'sub pc, pc, #1b-2b+8-2' results in address<1:0> == '10'.

sub pc, pc, #const (== ADR pc, #const) performs an interworking branch
(BXWritePC()) on ARMv7+ and a simple branch (BranchWritePC()) on earlier
versions.

In ARM state, BXWritePC() is UNPREDICTABLE when address<1:0> == '10'.

In ARM state on ARMv6+, BranchWritePC() ignores address<1:0>.  Before
ARMv6, BranchWritePC() is UNPREDICTABLE if address<1:0> != '00'

So the instruction is UNPREDICTABLE both before and after v6.
Acked-by: NJon Medhurst <tixy@yxit.co.uk>
Signed-off-by: NRabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

We currently return -EPERM if the user requests mode exclusion that is
not supported by the CPU. This looks pretty confusing from userspace
and is inconsistent with other architectures (ppc, x86).

This patch returns -EOPNOTSUPP instead.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This reverts commit 6b5c8045.

Conflicts:

	arch/arm/kernel/ptrace.c

The new syscall restarting code can lead to problems if we take an
interrupt in userspace just before restarting the svc instruction. If
a signal is delivered when returning from the interrupt, the
TIF_SYSCALL_RESTARTSYS will remain set and cause any syscalls executed
from the signal handler to be treated as a restart of the previously
interrupted system call. This includes the final sigreturn call, meaning
that we may fail to exit from the signal context. Furthermore, if a
system call made from the signal handler requires a restart via the
restart_block, it is possible to clear the thread flag and fail to
restart the originally interrupted system call.

The right solution to this problem is to perform the restarting in the
kernel, avoiding the possibility of handling a further signal before the
restart is complete. Since we're almost at -rc6, let's revert the new
method for now and aim for in-kernel restarting at a later date.
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This reverts commit fa18484d.

We need the restart trampoline back so that we can revert a related
problematic patch 6b5c8045 ("arm: new
way of handling ERESTART_RESTARTBLOCK").
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

ARM builds seem to be plagued by an occasional build error:

    Inconsistent kallsyms data
    This is a bug - please report about it
    Try "make KALLSYMS_EXTRA_PASS=1" as a workaround

The problem has to do with alignment of some sections by the linker.
The kallsyms data is built in two passes by first linking the kernel
without it, and then linking the kernel again with the symbols
included.  Normally, this just shifts the symbols, without changing
their order, and the compression used by the kallsyms gives the same
result.

On non SMP, the per CPU data is empty.  Depending on the where the
alignment ends up, it can come out as either:

   +-------------------+
   | last text segment |
   +-------------------+
   /* padding */
   +-------------------+     <- L1_CACHE_BYTES alignemnt
   | per cpu (empty)   |
   +-------------------+
__per_cpu_end:
   /* padding */
__data_loc:
   +-------------------+     <- THREAD_SIZE alignment
   | data              |
   +-------------------+

or

   +-------------------+
   | last text segment |
   +-------------------+
   /* padding */
   +-------------------+     <- L1_CACHE_BYTES alignemnt
   | per cpu (empty)   |
   +-------------------+
__per_cpu_end:
   /* no padding */
__data_loc:
   +-------------------+     <- THREAD_SIZE alignment
   | data              |
   +-------------------+

if the alignment satisfies both.  Because symbols that have the same
address are sorted by 'nm -n', the second case will be in a different
order than the first case.  This changes the compression, changing the
size of the kallsym data, causing the build failure.

The KALLSYMS_EXTRA_PASS=1 workaround usually works, but it is still
possible to have the alignment change between the second and third
pass.  It's probably even possible for it to never reach a fixedpoint.

The problem only occurs on non-SMP, when the per-cpu data is empty,
and when the data segment has alignment (and immediately follows the
text segments).  Fix this by only including the per_cpu section on
SMP, when it is not empty.
Signed-off-by: NDavid Brown <davidb@codeaurora.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Fixup entries in the kernel exception tables should be 4-byte aligned
since we return directly to them when handling a faulting instruction in
the kernel.

This patch adds the missing align directives to the fixup entries.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

t32_simulate_ldr_literal() can be run without an instruction slot, so it
should be using DECODE_SIMULATEX instead of DECODE_EMULATEX.
Acked-by: NJon Medhurst <tixy@yxit.co.uk>
Signed-off-by: NRabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Does block_sigmask() + tracehook_signal_handler();  called when
sigframe has been successfully built.  All architectures converted
to it; block_sigmask() itself is gone now (merged into this one).

I'm still not too happy with the signature, but that's a separate
story (IMO we need a structure that would contain signal number +
siginfo + k_sigaction, so that get_signal_to_deliver() would fill one,
signal_delivered(), handle_signal() and probably setup...frame() -
take one).
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Only 3 out of 63 do not.  Renamed the current variant to __set_current_blocked(),
added set_current_blocked() that will exclude unblockable signals, switched
open-coded instances to it.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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

replace boilerplate "should we use ->saved_sigmask or ->blocked?"
with calls of obvious inlined helper...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

first fruits of ..._restore_sigmask() helpers: now we can take
boilerplate "signal didn't have a handler, clear RESTORE_SIGMASK
and restore the blocked mask from ->saved_mask" into a common
helper.  Open-coded instances switched...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Checking for process->mm is not enough because process' main thread may
exit or detach its mm via use_mm(), but other threads may still have a
valid mm.

To fix this we would need to use find_lock_task_mm(), which would walk up
all threads and returns an appropriate task (with task lock held).

clear_tasks_mm_cpumask() has this issue fixed, so let's use it.
Suggested-by: NOleg Nesterov <oleg@redhat.com>
Signed-off-by: NAnton Vorontsov <anton.vorontsov@linaro.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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

guts of saved_sigmask-based sigsuspend/rt_sigsuspend.  Takes
kernel sigset_t *.

Open-coded instances replaced with calling it.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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

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

new "syscall start" flag; handled in syscall_trace() by switching
syscall number to that of syscall_restart(2).  Restarts of that
kind (ERESTART_RESTARTBLOCK) are handled by setting that bit;
syscall number is not modified until the actual call.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

checking in do_signal() is pointless - if we get there with !user_mode(regs)
(and we might), we'll end up looping indefinitely.  Check in work_pending
and break out of the loop if so.
Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

get_signal_to_deliver() will handle it itself
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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

Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This patch adds support for CMA to dma-mapping subsystem for ARM
architecture. By default a global CMA area is used, but specific devices
are allowed to have their private memory areas if required (they can be
created with dma_declare_contiguous() function during board
initialisation).

Contiguous memory areas reserved for DMA are remapped with 2-level page
tables on boot. Once a buffer is requested, a low memory kernel mapping
is updated to to match requested memory access type.

GFP_ATOMIC allocations are performed from special pool which is created
early during boot. This way remapping page attributes is not needed on
allocation time.

CMA has been enabled unconditionally for ARMv6+ systems.
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
CC: Michal Nazarewicz <mina86@mina86.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Tested-by: NRob Clark <rob.clark@linaro.org>
Tested-by: NOhad Ben-Cohen <ohad@wizery.com>
Tested-by: NBenjamin Gaignard <benjamin.gaignard@linaro.org>
Tested-by: NRobert Nelson <robertcnelson@gmail.com>
Tested-by: NBarry Song <Baohua.Song@csr.com>

No one uses the per-hw list of buses, so get rid of this.  Instead,
build the list locally.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

- Store uids and gids with kuid_t and kgid_t in struct kstat
- Convert uid and gids to userspace usable values with
  from_kuid and from_kgid
Acked-by: NSerge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>

Most PCI implementations perform simple root bus scanning.  Rather than
having each group of platforms provide a duplicated bus scan function,
provide the PCI configuration ops structure via the hw_pci structure,
and call the root bus scanning function from core ARM PCI code.
Acked-by: NKrzysztof Hałasa <khc@pm.waw.pl>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Most PCI implementations use the standard PCI swizzle function, which
handles the well defined behaviour of PCI-to-PCI bridges which can be
found on cards (eg, four port ethernet cards.)

Rather than having almost every platform specify the standard swizzle
function, make this the default when no swizzle function is supplied.
Therefore, a swizzle function only needs to be provided when there is
something exceptional which needs to be handled.

This gets rid of the swizzle initializer from 47 files, and leaves us
with just two platforms specifying a swizzle function: ARM Integrator
and Chalice CATS.
Acked-by: NKrzysztof Hałasa <khc@pm.waw.pl>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

We always need to pass the last sample period to
perf_sample_data_init(), otherwise the event distribution will be
wrong. Thus, modifiyng the function interface with the required period
as argument. So basically a pattern like this:

        perf_sample_data_init(&data, ~0ULL);
        data.period = event->hw.last_period;

will now be like that:

        perf_sample_data_init(&data, ~0ULL, event->hw.last_period);

Avoids unininitialized data.period and simplifies code.
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1333390758-10893-3-git-send-email-robert.richter@amd.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

cpuidle uses a generic function now. Remove the unused code.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@arm.linux.org.uk>
Link: http://lkml.kernel.org/r/20120507175652.260797846@linutronix.de

Commit 4e8ee7de (ARM: SMP: use
idmap_pgd for mapping MMU enable during secondary booting)
switched secondary boot to use idmap_pgd, which is initialized
during early_initcall, instead of a page table initialized during
__cpu_up.  This causes idmap_pgd to contain the static mappings
but be missing all dynamic mappings.

If a console is registered that creates a dynamic mapping, the
printk in secondary_start_kernel will trigger a data abort on
the missing mapping before the exception handlers have been
initialized, leading to a hang.  Initial boot is not affected
because no consoles have been registered, and resume is usually
not affected because the offending console is suspended.
Onlining a cpu with hotplug triggers the problem.

A workaround is to the printk in secondary_start_kernel until
after the page tables have been switched back to init_mm.

Cc: <stable@vger.kernel.org>
Signed-off-by: NColin Cross <ccross@android.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

At the moment, read_persistent_clock is implemented at the
platform level, which makes it impossible to compile these
platforms in a single kernel.

Implement these two functions at the architecture level, and
provide a thin registration interface for both read_boot_clock
and read_persistent_clock. The two affected platforms (OMAP and
Tegra) are converted at the same time.
Reported-by: NJeff Ohlstein <johlstei@codeaurora.org>
Tested-by: NStephen Warren <swarren@wwwdotorg.org>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The machine endianness has no direct correspondence to the syscall ABI,
so use only AUDIT_ARCH_ARM when identifying the ABI to the audit tools
in userspace.

Cc: stable@vger.kernel.org
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The ARM audit code incorrectly uses the saved application ip register
value to infer syscall entry or exit. Additionally, the saved value will
be clobbered if the current task is not being traced, which can lead to
libc corruption if ip is live (apparently glibc uses it for the TLS
pointer).

This patch fixes the syscall tracing code so that the why parameter is
used to infer the syscall direction and the saved ip is only updated if
we know that we will be signalling a ptrace trap.
Reported-and-Tested-by: NJon Masters <jcm@jonmasters.org>

Cc: stable@vger.kernel.org
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The inline assembly in kernel_execve() uses r8 and r9.  Since this
code sequence does not return, it usually doesn't matter if the
register clobber list is accurate.  However, I saw a case where a
particular version of gcc used r8 as an intermediate for the value
eventually passed to r9.  Because r8 is used in the inline
assembly, and not mentioned in the clobber list, r9 was set
to an incorrect value.

This resulted in a kernel panic on execution of the first user-space
program in the system.  r9 is used in ret_to_user as the thread_info
pointer, and if it's wrong, bad things happen.

Cc: <stable@vger.kernel.org>
Signed-off-by: NTim Bird <tim.bird@am.sony.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Same code. Use the generic version. The special Makefile treatment is
pointless anyway as init_task.o contains only data which is handled by
the linker script. So no point on being treated like head text.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NRussell King <linux@arm.linux.org.uk>
Link: http://lkml.kernel.org/r/20120503085034.221811388@linutronix.de

This patch removes support for ARMv3 CPUs, which haven't worked properly
for quite some time (see the FIXME comment in arch/arm/mm/fault.c).  The
only V3 parts left is the cache model for ARMv3, which is needed for some
odd reason by ARM740T CPUs, and being able to build with -march=armv3,
which is required for the RiscPC platform due to its bus structure.
Acked-by: NWill Deacon <will.deacon@arm.com>
Acked-by: NJean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

There is just no point mapping up to 512MB for a serial port.
Using a single 1MB entry is way sufficient for all users.
This will create less interference for the following debugging patch.
Signed-off-by: NNicolas Pitre <nico@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This allows platforms to set up things that need to be done at
late_initcall time.
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Tested-by: NRobert Lee <rob.lee@linaro.org>
Tested-by: NStephen Warren <swarren@wwwdotorg.org>
Reviewed-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The cacheflush syscall can fail for two reasons:

(1) The arguments are invalid (nonsensical address range or no VMA)

(2) The region generates a translation fault on a VIPT or PIPT cache

This patch allows do_cache_op to return an error code to userspace in
the case of the above. The various coherent_user_range implementations
are modified to return 0 in the case of VIVT caches or -EFAULT in the
case of an abort on v6/v7 cores.
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>