  sched: wakeup preemption fix
  sched: remove PREEMPT_RESTRICT
  sched: turn off PREEMPT_RESTRICT
  KVM: fix !SMP build error
  x86: make nmi_cpu_busy() always defined
  x86: make ipi_handler() always defined
  sched: cleanup, use NSEC_PER_MSEC and NSEC_PER_SEC
  sched: reintroduce SMP tunings again
  sched: restore deterministic CPU accounting on powerpc
  sched: fix delay accounting regression
  sched: reintroduce the sched_min_granularity tunable
  sched: documentation: place_entity() comments
  sched: fix vslice

* master.kernel.org:/pub/scm/linux/kernel/git/lethal/sh-2.6: (26 commits)
  sh: remove dead config symbols from SH code
  sh: Kill off broken snapgear ds1302 code.
  sh: Add a dummy vga.h.
  rtc: rtc-sh: Zero out tm value for invalid rtc states.
  rtc: sh-rtc: Handle rtc_device_register() failure properly.
  sh: Fix heartbeart on Solution Engine series
  sh: Remove SCI_NPORTS from sh-sci.h
  sh: Fix up PAGE_KERNEL_PCC() for nommu.
  sh: hs7751rvoip: Kill off dead IPR IRQ mappings.
  sh: hs7751rvoip: irq.c needs linux/interrupt.h.
  sh: Kill off __{copy,clear}_user_page().
  sh: Optimized copy_{to,from}_user_page() for SH-4.
  sh: Wire up clear_user_highpage().
  sh: Kill off the remaining ST40 cruft.
  superhyway: Handle device_register() retval properly.
  sh: kgdb sysrq depends on magic sysrq.
  sh: Add -Werror for clean directories.
  sh: Fix up kgdb build with modular sh-sci.
  sh: Export __{s,u}divsi3_i4i on all CPUs.
  sh: Fix up kgdb-on-NMI branch target.
  ...

* master.kernel.org:/home/rmk/linux-2.6-arm:
  [ARM] pxa: fix one-shot timer mode
  [ARM] 4645/1: Cyberpro: Trivial fix to restore 16bpp mode.
  [ARM] 4644/2: fix flush_kern_tlb_range() in module space
  [ARM] Allow watchdog drivers to be selected again
  [ARM] 4633/1: omap build fix when FB enabled
  [ARM] 4642/2: netX: default config for netx based boards
  [ARM] 4641/2: netX: fix kobject_name type
  [ARM] Fix iop3xx macro

* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  [LIB] crc32c: Keep intermediate crc state in cpu order

* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  Add UNPLUG traces to all appropriate places
  block: fix requeue handling in blk_queue_invalidate_tags()
  mmc: Fix sg helper copy-and-paste error
  pktcdvd: fix BUG caused by sysfs module reference semantics change
  ioprio: allow sys_ioprio_set() value of 0 to reset ioprio setting
  cfq_idle_class_timer: add paranoid checks for jiffies overflow
  cfq: fix IOPRIO_CLASS_IDLE delays
  cfq: fix IOPRIO_CLASS_IDLE accounting

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: (37 commits)
  [POWERPC] EEH: Make sure warning message is printed
  [POWERPC] Make altivec code in swsusp_32.S depend on CONFIG_ALTIVEC
  [POWERPC] windfarm: Fix windfarm thread freezer interaction
  [POWERPC] Fix si_addr value on low level hash failures
  [POWERPC] Refresh ppc64_defconfig and enable pasemi-related options
  [POWERPC] pasemi: Update defconfig
  [POWERPC] iSeries: Fix ref counting in vio setup
  [POWERPC] ] Fix memset size error
  [POWERPC] Fix link errors for allyesconfig
  [POWERPC] iSeries_init_IRQ non-PCI tidy
  [POWERPC] Change fallocate to match unistd.h on powerpc
  [POWERPC] EEH: Avoid crash on null device
  [POWERPC] EEH: Drivers that need reset trump others
  [POWERPC] EEH: Clean up comments
  [POWERPC] Fix off-by-one error in setting decrementer on Book E/4xx (v2)
  [POWERPC] Fix switch_slb handling of 1T ESID values
  [POWERPC] Fix build failure when CONFIG_VIRT_CPU_ACCOUNTING is not defined
  [POWERPC] Include udbg.h when using udbg_printf
  [POWERPC] Fix cache line vs. block size confusion
  [POWERPC] Fix sysctl table check failure on PowerMac
  ...

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mfasheh/ocfs2:
  ocfs2: fix rename vs unlink race
  [PATCH] Fix possibly too long write in o2hb_setup_one_bio()
  ocfs2: fix write() performance regression
  ocfs2: Commit journal on sync writes
  ocfs2: Re-order iput in ocfs2_drop_dentry_lock
  ocfs2: Create locks at initially requested level
  [PATCH] Fix priority mistakes in fs/ocfs2/{alloc.c, dlmglue.c}
  [2.6 patch] make ocfs2_find_entry_el() static

The old NO_IRQ define some platforms had was long ago declared obsolete
and wrong. FRV should therefore not be re-introducing this, especially as
IRQs are usually unsigned in the kernel. The "no IRQ" case is defined to be
zero and Linus made this rather clear at the time.

arch/frv shows no dependancy on this but it might show up driver fixes
needing doing I guess
Signed-off-by: Alan Cox <alan@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6:
  [SPARC64]: Use "is_power_of_2" macro for simplicity.
  [SPARC]: Remove duplicate includes.

* 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6: (44 commits)
  [NETLINK]: Fix unicast timeouts
  [INET]: Remove per bucket rwlock in tcp/dccp ehash table.
  [IPVS]: Synchronize closing of Connections
  [IPVS]: Bind connections on stanby if the destination exists
  [NET]: Remove Documentation/networking/pt.txt
  [NET]: Remove Documentation/networking/routing.txt
  [NET]: Remove Documentation/networking/ncsa-telnet
  [NET]: Remove comx driver docs.
  [NET]: Remove Documentation/networking/Configurable
  [NET]: Clean proto_(un)register from in-code ifdefs
  [IPSEC]: Fix crypto_alloc_comp error checking
  [VLAN]: Fix SET_VLAN_INGRESS_PRIORITY_CMD ioctl
  [NETNS]: Fix compiler error in net_namespace.c
  [TTY]: Use tty_mode_ioctl() in network drivers.
  [TTY]: Fix network driver interactions with TCGET/SET calls.
  [PKT_SCHED] CLS_U32: Fix endianness problem with u32 classifier hash masks.
  [NET]: Removing duplicit #includes
  [NET]: Let USB_USBNET always select MII.
  [RRUNNER]: Do not muck with sysctl_{r,w}mem_max
  [DLM] lowcomms: Do not muck with sysctl_rmem_max.
  ...

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
  firewire: fw-sbp2: fix refcounting

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/selinux-2.6:
  SELinux: add more validity checks on policy load
  SELinux: fix bug in new ebitmap code.
  SELinux: suppress a warning for 64k pages.

Remove the section annotation on FRV's free_initmem().  It can't be marked
__init, lest it free itself.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This patch adds a proper prototype for migration_init() in
include/linux/sched.h

Since there's no point in always returning 0 to a caller that doesn't check
the return value it also changes the function to return void.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

SMP balancing is done with IRQs disabled and can iterate the full rq.
When rqs are large this can cause large irq-latencies. Limit the nr of
iterations on each run.

This fixes a scheduling latency regression reported by the -rt folks.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Tested-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Sukadev Bhattiprolu reported a kernel crash with control groups.
There are couple of problems discovered by Suka's test:

- The test requires the cgroup filesystem to be mounted with
  atleast the cpu and ns options (i.e both namespace and cpu 
  controllers are active in the same hierarchy). 

	# mkdir /dev/cpuctl
	# mount -t cgroup -ocpu,ns none cpuctl
	(or simply)
	# mount -t cgroup none cpuctl -> Will activate all controllers
					 in same hierarchy.

- The test invokes clone() with CLONE_NEWNS set. This causes a a new child
  to be created, also a new group (do_fork->copy_namespaces->ns_cgroup_clone->
  cgroup_clone) and the child is attached to the new group (cgroup_clone->
  attach_task->sched_move_task). At this point in time, the child's scheduler 
  related fields are uninitialized (including its on_rq field, which it has
  inherited from parent). As a result sched_move_task thinks its on
  runqueue, when it isn't.

  As a solution to this problem, I moved sched_fork() call, which
  initializes scheduler related fields on a new task, before
  copy_namespaces(). I am not sure though whether moving up will
  cause other side-effects. Do you see any issue?

- The second problem exposed by this test is that task_new_fair()
  assumes that parent and child will be part of the same group (which 
  needn't be as this test shows). As a result, cfs_rq->curr can be NULL
  for the child.

  The solution is to test for curr pointer being NULL in
  task_new_fair().

With the patch below, I could run ns_exec() fine w/o a crash.
Reported-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

clean up the preemption check to not use unnecessary 64-bit
variables. This improves code size:

   text    data     bss     dec     hex filename
  44227    3326      36   47589    b9e5 sched.o.before
  44201    3326      36   47563    b9cb sched.o.after
Signed-off-by: Ingo Molnar <mingo@elte.hu>

clean up the wakeup preemption check. No code changed:

   text    data     bss     dec     hex filename
  44227    3326      36   47589    b9e5 sched.o.before
  44227    3326      36   47589    b9e5 sched.o.after
Signed-off-by: Ingo Molnar <mingo@elte.hu>

wakeup preemption fix: do not make it dependent on p->prio.
Preemption purely depends on ->vruntime.

This improves preemption in mixed-nice-level workloads.
Signed-off-by: Ingo Molnar <mingo@elte.hu>

remove PREEMPT_RESTRICT. (this is a separate commit so that any
regression related to the removal itself is bisectable)
Signed-off-by: Ingo Molnar <mingo@elte.hu>

PREEMPT_RESTRICT was a method aimed at reducing the amount of wakeup
related preemption. It has a disadvantage though, it can prevent
legitimate wakeups if a task is 'unlucky' to be hit too early by a tick
that clears peer_preempt.

Now that the wakeup preemption has been cleaned up we dont seem to have
excessive preemptions anymore, so this feature can be turned off. (and
removed in the next patch)
Signed-off-by: Ingo Molnar <mingo@elte.hu>

fix a !SMP build error:

drivers/kvm/kvm_main.c: In function 'kvm_flush_remote_tlbs':
drivers/kvm/kvm_main.c:220: error: implicit declaration of function 'smp_call_function_mask'

(and also avoid unused function warning related to up_smp_call_function()
not making use of the 'func' parameter.)
Signed-off-by: Ingo Molnar <mingo@elte.hu>

nmi_cpu_busy() must be available on !SMP too.

this is in preparation to a smp_call_function_mask() fix.
Signed-off-by: Ingo Molnar <mingo@elte.hu>

prepare for up_smp_call_function() to ensure that the 'func'
pointer is unused. (which is related to a KVM build fix)
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1) hardcoded 1000000000 value is used five times in places where
   NSEC_PER_SEC might be more readable.

2) A conversion from nsec to msec uses the hardcoded 1000000 value,
   which is a candidate for NSEC_PER_MSEC.

no code changed:

    text    data     bss     dec     hex filename
   44359    3326      36   47721    ba69 sched.o.before
   44359    3326      36   47721    ba69 sched.o.after
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Yanmin Zhang reported an aim7 regression and bisected it down to:

 |  commit 38ad464d
 |  Author: Ingo Molnar <mingo@elte.hu>
 |  Date:   Mon Oct 15 17:00:02 2007 +0200
 |
 |     sched: uniform tunings
 |
 |     use the same defaults on both UP and SMP.

fix this by reintroducing similar SMP tunings again. This resolves
the regression.

(also update the comments to match the ilog2(nr_cpus) tuning effect)
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Since powerpc started using CONFIG_GENERIC_CLOCKEVENTS, the
deterministic CPU accounting (CONFIG_VIRT_CPU_ACCOUNTING) has been
broken on powerpc, because we end up counting user time twice: once in
timer_interrupt() and once in update_process_times().

This fixes the problem by pulling the code in update_process_times
that updates utime and stime into a separate function called
account_process_tick.  If CONFIG_VIRT_CPU_ACCOUNTING is not defined,
there is a version of account_process_tick in kernel/timer.c that
simply accounts a whole tick to either utime or stime as before.  If
CONFIG_VIRT_CPU_ACCOUNTING is defined, then arch code gets to
implement account_process_tick.

This also lets us simplify the s390 code a bit; it means that the s390
timer interrupt can now call update_process_times even when
CONFIG_VIRT_CPU_ACCOUNTING is turned on, and can just implement a
suitable account_process_tick().

account_process_tick() now takes the task_struct * as an argument.
Tested both with and without CONFIG_VIRT_CPU_ACCOUNTING.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Fix the delay accounting regression introduced by commit
75d4ef16. rq no longer has sched_info
data associated with it. task_struct sched_info structure is used by delay
accounting to provide back statistics to user space.

also remove direct use of sched_clock() (which is not a valid thing to
do anymore) and use rq->clock instead.
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

we lost the sched_min_granularity tunable to a clever optimization
that uses the sched_latency/min_granularity ratio - but the ratio
is quite unintuitive to users and can also crash the kernel if the
ratio is set to 0. So reintroduce the min_granularity tunable,
while keeping the ratio maintained internally.

no functionality changed.

[ mingo@elte.hu: some fixlets. ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Add a few comments to place_entity(). No code changed.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

vslice was missing a factor NICE_0_LOAD, as weight is in
weight*NICE_0_LOAD units.

the effect of this bug was larger initial slices and
thus latency-noisier forks.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

On Altix (sn2) machines the "Error parsing MADT" message is
misleading because the lack of IOSAPIC entries is expected.

Since I am sure someone will ask, I have been told that
the chance of this changing anytime soon is close to nil.
Signed-off-by: George Beshers <gbeshers@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

Newer Itanium versions have added additional processor feature set
bits.  This patch prints all the implemented feature set bits.  Some
bit descriptions have not been made public.  For those bits, a generic
"Feature set X bit Y" message is printed.  Bits that are not implemented
will no longer be printed.
Signed-off-by: Russ Anderson <rja@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

Fix the problem that redirect hit bit in I/O SAPIC RTE is set even
when it must be disabled (e.g. nointroute boot option is set, CPU
hotplug is enabled or percpu vector is enabled).
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

Currently, XPC's heartbeat timer function runs on whatever CPU modprobe/insmod
ran on when XPC was started. To avoid the heartbeat from being delayed for
long periods the timer function must run on CPU 0.

N.B. Altix doesn't currently allow cpu0 to be taken offline, so this is
safe for now.  This code must be revised when offline of cpu0 is enabled.
Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

Added blk_unplug interface, allowing all invocations of unplugs to result
in a generated blktrace UNPLUG.
Signed-off-by: Alan D. Brunelle <Alan.Brunelle@hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Credit goes to juergen.kadidlo@exasol.com for diagnosing this issue
and supplying the initial patch.

blk_queue_invalidate_tags() must use the proper requeueing paths instead
of open coding the re-add of the request, otherwise we bug out in rq
accounting. Just switch to using blk_requeue_request(), that takes care
of end-tag handling as well and also adds the blktrace REQUEUE notify
event that is also appropriate here.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>