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By default, IRQ work is run from the tick interrupt (see
irq_work_run() in update_process_times()). When we're in full
NOHZ mode, restarting the tick requires the use of IRQ work and
if the only place we run IRQ work is in the tick interrupt we
have an unbreakable cycle. Implement arch_irq_work_raise() via
self IPIs to break this cycle and get the tick started again.
Note that we implement this via IPIs which are only available on
SMP builds. This shouldn't be a problem because full NOHZ is only
supported on SMP builds anyway.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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arch/arm/mach-footbridge/netwinder-hw.c:695:2: warning: passing argument 1 of 'spinlock_check' from incompatible pointer type
arch/arm/mach-footbridge/netwinder-hw.c:702:2: warning: passing argument 1 of 'spin_unlock_irqrestore' from incompatible pointer type
arch/arm/mach-footbridge/netwinder-hw.c:712:2: warning: passing argument 1 of 'spinlock_check' from incompatible pointer type
arch/arm/mach-footbridge/netwinder-hw.c:714:2: warning: passing argument 1 of 'spin_unlock_irqrestore' from incompatible pointer type
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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CPU hotplug and kexec rely on smp_ops.cpu_kill(), which is supposed
to wait for the CPU to park or power down, and perform the last
rites (such as disabling clocks etc., where the platform doesn't do
this automatically).
kexec in particular is unsafe without performing this
synchronisation to park secondaries. Without it, the secondaries
might not be parked when kexec trashes the kernel.
There is no generic way to do this synchronisation, so a new mcpm
platform_ops method power_down_finish() is added by this patch.
The new method is mandatory. A platform which provides no way to
detect when CPUs are parked is likely broken.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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This patch factors the logical-to-physical CPU translation out of
mcpm_boot_secondary(), so that it can be reused elsewhere.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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This removes the XSCALE_PMU Kconfig param, which is defined
but no longer used in makefiles and source files.
Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Use CONFIG_ARCH_PHYS_ADDR_T_64BIT to determine
if ignoring or truncating of memory banks is
neccessary. This may be needed in the case of
64-bit memory bank addresses but when phys_addr_t
is kept 32-bit.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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The DTB and/or the kernel command line may pass
64-bit addresses regardless of kernel configuration,
so update arm_add_memory() to take 64-bit arguments
independently of the phys_addr_t size.
This allows non-wrapping handling of high memory
banks such as the second memory bank of APE6EVM
(at 0x2_0000_0000) in case of 32-bit phys_addr_t.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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This is the ARM part of Christoph's patchset cleaning up the various
uses of __get_cpu_var across the tree.
The idea is to convert __get_cpu_var into either an explicit address
calculation using this_cpu_ptr() or into a use of this_cpu operations
that use the offset. Thereby address calculations are avoided and fewer
registers are used when code is generated.
[will: fixed debug ref counting checks and pcpu array accesses]
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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This code is becoming duplicated in many places. So let's consolidate
it into a handy macro that is known to be right and available for reuse.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Add debug uart support for MSM8974. This patch adds a Kconfig
entry and the base address for the debug uart.
Signed-off-by: Rohit Vaswani <rvaswani@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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for MSM
Create the hidden config DEBUG_MSM_UART and clean-up
the default selection for CONFIG_DEBUG_LL_INCLUDE.
Acked-by: David Brown <davidb@codeaurora.org>
Signed-off-by: Rohit Vaswani <rvaswani@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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This patch proposes to remove the use of the IRQF_DISABLED flag
It's a NOOP since 2.6.35 and it will be removed one day.
Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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The memory pinning code in uaccess_with_memcpy.c does not check
for HugeTLB or THP pmds, and will enter an infinite loop should
a __copy_to_user or __clear_user occur against a huge page.
This patch adds detection code for huge pages to pin_page_for_write.
As this code can be executed in a fast path it refers to the actual
pmds rather than the vma. If a HugeTLB or THP is found (they have
the same pmd representation on ARM), the page table spinlock is
taken to prevent modification whilst the page is pinned.
On ARM, huge pages are only represented as pmds, thus no huge pud
checks are performed. (For huge puds one would lock the page table
in a similar manner as in the pmd case).
Two helper functions are introduced; pmd_thp_or_huge will check
whether or not a page is huge or transparent huge (which have the
same pmd layout on ARM), and pmd_hugewillfault will detect whether
or not a page fault will occur on write to the page.
Running the following test (with the chunking from read_zero
removed):
$ dd if=/dev/zero of=/dev/null bs=10M count=1024
Gave: 2.3 GB/s backed by normal pages,
2.9 GB/s backed by huge pages,
5.1 GB/s backed by huge pages, with page mask=HPAGE_MASK.
After some discussion, it was decided not to adopt the HPAGE_MASK,
as this would have a significant detrimental effect on the overall
system latency due to page_table_lock being held for too long.
This could be revisited if split huge page locks are adopted.
Signed-off-by: Steve Capper <steve.capper@linaro.org>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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The work-around for A15 errata 798181 is not needed if appropriate ECO
fixes have been applied to r3p2 and earlier core revisions. This can be
checked by reading REVIDR register bits 4 and 9. If only bit 4 is set,
then the IPI broadcast can be skipped.
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Our spinlocks are only 32-bit (2x16-bit tickets) and, on processors
with 64-bit atomic instructions, cmpxchg64 makes use of the double-word
exclusive accessors.
This patch wires up the cmpxchg-based lockless lockref implementation
for ARM.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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This patch introduces cmpxchg64_relaxed for arm, which performs a 64-bit
cmpxchg operation without barrier semantics. cmpxchg64_local is updated
to use the new operation.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Our cmpxchg64 macros are wrappers around atomic64_cmpxchg. Whilst this is
great for code re-use, there is a case for barrier-less cmpxchg where it
is known to be safe (for example cmpxchg64_local and cmpxchg-based
lockrefs).
This patch introduces a 64-bit cmpxchg implementation specifically
for the cmpxchg64_* macros, so that it can be later used by the lockref
code.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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This implements output of debug messages on efm32 SoCs.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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With LPAE enabled, physical address space is larger than 4GB. Allow mapping any
part of it via /dev/mem by using PHYS_MASK to determine valid range.
PHYS_MASK covers 40 bits with LPAE enabled and 32 bits otherwise.
Reported-by: Vassili Karpov <av1474@comtv.ru>
Signed-off-by: Sergey Dyasly <dserrg@gmail.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
"Two fixlets:
- fix a (rare-config) build bug
- fix a next-gen SGI/UV hw/firmware enumeration bug"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: Update UV3 hub revision ID
x86/microcode: Correct Kconfig dependencies
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Pull device tree fixes and reverts from Grant Likely:
"One bug fix and three reverts. The reverts back out the slightly
controversial feeding the entire device tree into the random pool and
the reserved-memory binding which isn't fully baked yet. Expect the
reserved-memory patches at least to resurface for v3.13.
The bug fixes removes a scary but harmless warning on SPARC that was
introduced in the v3.12 merge window. v3.13 will contain a proper fix
that makes the new code work on SPARC.
On the plus side, the diffstat looks *awesome*. I love removing lines
of code"
* tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux:
Revert "drivers: of: add initialization code for dma reserved memory"
Revert "ARM: init: add support for reserved memory defined by device tree"
Revert "of: Feed entire flattened device tree into the random pool"
of: fix unnecessary warning on missing /cpus node
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git://git.linaro.org/people/mszyprowski/linux-dma-mapping
Pull DMA-mapping fix from Marek Szyprowski:
"A bugfix for the IOMMU-based implementation of dma-mapping subsystem
for ARM architecture"
* 'fixes-for-v3.12' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping:
ARM: dma-mapping: Always pass proper prot flags to iommu_map()
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Pull kvm fix from Gleb Natapov.
* git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: Enable pvspinlock after jump_label_init() to avoid VM hang
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git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull Xen fixes from Stefano Stabellini:
"A small fix for Xen on x86_32 and a build fix for xen-tpmfront on
arm64"
* tag 'stable/for-linus-3.12-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen: Fix possible user space selector corruption
tpm: xen-tpmfront: fix missing declaration of xen_domain
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We use jump label to enable pv-spinlock. With the changes in (442e0973e927
Merge branch 'x86/jumplabel'), the jump label behaviour has changed
that would result in eventual hang of the VM since we would end up in a
situation where slow path locks would halt the vcpus but we will not be
able to wakeup the vcpu by lock releaser using unlock kick.
Similar problem in Xen and more detailed description is available in
a945928ea270 (xen: Do not enable spinlocks before jump_label_init()
has executed)
This patch splits kvm_spinlock_init to separate jump label changes with
pvops patching and also make jump label enabling after jump_label_init().
Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
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This reverts commit 10bcdfb8ba24760f715f0a700c3812747eddddf5. There is
no consensus on the bindings for the reserved memory, so the code for
handing it will be reverted.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
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The UV3 hub revision ID is different than expected. The first
revision was supposed to start at 1 but instead will start at 0.
Signed-off-by: Russ Anderson <rja@sgi.com>
Cc: <stable@kernel.org> # v3.9, v3.10, v3.11
Link: http://lkml.kernel.org/r/20131014161733.GA6274@sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Pull ARM fixes from Russell King:
"Some more ARM fixes, nothing particularly major here. The biggest
change is to fix the SMP_ON_UP code so that it works with TI's Aegis
cores"
* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
ARM: 7851/1: check for number of arguments in syscall_get/set_arguments()
ARM: 7846/1: Update SMP_ON_UP code to detect A9MPCore with 1 CPU devices
ARM: 7845/1: sharpsl_param.c: fix invalid memory access for pxa devices
ARM: 7843/1: drop asm/types.h from generic-y
ARM: 7842/1: MCPM: don't explode if invoked without being initialized first
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I have a randconfig here which has enabled only
CONFIG_MICROCODE=y
CONFIG_MICROCODE_OLD_INTERFACE=y
with both
# CONFIG_MICROCODE_INTEL is not set
# CONFIG_MICROCODE_AMD is not set
off. Which makes building the microcode functionality a little
pointless. Don't do that in such cases then.
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1381682189-14470-1-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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In ftrace_syscall_enter(),
syscall_get_arguments(..., 0, n, ...)
if (i == 0) { <handle ORIG_r0> ...; n--;}
memcpy(..., n * sizeof(args[0]));
If 'number of arguments(n)' is zero and 'argument index(i)' is also zero in
syscall_get_arguments(), none of arguments should be copied by memcpy().
Otherwise 'n--' can be a big positive number and unexpected amount of data
will be copied. Tracing system calls which take no argument, say sync(void),
may hit this case and eventually make the system corrupted.
This patch fixes the issue both in syscall_get_arguments() and
syscall_set_arguments().
Cc: <stable@vger.kernel.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC fixes from Olof Johansson:
"A small batch of fixes this week, mostly OMAP related. Nothing stands
out as particularly controversial.
Also a fix for a 3.12-rc1 timer regression for Exynos platforms,
including the Chromebooks"
* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
ARM: exynos: dts: Update 5250 arch timer node with clock frequency
ARM: OMAP2: RX-51: Add missing max_current to rx51_lp5523_led_config
ARM: mach-omap2: board-generic: fix undefined symbol
ARM: dts: Fix pinctrl mask for omap3
ARM: OMAP3: Fix hardware detection for omap3630 when booted with device tree
ARM: OMAP2: gpmc-onenand: fix sync mode setup with DT
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Without the "clock-frequency" property in arch timer node, could able
to see the below crash dump.
[<c0014e28>] (unwind_backtrace+0x0/0xf4) from [<c0011808>] (show_stack+0x10/0x14)
[<c0011808>] (show_stack+0x10/0x14) from [<c036ac1c>] (dump_stack+0x7c/0xb0)
[<c036ac1c>] (dump_stack+0x7c/0xb0) from [<c01ab760>] (Ldiv0_64+0x8/0x18)
[<c01ab760>] (Ldiv0_64+0x8/0x18) from [<c0062f60>] (clockevents_config.part.2+0x1c/0x74)
[<c0062f60>] (clockevents_config.part.2+0x1c/0x74) from [<c0062fd8>] (clockevents_config_and_register+0x20/0x2c)
[<c0062fd8>] (clockevents_config_and_register+0x20/0x2c) from [<c02b8e8c>] (arch_timer_setup+0xa8/0x134)
[<c02b8e8c>] (arch_timer_setup+0xa8/0x134) from [<c04b47b4>] (arch_timer_init+0x1f4/0x24c)
[<c04b47b4>] (arch_timer_init+0x1f4/0x24c) from [<c04b40d8>] (clocksource_of_init+0x34/0x58)
[<c04b40d8>] (clocksource_of_init+0x34/0x58) from [<c049ed8c>] (time_init+0x20/0x2c)
[<c049ed8c>] (time_init+0x20/0x2c) from [<c049b95c>] (start_kernel+0x1e0/0x39c)
THis is because the Exynos u-boot, for example on the Chromebooks, doesn't set
up the CNTFRQ register as expected by arch_timer. Instead, we have to specify
the frequency in the device tree like this.
Signed-off-by: Yuvaraj Kumar C D <yuvaraj.cd@samsung.com>
[olof: Changed subject, added comment, elaborated on commit message]
Signed-off-by: Olof Johansson <olof@lixom.net>
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git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into fixes
From Tony Lindgren:
Few fixes for omap3 related hangs and errors that people have
noticed now that people are actually using the device tree
based booting for omap3.
Also one regression fix for timer compile for dra7xx when
omap5 is not selected, and a LED regression fix for n900.
* tag 'fixes-against-v3.12-rc3-take2' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap:
ARM: OMAP2: RX-51: Add missing max_current to rx51_lp5523_led_config
ARM: mach-omap2: board-generic: fix undefined symbol
ARM: dts: Fix pinctrl mask for omap3
ARM: OMAP3: Fix hardware detection for omap3630 when booted with device tree
ARM: OMAP2: gpmc-onenand: fix sync mode setup with DT
Signed-off-by: Olof Johansson <olof@lixom.net>
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Signed-off-by: Helge Deller <deller@gmx.de>
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The attached change defers the initialization of the variables tsk, mm
and flags until they are needed. As a result, the code won't crash if a
kernel probe is done with a corrupt context and the code will be better
optimized.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
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Running an "echo t > /proc/sysrq-trigger" crashes the parisc kernel. The
problem is, that in print_worker_info() we try to read the workqueue info via
the probe_kernel_read() functions which use pagefault_disable() to avoid
crashes like this:
probe_kernel_read(&pwq, &worker->current_pwq, sizeof(pwq));
probe_kernel_read(&wq, &pwq->wq, sizeof(wq));
probe_kernel_read(name, wq->name, sizeof(name) - 1);
The problem here is, that the first probe_kernel_read(&pwq) might return zero
in pwq and as such the following probe_kernel_reads() try to access contents of
the page zero which is read protected and generate a kernel segfault.
With this patch we fix the interruption handler to call parisc_terminate()
directly only if pagefault_disable() was not called (in which case
preempt_count()==0). Otherwise we hand over to the pagefault handler which
will try to look up the faulting address in the fixup tables.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v3.0+
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
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Signed-off-by: Helge Deller <deller@gmx.de>
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Signed-off-by: Helge Deller <deller@gmx.de>
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Commit 9a46ad6d6df3b54 "smp: make smp_call_function_many() use logic
similar to smp_call_function_single()" has unified the way to handle
single and multiple cross-CPU function calls. Now only one interrupt
is needed for architecture specific code to support generic SMP function
call interfaces, so kill the redundant single function call interrupt.
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Cc: Jiang Liu <liuj97@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
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ERROR: "flush_cache_page" [drivers/staging/lustre/lustre/libcfs/libcfs.ko] undefined!
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Helge Deller <deller@gmx.de>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull gcc "asm goto" miscompilation workaround from Ingo Molnar:
"This is the fix for the GCC miscompilation discussed in the following
lkml thread:
[x86] BUG: unable to handle kernel paging request at 00740060
The bug in GCC has been fixed by Jakub and the fix will be part of the
GCC 4.8.2 release expected to be released next week - so the quirk's
version test checks for <= 4.8.1.
The quirk is only added to compiler-gcc4.h and not to the higher level
compiler.h because all asm goto uses are behind a feature check"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
compiler/gcc4: Add quirk for 'asm goto' miscompilation bug
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
"A build fix and a reboot quirk"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/reboot: Add reboot quirk for Dell Latitude E5410
x86, build, pci: Fix PCI_MSI build on !SMP
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git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc
Pull ARC fix from Vineet Gupta:
"Fix for broken gdb 'jump'"
* tag 'arc-fixes-for-3.12-part3' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
ARC: Ignore ptrace SETREGSET request for synthetic register "stop_pc"
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ARCompact TRAP_S insn used for breakpoints, commits before exception is
taken (updating architectural PC). So ptregs->ret contains next-PC and
not the breakpoint PC itself. This is different from other restartable
exceptions such as TLB Miss where ptregs->ret has exact faulting PC.
gdb needs to know exact-PC hence ARC ptrace GETREGSET provides for
@stop_pc which returns ptregs->ret vs. EFA depending on the
situation.
However, writing stop_pc (SETREGSET request), which updates ptregs->ret
doesn't makes sense stop_pc doesn't always correspond to that reg as
described above.
This was not an issue so far since user_regs->ret / user_regs->stop_pc
had same value and both writing to ptregs->ret was OK, needless, but NOT
broken, hence not observed.
With gdb "jump", they diverge, and user_regs->ret updating ptregs is
overwritten immediately with stop_pc, which this patch fixes.
Reported-by: Anton Kolesov <akolesov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
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Pull MIPS fix from Ralf Baechle:
"Just one fix. The stack protector was loading the value of the canary
instead of its address"
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
MIPS: stack protector: Fix per-task canary switch
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Fengguang Wu, Oleg Nesterov and Peter Zijlstra tracked down
a kernel crash to a GCC bug: GCC miscompiles certain 'asm goto'
constructs, as outlined here:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670
Implement a workaround suggested by Jakub Jelinek.
Reported-and-tested-by: Fengguang Wu <fengguang.wu@intel.com>
Reported-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Suggested-by: Jakub Jelinek <jakub@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Pull kbuild fix from Michal Marek:
"Here is an ARM Makefile fix that you even acked. After nobody wanted
to take it, it ended up in the kbuild tree"
* 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
arm, kbuild: make "make install" not depend on vmlinux
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Pull kvm fixes from Paolo Bonzini:
"Fixes for 3.12-rc5: two old PPC bugs and one new (3.12-rc2) x86 bug"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
kvm: ppc: booke: check range page invalidation progress on page setup
KVM: PPC: Book3S HV: Fix typo in saving DSCR
KVM: nVMX: fix shadow on EPT
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Due to the way kernel is initialized under Xen is possible that the
ring1 selector used by the kernel for the boot cpu end up to be copied
to userspace leading to segmentation fault in the userspace.
Xen code in the kernel initialize no-boot cpus with correct selectors (ds
and es set to __USER_DS) but the boot one keep the ring1 (passed by Xen).
On task context switch (switch_to) we assume that ds, es and cs already
point to __USER_DS and __KERNEL_CSso these selector are not changed.
If processor is an Intel that support sysenter instruction sysenter/sysexit
is used so ds and es are not restored switching back from kernel to
userspace. In the case the selectors point to a ring1 instead of __USER_DS
the userspace code will crash on first memory access attempt (to be
precise Xen on the emulated iret used to do sysexit will detect and set ds
and es to zero which lead to GPF anyway).
Now if an userspace process call kernel using sysenter and get rescheduled
(for me it happen on a specific init calling wait4) could happen that the
ring1 selector is set to ds and es.
This is quite hard to detect cause after a while these selectors are fixed
(__USER_DS seems sticky).
Bisecting the code commit 7076aada1040de4ed79a5977dbabdb5e5ea5e249 appears
to be the first one that have this issue.
Signed-off-by: Frediano Ziglio <frediano.ziglio@citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
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When the MM code is invalidating a range of pages, it calls the KVM
kvm_mmu_notifier_invalidate_range_start() notifier function, which calls
kvm_unmap_hva_range(), which arranges to flush all the TLBs for guest pages.
However, the Linux PTEs for the range being flushed are still valid at
that point. We are not supposed to establish any new references to pages
in the range until the ...range_end() notifier gets called.
The PPC-specific KVM code doesn't get any explicit notification of that;
instead, we are supposed to use mmu_notifier_retry() to test whether we
are or have been inside a range flush notifier pair while we have been
referencing a page.
This patch calls the mmu_notifier_retry() while mapping the guest
page to ensure we are not referencing a page when in range invalidation.
This call is inside a region locked with kvm->mmu_lock, which is the
same lock that is called by the KVM MMU notifier functions, thus
ensuring that no new notification can proceed while we are in the
locked region.
Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
Acked-by: Alexander Graf <agraf@suse.de>
[Backported to 3.12 - Paolo]
Reviewed-by: Bharat Bhushan <bharat.bhushan@freescale.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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