Commit Graph

12425 Commits

Author SHA1 Message Date
H. Peter Anvin
ee1b06ea6a x86, reboot: Fix the use of passed arguments in 32-bit BIOS reboot
The initial version of this patch had %eax being a segment and %ecx
being the mode.  I had changed the interfaces, but not the actual
implementation!

Reported-by: Brian Gerst <brgerst@gmail.com>
LKML-Reference: <AANLkTikxqk=HEw9R-Du=v-1ti1HDGAY9vaNUep2XARaz@mail.gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Matthieu Castet <castet.matthieu@free.fr>
2011-02-18 15:47:42 -08:00
H. Peter Anvin
3d35ac346e x86, reboot: Move the real-mode reboot code to an assembly file
Move the real-mode reboot code out to an assembly file (reboot_32.S)
which is allocated using the common lowmem trampoline allocator.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
LKML-Reference: <4D5DFBE4.7090104@intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Matthieu Castet <castet.matthieu@free.fr>
2011-02-17 21:05:34 -08:00
H. Peter Anvin
014eea518a x86: Make the GDT_ENTRY() macro in <asm/segment.h> safe for assembly
Make the GDT_ENTRY() macro in  <asm/segment.h> safe for use in
assembly code by guarding the ULL suffixes with _AC() macros.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
LKML-Reference: <4D5DFBE4.7090104@intel.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Matthieu Castet <castet.matthieu@free.fr>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
2011-02-17 21:05:13 -08:00
H. Peter Anvin
d1ee433539 x86, trampoline: Use the unified trampoline setup for ACPI wakeup
Use the unified trampoline allocation setup to allocate and install
the ACPI wakeup code in low memory.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
LKML-Reference: <4D5DFBE4.7090104@intel.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Matthieu Castet <castet.matthieu@free.fr>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
2011-02-17 21:05:06 -08:00
H. Peter Anvin
4822b7fc6d x86, trampoline: Common infrastructure for low memory trampolines
Common infrastructure for low memory trampolines.  This code installs
the trampolines permanently in low memory very early.  It also permits
multiple pieces of code to be used for this purpose.

This code also introduces a standard infrastructure for computing
symbol addresses in the trampoline code.

The only change to the actual SMP trampolines themselves is that the
64-bit trampoline has been made reusable -- the previous version would
overwrite the code with a status variable; this moves the status
variable to a separate location.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
LKML-Reference: <4D5DFBE4.7090104@intel.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Matthieu Castet <castet.matthieu@free.fr>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
2011-02-17 21:02:43 -08:00
Linus Torvalds
1cecd791f2 Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Fix text_poke_smp_batch() deadlock
  perf tools: Fix thread_map event synthesizing in top and record
  watchdog, nmi: Lower the severity of error messages
  ARM: oprofile: Fix backtraces in timer mode
  oprofile: Fix usage of CONFIG_HW_PERF_EVENTS for oprofile_perf_init and friends
2011-02-15 10:18:48 -08:00
Linus Torvalds
fef86db8fe Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, dmi, debug: Log board name (when present) in dmesg/oops output
  x86, ioapic: Don't warn about non-existing IOAPICs if we have none
  x86: Fix mwait_usable section mismatch
  x86: Readd missing irq_to_desc() in fixup_irq()
  x86: Fix section mismatch in LAPIC initialization
2011-02-15 10:18:29 -08:00
Naga Chumbalkar
84e383b322 x86, dmi, debug: Log board name (when present) in dmesg/oops output
The "Type 2" SMBIOS record that contains Board Name is not
strictly required and may be absent in the SMBIOS on some
platforms.

( Please note that Type 2 is not listed in Table 3 in Sec 6.2
  ("Required Structures and Data") of the SMBIOS v2.7
  Specification. )

Use the Manufacturer Name (aka System Vendor) name.
Print Board Name only when it is present.

Before the fix:
  (i) dmesg output: DMI: /ProLiant DL380 G6, BIOS P62 01/29/2011
 (ii) oops output:  Pid: 2170, comm: bash Not tainted 2.6.38-rc4+ #3 /ProLiant DL380 G6

After the fix:
  (i) dmesg output: DMI: HP ProLiant DL380 G6, BIOS P62 01/29/2011
 (ii) oops output:  Pid: 2278, comm: bash Not tainted 2.6.38-rc4+ #4 HP ProLiant DL380 G6

Signed-off-by: Naga Chumbalkar <nagananda.chumbalkar@hp.com>
Reviewed-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: <stable@kernel.org> # .3x - good for debugging, please apply as far back as it applies cleanly
LKML-Reference: <20110214224423.2182.13929.sendpatchset@nchumbalkar.americas.hpqcorp.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-15 04:20:57 +01:00
Paul Bolle
678301ecad x86, ioapic: Don't warn about non-existing IOAPICs if we have none
mp_find_ioapic() prints errors like:

    ERROR: Unable to locate IOAPIC for GSI 13

if it can't find the IOAPIC that manages that specific GSI. I
see errors like that at every boot of a laptop that apparently
doesn't have any IOAPICs.

But if there are no IOAPICs it doesn't seem to be an error that
none can be found. A solution that gets rid of this message is
to directly return if nr_ioapics (still) is zero. (But keep
returning -1 in that case, so nothing breaks from this change.)

The call chain that generates this error is:

pnpacpi_allocated_resource()
    case ACPI_RESOURCE_TYPE_IRQ:
        pnpacpi_parse_allocated_irqresource()
            acpi_get_override_irq()
                 mp_find_ioapic()

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-15 04:15:04 +01:00
Borislav Petkov
1c9d16e359 x86: Fix mwait_usable section mismatch
We use it in non __cpuinit code now too so drop marker.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <20110211171754.GA21047@aftab>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-14 12:08:28 +01:00
Thomas Gleixner
5117348dea x86: Readd missing irq_to_desc() in fixup_irq()
commit a3c08e5d(x86: Convert irq_chip access to new functions)
accidentally zapped desc = irq_to_desc(irq); in the vector loop.
So we lock some random irq descriptor.

Add it back.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@kernel.org> # .37
2011-02-12 11:56:22 +01:00
Peter Zijlstra
d91309f69b x86: Fix text_poke_smp_batch() deadlock
Fix this deadlock - we are already holding the mutex:

=======================================================
[ INFO: possible circular locking dependency detected ] 2.6.38-rc4-test+ #1
-------------------------------------------------------
bash/1850 is trying to acquire lock:
 (text_mutex){+.+.+.}, at: [<ffffffff8100a9c1>] return_to_handler+0x0/0x2f

but task is already holding lock:
 (smp_alt){+.+...}, at: [<ffffffff8100a9c1>] return_to_handler+0x0/0x2f

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #2 (smp_alt){+.+...}:
       [<ffffffff81082d02>] lock_acquire+0xcd/0xf8
       [<ffffffff8192e119>] __mutex_lock_common+0x4c/0x339
       [<ffffffff8192e4ca>] mutex_lock_nested+0x3e/0x43
       [<ffffffff8101050f>] alternatives_smp_switch+0x77/0x1d8
       [<ffffffff81926a6f>] do_boot_cpu+0xd7/0x762
       [<ffffffff819277dd>] native_cpu_up+0xe6/0x16a
       [<ffffffff81928e28>] _cpu_up+0x9d/0xee
       [<ffffffff81928f4c>] cpu_up+0xd3/0xe7
       [<ffffffff82268d4b>] kernel_init+0xe8/0x20a
       [<ffffffff8100ba24>] kernel_thread_helper+0x4/0x10

-> #1 (cpu_hotplug.lock){+.+.+.}:
       [<ffffffff81082d02>] lock_acquire+0xcd/0xf8
       [<ffffffff8192e119>] __mutex_lock_common+0x4c/0x339
       [<ffffffff8192e4ca>] mutex_lock_nested+0x3e/0x43
       [<ffffffff810568cc>] get_online_cpus+0x41/0x55
       [<ffffffff810a1348>] stop_machine+0x1e/0x3e
       [<ffffffff819314c1>] text_poke_smp_batch+0x3a/0x3c
       [<ffffffff81932b6c>] arch_optimize_kprobes+0x10d/0x11c
       [<ffffffff81933a51>] kprobe_optimizer+0x152/0x222
       [<ffffffff8106bb71>] process_one_work+0x1d3/0x335
       [<ffffffff8106cfae>] worker_thread+0x104/0x1a4
       [<ffffffff810707c4>] kthread+0x9d/0xa5
       [<ffffffff8100ba24>] kernel_thread_helper+0x4/0x10

-> #0 (text_mutex){+.+.+.}:

other info that might help us debug this:

6 locks held by bash/1850:
 #0:  (&buffer->mutex){+.+.+.}, at: [<ffffffff8100a9c1>] return_to_handler+0x0/0x2f
 #1:  (s_active#75){.+.+.+}, at: [<ffffffff8100a9c1>] return_to_handler+0x0/0x2f
 #2:  (x86_cpu_hotplug_driver_mutex){+.+.+.}, at: [<ffffffff8100a9c1>] return_to_handler+0x0/0x2f
 #3:  (cpu_add_remove_lock){+.+.+.}, at: [<ffffffff8100a9c1>] return_to_handler+0x0/0x2f
 #4:  (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff8100a9c1>] return_to_handler+0x0/0x2f
 #5:  (smp_alt){+.+...}, at: [<ffffffff8100a9c1>] return_to_handler+0x0/0x2f

stack backtrace:
Pid: 1850, comm: bash Not tainted 2.6.38-rc4-test+ #1
Call Trace:

 [<ffffffff81080eb2>] print_circular_bug+0xa8/0xb7
 [<ffffffff8192e4ca>] mutex_lock_nested+0x3e/0x43
 [<ffffffff81010302>] alternatives_smp_unlock+0x3d/0x93
 [<ffffffff81010630>] alternatives_smp_switch+0x198/0x1d8
 [<ffffffff8102568a>] native_cpu_die+0x65/0x95
 [<ffffffff818cc4ec>] _cpu_down+0x13e/0x202
 [<ffffffff8117a619>] sysfs_write_file+0x108/0x144
 [<ffffffff8111f5a2>] vfs_write+0xac/0xff
 [<ffffffff8111f7a9>] sys_write+0x4a/0x6e

Reported-by: Steven Rostedt <rostedt@goodmis.org>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: mathieu.desnoyers@efficios.com
Cc: rusty@rustcorp.com.au
Cc: ananth@in.ibm.com
Cc: masami.hiramatsu.pt@hitachi.com
Cc: fweisbec@gmail.com
Cc: jbeulich@novell.com
Cc: jbaron@redhat.com
Cc: mhiramat@redhat.com
LKML-Reference: <1297458466.5226.93.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-12 02:34:34 +01:00
Linus Torvalds
3c6c0d6ca3 Merge branch 'kvm-updates/2.6.38' of git://git.kernel.org/pub/scm/virt/kvm/kvm
* 'kvm-updates/2.6.38' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: SVM: Make sure KERNEL_GS_BASE is valid when loading gs_index
2011-02-11 16:30:09 -08:00
Jan Beulich
2fb270f321 x86: Fix section mismatch in LAPIC initialization
Additionally doing things conditionally upon smp_processor_id()
being zero is generally a bad idea, as this means CPU 0 cannot
be offlined and brought back online later again.

While there may be other places where this is done, I think adding
more of those should be avoided so that some day SMP can really
become "symmetrical".

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
LKML-Reference: <4D525C7E0200007800030EE1@vpn.id2.novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-10 13:26:53 +01:00
Joerg Roedel
893a5ab6ee KVM: SVM: Make sure KERNEL_GS_BASE is valid when loading gs_index
The gs_index loading code uses the swapgs instruction to
switch to the user gs_base temporarily. This is unsave in an
lightweight exit-path in KVM on AMD because the
KERNEL_GS_BASE MSR is switches lazily. An NMI happening in
the critical path of load_gs_index may use the wrong GS_BASE
value then leading to unpredictable behavior, e.g. a
triple-fault.

This patch fixes the issue by making sure that load_gs_index
is called only with a valid KERNEL_GS_BASE value loaded in
KVM.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-02-09 18:31:36 +02:00
H. Peter Anvin
d344e38b2c x86, nx: Mark the ACPI resume trampoline code as +x
We reserve lowmem for the things that need it, like the ACPI
wakeup code, way early to guarantee availability.  This happens
before we set up the proper pagetables, so set_memory_x() has no
effect.

Until we have a better solution, use an initcall to mark the
wakeup code executable.

Originally-by: Matthieu Castet <castet.matthieu@free.fr>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Matthias Hopf <mhopf@suse.de>
Cc: rjw@sisk.pl
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <4D4F8019.2090104@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-07 09:07:13 +01:00
Linus Torvalds
07675f484b Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86-32: Make sure the stack is set up before we use it
  x86, mtrr: Avoid MTRR reprogramming on BP during boot on UP platforms
  x86, nx: Don't force pages RW when setting NX bits
2011-02-06 12:03:10 -08:00
H. Peter Anvin
11d4c3f9b6 x86-32: Make sure the stack is set up before we use it
Since checkin ebba638ae7 we call
verify_cpu even in 32-bit mode.  Unfortunately, calling a function
means using the stack, and the stack pointer was not initialized in
the 32-bit setup code!  This code initializes the stack pointer, and
simplifies the interface slightly since it is easier to rely on just a
pointer value rather than a descriptor; we need to have different
values for the segment register anyway.

This retains start_stack as a virtual address, even though a physical
address would be more convenient for 32 bits; the 64-bit code wants
the other way around...

Reported-by: Matthieu Castet <castet.matthieu@free.fr>
LKML-Reference: <4D41E86D.8060205@free.fr>
Tested-by: Kees Cook <kees.cook@canonical.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-02-04 22:27:28 -08:00
Suresh Siddha
831d52bc15 x86, mm: avoid possible bogus tlb entries by clearing prev mm_cpumask after switching mm
Clearing the cpu in prev's mm_cpumask early will avoid the flush tlb
IPI's while the cr3 is still pointing to the prev mm.  And this window
can lead to the possibility of bogus TLB fills resulting in strange
failures.  One such problematic scenario is mentioned below.

 T1. CPU-1 is context switching from mm1 to mm2 context and got a NMI
     etc between the point of clearing the cpu from the mm_cpumask(mm1)
     and before reloading the cr3 with the new mm2.

 T2. CPU-2 is tearing down a specific vma for mm1 and will proceed with
     flushing the TLB for mm1.  It doesn't send the flush TLB to CPU-1
     as it doesn't see that cpu listed in the mm_cpumask(mm1).

 T3. After the TLB flush is complete, CPU-2 goes ahead and frees the
     page-table pages associated with the removed vma mapping.

 T4. CPU-2 now allocates those freed page-table pages for something
     else.

 T5. As the CR3 and TLB caches for mm1 is still active on CPU-1, CPU-1
     can potentially speculate and walk through the page-table caches
     and can insert new TLB entries.  As the page-table pages are
     already freed and being used on CPU-2, this page walk can
     potentially insert a bogus global TLB entry depending on the
     (random) contents of the page that is being used on CPU-2.

 T6. This bogus TLB entry being global will be active across future CR3
     changes and can result in weird memory corruption etc.

To avoid this issue, for the prev mm that is handing over the cpu to
another mm, clear the cpu from the mm_cpumask(prev) after the cr3 is
changed.

Marking it for -stable, though we haven't seen any reported failure that
can be attributed to this.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: stable@kernel.org	[v2.6.32+]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-03 13:32:39 -08:00
Linus Torvalds
eb487ab4d5 Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf: Fix reading in perf_event_read()
  watchdog: Don't change watchdog state on read of sysctl
  watchdog: Fix sysctl consistency
  watchdog: Fix broken nowatchdog logic
  perf: Fix Pentium4 raw event validation
  perf: Fix alloc_callchain_buffers()
2011-02-03 08:52:05 -08:00
Suresh Siddha
f7448548a9 x86, mtrr: Avoid MTRR reprogramming on BP during boot on UP platforms
Markus Kohn ran into a hard hang regression on an acer aspire
1310, when acpi is enabled. git bisect showed the following
commit as the bad one that introduced the boot regression.

	commit d0af9eed5a
	Author: Suresh Siddha <suresh.b.siddha@intel.com>
	Date:   Wed Aug 19 18:05:36 2009 -0700

	    x86, pat/mtrr: Rendezvous all the cpus for MTRR/PAT init

Because of the UP configuration of that platform,
native_smp_prepare_cpus() bailed out (in smp_sanity_check())
before doing the set_mtrr_aps_delayed_init()

Further down the boot path, native_smp_cpus_done() will call the
delayed MTRR initialization for the AP's (mtrr_aps_init()) with
mtrr_aps_delayed_init not set. This resulted in the boot
processor reprogramming its MTRR's to the values seen during the
start of the OS boot. While this is not needed ideally, this
shouldn't have caused any side-effects. This is because the
reprogramming of MTRR's (set_mtrr_state() that gets called via
set_mtrr()) will check if the live register contents are
different from what is being asked to write and will do the actual
write only if they are different.

BP's mtrr state is read during the start of the OS boot and
typically nothing would have changed when we ask to reprogram it
on BP again because of the above scenario on an UP platform. So
on a normal UP platform no reprogramming of BP MTRR MSR's
happens and all is well.

However, on this platform, bios seems to be modifying the fixed
mtrr range registers between the start of OS boot and when we
double check the live registers for reprogramming BP MTRR
registers. And as the live registers are modified, we end up
reprogramming the MTRR's to the state seen during the start of
the OS boot.

During ACPI initialization, something in the bios (probably smi
handler?) don't like this fact and results in a hard lockup.

We didn't see this boot hang issue on this platform before the
commit d0af9eed5a, because only
the AP's (if any) will program its MTRR's to the value that BP
had at the start of the OS boot.

Fix this issue by checking mtrr_aps_delayed_init before
continuing further in the mtrr_aps_init(). Now, only AP's (if
any) will program its MTRR's to the BP values during boot.

Addresses https://bugzilla.novell.com/show_bug.cgi?id=623393

  [ By the way, this behavior of the bios modifying MTRR's after the start
    of the OS boot is not common and the kernel is not prepared to
    handle this situation well. Irrespective of this issue, during
    suspend/resume, linux kernel will try to reprogram the BP's MTRR values
    to the values seen during the start of the OS boot. So suspend/resume might
    be already broken on this platform for all linux kernel versions. ]

Reported-and-bisected-by: Markus Kohn <jabber@gmx.org>
Tested-by: Markus Kohn <jabber@gmx.org>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Thomas Renninger <trenn@novell.com>
Cc: Rafael Wysocki <rjw@novell.com>
Cc: Venkatesh Pallipadi <venki@google.com>
Cc: stable@kernel.org # [v2.6.32+]
LKML-Reference: <1296694975.4418.402.camel@sbsiddha-MOBL3.sc.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-03 12:10:38 +01:00
Matthieu CASTET
f12d3d04e8 x86, nx: Don't force pages RW when setting NX bits
Xen want page table pages read only.

But the initial page table (from head_*.S) live in .data or .bss.

That was broken by 64edc8ed5f.  There is
absolutely no reason to force these pages RW after they have already
been marked RO.

Signed-off-by: Matthieu CASTET <castet.matthieu@free.fr>
Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-02-02 16:02:36 -08:00
Linus Torvalds
1f0324caef Merge branch 'stable/bug-fixes-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
* 'stable/bug-fixes-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/setup: Route halt operations to safe_halt pvop.
  xen/e820: Guard against E820_RAM not having page-aligned size or start.
  xen/p2m: Mark INVALID_P2M_ENTRY the mfn_list past max_pfn.
2011-01-28 12:24:34 +10:00
Linus Torvalds
f7b548fa3d Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  percpu, x86: Fix percpu_xchg_op()
  x86: Remove left over system_64.h
  x86-64: Don't use pointer to out-of-scope variable in dump_trace()
2011-01-28 06:43:41 +10:00
Stephane Eranian
d038b12c6d perf: Fix Pentium4 raw event validation
This patch fixes some issues with raw event validation on
Pentium 4 (Netburst) based processors.

As I was testing libpfm4 Netburst support, I ran into two
problems in the p4_validate_raw_event() function:

   - the shared field must be checked ONLY when HT is on
   - the binding to ESCR register was missing

The second item was causing raw events to not be encoded
correctly compared to generic PMU events.

With this patch, I can now pass Netburst events to libpfm4
examples and get meaningful results:

  $ task -e global_power_events🏃u  noploop 1
  noploop for 1 seconds
  3,206,304,898 global_power_events:running

Signed-off-by: Stephane Eranian <eranian@google.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: peterz@infradead.org
Cc: paulus@samba.org
Cc: davem@davemloft.net
Cc: fweisbec@gmail.com
Cc: perfmon2-devel@lists.sf.net
Cc: eranian@gmail.com
Cc: robert.richter@amd.com
Cc: acme@redhat.com
Cc: gorcunov@gmail.com
Cc: ming.m.lin@intel.com
LKML-Reference: <4d3efb2f.1252d80a.1a80.ffffc83f@mx.google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-27 19:21:53 +01:00
Stefano Stabellini
23febeddbe xen/setup: Route halt operations to safe_halt pvop.
With this patch, the cpuidle driver does not load and
does not issue the mwait operations. Instead the hypervisor
is doing them (b/c we call the safe_halt pvops call).

This fixes quite a lot of bootup issues wherein the user had
to force interrupts for the continuation of the bootup.

Details are discussed in:

http://lists.xensource.com/archives/html/xen-devel/2011-01/msg00535.html

[v2: Wrote the commit description]

Reported-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Tested-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-01-27 12:00:24 -05:00
Stefano Stabellini
7cb31b752c xen/e820: Guard against E820_RAM not having page-aligned size or start.
Under Dell Inspiron 1525, and Intel SandyBridge SDP's the
BIOS e820 RAM is not page-aligned:

[   0.000000]  Xen: 0000000000100000 - 00000000df66d800 (usable)

We were not handling that and ended up setting up a pagetable
that included up to df66e000 with the disastrous effect that when

        memset(NODE_DATA(nodeid), 0, sizeof(pg_data_t));

tried to clear the page it would crash at the 2K mark.

Initially reported by Michael Young @
http://lists.xensource.com/archives/html/xen-devel/2011-01/msg00108.html

The fix is to page-align the size and also take into consideration
the start of the E820 (in case that is not page-aligned either). This
fixes the bootup failure on those affected machines.

This patch is a rework of the Micheal A Young initial patch and
considers the case if the start is not page-aligned.

Reported-by: Michael A Young <m.a.young@durham.ac.uk>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Michael A Young <m.a.young@durham.ac.uk>
2011-01-27 10:49:35 -05:00
Stefan Bader
cf04d120d9 xen/p2m: Mark INVALID_P2M_ENTRY the mfn_list past max_pfn.
In case the mfn_list does not have enough entries to fill
a p2m page we do not want the entries from max_pfn up to
the boundary to be filled with unknown values. Hence
set them to INVALID_P2M_ENTRY.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-01-27 10:49:34 -05:00
Eric Dumazet
889a7a6a5d percpu, x86: Fix percpu_xchg_op()
These recent percpu commits:

  2485b6464c: x86,percpu: Move out of place 64 bit ops into X86_64 section
  8270137a0d: cpuops: Use cmpxchg for xchg to avoid lock semantics

Caused this 'perf top' crash:

 Kernel panic - not syncing: Fatal exception in interrupt
 Pid: 0, comm: swapper Tainted: G     D
 2.6.38-rc2-00181-gef71723 #413 Call Trace: <IRQ> [<ffffffff810465b5>]
    ? panic
    ? kmsg_dump
    ? kmsg_dump
    ? oops_end
    ? no_context
    ? __bad_area_nosemaphore
    ? perf_output_begin
    ? bad_area_nosemaphore
    ? do_page_fault
    ? __task_pid_nr_ns
    ? perf_event_tid
    ? __perf_event_header__init_id
    ? validate_chain
    ? perf_output_sample
    ? trace_hardirqs_off
    ? page_fault
    ? irq_work_run
    ? update_process_times
    ? tick_sched_timer
    ? tick_sched_timer
    ? __run_hrtimer
    ? hrtimer_interrupt
    ? account_system_vtime
    ? smp_apic_timer_interrupt
    ? apic_timer_interrupt
 ...

Looking at assembly code, I found:

list = this_cpu_xchg(irq_work_list, NULL);

gives this wrong code : (gcc-4.1.2 cross compiler)

ffffffff810bc45e:
	mov    %gs:0xead0,%rax
	cmpxchg %rax,%gs:0xead0
	jne    ffffffff810bc45e <irq_work_run+0x3e>
	test   %rax,%rax
	je     ffffffff810bc4aa <irq_work_run+0x8a>

Tell gcc we dirty eax/rax register in percpu_xchg_op()

Compiler must use another register to store pxo_new__

We also dont need to reload percpu value after a jump,
since a 'failed' cmpxchg already updated eax/rax

Wrong generated code was :
	xor     %rax,%rax   /* load 0 into %rax */
1:	mov     %gs:0xead0,%rax
	cmpxchg %rax,%gs:0xead0
	jne     1b
	test    %rax,%rax

After patch :

	xor     %rdx,%rdx   /* load 0 into %rdx */
	mov     %gs:0xead0,%rax
1:	cmpxchg %rdx,%gs:0xead0
	jne     1b:
	test    %rax,%rax

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Tejun Heo <tj@kernel.org>
LKML-Reference: <1295973114.3588.312.camel@edumazet-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-26 08:10:49 +01:00
Yinghai Lu
9a57c3e487 x86: Remove left over system_64.h
Left-over from the x86 merge ...

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <4D3E23D1.7010405@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-26 08:05:58 +01:00
Andrea Arcangeli
cacf061c5e thp: fix PARAVIRT x86 32bit noPAE
This fixes TRANSPARENT_HUGEPAGE=y with PARAVIRT=y and HIGHMEM64=n.

The #ifdef that this patch removes was erratically introduced to fix a
build error for noPAE (where pmd.pmd doesn't exist).  So then the kernel
built but it failed at runtime because set_pmd_at was a noop.  This will
correct it by enabling set_pmd_at for noPAE mode too.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: werner <w.landgraf@ru.ru>
Reported-by: Minchan Kim <minchan.kim@gmail.com>
Tested-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-26 10:49:57 +10:00
Jesper Juhl
2e5aa6824d x86-64: Don't use pointer to out-of-scope variable in dump_trace()
In arch/x86/kernel/dumpstack_64.c::dump_trace() we have this code:

...
  		if (!stack) {
  			unsigned long dummy;
  			stack = &dummy;
  			if (task && task != current)
  				stack = (unsigned long *)task->thread.sp;
  		}

  		bp = stack_frame(task, regs);
  		/*
  		 * Print function call entries in all stacks, starting at the
  		 * current stack address. If the stacks consist of nested
  		 * exceptions
  		 */
  		tinfo = task_thread_info(task);

  		for (;;) {
  			char *id;
  			unsigned long *estack_end;
  			estack_end = in_exception_stack(cpu, (unsigned long)stack,
  							&used, &id);
...

You'll notice that we assign to 'stack' the address of the variable
'dummy' which is only in-scope inside the 'if (!stack)'. So when we later
access stack (at the end of the above, and assuming we did not take the
'if (task && task != current)' branch) we'll be using the address of a
variable that is no longer in scope. I believe this patch is the proper
fix, but I freely admit that I'm not 100% certain.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
LKML-Reference: <alpine.LNX.2.00.1101242232590.10252@swampdragon.chaosbits.net>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-01-24 13:46:15 -08:00
Linus Torvalds
4398f31ca7 Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Fix jump label with RO/NX module protection crash
  x86, hotplug: Fix powersavings with offlined cores on AMD
  x86, mcheck, therm_throt.c: Export symbol platform_thermal_notify to allow coretemp to handler intr
  x86: Use asm-generic/cacheflush.h
  x86: Update CPU cache attributes table descriptors
2011-01-25 05:24:12 +10:00
matthieu castet
8969691343 x86: Fix jump label with RO/NX module protection crash
If we use jump table in module init, there are marked
as removed in __jump_table section after init is done.

But we already applied ro permissions on the module, so
we can't modify a read only section (crash in
remove_jump_label_module_init).

Make the __jump_table section rw.

Signed-off-by: Matthieu CASTET <castet.matthieu@free.fr>
Cc: Xiaotian Feng <xtfeng@gmail.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Siarhei Liakh <sliakh.lkml@gmail.com>
Cc: Xuxian Jiang <jiang@cs.ncsu.edu>
Cc: James Morris <jmorris@namei.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Dave Jones <davej@redhat.com>
Cc: Kees Cook <kees.cook@canonical.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <4D3C3F20.7030203@free.fr>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-23 16:12:45 +01:00
Borislav Petkov
93789b32db x86, hotplug: Fix powersavings with offlined cores on AMD
ea53069231 made a CPU use monitor/mwait
when offline. This is not the optimal choice for AMD wrt to powersavings
and we'd prefer our cores to halt (i.e. enter C1) instead. For this, the
same selection whether to use monitor/mwait has to be used as when we
select the idle routine for the machine.

With this patch, offlining cores 1-5 on a X6 machine allows core0 to
boost again.

[ hpa: putting this in urgent since it is a (power) regression fix ]

Reported-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: stable@kernel.org # 37.x
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Venkatesh Pallipadi <venki@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.hl>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <1295534572-10730-1-git-send-email-bp@amd64.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-01-21 18:14:54 -08:00
Linus Torvalds
ebe0d80507 Merge branch 'fixes-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
* 'fixes-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  x86,percpu: Move out of place 64 bit ops into X86_64 section
2011-01-21 13:43:21 -08:00
Linus Torvalds
cfd74486ea Merge branch 'stable/bug-fixes-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
* 'stable/bug-fixes-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen: p2m: correctly initialize partial p2m leaf
  xen: fix non-ANSI function warning in irq.c
2011-01-21 13:35:10 -08:00
Stefan Bader
8e1b4cf210 xen: p2m: correctly initialize partial p2m leaf
After changing the p2m mapping to a tree by

  commit 58e05027b5
    xen: convert p2m to a 3 level tree

and trying to boot a DomU with 615MB of memory, the following crash was
observed in the dump:

kernel direct mapping tables up to 26f00000 @ 1ec4000-1fff000
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<c0107397>] xen_set_pte+0x27/0x60
*pdpt = 0000000000000000 *pde = 0000000000000000

Adding further debug statements showed that when trying to set up
pfn=0x26700 the returned mapping was invalid.

pfn=0x266ff calling set_pte(0xc1fe77f8, 0x6b3003)
pfn=0x26700 calling set_pte(0xc1fe7800, 0x3)

Although the last_pfn obtained from the startup info is 0x26700, which
should in turn not be hit, the additional 8MB which are added as extra
memory normally seem to be ok. This lead to looking into the initial
p2m tree construction, which uses the smaller value and assuming that
there is other code handling the extra memory.

When the p2m tree is set up, the leaves are directly pointed to the
array which the domain builder set up. But if the mapping is not on a
boundary that fits into one p2m page, this will result in the last leaf
being only partially valid. And as the invalid entries are not
initialized in that case, things go badly wrong.

I am trying to fix that by checking whether the current leaf is a
complete map and if not, allocate a completely new page and copy only
the valid pointers there. This may not be the most efficient or elegant
solution, but at least it seems to allow me booting DomUs with memory
assignments all over the range.

BugLink: http://bugs.launchpad.net/bugs/686692
[v2: Redid a bit of commit wording and fixed a compile warning]

Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-01-21 11:24:14 -05:00
Fenghua Yu
f21bbec9ff x86, mcheck, therm_throt.c: Export symbol platform_thermal_notify to allow coretemp to handler intr
In therm_throt.c, commit
9e76a97efd patch doesn't export
the symbol platform_thermal_notify.

Other drivers (e.g. drivers/hwmon/coretemp.c) can not find the
symbol platform_thermal_notify when defining threshould
interrupt handler.

Please apply this patch to allow threshold interrupt handler in
coretemp.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Cc: R Durgadoss <durgadoss.r@intel.com>
Cc: khali@linux-fr.org <khali@linux-fr.org>
Cc: lm-sensors@lm-sensors.org <lm-sensors@lm-sensors.org>
Cc: Guenter Roeck <guenter.roeck@ericsson.com>
LKML-Reference: <20110121041239.GB26954@linux-os.sc.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-21 14:11:12 +01:00
Akinobu Mita
cc67ba6352 x86: Use asm-generic/cacheflush.h
The implementation of the cache flushing interfaces on the x86
is identical with the default implementation in asm-generic.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: arnd@arndb.de
LKML-Reference: <1295523136-4277-2-git-send-email-akinobu.mita@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-21 14:11:12 +01:00
Linus Torvalds
2b1caf6ed7 Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  smp: Allow on_each_cpu() to be called while early_boot_irqs_disabled status to init/main.c
  lockdep: Move early boot local IRQ enable/disable status to init/main.c
2011-01-20 18:30:37 -08:00
Linus Torvalds
8d99641f6c Merge branch 'akpm'
* akpm:
  kernel/smp.c: consolidate writes in smp_call_function_interrupt()
  kernel/smp.c: fix smp_call_function_many() SMP race
  memcg: correctly order reading PCG_USED and pc->mem_cgroup
  backlight: fix 88pm860x_bl macro collision
  drivers/leds/ledtrig-gpio.c: make output match input, tighten input checking
  MAINTAINERS: update Atmel AT91 entry
  mm: fix truncate_setsize() comment
  memcg: fix rmdir, force_empty with THP
  memcg: fix LRU accounting with THP
  memcg: fix USED bit handling at uncharge in THP
  memcg: modify accounting function for supporting THP better
  fs/direct-io.c: don't try to allocate more than BIO_MAX_PAGES in a bio
  mm: compaction: prevent division-by-zero during user-requested compaction
  mm/vmscan.c: remove duplicate include of compaction.h
  memblock: fix memblock_is_region_memory()
  thp: keep highpte mapped until it is no longer needed
  kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT
2011-01-20 17:02:14 -08:00
David Rientjes
6a108a14fa kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT
The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option
is used to configure any non-standard kernel with a much larger scope than
only small devices.

This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes
references to the option throughout the kernel.  A new CONFIG_EMBEDDED
option is added that automatically selects CONFIG_EXPERT when enabled and
can be used in the future to isolate options that should only be
considered for embedded systems (RISC architectures, SLOB, etc).

Calling the option "EXPERT" more accurately represents its intention: only
expert users who understand the impact of the configuration changes they
are making should enable it.

Reviewed-by: Ingo Molnar <mingo@elte.hu>
Acked-by: David Woodhouse <david.woodhouse@intel.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Greg KH <gregkh@suse.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Robin Holt <holt@sgi.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-20 17:02:05 -08:00
Linus Torvalds
e55fdbd741 Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  virtio: remove virtio-pci root device
  LGUEST_GUEST: fix unmet direct dependencies (VIRTUALIZATION && VIRTIO)
  lguest: compile fixes
  lguest: Use this_cpu_ops
  lguest: document --rng in example Launcher
  lguest: example launcher to use guard pages, drop PROT_EXEC, fix limit logic
  lguest: --username and --chroot options
2011-01-20 16:31:20 -08:00
Randy Dunlap
7d81c3b9e2 xen: fix non-ANSI function warning in irq.c
Fix sparse warning for non-ANSI function declaration:

arch/x86/xen/irq.c:129:30: warning: non-ANSI function declaration of function 'xen_init_irq_ops'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc:	Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-01-20 14:52:13 -05:00
Tejun Heo
2ce802f62b lockdep: Move early boot local IRQ enable/disable status to init/main.c
During early boot, local IRQ is disabled until IRQ subsystem is
properly initialized.  During this time, no one should enable
local IRQ and some operations which usually are not allowed with
IRQ disabled, e.g. operations which might sleep or require
communications with other processors, are allowed.

lockdep tracked this with early_boot_irqs_off/on() callbacks.
As other subsystems need this information too, move it to
init/main.c and make it generally available.  While at it,
toggle the boolean to early_boot_irqs_disabled instead of
enabled so that it can be initialized with %false and %true
indicates the exceptional condition.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <20110120110635.GB6036@htj.dyndns.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-20 13:32:33 +01:00
Dave Jones
fb87ec382f x86: Update CPU cache attributes table descriptors
Update to latest definitions in:

   http://www.intel.com/Assets/PDF/appnote/241618.pdf

[ Note, this update of the doc has removed some old values which
  we have listed.  I think until we have clarification that they
  were never used in production, they should be left there. ]

Signed-off-by: Dave Jones <davej@redhat.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
LKML-Reference: <20110120012055.GA15985@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-20 12:13:20 +01:00
Randy Dunlap
2b8216e635 LGUEST_GUEST: fix unmet direct dependencies (VIRTUALIZATION && VIRTIO)
Honor the kconfig menu hierarchy to remove kconfig dependency warnings:
VIRTIO and VIRTIO_RING are subordinate to VIRTUALIZATION.

warning: (LGUEST_GUEST) selects VIRTIO which has unmet direct dependencies (VIRTUALIZATION)
warning: (LGUEST_GUEST && VIRTIO_PCI && VIRTIO_BALLOON) selects VIRTIO_RING which has unmet direct dependencies (VIRTUALIZATION && VIRTIO)

Reported-by: Toralf F_rster <toralf.foerster@gmx.de>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-01-20 21:37:30 +10:30
Rusty Russell
ced05dd741 lguest: compile fixes
arch/x86/lguest/boot.c: In function ‘lguest_init_IRQ’:
arch/x86/lguest/boot.c:824: error: macro "__this_cpu_write" requires 2 arguments, but only 1 given
arch/x86/lguest/boot.c:824: error: ‘__this_cpu_write’ undeclared (first use in this function)
arch/x86/lguest/boot.c:824: error: (Each undeclared identifier is reported only once
arch/x86/lguest/boot.c:824: error: for each function it appears in.)

drivers/lguest/x86/core.c: In function ‘copy_in_guest_info’:
drivers/lguest/x86/core.c:94: error: lvalue required as left operand of assignment

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-01-20 21:37:29 +10:30
Christoph Lameter
c9f2954964 lguest: Use this_cpu_ops
Use this_cpu_ops in a couple of places in lguest.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-01-20 21:37:29 +10:30