The Debian experimental linux source package (3.8.5-1) build fails
with the following errors:
...
MODPOST 2016 modules
ERROR: "__ucmpdi2" [fs/btrfs/btrfs.ko] undefined!
ERROR: "__ucmpdi2" [drivers/md/dm-verity.ko] undefined!

The attached patch resolves this problem.  It is based on the s390
implementation of ucmpdi2.c.
Signed-off-by: NJohn David Anglin <dave.anglin@bell.net>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Signed-off-by: NHelge Deller <deller@gmx.de>

Reported-by: NMeelis Roos <mroos@linux.ee>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit c17a6554.

Manuel Lauss writes:

lmo commit c17a6554 (MIPS: page.h: Provide more readable definition for
PAGE_MASK) apparently breaks ioremap of 36-bit addresses on my Alchemy
systems (PCI and PCMCIA) The reason is that in arch/mips/mm/ioremap.c
line 157  (phys_addr &= PAGE_MASK) bits 32-35 are cut off.  Seems the
new PAGE_MASK is explicitly 32bit, or one could make it signed instead
of unsigned long.

For each CPU vendor that implements CPU microcode patching, there will
be a minimum family for which this is implemented.  Verify this
minimum level of support.

This can be done in the dispatch function or early in the application
functions.  Doing the latter turned out to be somewhat awkward because
of the ineviable split between the BSP and the AP paths, and rather
than pushing deep into the application functions, do this in
the dispatch function.
Reported-by: N"Bryan O'Donoghue" <bryan.odonoghue.lkml@nexus-software.ie>
Suggested-by: NBorislav Petkov <bp@alien8.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1366392183-4149-1-git-send-email-bryan.odonoghue.lkml@nexus-software.ie

As reported by Dave Kleikamp, when we emit cross calls to do batched
TLB flush processing we have a race because we do not synchronize on
the sibling cpus completing the cross call.

So meanwhile the TLB batch can be reset (tb->tlb_nr set to zero, etc.)
and either flushes are missed or flushes will flush the wrong
addresses.

Fix this by using generic infrastructure to synchonize on the
completion of the cross call.

This first required getting the flush_tlb_pending() call out from
switch_to() which operates with locks held and interrupts disabled.
The problem is that smp_call_function_many() cannot be invoked with
IRQs disabled and this is explicitly checked for with WARN_ON_ONCE().

We get the batch processing outside of locked IRQ disabled sections by
using some ideas from the powerpc port. Namely, we only batch inside
of arch_{enter,leave}_lazy_mmu_mode() calls.  If we're not in such a
region, we flush TLBs synchronously.

1) Get rid of xcall_flush_tlb_pending and per-cpu type
   implementations.

2) Do TLB batch cross calls instead via:

	smp_call_function_many()
		tlb_pending_func()
			__flush_tlb_pending()

3) Batch only in lazy mmu sequences:

	a) Add 'active' member to struct tlb_batch
	b) Define __HAVE_ARCH_ENTER_LAZY_MMU_MODE
	c) Set 'active' in arch_enter_lazy_mmu_mode()
	d) Run batch and clear 'active' in arch_leave_lazy_mmu_mode()
	e) Check 'active' in tlb_batch_add_one() and do a synchronous
           flush if it's clear.

4) Add infrastructure for synchronous TLB page flushes.

	a) Implement __flush_tlb_page and per-cpu variants, patch
	   as needed.
	b) Likewise for xcall_flush_tlb_page.
	c) Implement smp_flush_tlb_page() to invoke the cross-call.
	d) Wire up global_flush_tlb_page() to the right routine based
           upon CONFIG_SMP

5) It turns out that singleton batches are very common, 2 out of every
   3 batch flushes have only a single entry in them.

   The batch flush waiting is very expensive, both because of the poll
   on sibling cpu completeion, as well as because passing the tlb batch
   pointer to the sibling cpus invokes a shared memory dereference.

   Therefore, in flush_tlb_pending(), if there is only one entry in
   the batch perform a completely asynchronous global_flush_tlb_page()
   instead.
Reported-by: NDave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Acked-by: NDave Kleikamp <dave.kleikamp@oracle.com>

cyc_to_sched_clock() is called by sched_clock() and cyc_to_ns()
is called by cyc_to_sched_clock(). I suspect that some compilers
inline both of these functions into sched_clock() and so we've
been getting away without having a notrace marking. It seems that
my compiler isn't inlining cyc_to_sched_clock() though, so I'm
hitting a recursion bug when I enable the function graph tracer,
causing my system to crash. Marking these functions notrace fixes
it. Technically cyc_to_ns() doesn't need the notrace because it's
already marked inline, but let's just add it so that if we ever
remove inline from that function it doesn't blow up.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The L1 data cache flush needs to be after highbank_set_cpu_jump call which
pollutes the cache with the l2x0_lock. This causes other cores to deadlock
waiting for the l2x0_lock. Moving the flush of the entire data cache after
highbank_set_cpu_jump fixes the problem. Use flush_cache_louis instead of
flush_cache_all are that is sufficient to flush only the L1 data cache.
flush_cache_louis did not exist when highbank_cpu_die was originally
written.

With PL310 errata 769419 enabled, a wmb is inserted into idle which takes
the l2x0_lock. This makes the problem much more easily hit and causes
reset to hang.
Reported-by: NPaolo Pisati <p.pisati@gmail.com>
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Signed-off-by: NOlof Johansson <olof@lixom.net>

Install the Hyper-V specific interrupt handler only when needed. This would
permit us to get rid of the Xen check. Note that when the vmbus drivers invokes
the call to register its handler, we are sure to be running on Hyper-V.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Link: http://lkml.kernel.org/r/1366299886-6399-1-git-send-email-kys@microsoft.comAcked-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

fixed the following compile error when use avr32 atstk1006_defconfig:

  drivers/mtd/nand/atmel_nand.c: In function 'pmecc_err_location':
  drivers/mtd/nand/atmel_nand.c:639: error: implicit declaration of function 'writel_relaxed'

which was introduced by commit 1c7b874d ("mtd: at91: atmel_nand: add
Programmable Multibit ECC controller support").  The PMECC for nand
flash code uses writel_relaxed().  But in avr32, there is no macro
"writel_relaxed" defined.

This patch add writex_relaxed macro definitions.
Signed-off-by: NJosh Wu <josh.wu@atmel.com>
Acked-by: NHavard Skinnemoen <havard@skinnemoen.net>
Acked-by: NHans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: David Woodhouse <David.Woodhouse@intel.com>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In the very unlikely event where a guest would be foolish enough to
*read* from a write-only cache maintainance register, we end up
with preemption disabled, due to a misplaced get_cpu().

Just move the "is_write" test outside of the critical section.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NChristoffer Dall <cdall@cs.columbia.edu>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Per hpa, use crashkernel=X,high crashkernel=Y,low instead of
crashkernel_hign=X crashkernel_low=Y. As that could be extensible.

-v2: according to Vivek, change delimiter to ;
-v3: let hign and low only handle simple form and it conforms to
	description in kernel-parameters.txt
     still keep crashkernel=X override any crashkernel=X,high
        crashkernel=Y,low
-v4: update get_last_crashkernel returning and add more strict
     checking in parse_crashkernel_simple() found by HATAYAMA.
-v5: Change delimiter back to , according to HPA.
     also separate parse_suffix from parse_simper according to vivek.
	so we can avoid @pos in that path.
-v6: Tight the checking about crashkernel=X,highblahblah,high
     found by HTYAYAMA.

Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1366089828-19692-5-git-send-email-yinghai@kernel.orgAcked-by: NVivek Goyal <vgoyal@redhat.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Vivek found old kexec-tools does not work new kernel anymore.

So change back crashkernel= back to old behavoir, and add crashkernel_high=
to let user decide if buffer could be above 4G, and also new kexec-tools will
be needed.

-v2: let crashkernel=X override crashkernel_high=
    update description about _high will be ignored by crashkernel=X
-v3: update description about kernel-parameters.txt according to Vivek.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1366089828-19692-4-git-send-email-yinghai@kernel.orgAcked-by: NVivek Goyal <vgoyal@redhat.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Chao said that kdump does does work well on his system on 3.8
without extra parameter, even iommu does not work with kdump.
And now have to append crashkernel_low=Y in first kernel to make
kdump work.

We have now modified crashkernel=X to allocate memory beyong 4G (if
available) and do not allocate low range for crashkernel if the user
does not specify that with crashkernel_low=Y.  This causes regression
if iommu is not enabled.  Without iommu, swiotlb needs to be setup in
first 4G and there is no low memory available to second kernel.

Set crashkernel_low automatically if the user does not specify that.

For system that does support IOMMU with kdump properly, user could
specify crashkernel_low=0 to save that 72M low ram.

-v3: add swiotlb_size() according to Konrad.
-v4: add comments what 8M is for according to hpa.
     also update more crashkernel_low= in kernel-parameters.txt
-v5: update changelog according to Vivek.
-v6: Change description about swiotlb referring according to HATAYAMA.
Reported-by: NWANG Chao <chaowang@redhat.com>
Tested-by: NWANG Chao <chaowang@redhat.com>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1366089828-19692-2-git-send-email-yinghai@kernel.orgAcked-by: NVivek Goyal <vgoyal@redhat.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Events may be created with attr->disabled == 1 and attr->enable_on_exec
== 1, which confuses the group validation code because events with the
PERF_EVENT_STATE_OFF are not considered candidates for scheduling, which
may lead to failure at group scheduling time.

This patch fixes the validation check for ARM, so that events in the
OFF state are still considered when enable_on_exec is true.

Cc: stable@vger.kernel.org
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Reported-by: NSudeep KarkadaNagesha <Sudeep.KarkadaNagesha@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

We must not declare dbg_cpu_pm_nb as __cpuinitdata as we need it after
system initialization for Suspend and CPUIdle.

This was done in commit 9a6eb310 ("ARM: hw_breakpoint: Debug powerdown
support for self-hosted debug").

Cc: stable@vger.kernel.org
Cc: Dietmar Eggemann <Dietmar.Eggemann@arm.com>
Signed-off-by: NBastian Hecht <hechtb+renesas@gmail.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

On Feroceon the L2 cache becomes non-coherent with the CPU
when the L1 caches are disabled. Thus the L2 needs to be invalidated
after both L1 caches are disabled.

On kexec before the starting the code for relocation the kernel,
the L1 caches are disabled in cpu_froc_fin (cpu_v7_proc_fin for Feroceon),
but after L2 cache is never invalidated, because inv_all is not set
in cache-feroceon-l2.c.
So kernel relocation and decompression may has (and usually has) errors.
Setting the function enables L2 invalidation and fixes the issue.

Cc: <stable@vger.kernel.org>
Signed-off-by: NIllia Ragozin <illia.ragozin@grapecom.com>
Acked-by: NJason Cooper <jason@lakedaemon.net>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

tcm_init() call iotable_init() and it use early_alloc variants which
do memblock allocation. Directly using memblock allocation after
initializing bootmem should not permitted, because bootmem can't know
where are additinally reserved.
So move tcm_init() to a safe place before initalizing bootmem.

(On the U300)
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Currently IOP3XX_PERIPHERAL_VIRT_BASE conflicts with PCI_IO_VIRT_BASE:

					address         size
	PCI_IO_VIRT_BASE                0xfee00000      0x200000
	IOP3XX_PERIPHERAL_VIRT_BASE     0xfeffe000      0x2000

Fix by moving IOP3XX_PERIPHERAL_VIRT_BASE below PCI_IO_VIRT_BASE.

The patch fixes the following kernel panic with 3.9-rc1 on iop3xx boards:

[    0.000000] Booting Linux on physical CPU 0x0
[    0.000000] Initializing cgroup subsys cpu
[    0.000000] Linux version 3.9.0-rc1-iop32x (aaro@blackmetal) (gcc version 4.7.2 (GCC) ) #20 PREEMPT Tue Mar 5 16:44:36 EET 2013
[    0.000000] bootconsole [earlycon0] enabled
[    0.000000] ------------[ cut here ]------------
[    0.000000] kernel BUG at mm/vmalloc.c:1145!
[    0.000000] Internal error: Oops - BUG: 0 [#1] PREEMPT ARM
[    0.000000] Modules linked in:
[    0.000000] CPU: 0    Not tainted  (3.9.0-rc1-iop32x #20)
[    0.000000] PC is at vm_area_add_early+0x4c/0x88
[    0.000000] LR is at add_static_vm_early+0x14/0x68
[    0.000000] pc : [<c03e74a8>]    lr : [<c03e1c40>]    psr: 800000d3
[    0.000000] sp : c03ffee4  ip : dfffdf88  fp : c03ffef4
[    0.000000] r10: 00000002  r9 : 000000cf  r8 : 00000653
[    0.000000] r7 : c040eca8  r6 : c03e2408  r5 : dfffdf60  r4 : 00200000
[    0.000000] r3 : dfffdfd8  r2 : feffe000  r1 : ff000000  r0 : dfffdf60
[    0.000000] Flags: Nzcv  IRQs off  FIQs off  Mode SVC_32  ISA ARM  Segment kernel
[    0.000000] Control: 0000397f  Table: a0004000  DAC: 00000017
[    0.000000] Process swapper (pid: 0, stack limit = 0xc03fe1b8)
[    0.000000] Stack: (0xc03ffee4 to 0xc0400000)
[    0.000000] fee0:          00200000 c03fff0c c03ffef8 c03e1c40 c03e7468 00200000 fee00000
[    0.000000] ff00: c03fff2c c03fff10 c03e23e4 c03e1c38 feffe000 c0408ee4 ff000000 c0408f04
[    0.000000] ff20: c03fff3c c03fff30 c03e2434 c03e23b4 c03fff84 c03fff40 c03e2c94 c03e2414
[    0.000000] ff40: c03f8878 c03f6410 ffff0000 000bffff 00001000 00000008 c03fff84 c03f6410
[    0.000000] ff60: c04227e8 c03fffd4 a0008000 c03f8878 69052e30 c02f96eb c03fffbc c03fff88
[    0.000000] ff80: c03e044c c03e268c 00000000 0000397f c0385130 00000001 ffffffff c03f8874
[    0.000000] ffa0: dfffffff a0004000 69052e30 a03f61a0 c03ffff4 c03fffc0 c03dd5cc c03e0184
[    0.000000] ffc0: 00000000 00000000 00000000 00000000 00000000 c03f8878 0000397d c040601c
[    0.000000] ffe0: c03f8874 c0408674 00000000 c03ffff8 a0008040 c03dd558 00000000 00000000
[    0.000000] Backtrace:
[    0.000000] [<c03e745c>] (vm_area_add_early+0x0/0x88) from [<c03e1c40>] (add_static_vm_early+0x14/0x68)
Tested-by: NMikael Pettersson <mikpe@it.uu.se>
Signed-off-by: NAaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Commit b4cbb197 ("vm: add vm_iomap_memory() helper function") added
a helper function wrapper around io_remap_pfn_range(), and every other
architecture defined it in <asm/pgtable.h>.

The s390 choice of <asm/io.h> may make sense, but is not very convenient
for this case, and gratuitous differences like that cause unexpected errors like this:

   mm/memory.c: In function 'vm_iomap_memory':
   mm/memory.c:2439:2: error: implicit declaration of function 'io_remap_pfn_range' [-Werror=implicit-function-declaration]

Glory be the kbuild test robot who noticed this, bisected it, and
reported it to the guilty parties (ie me).

Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Using this parameter one can disable the storage_size/2 check if
he is really sure that the UEFI does sane gc and fulfills the spec.

This parameter is useful if a devices uses more than 50% of the
storage by default.
The Intel DQSW67 desktop board is such a sucker for exmaple.
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Looks like our L_PTE_S2_RDWR definition is slightly wrong,
and is actually write only (see ARM ARM Table B3-9, Stage 2 control
of access permissions). Didn't make a difference for normal pages,
as we OR the flags together, but I'm still wondering how it worked
for Stage-2 mapped devices, such as the GIC.

Brown paper bag time, again.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NChristoffer Dall <cdall@cs.columbia.edu>

Commit 3401d546 (KVM: ARM: Introduce KVM_ARM_SET_DEVICE_ADDR
ioctl) added support for the KVM_CAP_ARM_SET_DEVICE_ADDR capability,
but failed to add a break in the relevant case statement, returning
the number of CPUs instead.

Luckilly enough, the CONFIG_NR_CPUS=0 patch hasn't been merged yet
(https://lkml.org/lkml/diff/2012/3/31/131/1), so the bug wasn't
noticed.

Just give it a break!
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NChristoffer Dall <cdall@cs.columbia.edu>

Fixes build with CONFIG_EFI_VARS=m which was broken after the commit
"x86, efivars: firmware bug workarounds should be in platform code".
Signed-off-by: NSergey Vlasov <vsu@altlinux.ru>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

The commit "efi: Distinguish between "remaining space" and actually used
space" added usage of ucs2_*() functions to arch/x86/platform/efi/efi.c,
but the only thing which selected UCS2_STRING was EFI_VARS, which is
technically optional and can be built as a module.
Signed-off-by: NSergey Vlasov <vsu@altlinux.ru>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

The valid mask for both offcore_response_0 and
offcore_response_1 was wrong for SNB/SNB-EP,
IVB/IVB-EP. It was possible to write to
reserved bit and cause a GP fault crashing
the kernel.

This patch fixes the problem by correctly marking the
reserved bits in the valid mask for all the processors
mentioned above.

A distinction between desktop and server parts is introduced
because bits 24-30 are only available on the server parts.

This version of the  patch is just a rebase to perf/urgent tree
and should apply to older kernels as well.
Signed-off-by: NStephane Eranian <eranian@google.com>
Cc: peterz@infradead.org
Cc: jolsa@redhat.com
Cc: gregkh@linuxfoundation.org
Cc: security@kernel.org
Cc: ak@linux.intel.com
Signed-off-by: NIngo Molnar <mingo@kernel.org>

EFI implementations distinguish between space that is actively used by a
variable and space that merely hasn't been garbage collected yet. Space
that hasn't yet been garbage collected isn't available for use and so isn't
counted in the remaining_space field returned by QueryVariableInfo().

Combined with commit 68d92986 this can cause problems. Some implementations
don't garbage collect until the remaining space is smaller than the maximum
variable size, and as a result check_var_size() will always fail once more
than 50% of the variable store has been used even if most of that space is
marked as available for garbage collection. The user is unable to create
new variables, and deleting variables doesn't increase the remaining space.

The problem that 68d92986 was attempting to avoid was one where certain
platforms fail if the actively used space is greater than 50% of the
available storage space. We should be able to calculate that by simply
summing the size of each available variable and subtracting that from
the total storage space. With luck this will fix the problem described in
https://bugzilla.kernel.org/show_bug.cgi?id=55471 without permitting
damage to occur to the machines 68d92986 was attempting to fix.
Signed-off-by: NMatthew Garrett <matthew.garrett@nebula.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

EFI variables can be flagged as being accessible only within boot services.
This makes it awkward for us to figure out how much space they use at
runtime. In theory we could figure this out by simply comparing the results
from QueryVariableInfo() to the space used by all of our variables, but
that fails if the platform doesn't garbage collect on every boot. Thankfully,
calling QueryVariableInfo() while still inside boot services gives a more
reliable answer. This patch passes that information from the EFI boot stub
up to the efi platform code.
Signed-off-by: NMatthew Garrett <matthew.garrett@nebula.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

A label 0 was missed in the patch a9c4e541 (powerpc/kprobe: Complete
kprobe and migrate exception frame). This will cause the kernel
branch to an undetermined address if there really has a conflict when
updating the thread flags.
Signed-off-by: NKevin Hao <haokexin@gmail.com>
Cc: stable@vger.kernel.org
Acked-By: NTiejun Chen <tiejun.chen@windriver.com>
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>

The current mainline crashes when hitting userspace with the following:

kernel BUG at kernel/auditsc.c:1769!
cpu 0x1: Vector: 700 (Program Check) at [c000000023883a60]
    pc: c0000000001047a8: .__audit_syscall_entry+0x38/0x130
    lr: c00000000000ed64: .do_syscall_trace_enter+0xc4/0x270
    sp: c000000023883ce0
   msr: 8000000000029032
  current = 0xc000000023800000
  paca    = 0xc00000000f080380   softe: 0        irq_happened: 0x01
    pid   = 1629, comm = start_udev
kernel BUG at kernel/auditsc.c:1769!
enter ? for help
[c000000023883d80] c00000000000ed64 .do_syscall_trace_enter+0xc4/0x270
[c000000023883e30] c000000000009b08 syscall_dotrace+0xc/0x38
 --- Exception: c00 (System Call) at 0000008010ec50dc

Bisecting found the following patch caused it:

commit 44e9309f
Author: Haren Myneni <haren@linux.vnet.ibm.com>
powerpc: Implement PPR save/restore

It was found this patch corrupted r9 when calling
SET_DEFAULT_THREAD_PPR()

Using r10 as a scratch register instead of r9 solved the problem.
Signed-off-by: NAlistair Popple <alistair@popple.id.au>
Acked-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>

This patch attempts to fix:

	https://bugzilla.kernel.org/show_bug.cgi?id=56461

The symptom is a crash and messages like this:

	chrome: Corrupted page table at address 34a03000
	*pdpt = 0000000000000000 *pde = 0000000000000000
	Bad pagetable: 000f [#1] PREEMPT SMP

Ingo guesses this got introduced by commit 611ae8e3 ("x86/tlb:
enable tlb flush range support for x86") since that code started to free
unused pagetables.

On x86-32 PAE kernels, that new code has the potential to free an entire
PMD page and will clear one of the four page-directory-pointer-table
(aka pgd_t entries).

The hardware aggressively "caches" these top-level entries and invlpg
does not actually affect the CPU's copy.  If we clear one we *HAVE* to
do a full TLB flush, otherwise we might continue using a freed pmd page.
(note, we do this properly on the population side in pud_populate()).

This patch tracks whenever we clear one of these entries in the 'struct
mmu_gather', and ensures that we follow up with a full tlb flush.

BTW, I disassembled and checked that:

	if (tlb->fullmm == 0)
and
	if (!tlb->fullmm && !tlb->need_flush_all)

generate essentially the same code, so there should be zero impact there
to the !PAE case.
Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Artem S Tashkinov <t.artem@mailcity.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When CONFIG_DEBUG_PAGEALLOC is set page table updates made by
kernel_map_pages() are not made visible (via TLB flush)
immediately if lazy MMU is on. In environments that support lazy
MMU (e.g. Xen) this may lead to fatal page faults, for example,
when zap_pte_range() needs to allocate pages in
__tlb_remove_page() -> tlb_next_batch().
Signed-off-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: konrad.wilk@oracle.com
Link: http://lkml.kernel.org/r/1365703192-2089-1-git-send-email-boris.ostrovsky@oracle.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

If the pmd is not present, _PAGE_PSE will not be set anymore.
Fix the false positive.
Reported-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com>
Cc: Stefan Bader <stefan.bader@canonical.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Borislav Petkov <bp@alien8.de>
Link: http://lkml.kernel.org/r/1365687369-30802-1-git-send-email-aarcange@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Some EFI implementations return always a MaximumVariableSize of 0,
check against max_size only if it is non-zero.
My Intel DQ67SW desktop board has such an implementation.
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Commit 523f0e54 ("KVM: PPC: E500:
Explicitly mark shadow maps invalid") began using E500_TLB_VALID
for guest TLB1 entries, and skipping invalidations if it's not set.

However, when E500_TLB_VALID was set for such entries, it was on a
fake local ref, and so the invalidations never happen.  gtlb_privs
is documented as being only for guest TLB0, though we already violate
that with E500_TLB_BITMAP.

Now that we have MMU notifiers, and thus don't need to actually
retain a reference to the mapped pages, get rid of tlb_refs, and
use gtlb_privs for E500_TLB_VALID in TLB1.

Since we can have more than one host TLB entry for a given tlbe_ref,
be careful not to clear existing flags that are relevant to other
host TLB entries when preparing a new host TLB entry.
Signed-off-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

It's possible that we're using the same host TLB1 slot to map (a
presumably different portion of) the same guest TLB1 entry.  Clear
the bit in the map before setting it, so that if the esels are the same
the bit will remain set.
Signed-off-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

Add one to esel values in h2g_tlb1_rmap, so that "no mapping" can be
distinguished from "esel 0".  Note that we're not saved by the fact
that host esel 0 is reserved for non-KVM use, because KVM host esel
numbering is not the raw host numbering (see to_htlb1_esel).
Signed-off-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

Commit:

  a8aed3e0 ("x86/mm/pageattr: Prevent PSE and GLOABL leftovers to confuse pmd/pte_present and pmd_huge")

introduced a valid fix but one location that didn't trigger the bug that
lead to finding those (small) problems, wasn't updated using the
right variable.

The wrong variable was also initialized for no good reason, that
may have been the source of the confusion. Remove the noop
initialization accordingly.

Commit a8aed3e0 also erroneously removed one canon_pgprot pass meant
to clear pmd bitflags not supported in hardware by older CPUs, that
automatically gets corrected by this patch too by applying it to the right
variable in the new location.
Reported-by: NStefan Bader <stefan.bader@canonical.com>
Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com>
Acked-by: NBorislav Petkov <bp@alien8.de>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Mel Gorman <mgorman@suse.de>
Link: http://lkml.kernel.org/r/1365600505-19314-1-git-send-email-aarcange@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

The existing check handles the case where we've migrated to a different
core than we last ran on, but it doesn't handle the case where we're
still on the same cpu we last ran on, but some other vcpu has run on
this cpu in the meantime.

Without this, guest segfaults (and other misbehavior) have been seen in
smp guests.

Cc: stable@vger.kernel.org # 3.8.x
Signed-off-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

Invoking arch_flush_lazy_mmu_mode() results in calls to
preempt_enable()/disable() which may have performance impact.

Since lazy MMU is not used on bare metal we can patch away
arch_flush_lazy_mmu_mode() so that it is never called in such
environment.

[ hpa: the previous patch "Fix vmalloc_fault oops during lazy MMU
  updates" may cause a minor performance regression on
  bare metal.  This patch resolves that performance regression.  It is
  somewhat unclear to me if this is a good -stable candidate. ]
Signed-off-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Link: http://lkml.kernel.org/r/1364045796-10720-2-git-send-email-konrad.wilk@oracle.comTested-by: NJosh Boyer <jwboyer@redhat.com>
Tested-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org> SEE NOTE ABOVE

In paravirtualized x86_64 kernels, vmalloc_fault may cause an oops
when lazy MMU updates are enabled, because set_pgd effects are being
deferred.

One instance of this problem is during process mm cleanup with memory
cgroups enabled. The chain of events is as follows:

- zap_pte_range enables lazy MMU updates
- zap_pte_range eventually calls mem_cgroup_charge_statistics,
  which accesses the vmalloc'd mem_cgroup per-cpu stat area
- vmalloc_fault is triggered which tries to sync the corresponding
  PGD entry with set_pgd, but the update is deferred
- vmalloc_fault oopses due to a mismatch in the PUD entries

The OOPs usually looks as so:

------------[ cut here ]------------
kernel BUG at arch/x86/mm/fault.c:396!
invalid opcode: 0000 [#1] SMP
.. snip ..
CPU 1
Pid: 10866, comm: httpd Not tainted 3.6.10-4.fc18.x86_64 #1
RIP: e030:[<ffffffff816271bf>]  [<ffffffff816271bf>] vmalloc_fault+0x11f/0x208
.. snip ..
Call Trace:
 [<ffffffff81627759>] do_page_fault+0x399/0x4b0
 [<ffffffff81004f4c>] ? xen_mc_extend_args+0xec/0x110
 [<ffffffff81624065>] page_fault+0x25/0x30
 [<ffffffff81184d03>] ? mem_cgroup_charge_statistics.isra.13+0x13/0x50
 [<ffffffff81186f78>] __mem_cgroup_uncharge_common+0xd8/0x350
 [<ffffffff8118aac7>] mem_cgroup_uncharge_page+0x57/0x60
 [<ffffffff8115fbc0>] page_remove_rmap+0xe0/0x150
 [<ffffffff8115311a>] ? vm_normal_page+0x1a/0x80
 [<ffffffff81153e61>] unmap_single_vma+0x531/0x870
 [<ffffffff81154962>] unmap_vmas+0x52/0xa0
 [<ffffffff81007442>] ? pte_mfn_to_pfn+0x72/0x100
 [<ffffffff8115c8f8>] exit_mmap+0x98/0x170
 [<ffffffff810050d9>] ? __raw_callee_save_xen_pmd_val+0x11/0x1e
 [<ffffffff81059ce3>] mmput+0x83/0xf0
 [<ffffffff810624c4>] exit_mm+0x104/0x130
 [<ffffffff8106264a>] do_exit+0x15a/0x8c0
 [<ffffffff810630ff>] do_group_exit+0x3f/0xa0
 [<ffffffff81063177>] sys_exit_group+0x17/0x20
 [<ffffffff8162bae9>] system_call_fastpath+0x16/0x1b

Calling arch_flush_lazy_mmu_mode immediately after set_pgd makes the
changes visible to the consistency checks.

Cc: <stable@vger.kernel.org>
RedHat-Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=914737Tested-by: NJosh Boyer <jwboyer@redhat.com>
Reported-and-Tested-by: NKrishna Raman <kraman@redhat.com>
Signed-off-by: NSamu Kallio <samu.kallio@aberdeencloud.com>
Link: http://lkml.kernel.org/r/1364045796-10720-1-git-send-email-konrad.wilk@oracle.comTested-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>