This is a very simple method for code running in an emulator, or under
the supervision of a debugger, to use I/O facilities on the controlling
host.

Tested with OpenOCD, and ARM's Fast Models.

Details on semihosting can be found in chapter 8 of
DUI0203I_rvct_developer_guide.pdf from ARM Ltd.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

As described in e6fa16ab ("signal: sigprocmask() should do
retarget_shared_pending()") the modification of current->blocked is
incorrect as we need to check for shared signals we're about to block.

Also, use the new helper function introduced in commit 5e6292c0
("signal: add block_sigmask() for adding sigmask to current->blocked")
which centralises the code for updating current->blocked after
successfully delivering a signal and reduces the amount of duplicate code
across architectures.  In the past some architectures got this code wrong,
so using this helper function should stop that from happening again.

Cc: Arnd Bergmann <arnd.bergmann@linaro.org>
Cc: Dave Martin <dave.martin@linaro.org>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The address limit is already set in flush_old_exec() so this
set_fs(USER_DS) is redundant.
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Extract out the code patching code from kprobes so that it can be used
from the jump label code.  Additionally, the separated code:

 - Uses the IS_ENABLED() macros instead of the #ifdefs for THUMB2
   support

 - Unifies the two separate functions in kprobes, providing one function
   that uses stop_machine() internally, and one that can be called from
   stop_machine() directly

 - Patches the text on all CPUs only on processors requiring software
   broadcasting of cache operations
Acked-by: Jon Medhurst <tixy@yxit.co.uk>
Tested-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Extract out the instruction generation code so that it can be used
for jump labels too.
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

As commit 592201a9 (ARM: Thumb-2: Support Thumb-2 in undefined
instruction handler) says:

    32-bit Thumb instructions are specified in the form:
        ((first_half << 16 ) | second_half)
    which matches the layout used by the ARM ARM.

Convert the ftrace code to use the same format to avoid the usage of
different formats in kernel code.
Acked-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Before replacing an instruction, the ftrace code determines what the old
instruction should be and verifies that that's what's really there in
memory before replacing it.  This is useful if for example a bug in
mcountrecord causes it to record wrong locations.

However, in cases where we replace call sites in entry-common.S, these
checks are not needed.  For these, we currently just memcpy() the memory
content and then "verify" it -- this is quite useless and can be
removed.
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The kexec machine crash code can be called in interrupt context via a
sysrq trigger made using the magic key combination. If the irq chip
dealing with the serial interrupt is using the fasteoi flow handler,
then we will never EOI the interrupt because the interrupt handler will
be fatal. In the case of a GIC, this results in the crash kernel not
receiving interrupts on that CPU interface.

This patch adds code (based on the PowerPC implementation) to EOI any
pending interrupts on the crash CPU before masking and disabling all
interrupts. Secondary cores are not a problem since they are placed into
a cpu_relax() loop via an IPI.
Reported-by: Lei Wen <leiwen@marvell.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

On Versatile Express, the PCI Express buses are broken and unusable, so
we aren't going to support PCI/ISA IO cycles on this platform.  Remove
the PCI/ISA IO inb et.al. support for this platform.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Avoid potential build problems caused by lacking mach/irqs.h includes
on non-OF builds caused by an errant include in asm/prom.h.  asm/prom.h
requires nothing from asm/irq.h, as Grant says:

On Mon, Feb 06, 2012 at 05:56:23AM +0000, Grant Likely wrote:
> On Sat, Feb 04, 2012 at 10:17:48PM +0000, Russell King wrote:
> > Finally, do we need asm/irq.h in our asm/prom.h ?  That's causing
> > fragility between DT and non-DT builds, because people are finding
> > that their DT builds work without their mach/irqs.h includes but
> > fail when built with non-DT.  The only thing which DT might need -
> > at the most - is NR_IRQS, but I'd hope with things like irq domains
> > it doesn't actually require it.
>
> I don't think so.  There may be a file or two that break because they're
> not including everything they need, but I don't think anything in the
> header requires it.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Print debug information on user faults for SIGBUS if user_debug = 16
in the kernel command line.

Reference: <1327333344-26340-1-git-send-email-javi.merino@arm.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The irq_start and hwirq_base assignment code is fairly hairy and ended
up being difficult to read following a conflict resolution for 3.2.

This patch rearranges the code slightly to make it easier to read.

Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM unconditionally selects CONFIG_GENERIC_HARDIRQS, so the definition
of for_each_irq_desc will check that the desc is non-NULL anyway.

This patch removes a redundant check from the IRQ migration code.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Cortex-A7 implements an ARMv7-compatible PMU compliant with the PMUv2
architecture specification.

This patch adds support for the PMU to the ARM perf backend.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Ensure that the software state for sched_clock() is updated at the
point of suspend so that we avoid losing ticks since the last update.

This prevents the platform dependent possibility that sched_clock()
may appear to go backwards across a suspend/resume cycle.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Add the compiled ISA to oops dumps, along side the preempt/smp
configuration.  This allows us to see immediately whether the kernel
was compiled for Thumb-2 or not.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The compiler does not conditionalize the assembly instructions for
the tlb operations, which leads to sub-optimal code being generated
when building a kernel for multiple CPUs.

We can tweak things fairly simply as the code fragment below shows:

    17f8:       e3120001        tst     r2, #1  ; 0x1
...
    1800:       0a000000        beq     1808 <handle_pte_fault+0x194>
    1804:       ee061f10        mcr     15, 0, r1, cr6, cr0, {0}
    1808:       e3120004        tst     r2, #4  ; 0x4
    180c:       0a000000        beq     1814 <handle_pte_fault+0x1a0>
    1810:       ee081f36        mcr     15, 0, r1, cr8, cr6, {1}
becomes:
    17f0:       e3120001        tst     r2, #1  ; 0x1
    17f4:       1e063f10        mcrne   15, 0, r3, cr6, cr0, {0}
    17f8:       e3120004        tst     r2, #4  ; 0x4
    17fc:       1e083f36        mcrne   15, 0, r3, cr8, cr6, {1}

Overall, for Realview with V6 and V7 CPUs configured:

   text    data     bss     dec     hex filename
4153998  207340 5371036 9732374  948116 ../build/realview/vmlinux.before
4153366  207332 5371036 9731734  947e96 ../build/realview/vmlinux.after
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

This line is irritating and wrong when modules are not supported, so
don't show it then.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Wire up support for the XZ decompressor
Signed-off-by: Imre Kaloz <kaloz@openwrt.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

This patch adds some endianness-agnostic helpers to convert machine
instructions between canonical integer form and in-memory
representation.

A canonical integer form for representing instructions is also
formalised here.
Signed-off-by: Dave Martin <dave.martin@linaro.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Now that we can select a sched_clock at runtime, let's implement
it for the Integrator AP, default-select the one found in all
other board it for all plat-versatile boards and make the right
clock kick in at runtime.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The current user mapping for the vectors page is inserted as a `horrible
hack vma' into each task via arch_setup_additional_pages. This causes
problems with the MM subsystem and vm_normal_page, as described here:

https://lkml.org/lkml/2012/1/14/55

Following the suggestion from Hugh in the above thread, this patch uses
the gate_vma for the vectors user mapping, therefore consolidating
the horrible hack VMAs into one.
Acked-and-Tested-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Avoid namespace conflicts with drivers over the CP15 definitions by
moving CP15 related prototypes and definitions to a private header
file.
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com> [Tegra]
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Tested-by: H Hartley Sweeten <hsweeten@visionengravers.com> [EP93xx]
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Rather than open-coding the jiffy-based wait, and polling for the
secondary CPU to come online, use a completion instead.  This
removes the need to poll, instead we will be notified when the
secondary CPU has initialized.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Initialize the contents of the vectors page immediately after we
allocate the page, but before we map it.  This avoids any possible
aliases with other mappings which may need to be flushed after the
page has been mapped irrespective of the cache type.

We follow this later with a flush_cache_all() after all static memory
mappings have been initialized, which ensures that this is safe from
any cache effects.
Tested-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Add a new seqfile for reporting coherent DMA allocations.  This contains
the address range, size and the function which was used to allocate
each region, allowing these allocations to be viewed in much the same
way as /proc/vmallocinfo.

The DMA coherent region has limited space, so this allows allocation
failures to be viewed, as well as finding out how much space is being
used.

Make sure this file is only readable by root - same as vmallocinfo - to
prevent information leakage.
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

This updates the Integrator defconfig to include the hardware
found on the Integrator/CP: SMC91X, CLCD, MMCI/PL180. Further
the sometimes disrupting VGA_CONSOLE is disabled (those who
have a VGA card can enable it) and typical default VFAT
layouts of the MMC cards are supported by enabling VFAT and
CP437 encoding of the file system.

After this my default kernels boot successfully on Integrator
AP and CP alike.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Merge branches 'sched-urgent-for-linus', 'perf-urgent-for-linus' and 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/accounting, proc: Fix /proc/stat interrupts sum

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tracepoints/module: Fix disabling tracepoints with taint CRAP or OOT
  x86/kprobes: Add arch/x86/tools/insn_sanity to .gitignore
  x86/kprobes: Fix typo transferred from Intel manual

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, syscall: Need __ARCH_WANT_SYS_IPC for 32 bits
  x86, tsc: Fix SMI induced variation in quick_pit_calibrate()
  x86, opcode: ANDN and Group 17 in x86-opcode-map.txt
  x86/kconfig: Move the ZONE_DMA entry under a menu
  x86/UV2: Add accounting for BAU strong nacks
  x86/UV2: Ack BAU interrupt earlier
  x86/UV2: Remove stale no-resources test for UV2 BAU
  x86/UV2: Work around BAU bug
  x86/UV2: Fix BAU destination timeout initialization
  x86/UV2: Fix new UV2 hardware by using native UV2 broadcast mode
  x86: Get rid of dubious one-bit signed bitfield

gpio bug fixes for v3.3

* tag 'gpio-for-linus' of git://git.secretlab.ca/git/linux-2.6:
  gpio: tps65910: Use correct offset for gpio initialization
  gpio/it8761e: Restrict it8761e gpio driver to x86.
  gpio-ml-ioh: cleanup __iomem annotation usage
  gpio-ml-ioh: cleanup NULL pointer checking
  gpio-pch: cleanup __iomem annotation usage
  gpio-pch: cleanup NULL pointer checking

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  qnx4: don't leak ->BitMap on late failure exits
  qnx4: reduce the insane nesting in qnx4_checkroot()
  qnx4: di_fname is an array, for crying out loud...
  vfs: remove printk from set_nlink()
  wake up s_wait_unfrozen when ->freeze_fs fails

In checkin

  303395ac x86: Generate system call tables and unistd_*.h from tables

the feature macros in <asm/unistd.h> were unified between 32 and 64
bits.  Unfortunately 32 bits requires __ARCH_WANT_SYS_IPC and this was
inadvertently dropped.
Reported-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/CALLzPKbeXN5gdngo8uYYU8mAow=XhrwBFBhKfG811f37BubQOg@mail.gmail.com

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  KEYS: Permit key_serial() to be called with a const key pointer
  keys: fix user_defined key sparse messages
  ima: fix cred sparse warning
  MPILIB: Add a missing ENOMEM check

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

(struct qnx4_inode_entry *)(bh->b_data + some_offset)->di_fname
is not going to be NULL, TYVM...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Permit key_serial() to be called with a const key pointer.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>

Replace the rcu_assign_pointer() calls with rcu_assign_keypointer().
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>

Fix ima_policy.c sparse "warning: dereference of noderef expression"
message, by accessing cred->uid using current_cred().

Changelog v1:
- Change __cred to just cred (based on David Howell's comment)
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>