With the addition of caches to the V7M Architecture a new Cache Type
Register (CTR) is defined at 0xE000ED7C. This register serves the same
purpose as the V7A/R version and accessed via the read_cpuid_cachetype.
Signed-off-by: NJonathan Austin <jonathan.austin@arm.com>
Signed-off-by: NVladimir Murzin <vladimir.murzin@arm.com>
Tested-by: NAndras Szemzo <sza@esh.hu>
Tested-by: NJoachim Eastwood <manabian@gmail.com>
Tested-by: NAlexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Currently we use raw cp15 operations to access the cache setup data.

This patch abstracts the CSSELR and CCSIDR accessors out to a header so
that the implementation for them can be switched out as we do with other
cpu/cachetype operations.
Signed-off-by: NJonathan Austin <jonathan.austin@arm.com>
Signed-off-by: NVladimir Murzin <vladimir.murzin@arm.com>
Tested-by: NAndras Szemzo <sza@esh.hu>
Tested-by: NJoachim Eastwood <manabian@gmail.com>
Tested-by: NAlexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

vdso_data_mapping is never modified, so mark it as const.

vdso_total_pages, vdso_data_page, vdso_text_mapping and cntvct_ok are
initialized by vdso_init(), thereafter are read only.

The fact that they are read only after init makes them candidates for
__ro_after_init declarations.
Signed-off-by: NJisheng Zhang <jszhang@marvell.com>
Reviewed-by: NKees Cook <keescook@chromium.org>
Acked-by: NNathan Lynch <nathan_lynch@mentor.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Guided by grsecurity's analogous __read_only markings in arch/arm,
this applies several uses of __ro_after_init to structures that are
only updated during __init.
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The jump table can reference text found in an __exit section.  Thus,
instead of discarding it at build time, include EXIT_TEXT as part of
__init and it will be released when the system boots.

Link: http://lkml.kernel.org/r/60284113bb759121e8ae3e99af1535647e52123f.1467837322.git.jbaron@akamai.comSigned-off-by: NJason Baron <jbaron@akamai.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Joe Perches <joe@perches.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Provide kexec with the boot view of memory by overriding the normal
kexec translation functions added in a previous patch.  We also need to
fix a call to memblock in machine_kexec_prepare() so that we provide it
with a running-view physical address rather than a boot- view physical
address.

Link: http://lkml.kernel.org/r/E1b8koa-0004Hl-Ey@rmk-PC.armlinux.org.ukSigned-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Cc: Keerthy <j-keerthy@ti.com>
Cc: Pratyush Anand <panand@redhat.com>
Cc: Vitaly Andrianov <vitalya@ti.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Simon Horman <horms@verge.net.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Advertise the location of bootable RAM to kexec-tools.  kexec needs to
know where it can place the kernel in RAM, and so be executable when the
system needs to jump into it.

Advertise these areas in /proc/iomem with a "System RAM (boot alias)"
tag.

Link: http://lkml.kernel.org/r/E1b8ko4-0004HA-GF@rmk-PC.armlinux.org.ukSigned-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Reviewed-by: NPratyush Anand <panand@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Keerthy <j-keerthy@ti.com>
Cc: Vitaly Andrianov <vitalya@ti.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Simon Horman <horms@verge.net.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Advertise a resource which describes where the crash kernel is located
in the boot view of RAM.  This allows kexec-tools to have this vital
information.

Link: http://lkml.kernel.org/r/E1b8knz-0004H4-Bd@rmk-PC.armlinux.org.ukSigned-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Cc: Baoquan He <bhe@redhat.com>
Cc: Keerthy <j-keerthy@ti.com>
Cc: Pratyush Anand <panand@redhat.com>
Cc: Vitaly Andrianov <vitalya@ti.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Simon Horman <horms@verge.net.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Install the callbacks via the state machine. The callbacks won't be invoked on
already online CPUs.
Signed-off-by: NRichard Cochran <rcochran@linutronix.de>
Signed-off-by: NAnna-Maria Gleixner <anna-maria@linutronix.de>
Reviewed-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Eric Anholt <eric@anholt.net>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153336.881124821@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

Currently, we check cpuidle_ops.suspend every time when entering a
low-power idle state. But this check could be avoided in this hot path
by moving it into arm_cpuidle_read_ops() to reduce arm_cpuidle_suspend
overhead a bit.
Signed-off-by: NJisheng Zhang <jszhang@marvell.com>
Acked-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Let's assume cpuidle_ops exists but it doesn't implement the according
init callback, current arm_cpuidle_init() will return success to its
caller, but in fact it should return -EOPNOTSUPP.
Signed-off-by: NJisheng Zhang <jszhang@marvell.com>
Acked-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

When we enter an exception, the current address limit should not apply
to the exception context: if the exception context wishes to access
kernel space via the user accessors (eg, perf code), it must explicitly
request such access.
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>

Move xen_early_init() before efi_init(), then when calling efi_init()
could initialize Xen specific UEFI.

Check if it runs on Xen hypervisor through the flat dts.

Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: NShannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: NJulien Grall <julien.grall@arm.com>
Tested-by: NJulien Grall <julien.grall@arm.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>

Current errata initialization doesn't take properly revision and REVIDR
into account. Depending on the core revision, revidr bits should not be
taken into account. Errata misleadingly declares r3p3 to be error-free,
but this is not the case. Include rp3p3 in errata initialization.

Here are possible fixes defined in revidr register for r2 and r3 [1,2]:

r0p0-r2p1: No fixes applied

r2p2,r2p3:

REVIDR[4]: 798181 Moving a virtual page that is being accessed by
    an active process can lead to unexpected behavior
REVIDR[9]: Not defined

r2p4,r3p0,r3p1,r3p2:

REVIDR[4]: 798181 Moving a virtual page that is being accessed by
   an active process can lead to unexpected behavior
REVIDR[9]: 798181 Moving a virtual page that is being accessed by
   an active process can lead to unexpected behavior
   - This is an update to a previously released ECO.

r3p3:

REVIDR[4]: Reserved
REVIDR[9]: 798181 Moving a virtual page that is being accessed by
   an active process can lead to unexpected behavior
   - This is an update to a previously released ECO.

And here is proposed handling from the same document:

* In r3p2 and earlier versions with REVIDR[4]= 0,the full workaround is
  required.
* In r3p2 and earlier versions with REVIDR[4]=1, REVIDR[9]=0, only the
  portion of the workaround up to the end of step 6 is required.
* In r3p2 and earlier versions with REVIDR[4]=1, REVIDR[9]=1, no
  workaround is required.
* In r3p3, if REVIDR[9]=0, only the portion of the workaround up
  to the end of step 6 is required.
* In r3p3, if REVIDR[9]=1, no workaround is required.

These imply following:

REVIDR[9] set -> No WA
REVIDR[4] set, REVIDR[9] cleared -> Partial WA
Both cleared -> Full WA

Where certain bits should and should not be taken into account
depending on whether they are defined for the revision.

Although not explicitly mentioned in the errata note, REVIDR[9] set,
with REVIDR[4] cleared is valid combination which requires no WA. This
is confirmed by ARM support and errata will be updated.

[1] ARM CortexTM-A15 MPCore - NEON
    Product revision r3
    Software Developers Errata Notice
    ARM-EPM-028093 v20.0 Released

[2] ARM CortexTM-A15 MPCore - NEON
    Product Revision r2
    Software Developers Errata Notice
    ARM-EPM-028090 v19.3 Released
Signed-off-by: NMatija Glavinic Pecotic <matija.glavinic-pecotic.ext@nokia.com>
Reviewed-by: NAlexander Sverdlin <alexander.sverdlin@nokia.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The _etext position is defined to be the end of the kernel text code,
and should not include any part of the data segments. This interferes
with things that might check memory ranges and expect executable code
up to _etext. Just to be conservative, leave the kernel resource as
it was, using __init_begin instead of _etext as the end mark.
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

All the clocksource drivers's init function are now converted to return
an error code. CLOCKSOURCE_OF_DECLARE is no longer used as well as the
clksrc-of table.

Let's convert back the names:
 - CLOCKSOURCE_OF_DECLARE_RET => CLOCKSOURCE_OF_DECLARE
 - clksrc-of-ret              => clksrc-of
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

For exynos_mct and samsung_pwm_timer:
Acked-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>

For arch/arc:
Acked-by: NVineet Gupta <vgupta@synopsys.com>

For mediatek driver:
Acked-by: NMatthias Brugger <matthias.bgg@gmail.com>

For the Rockchip-part
Acked-by: NHeiko Stuebner <heiko@sntech.de>

For STi :
Acked-by: NPatrice Chotard <patrice.chotard@st.com>

For the mps2-timer.c and versatile.c changes:
Acked-by: NLiviu Dudau <Liviu.Dudau@arm.com>

For the OXNAS part :
Acked-by: NNeil Armstrong <narmstrong@baylibre.com>

For LPC32xx driver:
Acked-by: NSylvain Lemieux <slemieux.tyco@gmail.com>

For Broadcom Kona timer change:
Acked-by: NRay Jui <ray.jui@broadcom.com>

For Sun4i and Sun5i:
Acked-by: NChen-Yu Tsai <wens@csie.org>

For Meson6:
Acked-by: NCarlo Caione <carlo@caione.org>

For Keystone:
Acked-by: NSantosh Shilimkar <ssantosh@kernel.org>

For NPS:
Acked-by: NNoam Camus <noamca@mellanox.com>

For bcm2835:
Acked-by: NEric Anholt <eric@anholt.net>

The init functions do not return any error. They behave as the following:

  - panic, thus leading to a kernel crash while another timer may work and
       make the system boot up correctly

  or

  - print an error and let the caller unaware if the state of the system

Change that by converting the init functions to return an error conforming
to the CLOCKSOURCE_OF_RET prototype.

Proper error handling (rollback, errno value) will be changed later case
by case, thus this change just return back an error or success in the init
function.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

On systems with PCI_PROBE_ONLY set, we rely on BAR assignments from
firmware.  Previously we did not insert those resources into the resource
tree, so we had to skip pci_enable_resources() because it fails if
resources are not in the resource tree.

Now that we *do* insert resources even when PCI_PROBE_ONLY is set, we no
longer need the ARM-specific pcibios_enable_device().  Remove it so we
use the generic version.

[bhelgaas: changelog]
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NWill Deacon <will.deacon@arm.com>
CC: Arnd Bergmann <arnd@arndb.de>
CC: Russell King <linux@arm.linux.org.uk>

We claim PCI BAR and bridge window resources in pci_bus_assign_resources(),
but when PCI_PROBE_ONLY is set, we treat those resources as immutable and
don't call pci_bus_assign_resources(), so the resources aren't put in the
resource tree.

When the resources aren't in the tree, they don't show up in /proc/iomem,
we can't detect conflicts, and we need special cases elsewhere for
PCI_PROBE_ONLY or resources without a parent pointer.

Claim all PCI BAR and window resources in the PCI_PROBE_ONLY case.

If a PCI_PROBE_ONLY platform assigns conflicting resources, Linux can't fix
the conflicts.  Previously we didn't notice the conflicts, but now we will,
which may expose new failures.

[bhelgaas: changelog, add resource comment, remove size/assign comments]
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
CC: Russell King <linux@armlinux.org.uk>

After patch "of/platform: Add common method to populate default bus",
it is possible for arch code to remove unnecessary callers of
of_platform_populate with default match table.
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Ray Jui <rjui@broadcom.com>
Cc: Lee Jones <lee@kernel.org>
Cc: Krzysztof Halasa <khalasa@piap.pl>
Cc: Kukjin Kim <kgene@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Santosh Shilimkar <ssantosh@kernel.org>
Cc: Roland Stigge <stigge@antcom.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Haojian Zhuang <haojian.zhuang@gmail.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Viresh Kumar <vireshk@kernel.org>
Cc: Shiraz Hashim <shiraz.linux.kernel@gmail.com>
Cc: Tony Prisk <linux@prisktech.co.nz>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NRob Herring <robh@kernel.org>

The of_iommu_init() is called multiple times by arch code,
make it postcore_initcall_sync, then we can drop relevant
calls fully.

Note, the IOMMUs should have a chance to perform some basic
initialisation before we start adding masters to them. So
postcore_initcall_sync is good choice, it ensures of_iommu_init()
called before of_platform_populate.
Acked-by: NRich Felker <dalias@libc.org>
Tested-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: NJoerg Roedel <jroedel@suse.de>
Signed-off-by: NRob Herring <robh@kernel.org>

Fix the following warnings by including declarations
from <asm/prom.h>:

arch/arm/kernel/devtree.c:69:13: warning: symbol 'arm_dt_init_cpu_maps' was not declared. Should it be static?
arch/arm/kernel/devtree.c:210:27: warning: symbol 'setup_machine_fdt' was not declared. Should it be static?
Signed-off-by: NBen Dooks <ben.dooks@codethink.co.uk>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Set no bits, mask all bits in the AUX l2x0 register for the
default DT ARM system: if anything needs to be modified, it
should be done using DT bindings.
Suggested-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Get rid of the horrible "*(unsigned int *)(regs + 1)" to get at the
parent context domain access register value, instead using the newly
introduced svc_pt_regs structure.
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>

Since the privileged mode pt_regs are an extended version of the saved
userland pt_regs, introduce a new svc_pt_regs structure to describe this
layout.
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>

S_FRAME_SIZE is no longer the size of the kernel stack frame, so this
name is misleading.  It is the size of the kernel pt_regs structure.
Name it so.
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>

For callers of pci_common_init_dev(), we previously always required a PCI
I/O port resource.  If the caller's ->setup() function had added an I/O
resource, we used that; otherwise, we added a default 64K I/O port space
for it.

There are PCI host bridges that do not support I/O port space, and we
should not add fictitious spaces for them.

If a caller sets struct hw_pci.io_optional, assume it is responsible for
adding any I/O port resource it desires, and do not add any default I/O
port space.
Tested-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Further testing with false negatives suppressed by commit 293e2421
("rcu: Remove superfluous versions of rcu_read_lock_sched_held()")
identified another unprotected use of RCU from the idle loop.  Because RCU
actively ignores idle-loop code (for energy-efficiency reasons, among
other things), using RCU from the idle loop can result in too-short
grace periods, in turn resulting in arbitrary misbehavior.

The resulting lockdep-RCU splat is as follows:

------------------------------------------------------------------------

===============================
[ INFO: suspicious RCU usage. ]
4.6.0-rc5-next-20160426+ #1112 Not tainted
-------------------------------
include/trace/events/ipi.h:35 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

RCU used illegally from idle CPU!
rcu_scheduler_active = 1, debug_locks = 0
RCU used illegally from extended quiescent state!
no locks held by swapper/0/0.

stack backtrace:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.6.0-rc5-next-20160426+ #1112
Hardware name: Generic OMAP4 (Flattened Device Tree)
[<c0110308>] (unwind_backtrace) from [<c010c3a8>] (show_stack+0x10/0x14)
[<c010c3a8>] (show_stack) from [<c047fec8>] (dump_stack+0xb0/0xe4)
[<c047fec8>] (dump_stack) from [<c010dcfc>] (smp_cross_call+0xbc/0x188)
[<c010dcfc>] (smp_cross_call) from [<c01c9e28>] (generic_exec_single+0x9c/0x15c)
[<c01c9e28>] (generic_exec_single) from [<c01ca0a0>] (smp_call_function_single_async+0 x38/0x9c)
[<c01ca0a0>] (smp_call_function_single_async) from [<c0603728>] (cpuidle_coupled_poke_others+0x8c/0xa8)
[<c0603728>] (cpuidle_coupled_poke_others) from [<c0603c10>] (cpuidle_enter_state_coupled+0x26c/0x390)
[<c0603c10>] (cpuidle_enter_state_coupled) from [<c0183c74>] (cpu_startup_entry+0x198/0x3a0)
[<c0183c74>] (cpu_startup_entry) from [<c0b00c0c>] (start_kernel+0x354/0x3c8)
[<c0b00c0c>] (start_kernel) from [<8000807c>] (0x8000807c)

------------------------------------------------------------------------
Reported-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Tested-by: NGuenter Roeck <linux@roeck-us.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: <linux-omap@vger.kernel.org>
Cc: <linux-arm-kernel@lists.infradead.org>

Close the hole where ptrace can change a syscall out from under seccomp.
Signed-off-by: NKees Cook <keescook@chromium.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org

Currently, if arch code wants to supply seccomp_data directly to
seccomp (which is generally much faster than having seccomp do it
using the syscall_get_xyz() API), it has to use the two-phase
seccomp hooks. Add it to the easy hooks, too.

Cc: linux-arch@vger.kernel.org
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Signed-off-by: NKees Cook <keescook@chromium.org>

PTRACE_SETVFPREGS fails to properly mark the VFP register set to be
reloaded, because it undoes one of the effects of vfp_flush_hwstate().

Specifically vfp_flush_hwstate() sets thread->vfpstate.hard.cpu to
an invalid CPU number, but vfp_set() overwrites this with the original
CPU number, thereby rendering the hardware state as apparently "valid",
even though the software state is more recent.

Fix this by reverting the previous change.

Cc: <stable@vger.kernel.org>
Fixes: 8130b9d7 ("ARM: 7308/1: vfp: flush thread hwstate before copying ptrace registers")
Acked-by: NWill Deacon <will.deacon@arm.com>
Tested-by: NSimon Marchi <simon.marchi@ericsson.com>
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>

most architectures are relying on mmap_sem for write in their
arch_setup_additional_pages.  If the waiting task gets killed by the oom
killer it would block oom_reaper from asynchronous address space reclaim
and reduce the chances of timely OOM resolving.  Wait for the lock in
the killable mode and return with EINTR if the task got killed while
waiting.
Signed-off-by: NMichal Hocko <mhocko@suse.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>	[x86 vdso]
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

printk() takes some locks and could not be used a safe way in NMI
context.

The chance of a deadlock is real especially when printing stacks from
all CPUs.  This particular problem has been addressed on x86 by the
commit a9edc880 ("x86/nmi: Perform a safe NMI stack trace on all
CPUs").

The patchset brings two big advantages.  First, it makes the NMI
backtraces safe on all architectures for free.  Second, it makes all NMI
messages almost safe on all architectures (the temporary buffer is
limited.  We still should keep the number of messages in NMI context at
minimum).

Note that there already are several messages printed in NMI context:
WARN_ON(in_nmi()), BUG_ON(in_nmi()), anything being printed out from MCE
handlers.  These are not easy to avoid.

This patch reuses most of the code and makes it generic.  It is useful
for all messages and architectures that support NMI.

The alternative printk_func is set when entering and is reseted when
leaving NMI context.  It queues IRQ work to copy the messages into the
main ring buffer in a safe context.

__printk_nmi_flush() copies all available messages and reset the buffer.
Then we could use a simple cmpxchg operations to get synchronized with
writers.  There is also used a spinlock to get synchronized with other
flushers.

We do not longer use seq_buf because it depends on external lock.  It
would be hard to make all supported operations safe for a lockless use.
It would be confusing and error prone to make only some operations safe.

The code is put into separate printk/nmi.c as suggested by Steven
Rostedt.  It needs a per-CPU buffer and is compiled only on
architectures that call nmi_enter().  This is achieved by the new
HAVE_NMI Kconfig flag.

The are MN10300 and Xtensa architectures.  We need to clean up NMI
handling there first.  Let's do it separately.

The patch is heavily based on the draft from Peter Zijlstra, see

  https://lkml.org/lkml/2015/6/10/327

[arnd@arndb.de: printk-nmi: use %zu format string for size_t]
[akpm@linux-foundation.org: min_t->min - all types are size_t here]
Signed-off-by: NPetr Mladek <pmladek@suse.com>
Suggested-by: NPeter Zijlstra <peterz@infradead.org>
Suggested-by: NSteven Rostedt <rostedt@goodmis.org>
Cc: Jan Kara <jack@suse.cz>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>	[arm part]
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Jiri Kosina <jkosina@suse.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: David Miller <davem@davemloft.net>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We need to call exit_thread from copy_process in a fail path.  So make it
accept task_struct as a parameter.

[v2]
* s390: exit_thread_runtime_instr doesn't make sense to be called for
  non-current tasks.
* arm: fix the comment in vfp_thread_copy
* change 'me' to 'tsk' for task_struct
* now we can change only archs that actually have exit_thread

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: David Howells <dhowells@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We will use it to count how many addresses are in the entry->ip[] array,
excluding PERF_CONTEXT_{KERNEL,USER,etc} entries, so that we can really
return the number of entries specified by the user via the relevant
sysctl, kernel.perf_event_max_contexts, or via the per event
perf_event_attr.sample_max_stack knob.

This way we keep the perf_sample->ip_callchain->nr meaning, that is the
number of entries, be it real addresses or PERF_CONTEXT_ entries, while
honouring the max_stack knobs, i.e. the end result will be max_stack
entries if we have at least that many entries in a given stack trace.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-s8teto51tdqvlfhefndtat9r@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

This makes perf_callchain_{user,kernel}() receive the max stack
as context for the perf_callchain_entry, instead of accessing
the global sysctl_perf_event_max_stack.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Zefan Li <lizefan@huawei.com>
Link: http://lkml.kernel.org/n/tip-kolmn1yo40p7jhswxwrc7rrd@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Commit 19accfd3 (ARM: move vector stubs) moved the vector stubs in an
additional page above the base vector one. This change wasn't taken into
account by the nommu memreserve.
This patch ensures that the kernel won't overwrite any vector stub on
nommu.

[changed the MPU side too]
Signed-off-by: NJean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: NVladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Once entering machine_halt() and machine_restart(), local_irq_disable()
is called, and local irq is kept disabled, so the local_irq_disable()
at the end of these two functions are not necessary, remove it.
Signed-off-by: NJisheng Zhang <jszhang@marvell.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The real limit is the top of the visible physical address space with
the MMU turned off.  Hence, we need to limit the crash kernel allocation
running-view physical address of the top of the boot-view physical
address space.
Reviewed-by: NPratyush Anand <panand@redhat.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

When the kernel crashkernel parameter is specified with just a size, we
are supposed to allocate a region from RAM to store the crashkernel.
However, ARM merely reserves physical address zero with no checking that
there is even RAM there.

Fix this by lifting similar code from x86, importing it to ARM with the
ARM specific parameters added.  In the absence of any platform specific
information, we allocate the crashkernel region from the first 512MB of
physical memory.

Update the kdump documentation to reflect this change.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Reviewed-by: NPratyush Anand <panand@redhat.com>