Commit graph

5001 commits

Author SHA1 Message Date
Jaswinder Singh Rajput
26dc67eda1 x86: Clean up mtrr/if.c
Fix:

  WARNING: Use #include <linux/uaccess.h> instead of <asm/uaccess.h>
  ERROR: trailing whitespace X 7
  ERROR: trailing statements should be on next line X 3
  WARNING: line over 80 characters X 5
  ERROR: space required before the open parenthesis '('

arch/x86/kernel/cpu/mtrr/if.o:

   text	   data	    bss	    dec	    hex	filename
   2239	      4	      0	   2243	    8c3	if.o.before
   2239	      4	      0	   2243	    8c3	if.o.after

md5:
   78d1f2aa4843ec6509c18e2dee54bc7f  if.o.before.asm
   78d1f2aa4843ec6509c18e2dee54bc7f  if.o.after.asm

Suggested-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <20090703164225.GA21447@elte.hu>
[ More cleanups to make the code more consistent. ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-04 11:19:48 +02:00
Jaswinder Singh Rajput
a1a499a399 x86: Clean up mtrr/generic.c
Fix following trivial style problems:

  ERROR: trailing whitespace X 4
  WARNING: Use #include <linux/io.h> instead of <asm/io.h>
  WARNING: braces {} are not necessary for single statement blocks X 3
  ERROR: "foo * bar" should be "foo *bar"
  WARNING: line over 80 characters X 6
  ERROR: "foo * bar" should be "foo *bar"
  ERROR: spaces required around that '=' (ctx:VxO)
  ERROR: space required before that '-' (ctx:OxV)
  WARNING: suspect code indent for conditional statements (8, 12)
  ERROR: spaces required around that '=' (ctx:VxV)
  ERROR: do not initialise statics to 0 or NULL
  ERROR: space prohibited after that open parenthesis '(' X 2
  ERROR: space prohibited before that close parenthesis ')' X 2
  ERROR: trailing statements should be on next line
  ERROR: return is not a function, parentheses are not required

Also use pr_debug and pr_warning where possible.

arch/x86/kernel/cpu/mtrr/generic.o:

   text	   data	    bss	    dec	    hex	filename
   5652	     77	   4224	   9953	   26e1	generic.o.before
   5652	     77	   4220	   9949	   26dd	generic.o.after

The md5 changed:
   b34d6c045f06daa4ed092b90cc760e8f  generic.o.before.asm
   a490c6251cfd8442fbffecc0e09a573d  generic.o.after.asm

Because mtrr_state moved from data to bss, changing its
offsets - and also because __LINE__ numbers changed.

Suggested-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <20090703164225.GA21447@elte.hu>
[ Further cleanups to make the code more consistent ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-04 11:10:47 +02:00
Jaswinder Singh Rajput
2311037708 x86: Clean up mtrr/cyrix.c
Fix trivial style problems:

  WARNING: Use #include <linux/io.h> instead of <asm/io.h>
  WARNING: line over 80 characters
  ERROR: do not initialise statics to 0 or NULL
  ERROR: space prohibited after that open parenthesis '(' X 2
  ERROR: space prohibited before that close parenthesis ')' X 2
  ERROR: trailing whitespace X 2
  ERROR: trailing statements should be on next line
  ERROR: do not use C99 // comments X 2

arch/x86/kernel/cpu/mtrr/cyrix.o:

   text	   data	    bss	    dec	    hex	filename
   1637	     32	      8	   1677	    68d	cyrix.o.before
   1637	     32	      8	   1677	    68d	cyrix.o.after

md5:
   6f52abd06905be3f4cabb5239f9b0ff0  cyrix.o.before.asm
   6f52abd06905be3f4cabb5239f9b0ff0  cyrix.o.after.asm

Suggested-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <20090703164225.GA21447@elte.hu>
[ Made the code more consistent ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-04 11:10:47 +02:00
Jaswinder Singh Rajput
63f9600fad x86: Clean up mtrr/cleanup.c
Fix trivial style problems:

  WARNING: Use #include <linux/uaccess.h> instead of <asm/uaccess.h>
  WARNING: Use #include <linux/kvm_para.h> instead of <asm/kvm_para.h>

Also, nr_mtrr_spare_reg should be unsigned long.

arch/x86/kernel/cpu/mtrr/cleanup.o:

   text	   data	    bss	    dec	    hex	filename
   6241	   8992	   2056	  17289	   4389	cleanup.o.before
   6241	   8992	   2056	  17289	   4389	cleanup.o.after

The md5 has changed:
   1a7a27513aef1825236daf29110fe657  cleanup.o.before.asm
   bcea358efa2532b6020e338e158447af  cleanup.o.after.asm

Because a WARN_ON()'s __LINE__ value changed by 3 lines.

Suggested-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <20090703164225.GA21447@elte.hu>
[ Did lots of other cleanups to make the code look more consistent. ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-04 11:10:46 +02:00
Jaswinder Singh Rajput
6c4caa1ab7 x86: Clean up mtrr/centaur.c
Remove dead code and fix trivial style problems:

  ERROR: trailing whitespace X 2
  WARNING: line over 80 characters X 3
  ROR: trailing whitespace
  ERROR: do not use C99 // comments X 2

arch/x86/kernel/cpu/mtrr/centaur.o:

   text	   data	    bss	    dec	    hex	filename
    605	     32	     68	    705	    2c1	centaur.o.before
    605	     32	     68	    705	    2c1	centaur.o.after

md5:
   a4865ea98ce3c163bb1d376a3949b3e3  centaur.o.before.asm
   a4865ea98ce3c163bb1d376a3949b3e3  centaur.o.after.asm

Suggested-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <20090703164225.GA21447@elte.hu>
[ Standardized comments, DocBook, curly braces, newlines. ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-04 11:10:45 +02:00
Jaswinder Singh Rajput
42204455f1 x86: Clean up mtrr/amd.c:
Fix trivial style problems :

  ERROR: trailing whitespace
  WARNING: line over 80 characters
  ERROR: do not use C99 // comments

arch/x86/kernel/cpu/mtrr/amd.o:

   text	   data	    bss	    dec	    hex	filename
    501	     32	      0	    533	    215	amd.o.before
    501	     32	      0	    533	    215	amd.o.after

md5:
   62f795eb840ee2d17b03df89e789e76c  amd.o.before.asm
   62f795eb840ee2d17b03df89e789e76c  amd.o.after.asm

Suggested-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <20090703164225.GA21447@elte.hu>
[ Also restructured comments to be standard, removed stray return,
  converted function description to DocBook style, etc. ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-04 11:10:45 +02:00
Ingo Molnar
d7e57676e3 Merge branch 'linus' into x86/cleanups
Merge reason: We were on an older pre-rc1 base, move to almost-rc2.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-04 11:00:42 +02:00
Linus Torvalds
405d7ca515 Merge git://git.infradead.org/iommu-2.6
* git://git.infradead.org/iommu-2.6: (38 commits)
  intel-iommu: Don't keep freeing page zero in dma_pte_free_pagetable()
  intel-iommu: Introduce first_pte_in_page() to simplify PTE-setting loops
  intel-iommu: Use cmpxchg64_local() for setting PTEs
  intel-iommu: Warn about unmatched unmap requests
  intel-iommu: Kill superfluous mapping_lock
  intel-iommu: Ensure that PTE writes are 64-bit atomic, even on i386
  intel-iommu: Make iommu=pt work on i386 too
  intel-iommu: Performance improvement for dma_pte_free_pagetable()
  intel-iommu: Don't free too much in dma_pte_free_pagetable()
  intel-iommu: dump mappings but don't die on pte already set
  intel-iommu: Combine domain_pfn_mapping() and domain_sg_mapping()
  intel-iommu: Introduce domain_sg_mapping() to speed up intel_map_sg()
  intel-iommu: Simplify __intel_alloc_iova()
  intel-iommu: Performance improvement for domain_pfn_mapping()
  intel-iommu: Performance improvement for dma_pte_clear_range()
  intel-iommu: Clean up iommu_domain_identity_map()
  intel-iommu: Remove last use of PHYSICAL_PAGE_MASK, for reserving PCI BARs
  intel-iommu: Make iommu_flush_iotlb_psi() take pfn as argument
  intel-iommu: Change aligned_size() to aligned_nrpages()
  intel-iommu: Clean up intel_map_sg(), remove domain_page_mapping()
  ...
2009-07-02 16:51:09 -07:00
Yinghai Lu
7c5371c403 x86: add boundary check for 32bit res before expand e820 resource to alignment
fix hang with HIGHMEM_64G and 32bit resource.  According to hpa and
Linus, use (resource_size_t)-1 to fend off big ranges.

Analyzed by hpa

Reported-and-tested-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-02 12:11:12 -07:00
David Woodhouse
3238c0c4d6 intel-iommu: Make iommu=pt work on i386 too
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-07-01 18:56:16 +01:00
Linus Torvalds
55bcab4695 Merge branch 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (47 commits)
  perf report: Add --symbols parameter
  perf report: Add --comms parameter
  perf report: Add --dsos parameter
  perf_counter tools: Adjust only prelinked symbol's addresses
  perf_counter: Provide a way to enable counters on exec
  perf_counter tools: Reduce perf stat measurement overhead/skew
  perf stat: Use percentages for scaling output
  perf_counter, x86: Update x86_pmu after WARN()
  perf stat: Micro-optimize the code: memcpy is only required if no event is selected and !null_run
  perf stat: Improve output
  perf stat: Fix multi-run stats
  perf stat: Add -n/--null option to run without counters
  perf_counter tools: Remove dead code
  perf_counter: Complete counter swap
  perf report: Print sorted callchains per histogram entries
  perf_counter tools: Prepare a small callchain framework
  perf record: Fix unhandled io return value
  perf_counter tools: Add alias for 'l1d' and 'l1i'
  perf-report: Add bare minimum PERF_EVENT_READ parsing
  perf-report: Add modes for inherited stats and no-samples
  ...
2009-06-30 19:02:59 -07:00
Linus Torvalds
e717f33e98 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:
  Revert "x86: cap iomem_resource to addressable physical memory"
2009-06-29 09:42:01 -07:00
Yinghai Lu
4078c444cf perf_counter, x86: Update x86_pmu after WARN()
The print out should read the value before changing the value.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4A487017.4090007@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-29 10:19:25 +02:00
Linus Torvalds
8326e284f8 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, delay: tsc based udelay should have rdtsc_barrier
  x86, setup: correct include file in <asm/boot.h>
  x86, setup: Fix typo "CONFIG_x86_64" in <asm/boot.h>
  x86, mce: percpu mcheck_timer should be pinned
  x86: Add sysctl to allow panic on IOCK NMI error
  x86: Fix uv bau sending buffer initialization
  x86, mce: Fix mce resume on 32bit
  x86: Move init_gbpages() to setup_arch()
  x86: ensure percpu lpage doesn't consume too much vmalloc space
  x86: implement percpu_alloc kernel parameter
  x86: fix pageattr handling for lpage percpu allocator and re-enable it
  x86: reorganize cpa_process_alias()
  x86: prepare setup_pcpu_lpage() for pageattr fix
  x86: rename remap percpu first chunk allocator to lpage
  x86: fix duplicate free in setup_pcpu_remap() failure path
  percpu: fix too lazy vunmap cache flushing
  x86: Set cpu_llc_id on AMD CPUs
2009-06-28 11:05:28 -07:00
H. Peter Anvin
ff8a4bae45 Revert "x86: cap iomem_resource to addressable physical memory"
This reverts commit 95ee14e437.
Mikael Petterson <mikepe@it.uu.se> reported that at least one of his
systems will not boot as a result.  We have ruled out the detection
algorithm malfunctioning, so it is not a matter of producing the
incorrect bitmasks; rather, something in the application of them
fails.

Revert the commit until we can root cause and correct this problem.

-stable team: this means the underlying commit should be rejected.

Reported-and-isolated-by: Mikael Petterson <mikpe@it.uu.se>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
LKML-Reference: <200906261559.n5QFxJH8027336@pilspetsen.it.uu.se>
Cc: stable@kernel.org
Cc: Grant Grundler <grundler@parisc-linux.org>
2009-06-28 09:38:47 +02:00
Hidetoshi Seto
5be6066a7f x86, mce: percpu mcheck_timer should be pinned
If CONFIG_NO_HZ + CONFIG_SMP, timer added via add_timer() might
be migrated on other cpu.  Use add_timer_on() instead.

Avoids the following failure:

Maciej Rutecki wrote:
> > After normal boot I try:
> >
> > echo 1 > /sys/devices/system/machinecheck/machinecheck0/check_interval
> >
> > I found this in dmesg:
> >
> > [  141.704025] ------------[ cut here ]------------
> > [  141.704039] WARNING: at arch/x86/kernel/cpu/mcheck/mce.c:1102
> > mcheck_timer+0xf5/0x100()

Reported-by: Maciej Rutecki <maciej.rutecki@gmail.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Tested-by: Maciej Rutecki <maciej.rutecki@gmail.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-06-25 13:33:02 -07:00
Kurt Garloff
5211a242d0 x86: Add sysctl to allow panic on IOCK NMI error
This patch introduces a new sysctl:

    /proc/sys/kernel/panic_on_io_nmi

which defaults to 0 (off).

When enabled, the kernel panics when the kernel receives an NMI
caused by an IO error.

The IO error triggered NMI indicates a serious system
condition, which could result in IO data corruption. Rather
than contiuing, panicing and dumping might be a better choice,
so one can figure out what's causing the IO error.

This could be especially important to companies running IO
intensive applications where corruption must be avoided, e.g. a
bank's databases.

[ SuSE has been shipping it for a while, it was done at the
  request of a large database vendor, for their users. ]

Signed-off-by: Kurt Garloff <garloff@suse.de>
Signed-off-by: Roberto Angelino <robertangelino@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
LKML-Reference: <20090624213211.GA11291@kroah.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-25 22:06:11 +02:00
Peter Zijlstra
194002b274 perf_counter, x86: Add mmap counter read support
Update the mmap control page with the needed information to
use the userspace RDPMC instruction for self monitoring.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-25 21:39:06 +02:00
Linus Torvalds
0c26d7cc31 Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6: (72 commits)
  asus-laptop: remove EXPERIMENTAL dependency
  asus-laptop: use pr_fmt and pr_<level>
  eeepc-laptop: cpufv updates
  eeepc-laptop: sync eeepc-laptop with asus_acpi
  asus_acpi: Deprecate in favor of asus-laptop
  acpi4asus: update MAINTAINER and KConfig links
  asus-laptop: platform dev as parent for led and backlight
  eeepc-laptop: enable camera by default
  ACPI: Rename ACPI processor device bus ID
  acerhdf: Acer Aspire One fan control
  ACPI: video: DMI workaround broken Acer 7720 BIOS enabling display brightness
  ACPI: run ACPI device hot removal in kacpi_hotplug_wq
  ACPI: Add the reference count to avoid unloading ACPI video bus twice
  ACPI: DMI to disable Vista compatibility on some Sony laptops
  ACPI: fix a deadlock in hotplug case
  Show the physical device node of backlight class device.
  ACPI: pdc init related memory leak with physical CPU hotplug
  ACPI: pci_root: remove unused dev/fn information
  ACPI: pci_root: simplify list traversals
  ACPI: pci_root: use driver data rather than list lookup
  ...
2009-06-24 10:17:07 -07:00
Cliff Wickman
9c26f52b90 x86: Fix uv bau sending buffer initialization
The initialization of the UV Broadcast Assist Unit's sending
buffers was making an invalid assumption about the
initialization of an MMR that defines its address.

The BIOS will not be providing that MMR.  So
uv_activation_descriptor_init() should unconditionally set it.

Tested on UV simulator.

Signed-off-by: Cliff Wickman <cpw@sgi.com>
Cc: <stable@kernel.org> # for v2.6.30.x
LKML-Reference: <E1MJTfj-0005i1-W8@eag09.americas.sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-24 17:33:58 +02:00
Yong Wang
c14dab5c07 perf_counter, x86: Set global control MSR correctly
Previous code made an assumption that the power on value of global
control MSR has enabled all fixed and general purpose counters properly.

However, this is not the case for certain Intel processors, such as
Atom - and it might also be firmware dependent.

Each enable bit in IA32_PERF_GLOBAL_CTRL is AND'ed with the
enable bits for all privilege levels in the respective IA32_PERFEVTSELx
or IA32_PERF_FIXED_CTR_CTRL MSRs to start/stop the counting of
respective counters. Counting is enabled if the AND'ed results is true;
counting is disabled when the result is false.

The end result is that all fixed counters are always disabled on Atom
processors because the assumption is just invalid.

Fix this by not initializing the ctrl-mask out of the global MSR,
but setting it to perf_counter_mask.

Reported-by: Stephane Eranian <eranian@googlemail.com>
Signed-off-by: Yong Wang <yong.y.wang@intel.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20090624021324.GA2788@ywang-moblin2.bj.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-24 10:51:24 +02:00
Len Brown
fbe8cddd2d Merge branches 'acerhdf', 'acpi-pci-bind', 'bjorn-pci-root', 'bugzilla-12904', 'bugzilla-13121', 'bugzilla-13396', 'bugzilla-13533', 'bugzilla-13612', 'c3_lock', 'hid-cleanups', 'misc-2.6.31', 'pdc-leak-fix', 'pnpacpi', 'power_nocheck', 'thinkpad_acpi', 'video' and 'wmi' into release 2009-06-24 01:19:50 -04:00
Weidong Han
f007e99c8e Intel-IOMMU, intr-remap: source-id checking
To support domain-isolation usages, the platform hardware must be
capable of uniquely identifying the requestor (source-id) for each
interrupt message. Without source-id checking for interrupt remapping
, a rouge guest/VM with assigned devices can launch interrupt attacks
to bring down anothe guest/VM or the VMM itself.

This patch adds source-id checking for interrupt remapping, and then
really isolates interrupts for guests/VMs with assigned devices.

Because PCI subsystem is not initialized yet when set up IOAPIC
entries, use read_pci_config_byte to access PCI config space directly.

Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-23 22:09:17 +01:00
Pekka J Enberg
854c879f5a x86: Move init_gbpages() to setup_arch()
The init_gbpages() function is conditionally called from
init_memory_mapping() function. There are two call-sites where
this 'after_bootmem' condition can be true: setup_arch() and
mem_init() via pci_iommu_alloc().

Therefore, it's safe to move the call to init_gbpages() to
setup_arch() as it's always called before mem_init().

This removes an after_bootmem use - paving the way to remove
all uses of that state variable.

Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <Pine.LNX.4.64.0906221731210.19474@melkki.cs.Helsinki.FI>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-23 10:33:32 +02:00
Linus Torvalds
687d680985 Merge git://git.infradead.org/~dwmw2/iommu-2.6.31
* git://git.infradead.org/~dwmw2/iommu-2.6.31:
  intel-iommu: Fix one last ia64 build problem in Pass Through Support
  VT-d: support the device IOTLB
  VT-d: cleanup iommu_flush_iotlb_psi and flush_unmaps
  VT-d: add device IOTLB invalidation support
  VT-d: parse ATSR in DMA Remapping Reporting Structure
  PCI: handle Virtual Function ATS enabling
  PCI: support the ATS capability
  intel-iommu: dmar_set_interrupt return error value
  intel-iommu: Tidy up iommu->gcmd handling
  intel-iommu: Fix tiny theoretical race in write-buffer flush.
  intel-iommu: Clean up handling of "caching mode" vs. IOTLB flushing.
  intel-iommu: Clean up handling of "caching mode" vs. context flushing.
  VT-d: fix invalid domain id for KVM context flush
  Fix !CONFIG_DMAR build failure introduced by Intel IOMMU Pass Through Support
  Intel IOMMU Pass Through Support

Fix up trivial conflicts in drivers/pci/{intel-iommu.c,intr_remapping.c}
2009-06-22 21:38:22 -07:00
Ingo Molnar
b7f797cb60 Merge branch 'for-tip' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu into x86/urgent 2009-06-22 10:24:43 +02:00
Tejun Heo
0017c869dd x86: ensure percpu lpage doesn't consume too much vmalloc space
On extreme configuration (e.g. 32bit 32-way NUMA machine), lpage
percpu first chunk allocator can consume too much of vmalloc space.
Make it fall back to 4k allocator if the consumption goes over 20%.

[ Impact: add sanity check for lpage percpu first chunk allocator ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Jan Beulich <JBeulich@novell.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
2009-06-22 11:56:24 +09:00
Tejun Heo
fa8a7094ba x86: implement percpu_alloc kernel parameter
According to Andi, it isn't clear whether lpage allocator is worth the
trouble as there are many processors where PMD TLB is far scarcer than
PTE TLB.  The advantage or disadvantage probably depends on the actual
size of percpu area and specific processor.  As performance
degradation due to TLB pressure tends to be highly workload specific
and subtle, it is difficult to decide which way to go without more
data.

This patch implements percpu_alloc kernel parameter to allow selecting
which first chunk allocator to use to ease debugging and testing.

While at it, make sure all the failure paths report why something
failed to help determining why certain allocator isn't working.  Also,
kill the "Great future plan" comment which had already been realized
quite some time ago.

[ Impact: allow explicit percpu first chunk allocator selection ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Jan Beulich <JBeulich@novell.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
2009-06-22 11:56:24 +09:00
Tejun Heo
e59a1bb2fd x86: fix pageattr handling for lpage percpu allocator and re-enable it
lpage allocator aliases a PMD page for each cpu and returns whatever
is unused to the page allocator.  When the pageattr of the recycled
pages are changed, this makes the two aliases point to the overlapping
regions with different attributes which isn't allowed and known to
cause subtle data corruption in certain cases.

This can be handled in simliar manner to the x86_64 highmap alias.
pageattr code should detect if the target pages have PMD alias and
split the PMD alias and synchronize the attributes.

pcpur allocator is updated to keep the allocated PMD pages map sorted
in ascending address order and provide pcpu_lpage_remapped() function
which binary searches the array to determine whether the given address
is aliased and if so to which address.  pageattr is updated to use
pcpu_lpage_remapped() to detect the PMD alias and split it up as
necessary from cpa_process_alias().

Jan Beulich spotted the original problem and incorrect usage of vaddr
instead of laddr for lookup.

With this, lpage percpu allocator should work correctly.  Re-enable
it.

[ Impact: fix subtle lpage pageattr bug and re-enable lpage ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Jan Beulich <JBeulich@novell.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
2009-06-22 11:56:24 +09:00
Tejun Heo
0ff2587fd5 x86: prepare setup_pcpu_lpage() for pageattr fix
Make the following changes in preparation of coming pageattr updates.

* Define and use array of struct pcpul_ent instead of array of
  pointers.  The only difference is ->cpu field which is set but
  unused yet.

* Rename variables according to the above change.

* Rename local variable vm to pcpul_vm and move it out of the
  function.

[ Impact: no functional difference ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jan Beulich <JBeulich@novell.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
2009-06-22 11:56:24 +09:00
Tejun Heo
97c9bf0618 x86: rename remap percpu first chunk allocator to lpage
The "remap" allocator remaps large pages to build the first chunk;
however, the name isn't very good because 4k allocator remaps too and
the whole point of the remap allocator is using large page mapping.
The allocator will be generalized and exported outside of x86, rename
it to lpage before that happens.

percpu_alloc kernel parameter is updated to accept both "remap" and
"lpage" for lpage allocator.

[ Impact: code cleanup, kernel parameter argument updated ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
2009-06-22 11:56:24 +09:00
Tejun Heo
c5806df923 x86: fix duplicate free in setup_pcpu_remap() failure path
In the failure path, setup_pcpu_remap() tries to free the area which
has already been freed to make holes in the large page.  Fix it.

[ Impact: fix duplicate free in failure path ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
2009-06-22 11:56:24 +09:00
Jaswinder Singh Rajput
d9f2a5ecb2 perf_counter, x8: Fix L1-data-Cache-Store-Referencees for AMD
Fix AMD's Data Cache Refills from System event.

After this patch :

 ./tools/perf/perf stat -e l1d -e l1d-misses -e l1d-write -e l1d-prefetch -e l1d-prefetch-miss -e l1i -e l1i-misses -e l1i-prefetch -e l2 -e l2-misses -e l2-write -e dtlb -e dtlb-misses -e itlb -e itlb-misses -e bpu -e bpu-misses ls /dev/ > /dev/null

 Performance counter stats for 'ls /dev/':

        2499484  L1-data-Cache-Load-Referencees             (scaled from 3.97%)
          70347  L1-data-Cache-Load-Misses                  (scaled from 7.30%)
           9360  L1-data-Cache-Store-Referencees            (scaled from 8.64%)
          32804  L1-data-Cache-Prefetch-Referencees         (scaled from 17.72%)
           7693  L1-data-Cache-Prefetch-Misses              (scaled from 22.97%)
        2180945  L1-instruction-Cache-Load-Referencees      (scaled from 28.48%)
          14518  L1-instruction-Cache-Load-Misses           (scaled from 35.00%)
           2405  L1-instruction-Cache-Prefetch-Referencees  (scaled from 34.89%)
          71387  L2-Cache-Load-Referencees                  (scaled from 34.94%)
          18732  L2-Cache-Load-Misses                       (scaled from 34.92%)
          79918  L2-Cache-Store-Referencees                 (scaled from 36.02%)
        1295294  Data-TLB-Cache-Load-Referencees            (scaled from 35.99%)
          30896  Data-TLB-Cache-Load-Misses                 (scaled from 33.36%)
        1222030  Instruction-TLB-Cache-Load-Referencees     (scaled from 29.46%)
            357  Instruction-TLB-Cache-Load-Misses          (scaled from 20.46%)
         530888  Branch-Cache-Load-Referencees              (scaled from 11.48%)
           8638  Branch-Cache-Load-Misses                   (scaled from 5.09%)

    0.011295149  seconds time elapsed.

Earlier it always shows value 0.

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
LKML-Reference: <1245484165.3102.6.camel@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-21 13:25:55 +02:00
Andreas Herrmann
99bd0c0fc4 x86: Set cpu_llc_id on AMD CPUs
This counts when building sched domains in case NUMA information
is not available.

( See cpu_coregroup_mask() which uses llc_shared_map which in turn is
  created based on cpu_llc_id. )

Currently Linux builds domains as follows:
(example from a dual socket quad-core system)

 CPU0 attaching sched-domain:
  domain 0: span 0-7 level CPU
   groups: 0 1 2 3 4 5 6 7

  ...

 CPU7 attaching sched-domain:
  domain 0: span 0-7 level CPU
   groups: 7 0 1 2 3 4 5 6

Ever since that is borked for multi-core AMD CPU systems.
This patch fixes that and now we get a proper:

 CPU0 attaching sched-domain:
  domain 0: span 0-3 level MC
   groups: 0 1 2 3
   domain 1: span 0-7 level CPU
    groups: 0-3 4-7

  ...

 CPU7 attaching sched-domain:
  domain 0: span 4-7 level MC
   groups: 7 4 5 6
   domain 1: span 0-7 level CPU
    groups: 4-7 0-3

This allows scheduler to assign tasks to cores on different sockets
(i.e. that don't share last level cache) for performance reasons.

Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
LKML-Reference: <20090619085909.GJ5218@alberich.amd.com>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-21 10:13:32 +02:00
Linus Torvalds
12e24f34cb Merge branch 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (49 commits)
  perfcounter: Handle some IO return values
  perf_counter: Push perf_sample_data through the swcounter code
  perf_counter tools: Define and use our own u64, s64 etc. definitions
  perf_counter: Close race in perf_lock_task_context()
  perf_counter, x86: Improve interactions with fast-gup
  perf_counter: Simplify and fix task migration counting
  perf_counter tools: Add a data file header
  perf_counter: Update userspace callchain sampling uses
  perf_counter: Make callchain samples extensible
  perf report: Filter to parent set by default
  perf_counter tools: Handle lost events
  perf_counter: Add event overlow handling
  fs: Provide empty .set_page_dirty() aop for anon inodes
  perf_counter: tools: Makefile tweaks for 64-bit powerpc
  perf_counter: powerpc: Add processor back-end for MPC7450 family
  perf_counter: powerpc: Make powerpc perf_counter code safe for 32-bit kernels
  perf_counter: powerpc: Change how processor-specific back-ends get selected
  perf_counter: powerpc: Use unsigned long for register and constraint values
  perf_counter: powerpc: Enable use of software counters on 32-bit powerpc
  perf_counter tools: Add and use isprint()
  ...
2009-06-20 11:29:32 -07:00
Linus Torvalds
1eb51c33b2 Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: Fix out of scope variable access in sched_slice()
  sched: Hide runqueues from direct refer at source code level
  sched: Remove unneeded __ref tag
  sched, x86: Fix cpufreq + sched_clock() TSC scaling
2009-06-20 10:57:40 -07:00
Linus Torvalds
b0b7065b64 Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (24 commits)
  tracing/urgent: warn in case of ftrace_start_up inbalance
  tracing/urgent: fix unbalanced ftrace_start_up
  function-graph: add stack frame test
  function-graph: disable when both x86_32 and optimize for size are configured
  ring-buffer: have benchmark test print to trace buffer
  ring-buffer: do not grab locks in nmi
  ring-buffer: add locks around rb_per_cpu_empty
  ring-buffer: check for less than two in size allocation
  ring-buffer: remove useless compile check for buffer_page size
  ring-buffer: remove useless warn on check
  ring-buffer: use BUF_PAGE_HDR_SIZE in calculating index
  tracing: update sample event documentation
  tracing/filters: fix race between filter setting and module unload
  tracing/filters: free filter_string in destroy_preds()
  ring-buffer: use commit counters for commit pointer accounting
  ring-buffer: remove unused variable
  ring-buffer: have benchmark test handle discarded events
  ring-buffer: prevent adding write in discarded area
  tracing/filters: strloc should be unsigned short
  tracing/filters: operand can be negative
  ...

Fix up kmemcheck-induced conflict in kernel/trace/ring_buffer.c manually
2009-06-20 10:56:46 -07:00
Linus Torvalds
c4c5ab3089 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: (45 commits)
  x86, mce: fix error path in mce_create_device()
  x86: use zalloc_cpumask_var for mce_dev_initialized
  x86: fix duplicated sysfs attribute
  x86: de-assembler-ize asm/desc.h
  i386: fix/simplify espfix stack switching, move it into assembly
  i386: fix return to 16-bit stack from NMI handler
  x86, ioapic: Don't call disconnect_bsp_APIC if no APIC present
  x86: Remove duplicated #include's
  x86: msr.h linux/types.h is only required for __KERNEL__
  x86: nmi: Add Intel processor 0x6f4 to NMI perfctr1 workaround
  x86, mce: mce_intel.c needs <asm/apic.h>
  x86: apic/io_apic.c: dmar_msi_type should be static
  x86, io_apic.c: Work around compiler warning
  x86: mce: Don't touch THERMAL_APIC_VECTOR if no active APIC present
  x86: mce: Handle banks == 0 case in K7 quirk
  x86, boot: use .code16gcc instead of .code16
  x86: correct the conversion of EFI memory types
  x86: cap iomem_resource to addressable physical memory
  x86, mce: rename _64.c files which are no longer 64-bit-specific
  x86, mce: mce.h cleanup
  ...

Manually fix up trivial conflict in arch/x86/mm/fault.c
2009-06-20 10:49:48 -07:00
Jaswinder Singh Rajput
feaa0457ec x86: ds.c fix invalid assignment
Fixes the type mixups that cause the following sparse warnings:

  CHECK   arch/x86/kernel/ds.c
arch/x86/kernel/ds.c:549:19: warning: incorrect type in argument 2 (invalid types)
arch/x86/kernel/ds.c:549:19:    expected bad type enum bts_field field
arch/x86/kernel/ds.c:549:19:    got int
arch/x86/kernel/ds.c:514:35: error: incompatible types for operation (*)
arch/x86/kernel/ds.c:514:35:    left side has type unsigned char static [unsigned] [toplevel] sizeof_ptr_field
arch/x86/kernel/ds.c:514:35:    right side has type bad type enum bts_field field
arch/x86/kernel/ds.c:514:7: error: invalid assignment
arch/x86/kernel/ds.c:514:35: error: incompatible types for operation (*)
arch/x86/kernel/ds.c:514:35:    left side has type unsigned char static [unsigned] [toplevel] sizeof_ptr_field
arch/x86/kernel/ds.c:514:35:    right side has type bad type enum bts_field field
arch/x86/kernel/ds.c:514:7: error: invalid assignment
arch/x86/kernel/ds.c:514:35: error: incompatible types for operation (*)
arch/x86/kernel/ds.c:514:35:    left side has type unsigned char static [unsigned] [toplevel] sizeof_ptr_field
arch/x86/kernel/ds.c:514:35:    right side has type bad type enum bts_field field
arch/x86/kernel/ds.c:514:7: error: invalid assignment
arch/x86/kernel/ds.c:514:35: error: incompatible types for operation (*)
arch/x86/kernel/ds.c:514:35:    left side has type unsigned char static [unsigned] [toplevel] sizeof_ptr_field
arch/x86/kernel/ds.c:514:35:    right side has type bad type enum bts_field field
arch/x86/kernel/ds.c:514:7: error: invalid assignment
arch/x86/kernel/ds.c:514:35: error: incompatible types for operation (*)
arch/x86/kernel/ds.c:514:35:    left side has type unsigned char static [unsigned] [toplevel] sizeof_ptr_field
arch/x86/kernel/ds.c:514:35:    right side has type bad type enum bts_field field
arch/x86/kernel/ds.c:514:7: error: invalid assignment
arch/x86/kernel/ds.c:514:35: error: incompatible types for operation (*)
arch/x86/kernel/ds.c:514:35:    left side has type unsigned char static [unsigned] [toplevel] sizeof_ptr_field
arch/x86/kernel/ds.c:514:35:    right side has type bad type enum bts_field field
arch/x86/kernel/ds.c:514:7: error: invalid assignment
arch/x86/kernel/ds.c:520:35: error: incompatible types for operation (*)
arch/x86/kernel/ds.c:520:35:    left side has type unsigned char static [unsigned] [toplevel] sizeof_ptr_field
arch/x86/kernel/ds.c:520:35:    right side has type bad type enum bts_field field
arch/x86/kernel/ds.c:520:7: error: invalid assignment
arch/x86/kernel/ds.c:520:35: error: incompatible types for operation (*)

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Markus Metzger <markus.t.metzger@intel.com>
LKML-Reference: <1245494740.8613.12.camel@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-20 17:53:13 +02:00
Ingo Molnar
1d99100120 Merge branch 'x86/mce3' into x86/urgent 2009-06-20 10:54:22 +02:00
Pallipadi, Venkatesh
7b768f07dc ACPI: pdc init related memory leak with physical CPU hotplug
arch_acpi_processor_cleanup_pdc() in x86 and ia64 results in memory allocated
for _PDC objects that is never freed and will cause memory leak in case of
physical CPU remove and add. Patch fixes the memory leak by freeing the
objects soon after _PDC is evaluated.

Reported-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-06-20 00:50:52 -04:00
Peter Zijlstra
f9188e023c perf_counter: Make callchain samples extensible
Before exposing upstream tools to a callchain-samples ABI, tidy it
up to make it more extensible in the future:

Use markers in the IP chain to denote context, use (u64)-1..-4095 range
for these context markers because we use them for ERR_PTR(), so these
addresses are unlikely to be mapped.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-19 13:42:34 +02:00
Steven Rostedt
71e308a239 function-graph: add stack frame test
In case gcc does something funny with the stack frames, or the return
from function code, we would like to detect that.

An arch may implement passing of a variable that is unique to the
function and can be saved on entering a function and can be tested
when exiting the function. Usually the frame pointer can be used for
this purpose.

This patch also implements this for x86. Where it passes in the stack
frame of the parent function, and will test that frame on exit.

There was a case in x86_32 with optimize for size (-Os) where, for a
few functions, gcc would align the stack frame and place a copy of the
return address into it. The function graph tracer modified the copy and
not the actual return address. On return from the funtion, it did not go
to the tracer hook, but returned to the parent. This broke the function
graph tracer, because the return of the parent (where gcc did not do
this funky manipulation) returned to the location that the child function
was suppose to. This caused strange kernel crashes.

This test detected the problem and pointed out where the issue was.

This modifies the parameters of one of the functions that the arch
specific code calls, so it includes changes to arch code to accommodate
the new prototype.

Note, I notice that the parsic arch implements its own push_return_trace.
This is now a generic function and the ftrace_push_return_trace should be
used instead. This patch does not touch that code.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-18 18:40:18 -04:00
Peter Oberparleiter
7bf99fb673 gcov: enable GCOV_PROFILE_ALL for x86_64
Enable gcov profiling of the entire kernel on x86_64. Required changes
include disabling profiling for:

* arch/kernel/acpi/realmode and arch/kernel/boot/compressed:
  not linked to main kernel
* arch/vdso, arch/kernel/vsyscall_64 and arch/kernel/hpet:
  profiling causes segfaults during boot (incompatible context)

Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Li Wei <W.Li@Sun.COM>
Cc: Michael Ellerman <michaele@au1.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Heiko Carstens <heicars2@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <mschwid2@linux.vnet.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:58 -07:00
Hidetoshi Seto
b1f49f9582 x86, mce: fix error path in mce_create_device()
Don't skip removing mce_attrs in route from error2.

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Huang Ying <ying.huang@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-06-18 07:02:32 -07:00
Yinghai Lu
e92fae064a x86: use zalloc_cpumask_var for mce_dev_initialized
We need a cleared cpu_mask to record if mce is initialized, especially
when MAXSMP is used.

used zalloc_... instead

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: stable@kernel.org
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-06-17 21:47:18 -07:00
Yinghai Lu
74b602c714 x86: fix duplicated sysfs attribute
The sysfs attribute cmci_disabled was accidentall turned into a
duplicate of ignore_ce, breaking all other attributes.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-06-17 21:43:16 -07:00
Alexander van Heukelum
bc3f5d3dbd x86: de-assembler-ize asm/desc.h
asm/desc.h is included in three assembly files, but the only macro
it defines, GET_DESC_BASE, is never used. This patch removes the
includes, removes the macro GET_DESC_BASE and the ASSEMBLY guard
from asm/desc.h.

Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-06-17 21:35:10 -07:00
Alexander van Heukelum
dc4c2a0aed i386: fix/simplify espfix stack switching, move it into assembly
The espfix code triggers if we have a protected mode userspace
application with a 16-bit stack. On returning to userspace, with iret,
the CPU doesn't restore the high word of the stack pointer. This is an
"official" bug, and the work-around used in the kernel is to temporarily
switch to a 32-bit stack segment/pointer pair where the high word of the
pointer is equal to the high word of the userspace stackpointer.

The current implementation uses THREAD_SIZE to determine the cut-off,
but there is no good reason not to use the more natural 64kb... However,
implementing this by simply substituting THREAD_SIZE with 65536 in
patch_espfix_desc crashed the test application. patch_espfix_desc tries
to do what is described above, but gets it subtly wrong if the userspace
stack pointer is just below a multiple of THREAD_SIZE: an overflow
occurs to bit 13... With a bit of luck, when the kernelspace
stackpointer is just below a 64kb-boundary, the overflow then ripples
trough to bit 16 and userspace will see its stack pointer changed by
65536.

This patch moves all espfix code into entry_32.S. Selecting a 16-bit
cut-off simplifies the code. The game with changing the limit dynamically
is removed too. It complicates matters and I see no value in it. Changing
only the top 16-bit word of ESP is one instruction and it also implies
that only two bytes of the ESPFIX GDT entry need to be changed and this
can be implemented in just a handful simple to understand instructions.
As a side effect, the operation to compute the original ESP from the
ESPFIX ESP and the GDT entry simplifies a bit too, and the remaining
three instructions have been expanded inline in entry_32.S.

impact: can now reliably run userspace with ESP=xxxxfffc on 16-bit
stack segment

Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Acked-by: Stas Sergeev <stsp@aknet.ru>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-06-17 21:35:09 -07:00
Alexander van Heukelum
2e04bc7656 i386: fix return to 16-bit stack from NMI handler
Returning to a task with a 16-bit stack requires special care: the iret
instruction does not restore the high word of esp in that case. The
espfix code fixes this, but currently is not invoked on NMIs. This means
that a running task gets the upper word of esp clobbered due intervening
NMIs. To reproduce, compile and run the following program with the nmi
watchdog enabled (nmi_watchdog=2 on the command line). Using gdb you can
see that the high bits of esp contain garbage, while the low bits are
still correct.

This patch puts the espfix code back into the NMI code path.

The patch is slightly complicated due to the irqtrace infrastructure not
being NMI-safe. The NMI return path cannot call TRACE_IRQS_IRET.
Otherwise, the tail of the normal iret-code is correct for the nmi code
path too. To be able to share this code-path, the TRACE_IRQS_IRET was
move up a bit. The espfix code exists after the TRACE_IRQS_IRET, but
this code explicitly disables interrupts. This short interrupts-off
section is now not traced anymore. The return-to-kernel path now always
includes the preliminary test to decide if the espfix code should be
called. This is never the case, but doing it this way keeps the patch as
simple as possible and the few extra instructions should not affect
timing in any significant way.

 #define _GNU_SOURCE
 #include <stdio.h>
 #include <sys/types.h>
 #include <sys/mman.h>
 #include <unistd.h>
 #include <sys/syscall.h>
 #include <asm/ldt.h>

int modify_ldt(int func, void *ptr, unsigned long bytecount)
{
        return syscall(SYS_modify_ldt, func, ptr, bytecount);
}

/* this is assumed to be usable */
 #define SEGBASEADDR 0x10000
 #define SEGLIMIT 0x20000

/* 16-bit segment */
struct user_desc desc = {
        .entry_number = 0,
        .base_addr = SEGBASEADDR,
        .limit = SEGLIMIT,
        .seg_32bit = 0,
        .contents = 0, /* ??? */
        .read_exec_only = 0,
        .limit_in_pages = 0,
        .seg_not_present = 0,
        .useable = 1
};

int main(void)
{
        setvbuf(stdout, NULL, _IONBF, 0);

        /* map a 64 kb segment */
        char *pointer = mmap((void *)SEGBASEADDR, SEGLIMIT+1,
                        PROT_EXEC|PROT_READ|PROT_WRITE,
                        MAP_SHARED|MAP_ANONYMOUS, -1, 0);
        if (pointer == NULL) {
                printf("could not map space\n");
                return 0;
        }

        /* write ldt, new mode */
        int err = modify_ldt(0x11, &desc, sizeof(desc));
        if (err) {
                printf("error modifying ldt: %i\n", err);
                return 0;
        }

        for (int i=0; i<1000; i++) {
        asm volatile (
                "pusha\n\t"
                "mov %ss, %eax\n\t" /* preserve ss:esp */
                "mov %esp, %ebp\n\t"
                "push $7\n\t" /* index 0, ldt, user mode */
                "push $65536-4096\n\t" /* esp */
                "lss (%esp), %esp\n\t" /* switch to new stack */
                "push %eax\n\t" /* save old ss:esp on new stack */
                "push %ebp\n\t"
                "add $17*65536, %esp\n\t" /* set high bits */
                "mov %esp, %edx\n\t"

                "mov $10000000, %ecx\n\t" /* wait... */
                "1: loop 1b\n\t" /* ... a bit */

                "cmp %esp, %edx\n\t"
                "je 1f\n\t"
                "ud2\n\t" /* esp changed inexplicably! */
                "1:\n\t"
                "sub $17*65536, %esp\n\t" /* restore high bits */
                "lss (%esp), %esp\n\t" /* restore old ss:esp */
                "popa\n\t");

                printf("\rx%ix", i);
        }

        return 0;
}

Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Acked-by: Stas Sergeev <stsp@aknet.ru>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-06-17 21:35:09 -07:00