The cache flush denied error is an erratum on some AMD 486 clones.  If an invd
instruction is executed in userspace, the processor calls exception 19 (13 hex)
instead of #GP (13 decimal).  On cpus where XMM is not supported, redirect
exception 19 to do_general_protection().  Also, remove die_if_kernel(), since
this was the last user.
Signed-off-by: NBrian Gerst <brgerst@gmail.com>
LKML-Reference: <1269176446-2489-2-git-send-email-brgerst@gmail.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

ACPI _CRS Address Space Descriptors have _MIN, _MAX, and _LEN.  Linux has
been computing Address Spaces as [_MIN to _MIN + _LEN - 1].  Based on the
tests in the bug reports below, Windows apparently uses [_MIN to _MAX].

Per spec (ACPI 4.0, Table 6-40), for _CRS fixed-size, fixed location
descriptors, "_LEN must be (_MAX - _MIN + 1)", and when that's true, it
doesn't matter which way we compute the end.  But of course, there are
BIOSes that don't follow this rule, and we're better off if Linux handles
those exceptions the same way as Windows.

This patch makes Linux use [_MIN to _MAX], as Windows seems to do.  This
effectively reverts d558b483 and 03db42ad and replaces them with
simpler code.

    https://bugzilla.kernel.org/show_bug.cgi?id=14337 (round)
    https://bugzilla.kernel.org/show_bug.cgi?id=15480 (truncate)
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

When we move a PCI device or assign resources to a device not configured
by the BIOS, we want to avoid the BIOS region below 1MB.  Note that if the
BIOS places devices below 1MB, we leave them there.

See https://bugzilla.kernel.org/show_bug.cgi?id=15744
and https://bugzilla.kernel.org/show_bug.cgi?id=15841Tested-by: NAndy Isaacson <adi@hexapodia.org>
Tested-by: NAndy Bailey <bailey@akamai.com>
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

This is a standalone version of VMware Balloon driver.  Ballooning is a
technique that allows hypervisor dynamically limit the amount of memory
available to the guest (with guest cooperation).  In the overcommit
scenario, when hypervisor set detects that it needs to shuffle some
memory, it instructs the driver to allocate certain number of pages, and
the underlying memory gets returned to the hypervisor.  Later hypervisor
may return memory to the guest by reattaching memory to the pageframes and
instructing the driver to "deflate" balloon.

We are submitting a standalone driver because KVM maintainer (Avi Kivity)
expressed opinion (rightly) that our transport does not fit well into
virtqueue paradigm and thus it does not make much sense to integrate with
virtio.

There were also some concerns whether current ballooning technique is the
right thing.  If there appears a better framework to achieve this we are
prepared to evaluate and switch to using it, but in the meantime we'd like
to get this driver upstream.

We want to get the driver accepted in distributions so that users do not
have to deal with an out-of-tree module and many distributions have
"upstream first" requirement.

The driver has been shipping for a number of years and users running on
VMware platform will have it installed as part of VMware Tools even if it
will not come from a distribution, thus there should not be additional
risk in pulling the driver into mainline.  The driver will only activate
if host is VMware so everyone else should not be affected at all.
Signed-off-by: NDmitry Torokhov <dtor@vmware.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Atom erratum AAE44/AAF40/AAG38/AAH41:

"If software clears the PS (page size) bit in a present PDE (page
directory entry), that will cause linear addresses mapped through this
PDE to use 4-KByte pages instead of using a large page after old TLB
entries are invalidated. Due to this erratum, if a code fetch uses
this PDE before the TLB entry for the large page is invalidated then
it may fetch from a different physical address than specified by
either the old large page translation or the new 4-KByte page
translation. This erratum may also cause speculative code fetches from
incorrect addresses."

[http://download.intel.com/design/processor/specupdt/319536.pdf]

Where as commit 211b3d03 seems to
workaround errata AAH41 (mixed 4K TLBs) it reduces the window of
opportunity for the bug to occur and does not totally remove it.  This
patch disables mixed 4K/4MB page tables totally avoiding the page
splitting and not tripping this processor issue.

This is based on an original patch by Colin King.
Originally-by: NColin Ian King <colin.king@canonical.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
LKML-Reference: <1269271251-19775-1-git-send-email-colin.king@canonical.com>
Cc: <stable@kernel.org>

When we do a thread switch, we clear the outgoing FS/GS base if the
corresponding selector is nonzero.  This is taken by __switch_to() as
an entry invariant; it does not verify that it is true on entry.
However, copy_thread() doesn't enforce this constraint, which can
result in inconsistent results after fork().

Make copy_thread() match the behavior of __switch_to().
Reported-and-tested-by: NSamuel Thibault <samuel.thibault@inria.fr>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
LKML-Reference: <4BD1E061.8030605@zytor.com>
Cc: <stable@kernel.org>

This adds support for Memory24, Memory32, and Memory32Fixed descriptors in
PCI host bridge _CRS.

I experimentally determined that Windows (2008 R2) accepts these descriptors
and treats them as windows that are forwarded to the PCI bus, e.g., if
it finds any PCI devices with BARs outside the windows, it moves them into
the windows.

I don't know whether any machines actually use these descriptors in PCI
host bridge _CRS methods, but if any exist and they're new enough that we
automatically turn on "pci=use_crs", they will work with Windows but not
with Linux.

Here are the details: https://bugzilla.kernel.org/show_bug.cgi?id=15817Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

A 16-bit TSS is only 44 bytes long. So make sure to test for the correct
size on task switch.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

APB timer is used on Moorestown platforms but not on a standard PC.
If APB timer code is compiled in but not initialized at run-time due
to lack of FW reported SFI table, kernel would panic when the non-boot
CPUs are offlined and notifier is called.

https://bugzilla.kernel.org/show_bug.cgi?id=15786

This patch ensures CPU hotplug notifier for APB timer is only registered
when the APBT timer block is initialized.
Signed-off-by: NJacob Pan <jacob.jun.pan@linux.intel.com>
LKML-Reference: <1271701423-1162-1-git-send-email-jacob.jun.pan@linux.intel.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Before commit e28cbf22 ("improve
sys_newuname() for compat architectures") 64-bit x86 had a private
implementation of sys_uname which was just called sys_uname, which other
architectures used for the old uname.

Due to some merge issues with the uname refactoring patches we ended up
calling the old uname version for both the old and new system call
slots, which lead to the domainname filed never be set which caused
failures with libnss_nis.
Reported-and-tested-by: NAndy Isaacson <adi@hexapodia.org>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Int is not long enough to store the size of a dirty bitmap.

This patch fixes this problem with the introduction of a wrapper
function to calculate the sizes of dirty bitmaps.

Note: in mark_page_dirty(), we have to consider the fact that
  __set_bit() takes the offset as int, not long.
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

This patch fix:

- calculate zapped page number properly in mmu_zap_unsync_children()
- calculate freeed page number properly kvm_mmu_change_mmu_pages()
- if zapped children page it shoud restart hlist walking

KVM-Stable-Tag.
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Currently we set eflags.vm unconditionally when entering real mode emulation
through virtual-8086 mode, and clear it unconditionally when we enter protected
mode.  The means that the following sequence

  KVM_SET_REGS  (rflags.vm=1)
  KVM_SET_SREGS (cr0.pe=1)

Ends up with rflags.vm clear due to KVM_SET_SREGS triggering enter_pmode().

Fix by shadowing rflags.vm (and rflags.iopl) correctly while in real mode:
reads and writes to those bits access a shadow register instead of the actual
register.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

There is a quirk for AMD K8 CPUs in many Linux kernels (see
arch/x86/kernel/cpu/mcheck/mce.c:__mcheck_cpu_apply_quirks()) that
clears bit 10 in that MCE related MSR. KVM can only cope with all
zeros or all ones, so it will inject a #GP into the guest, which
will let it panic.
So lets add a quirk to the quirk and ignore this single cleared bit.
This fixes -cpu kvm64 on all machines and -cpu host on K8 machines
with some guest Linux kernels.
Signed-off-by: NAndre Przywara <andre.przywara@amd.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

These are guest-triggerable.
Signed-off-by: NAvi Kivity <avi@redhat.com>

svm_create_vcpu() does not free the pages allocated during the creation
when it fails to complete the allocations. This patch fixes it.
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NAvi Kivity <avi@redhat.com>

complete_pio() may use slot table which is protected by srcu.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Cc: stable@kernel.org
Signed-off-by: NAvi Kivity <avi@redhat.com>

This is a partial revert of 4cd8b5e2 "lguest: use KVM hypercalls";
we revert to using (just as questionable but more reliable) int $15 for
hypercalls.  I didn't revert the register mapping, so we still use the
same calling convention as kvm.

KVM in more recent incarnations stopped injecting a fault when a guest
tried to use the VMCALL instruction from ring 1, so lguest under kvm
fails to make hypercalls.  It was nice to share code with our KVM
cousins, but this was overreach.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: Matias Zabaljauregui <zabaljauregui@gmail.com>
Cc: Avi Kivity <avi@redhat.com>

When we fetch the hot regs and rewind to the nth caller, it
might happen that we dereference a frame pointer outside the
kernel stack boundaries, like in this example:

	perf_trace_sched_switch+0xd5/0x120
        schedule+0x6b5/0x860
        retint_careful+0xd/0x21

Since we directly dereference a userspace frame pointer here while
rewinding behind retint_careful, this may end up in a crash.

Fix this by simply using probe_kernel_address() when we rewind the
frame pointer.

This issue will have a much more proper fix in the next version of the
perf_arch_fetch_caller_regs() API that will only need to rewind to the
first caller.
Reported-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Tested-by: NEric Dumazet <eric.dumazet@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: David Miller <davem@davemloft.net>
Cc: Archs <linux-arch@vger.kernel.org>

ACPI Address Space Descriptors (used in _CRS) have a Consumer/Producer
bit that is supposed to distinguish regions that are consumed directly
by a device from those that are forwarded ("produced") by a bridge.
But BIOSes have apparently not used this consistently, and Windows
seems to ignore it, so I think Linux should ignore it as well.

I can't point to any of these supposed broken BIOSes, but since we
now rely on _CRS by default, I think it's safer to ignore this bit
from the start.

Here are details of my experiments with how Windows handles it:
    https://bugzilla.kernel.org/show_bug.cgi?id=15701Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

If we boot into a crash-kernel the gart might still be
enabled and its caches might be dirty. This can result in
undefined behavior later. Fix it by explicitly disabling the
gart hardware before initialization and flushing the caches
after enablement.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

Replace open coded version with for_each_pci_dev
Signed-off-by: NChris Wright <chrisw@sous-sol.org>
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

This effectively reverts commit 61d047be.

Disabling the IOMMU can potetially allow DMA transactions to
complete without being translated.  Leave it enabled, and allow
crash kernel to do the IOMMU reinitialization properly.

Cc: stable@kernel.org
Cc: Joerg Roedel <joerg.roedel@amd.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: NChris Wright <chrisw@sous-sol.org>
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

To catch future potential issues we can add a warning whenever we issue
a command before the command buffer is fully initialized.
Signed-off-by: NChris Wright <chrisw@sous-sol.org>
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

Hit another kdump problem as reported by Neil Horman.  When initializaing
the IOMMU, we attach devices to their domains before the IOMMU is
fully (re)initialized.  Attaching a device will issue some important
invalidations.  In the context of the newly kexec'd kdump kernel, the
IOMMU may have stale cached data from the original kernel.  Because we
do the attach too early, the invalidation commands are placed in the new
command buffer before the IOMMU is updated w/ that buffer.  This leaves
the stale entries in the kdump context and can renders device unusable.
Simply enable the IOMMU before we do the attach.

Cc: stable@kernel.org
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: NChris Wright <chrisw@sous-sol.org>
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

According to Intel Software Devel Manual Volume 3B, the
Nehalem-EX PMU is just like regular Nehalem (except for the
uncore support, which is completely different).
Signed-off-by: NVince Weaver <vweaver1@eecs.utk.edu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Lin Ming <ming.m.lin@intel.com>
LKML-Reference: <alpine.DEB.2.00.1004060956580.1417@cl320.eecs.utk.edu>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Jan Grossmann reported kernel boot panic while booting SMP
kernel on his system with a single core cpu. SMP kernels call
enable_IR_x2apic() from native_smp_prepare_cpus() and on
platforms where the kernel doesn't find SMP configuration we
ended up again calling enable_IR_x2apic() from the
APIC_init_uniprocessor() call in the smp_sanity_check(). Thus
leading to kernel panic.

Don't call enable_IR_x2apic() and default_setup_apic_routing()
from APIC_init_uniprocessor() in CONFIG_SMP case.

NOTE: this kind of non-idempotent and assymetric initialization
sequence is rather fragile and unclean, we'll clean that up
in v2.6.35. This is the minimal fix for v2.6.34.

Reported-by: Jan.Grossmann@kielnet.net
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Cc: <jbarnes@virtuousgeek.org>
Cc: <david.woodhouse@intel.com>
Cc: <weidong.han@intel.com>
Cc: <youquan.song@intel.com>
Cc: <Jan.Grossmann@kielnet.net>
Cc: <stable@kernel.org> # [v2.6.32.x, v2.6.33.x]
LKML-Reference: <1270083887.7835.78.camel@sbs-t61.sc.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

When profiling a 32-bit process on a 64-bit kernel, callgraph tracing
stopped after the first function, because it has seen a garbage memory
address (tried to interpret the frame pointer, and return address as a
64-bit pointer).

Fix this by using a struct stack_frame with 32-bit pointers when the
TIF_IA32 flag is set.

Note that TIF_IA32 flag must be used, and not is_compat_task(), because
the latter is only set when the 32-bit process is executing a syscall,
which may not always be the case (when tracing page fault events for
example).
Signed-off-by: NTörök Edwin <edwintorok@gmail.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: x86@kernel.org
Cc: linux-kernel@vger.kernel.org
LKML-Reference: <1268820436-13145-1-git-send-email-edwintorok@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Commit 3f6da390 ("perf: Rework and fix the arch CPU-hotplug hooks") moved
the amd northbridge allocation from CPUS_ONLINE to CPUS_PREPARE_UP
however amd_nb_id() doesn't work yet on prepare so it would simply bail
basically reverting to a state where we do not properly track node wide
constraints - causing weird perf results.

Fix up the AMD NorthBridge initialization code by allocating from
CPU_UP_PREPARE and installing it from CPU_STARTING once we have the
proper nb_id. It also properly deals with the allocation failing.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
[ robustify using amd_has_nb() ]
Signed-off-by: NStephane Eranian <eranian@google.com>
LKML-Reference: <1269353485.5109.48.camel@twins>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Because we need to have cpu identification things done by the time we run
CPU_STARTING notifiers.

( This init ordering will be relied on by the next fix. )
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1269353485.5109.48.camel@twins>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Some larger systems require more than 512 nodes, so increase the
maximum CONFIG_NODES_SHIFT to 10 for a new max of 1024 nodes.

This was tested with numa=fake=64M on systems with more than
64GB of RAM. A total of 1022 nodes were initialized.

Successfully builds with no additional warnings on x86_64
allyesconfig.

( No effect on any existing config. Newly enabled CONFIG_MAXSMP=y
  will see the new default. )
Signed-off-by: NDavid Rientjes <rientjes@google.com>
LKML-Reference: <alpine.DEB.2.00.1003251538060.8589@chino.kir.corp.google.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This allows arch code could decide the way to reserve the ibft.

And we should reserve ibft as early as possible, instead of BOOTMEM
stage, in case the table is in RAM range and is not reserved by BIOS
(this will often be the case.)

Move to just after find_smp_config().

Also when CONFIG_NO_BOOTMEM=y, We will not have reserve_bootmem() anymore.

-v2: fix typo about ibft pointed by Konrad Rzeszutek Wilk <konrad@darnok.org>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
LKML-Reference: <4BB510FB.80601@kernel.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Peter Jones <pjones@redhat.com>
Cc: Konrad Rzeszutek Wilk <konrad@kernel.org>
CC: Jan Beulich <jbeulich@novell.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

We think there exists a bug in the HPET code that emulates the RTC.

In the normal case, when the RTC frequency is set, the rtc driver tells
the hpet code about it here:

int hpet_set_periodic_freq(unsigned long freq)
{
        uint64_t clc;

        if (!is_hpet_enabled())
                return 0;

        if (freq <= DEFAULT_RTC_INT_FREQ)
                hpet_pie_limit = DEFAULT_RTC_INT_FREQ / freq;
        else {
                clc = (uint64_t) hpet_clockevent.mult * NSEC_PER_SEC;
                do_div(clc, freq);
                clc >>= hpet_clockevent.shift;
                hpet_pie_delta = (unsigned long) clc;
        }
        return 1;
}

If freq is set to 64Hz (DEFAULT_RTC_INT_FREQ) or lower, then
hpet_pie_limit (a static) is set to non-zero.  Then, on every one-shot
HPET interrupt, hpet_rtc_timer_reinit is called to compute the next
timeout.  Well, that function has this logic:

        if (!(hpet_rtc_flags & RTC_PIE) || hpet_pie_limit)
                delta = hpet_default_delta;
        else
                delta = hpet_pie_delta;

Since hpet_pie_limit is not 0, hpet_default_delta is used.  That
corresponds to 64Hz.

Now, if you set a different rtc frequency, you'll take the else path
through hpet_set_periodic_freq, but unfortunately no one resets
hpet_pie_limit back to 0.

Boom....now you are stuck with 64Hz RTC interrupts forever.

The patch below just resets the hpet_pie_limit value when requested freq
is greater than DEFAULT_RTC_INT_FREQ, which we think fixes this problem.
Signed-off-by: NAlok N Kataria <akataria@vmware.com>
LKML-Reference: <201003112200.o2BM0Hre012875@imap1.linux-foundation.org>
Signed-off-by: NDaniel Hecht <dhecht@vmware.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

On Wed, Feb 24, 2010 at 03:37:04PM -0800, Justin Piszcz wrote:
> Hello,
>
> Again, on the Intel DP55KG board:
>
> # uname -a
> Linux host 2.6.33 #1 SMP Wed Feb 24 18:31:00 EST 2010 x86_64 GNU/Linux
>
> [    1.237600] ------------[ cut here ]------------
> [    1.237890] WARNING: at arch/x86/kernel/hpet.c:404 hpet_next_event+0x70/0x80()
> [    1.238221] Hardware name:
> [    1.238504] hpet: compare register read back failed.
> [    1.238793] Modules linked in:
> [    1.239315] Pid: 0, comm: swapper Not tainted 2.6.33 #1
> [    1.239605] Call Trace:
> [    1.239886]  <IRQ>  [<ffffffff81056c13>] ? warn_slowpath_common+0x73/0xb0
> [    1.240409]  [<ffffffff81079608>] ? tick_dev_program_event+0x38/0xc0
> [    1.240699]  [<ffffffff81056cb0>] ? warn_slowpath_fmt+0x40/0x50
> [    1.240992]  [<ffffffff81079608>] ? tick_dev_program_event+0x38/0xc0
> [    1.241281]  [<ffffffff81041ad0>] ? hpet_next_event+0x70/0x80
> [    1.241573]  [<ffffffff81079608>] ? tick_dev_program_event+0x38/0xc0
> [    1.241859]  [<ffffffff81078e32>] ? tick_handle_oneshot_broadcast+0xe2/0x100
> [    1.246533]  [<ffffffff8102a67a>] ? timer_interrupt+0x1a/0x30
> [    1.246826]  [<ffffffff81085499>] ? handle_IRQ_event+0x39/0xd0
> [    1.247118]  [<ffffffff81087368>] ? handle_edge_irq+0xb8/0x160
> [    1.247407]  [<ffffffff81029f55>] ? handle_irq+0x15/0x20
> [    1.247689]  [<ffffffff810294a2>] ? do_IRQ+0x62/0xe0
> [    1.247976]  [<ffffffff8146be53>] ? ret_from_intr+0x0/0xa
> [    1.248262]  <EOI>  [<ffffffff8102f277>] ? mwait_idle+0x57/0x80
> [    1.248796]  [<ffffffff8102645c>] ? cpu_idle+0x5c/0xb0
> [    1.249080] ---[ end trace db7f668fb6fef4e1 ]---
>
> Is this something Intel has to fix or is it a bug in the kernel?

This is a chipset erratum.

Thomas: You mentioned we can retain this check only for known-buggy and
hpet debug kind of options. But here is the simple workaround patch for
this particular erratum.

Some chipsets have a erratum due to which read immediately following a
write of HPET comparator returns old comparator value instead of most
recently written value.

Erratum 15 in
"Intel I/O Controller Hub 9 (ICH9) Family Specification Update"
(http://www.intel.com/assets/pdf/specupdate/316973.pdf)

Workaround for the errata is to read the comparator twice if the first
one fails.
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
LKML-Reference: <20100225185348.GA9674@linux-os.sc.intel.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@gmail.com>
Cc: <stable@kernel.org>

We found a system where the MP table MPC and MPF structures overlap.

That doesn't really matter because the mptable is not used anyways with ACPI,
but it leads to a panic in the early allocator due to the overlapping
reservations in 2.6.33.

Earlier kernels handled this without problems.

Simply change these reservations to reserve_early_overlap_ok to avoid
the panic.
Reported-by: NThomas Renninger <trenn@suse.de>
Tested-by: NThomas Renninger <trenn@suse.de>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
LKML-Reference: <20100329074111.GA22821@basil.fritz.box>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Cc: <stable@kernel.org>

It is required to call hw_breakpoint_init() on an attr before using it
in any other calls.  This fixes the problem where kgdb will sometimes
fail to initialize on x86_64.
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: 2.6.33 <stable@kernel.org>
LKML-Reference: <1269975907-27602-1-git-send-email-jason.wessel@windriver.com>
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>

Scheduler's task migration events don't work because they always
pass NULL regs perf_sw_event(). The event hence gets filtered
in perf_swevent_add().

Scheduler's context switches events use task_pt_regs() to get
the context when the event occured which is a wrong thing to
do as this won't give us the place in the kernel where we went
to sleep but the place where we left userspace. The result is
even more wrong if we switch from a kernel thread.

Use the hot regs snapshot for both events as they belong to the
non-interrupt/exception based events family. Unlike page faults
or so that provide the regs matching the exact origin of the event,
we need to save the current context.

This makes the task migration event working and fix the context
switch callchains and origin ip.

Example: perf record -a -e cs

Before:

    10.91%      ksoftirqd/0                  0  [k] 0000000000000000
                |
                --- (nil)
                    perf_callchain
                    perf_prepare_sample
                    __perf_event_overflow
                    perf_swevent_overflow
                    perf_swevent_add
                    perf_swevent_ctx_event
                    do_perf_sw_event
                    __perf_sw_event
                    perf_event_task_sched_out
                    schedule
                    run_ksoftirqd
                    kthread
                    kernel_thread_helper

After:

    23.77%  hald-addon-stor  [kernel.kallsyms]  [k] schedule
            |
            --- schedule
               |
               |--60.00%-- schedule_timeout
               |          wait_for_common
               |          wait_for_completion
               |          blk_execute_rq
               |          scsi_execute
               |          scsi_execute_req
               |          sr_test_unit_ready
               |          |
               |          |--66.67%-- sr_media_change
               |          |          media_changed
               |          |          cdrom_media_changed
               |          |          sr_block_media_changed
               |          |          check_disk_change
               |          |          cdrom_open

v2: Always build perf_arch_fetch_caller_regs() now that software
events need that too. They don't need it from modules, unlike trace
events, so we keep the EXPORT_SYMBOL in trace_event_perf.c
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>

Rusty found on lguest with trim_bios_range, max_pfn is not right anymore, and
looks e820_remove_range does not work right.

[    0.000000] BIOS-provided physical RAM map:
[    0.000000]  LGUEST: 0000000000000000 - 0000000004000000 (usable)
[    0.000000] Notice: NX (Execute Disable) protection missing in CPU or disabled in BIOS!
[    0.000000] DMI not present or invalid.
[    0.000000] last_pfn = 0x3fa0 max_arch_pfn = 0x100000
[    0.000000] init_memory_mapping: 0000000000000000-0000000003fa0000

root cause is: the e820_remove_range doesn't handle the all covered
case.  e820_remove_range(BIOS_START, BIOS_END - BIOS_START, ...)
produces a bogus range as a result.

Make it match e820_update_range() by handling that case too.
Reported-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Tested-by: NRusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <4BB18E55.6090903@kernel.org>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Colin King reported a strange oops in S4 resume code path (see below). The test
system has i5/i7 CPU. The kernel doesn't open PAE, so 4M page table is used.
The oops always happen a virtual address 0xc03ff000, which is mapped to the
last 4k of first 4M memory. Doing a global tlb flush fixes the issue.

EIP: 0060:[<c0493a01>] EFLAGS: 00010086 CPU: 0
EIP is at copy_loop+0xe/0x15
EAX: 36aeb000 EBX: 00000000 ECX: 00000400 EDX: f55ad46c
ESI: 0f800000 EDI: c03ff000 EBP: f67fbec4 ESP: f67fbea8
DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
...
...
CR2: 00000000c03ff000
Tested-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
LKML-Reference: <20100305005932.GA22675@sli10-desk.sh.intel.com>
Acked-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Cc: <stable@kernel.org>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: NTejun Heo <tj@kernel.org>
Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>