Linus noticed that the 32-bit version of atomic64_read() was
being overly complex with re-reading the value and doing a
retry loop over that.
Instead we can just rely on cmpxchg8b returning either the new
value or returning the current value.
We can use any 'old' value, which will be faster as it can be
loaded via immediates. Using some value that is not equal to
the real value in memory the instruction gets faster.
This also has the advantage that the CPU could avoid dirtying
the cacheline.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: 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>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
LKML-Reference: <alpine.LFD.2.01.0907021653030.3210@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Linus noted that the atomic64_t primitives are all inlines
currently which is crazy because these functions have a large
register footprint anyway.
Move them to a separate file: arch/x86/lib/atomic64_32.c
Also, while at it, rename all uses of 'unsigned long long' to
the much shorter u64.
This makes the appearance of the prototypes a lot nicer - and
it also uncovered a few bugs where (yet unused) API variants
had 'long' as their return type instead of u64.
[ More intrusive changes are not yet done in this patch. ]
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: 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>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
LKML-Reference: <alpine.LFD.2.01.0907021653030.3210@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Locked instructions on two cache lines at once are painful. If
atomic64_t uses two cache lines, my test program is 10x slower.
The chance for that is significant: 4/32 or 12.5%.
Make sure an atomic64_t is 8 bytes aligned.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: 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>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
LKML-Reference: <alpine.LFD.2.01.0907021653030.3210@localhost.localdomain>
[ changed it to __aligned(8) as per Andrew's suggestion ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 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()
...
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>
These macros had two bugs:
- the type of the mask was not correctly expanded to the full size of
the argument being expanded, resulting in possible loss of high bits
when mixing types.
- the alignment argument was evaluated twice, despite the macro looking
like a fancy function (but it really does need to be a macro, since
it works on arbitrary integer types)
Noticed by Peter Anvin, and with a fix that is a modification of his
suggestion (bug noticed by Yinghai Lu).
Cc: Peter Anvin <hpa@zytor.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The setting of this variable got lost during the suspend/resume
implementation. But keeping this variable zero causes a divide-by-zero
error in the interrupt handler. This patch fixes this.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
An alias entry in the ACPI table means that the device can send requests to the
IOMMU with both device ids, its own and the alias. This is not handled properly
in the ACPI init code. This patch fixes the issue.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
About every callchains recorded with perf record are filled up
including the internal perfcounter nmi frame:
perf_callchain
perf_counter_overflow
intel_pmu_handle_irq
perf_counter_nmi_handler
notifier_call_chain
atomic_notifier_call_chain
notify_die
do_nmi
nmi
We want ignore this frame as it's not interesting for
instrumentation. To solve this, we simply ignore every frames
from nmi context.
New example of "perf report -s sym -c" after this patch:
9.59% [k] search_by_key
4.88%
search_by_key
reiserfs_read_locked_inode
reiserfs_iget
reiserfs_lookup
do_lookup
__link_path_walk
path_walk
do_path_lookup
user_path_at
vfs_fstatat
vfs_lstat
sys_newlstat
system_call_fastpath
__lxstat
0x406fb1
3.19%
search_by_key
search_by_entry_key
reiserfs_find_entry
reiserfs_lookup
do_lookup
__link_path_walk
path_walk
do_path_lookup
user_path_at
vfs_fstatat
vfs_lstat
sys_newlstat
system_call_fastpath
__lxstat
0x406fb1
[...]
For now this patch only solves the problem in x86-64.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Anton Blanchard <anton@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <1246474930-6088-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
We can run a 32-bit kernel on boxes with an IOMMU, so we need
pci_unmap_addr() etc. to work -- without it, drivers will leak mappings.
To be honest, this whole thing looks like it's more pain than it's
worth; I'm half inclined to remove the no-op #else case altogether.
But this is the minimal fix, which just does the right thing if
CONFIG_DMAR is set.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Cc: stable@kernel.org [ for 2.6.30 ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This sparse warning:
arch/x86/mm/init.c:83:16: warning: symbol 'check_efer' was not declared. Should it be static?
triggers because check_efer() is not decalared before using it.
asm/proto.h includes the declaration of check_efer(), so
including asm/proto.h to fix that - this also addresses the
sparse warning.
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <1246458263.6940.22.camel@hpdv5.satnam>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This sparse warning:
arch/x86/kernel/amd_iommu.c:1195:23: warning: symbol 'device_nb' was not declared. Should it be static?
triggers because device_nb is global but is only used in a
single .c file. change device_nb to static to fix that - this
also addresses the sparse warning.
This sparse warning:
arch/x86/kernel/amd_iommu.c:1766:10: warning: Using plain integer as NULL pointer
triggers because plain integer 0 is used in place of a NULL
pointer. change 0 to NULL to fix that - this also address the
sparse warning.
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Joerg Roedel <joerg.roedel@amd.com>
LKML-Reference: <1246458194.6940.20.camel@hpdv5.satnam>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* '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
...
Nathan reported that
| commit 73d60b7f74
| Author: Yinghai Lu <yinghai@kernel.org>
| Date: Tue Jun 16 15:33:00 2009 -0700
|
| page-allocator: clear N_HIGH_MEMORY map before we set it again
|
| SRAT tables may contains nodes of very small size. The arch code may
| decide to not activate such a node. However, currently the early boot
| code sets N_HIGH_MEMORY for such nodes. These nodes therefore seem to be
| active although these nodes have no present pages.
|
| For 64bit N_HIGH_MEMORY == N_NORMAL_MEMORY, so that works for 64 bit too
unintentionally and incorrectly clears the cpuset.mems cgroup attribute on
an i386 kvm guest, meaning that cpuset.mems can not be used.
Fix this by only clearing node_states[N_NORMAL_MEMORY] for 64bit only.
and need to do save/restore for that in find_zone_movable_pfn
Reported-by: Nathan Lynch <ntl@pobox.com>
Tested-by: Nathan Lynch <ntl@pobox.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>,
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The merge of the 32- and 64-bit fixmap headers made a latent
bug on x86-64 a real one: with the right config settings
it is possible for FIX_OHCI1394_BASE to overlap the FIX_BTMAP_*
range.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: <stable@kernel.org> # for 2.6.30.x
LKML-Reference: <4A4A0A8702000078000082E8@vpn.id2.novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Noticed the zero-sized function symbol while looking at 'perf' profiles,
it causes the profiler to display those addresses in hexa.
Turns out that this was wrong/bogus for an eternity.
Signed-off-by: Mike Galbraith <efault@gmx.de>
Acked-by: Alexander van Heukelum <heukelum@fastmail.fm>
Acked-by: Cyrill Gorcunov <gorcunov@gmail.com>
LKML-Reference: <1246366820.6538.1.camel@marge.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This allows us to remove adjust_transparent_bridge_resources and give
x86_pci_root_bus_res_quirks a chance when _CRS is not used or not there.
Acked-by: Gary Hade <garyhade@us.ibm.com>
Tested-by: Gary Hade <garyhade@us.ibm.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Don't touch info->res_num if we are out of space.
Acked-by: Gary Hade <garyhade@us.ibm.com>
Tested-by: Gary Hade <garyhade@us.ibm.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
* '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"
There's no need for the GFX workaround now we have 'iommu=pt' for the
cases where people really care about performance. There's no need to
have a special case for just one type of device.
This also speeds up the iommu=pt path and reduces memory usage by
setting up the si_domain _once_ and then using it for all devices,
rather than giving each device its own private page tables.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
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>
* 'kvm-updates/2.6.31' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: shut up uninit compiler warning in paging_tmpl.h
KVM: Ignore reads to K7 EVNTSEL MSRs
KVM: VMX: Handle vmx instruction vmexits
KVM: s390: Allow stfle instruction in the guest
KVM: kvm/x86_emulate.c toggle_interruptibility() should be static
KVM: ia64: fix ia64 build due to missing kallsyms_lookup() and double export
KVM: protect concurrent make_all_cpus_request
KVM: MMU: Allow 4K ptes with bit 7 (PAT) set
KVM: Fix dirty bit tracking for slots with large pages
* '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
Dixes compilation warning:
CC arch/x86/kernel/io_delay.o
arch/x86/kvm/paging_tmpl.h: In function ‘paging64_fetch’:
arch/x86/kvm/paging_tmpl.h:279: warning: ‘sptep’ may be used uninitialized in this function
arch/x86/kvm/paging_tmpl.h: In function ‘paging32_fetch’:
arch/x86/kvm/paging_tmpl.h:279: warning: ‘sptep’ may be used uninitialized in this function
warning is bogus (always have a least one level), but need to shut the compiler
up.
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
In commit 7fe29e0faa we ignored the
reads to the P6 EVNTSEL MSRs. That fixed crashes on Intel machines.
Ignore the reads to K7 EVNTSEL MSRs as well to fix this on AMD
hosts.
This fixes Kaspersky antivirus crashing Windows guests on AMD hosts.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
IF a guest tries to use vmx instructions, inject a #UD to let it know the
instruction is not implemented, rather than crashing.
This prevents guest userspace from crashing the guest kernel.
Cc: stable@kernel.org
Signed-off-by: Avi Kivity <avi@redhat.com>
toggle_interruptibility() is used only by same file, it should be static.
Fixed following sparse warning :
arch/x86/kvm/x86_emulate.c:1364:6: warning: symbol 'toggle_interruptibility' was not declared. Should it be static?
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
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>
<asm/boot.h> needs <asm/pgtable_types.h>, not <asm/page_types.h> in
order to resolve PMD_SHIFT. Also, correct a +1 which really should be
+ THREAD_ORDER.
This is a build error which was masked by a typoed #ifdef.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
CONFIG_X86_64 was misspelled (wrong case), which caused the x86-64
kernel to advertise itself as more relocatable than it really is.
This could in theory cause boot failures once bootloaders start
support the new relocation fields.
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
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>
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>
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>
This reverts commit 9e9f46c44e.
Quoting from the commit message:
"At this point, it seems to solve more problems than it causes, so let's
try using it by default. It's an easy revert if it ends up causing
trouble."
And guess what? The _CRS code causes trouble.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* '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
...
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>
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>
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>
Calling mcheck_init() on resume is required only with
CONFIG_X86_OLD_MCE=y.
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Acked-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
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>
* 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}
* 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: (74 commits)
PCI: make msi_free_irqs() to use msix_mask_irq() instead of open coded write
PCI: Fix the NIU MSI-X problem in a better way
PCI ASPM: remove get_root_port_link
PCI ASPM: cleanup pcie_aspm_sanity_check
PCI ASPM: remove has_switch field
PCI ASPM: cleanup calc_Lx_latency
PCI ASPM: cleanup pcie_aspm_get_cap_device
PCI ASPM: cleanup clkpm checks
PCI ASPM: cleanup __pcie_aspm_check_state_one
PCI ASPM: cleanup initialization
PCI ASPM: cleanup change input argument of aspm functions
PCI ASPM: cleanup misc in struct pcie_link_state
PCI ASPM: cleanup clkpm state in struct pcie_link_state
PCI ASPM: cleanup latency field in struct pcie_link_state
PCI ASPM: cleanup aspm state field in struct pcie_link_state
PCI ASPM: fix typo in struct pcie_link_state
PCI: drivers/pci/slot.c should depend on CONFIG_SYSFS
PCI: remove redundant __msi_set_enable()
PCI PM: consistently use type bool for wake enable variable
x86/ACPI: Correct maximum allowed _CRS returned resources and warn if exceeded
...
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>
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>
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>
Reorganize cpa_process_alias() so that new alias condition can be
added easily.
Jan Beulich spotted problem in the original cleanup thread which
incorrectly assumed the two existing conditions were mutially
exclusive.
[ Impact: code reorganization ]
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>
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>
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>
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>
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: aes-ni - Remove CRYPTO_TFM_REQ_MAY_SLEEP from fpu template
crypto: aes-ni - Do not sleep when using the FPU
crypto: aes-ni - Fix cbc mode IV saving
crypto: padlock-aes - work around Nano CPU errata in CBC mode
crypto: padlock-aes - work around Nano CPU errata in ECB mode
This allows the callers to now pass down the full set of FAULT_FLAG_xyz
flags to handle_mm_fault(). All callers have been (mechanically)
converted to the new calling convention, there's almost certainly room
for architectures to clean up their code and then add FAULT_FLAG_RETRY
when that support is added.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
The discussion about using "access_ok()" in get_user_pages_fast() (see
commit 7f81890687: "x86: don't use
'access_ok()' as a range check in get_user_pages_fast()" for details and
end result), made us notice that x86-64 was really being very sloppy
about virtual address checking.
So be way more careful and straightforward about masking x86-64 virtual
addresses:
- All the VIRTUAL_MASK* variants now cover half of the address
space, it's not like we can use the full mask on a signed
integer, and the larger mask just invites mistakes when
applying it to either half of the 48-bit address space.
- /proc/kcore's kc_offset_to_vaddr() becomes a lot more
obvious when it transforms a file offset into a
(kernel-half) virtual address.
- Unify/simplify the 32-bit and 64-bit USER_DS definition to
be based on TASK_SIZE_MAX.
This cleanup and more careful/obvious user virtual address checking also
uncovered a buglet in the x86-64 implementation of strnlen_user(): it
would do an "access_ok()" check on the whole potential area, even if the
string itself was much shorter, and thus return an error even for valid
strings. Our sloppy checking had hidden this.
So this fixes 'strnlen_user()' to do this properly, the same way we
already handled user strings in 'strncpy_from_user()'. Namely by just
checking the first byte, and then relying on fault handling for the
rest. That always works, since we impose a guard page that cannot be
mapped at the end of the user space address space (and even if we
didn't, we'd have the address space hole).
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* '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()
...
* '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
* '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
* '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
It's really not right to use 'access_ok()', since that is meant for the
normal "get_user()" and "copy_from/to_user()" accesses, which are done
through the TLB, rather than through the page tables.
Why? access_ok() does both too few, and too many checks. Too many,
because it is meant for regular kernel accesses that will not honor the
'user' bit in the page tables, and because it honors the USER_DS vs
KERNEL_DS distinction that we shouldn't care about in GUP. And too few,
because it doesn't do the 'canonical' check on the address on x86-64,
since the TLB will do that for us.
So instead of using a function that isn't meant for this, and does
something else and much more complicated, just do the real rules: we
don't want the range to overflow, and on x86-64, we want it to be a
canonical low address (on 32-bit, all addresses are canonical).
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
Improve a few details in perfcounter call-chain recording that
makes use of fast-GUP:
- Use ACCESS_ONCE() to observe the pte value. ptes are fundamentally
racy and can be changed on another CPU, so we have to be careful
about how we access them. The PAE branch is already careful with
read-barriers - but the non-PAE and 64-bit side needs an
ACCESS_ONCE() to make sure the pte value is observed only once.
- make the checks a bit stricter so that we can feed it any kind of
cra^H^H^H user-space input ;-)
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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>
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>
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>
kernel_fpu_begin/end used preempt_disable/enable, so sleep should be
prevented between kernel_fpu_begin/end.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Because AES-NI instructions will touch XMM state, corresponding code
must be enclosed within kernel_fpu_begin/end, which used
preempt_disable/enable. So sleep should be prevented between
kernel_fpu_begin/end.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Original implementation of aesni_cbc_dec do not save IV if input
length % 4 == 0. This will make decryption of next block failed.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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>
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>
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>
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>
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>
Instead of open-coding pci_find_parent_resource and request_resource,
just call pci_claim_resource.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 9e350de37a ("perf_counter: Accurate period data")
missed a spot, which caused all Intel-PMU samples to have a
period of 0.
This broke auto-freq sampling.
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>
<linux/types.h> is only required for __KERNEL__ as whole file is covered with it
Also fixed some spacing issues for usr/include/asm-x86/msr.h
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: "H. Peter Anvin" <hpa@kernel.org>
LKML-Reference: <1245228070.2662.1.camel@ht.satnam>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq:
[CPUFREQ] cpumask: new cpumask operators for arch/x86/kernel/cpu/cpufreq/powernow-k8.c
[CPUFREQ] cpumask: avoid playing with cpus_allowed in powernow-k8.c
[CPUFREQ] cpumask: avoid cpumask games in arch/x86/kernel/cpu/cpufreq/speedstep-centrino.c
[CPUFREQ] cpumask: avoid playing with cpus_allowed in speedstep-ich.c
[CPUFREQ] powernow-k8: get drv data for correct CPU
[CPUFREQ] powernow-k8: read P-state from HW
[CPUFREQ] reduce scope of ACPI_PSS_BIOS_BUG_MSG[]
[CPUFREQ] Clean up convoluted code in arch/x86/kernel/tsc.c:time_cpufreq_notifier()
[CPUFREQ] minor correction to cpu-freq documentation
[CPUFREQ] powernow-k8.c: mess cleanup
[CPUFREQ] Only set sampling_rate_max deprecated, sampling_rate_min is useful
[CPUFREQ] powernow-k8: Set transition latency to 1 if ACPI tables export 0
[CPUFREQ] ondemand: Uncouple minimal sampling rate from HZ in NO_HZ case
Expand Intel NMI perfctr1 workaround to include a Core2 processor stepping
(cpuid family-6, model-f, stepping-4). Resolves a situation where the NMI
would not enable on these processors.
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: prarit@redhat.com
Cc: suresh.b.siddha@intel.com
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
mce_intel.c uses apic_write() and lapic_get_maxlvt(), and so it needs
<asm/apic.h>.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
This compiler warning:
arch/x86/kernel/apic/io_apic.c: In function ‘ioapic_write_entry’:
arch/x86/kernel/apic/io_apic.c:466: warning: ‘eu’ is used uninitialized in this function
arch/x86/kernel/apic/io_apic.c:465: note: ‘eu’ was declared here
Is bogus as 'eu' is always initialized. But annotate it away by
initializing the variable, to make it easier for people to notice
real warnings. A compiler that sees through this logic will
optimize away the initialization.
Signed-off-by: Figo.zhang <figo1802@gmail.com>
LKML-Reference: <1245248720.3312.27.camel@myhost>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
If APIC was disabled (for some reason) and as result
it's not even mapped we should not try to enable thermal
interrupts at all.
Reported-by: Simon Holm Thøgersen <odie@cs.aau.dk>
Tested-by: Simon Holm Thøgersen <odie@cs.aau.dk>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
LKML-Reference: <20090615182633.GA7606@lenovo>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
For freqency dependent TSCs we only scale the cycles, we do not account
for the discrepancy in absolute value.
Our current formula is: time = cycles * mult
(where mult is a function of the cpu-speed on variable tsc machines)
Suppose our current cycle count is 10, and we have a multiplier of 5,
then our time value would end up being 50.
Now cpufreq comes along and changes the multiplier to say 3 or 7,
which would result in our time being resp. 30 or 70.
That means that we can observe random jumps in the time value due to
frequency changes in both fwd and bwd direction.
So what this patch does is change the formula to:
time = cycles * frequency + offset
And we calculate offset so that time_before == time_after, thereby
ridding us of these jumps in time.
[ Impact: fix/reduce sched_clock() jumps across frequency changing events ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Chucked-on-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* akpm: (182 commits)
fbdev: bf54x-lq043fb: use kzalloc over kmalloc/memset
fbdev: *bfin*: fix __dev{init,exit} markings
fbdev: *bfin*: drop unnecessary calls to memset
fbdev: bfin-t350mcqb-fb: drop unused local variables
fbdev: blackfin has __raw I/O accessors, so use them in fb.h
fbdev: s1d13xxxfb: add accelerated bitblt functions
tcx: use standard fields for framebuffer physical address and length
fbdev: add support for handoff from firmware to hw framebuffers
intelfb: fix a bug when changing video timing
fbdev: use framebuffer_release() for freeing fb_info structures
radeon: P2G2CLK_ALWAYS_ONb tested twice, should 2nd be P2G2CLK_DAC_ALWAYS_ONb?
s3c-fb: CPUFREQ frequency scaling support
s3c-fb: fix resource releasing on error during probing
carminefb: fix possible access beyond end of carmine_modedb[]
acornfb: remove fb_mmap function
mb862xxfb: use CONFIG_OF instead of CONFIG_PPC_OF
mb862xxfb: restrict compliation of platform driver to PPC
Samsung SoC Framebuffer driver: add Alpha Channel support
atmel-lcdc: fix pixclock upper bound detection
offb: use framebuffer_alloc() to allocate fb_info struct
...
Manually fix up conflicts due to kmemcheck in mm/slab.c
Convert most arches to use asm-generic/kmap_types.h.
Move the KM_FENCE_ macro additions into asm-generic/kmap_types.h,
controlled by __WITH_KM_FENCE from each arch's kmap_types.h file.
Would be nice to be able to add custom KM_types per arch, but I don't yet
see a nice, clean way to do that.
Built on x86_64, i386, mips, sparc, alpha(tonyb), powerpc(tonyb), and
68k(tonyb).
Note: avr32 should be able to remove KM_PTE2 (since it's not used) and
then just use the generic kmap_types.h file. Get avr32 maintainer
approval.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: <linux-arch@vger.kernel.org>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Bryan Wu <cooloney@kernel.org>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: "Luck Tony" <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
