Without this patch arch/arm/compressed/head.S defaults to generic
DCC code that does not work for v7.

For more information on the v7 DCC, see Cortex-A8 TRM
"12.11.1 Debug communications channel".

To use it with post 2.6.33-rc1 or later, you need to have:

CONFIG_DEBUG_LL=y
ONFIG_DEBUG_ICEDCC=y
CONFIG_EARLY_PRINTK=y

Earlier kernels need commit 93fd03a8
backported.

Tested on omap3430.
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This reverts commit 14f0aa35.

That commit was needed earlier because system call restarting for
OABI (compat) required an executable stack and thus had problems
with NX.  Since ab72b007 ("ARM: Fix signal restart issues
with NX and OABI compat") has reworked the code to not require an
executable stack anymore, we can re-enable NX support for kernels
with OABI (compat) support.
Signed-off-by: NRabin Vincent <rabin@rab.in>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The __kuser_cmpxchg code uses an ARMv6 dmb instruction, rather than
one based upon the architecture being built for.  Switch to using
the macro provided for this purpose, which also eliminates the
need for an ifdef.
Acked-by: NNicolas Pitre <nico@fluxnic.net>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Fix the following warning, which appears when the register dump for a
faulting process is printed in a kernel with SMP, DEBUG_PREEMPT, and
DEBUG_USER (with user_debug=31) enabled:

BUG: using smp_processor_id() in preemptible [00000000] code: init/1
caller is __show_regs+0x18/0x234
Backtrace:
[<c0159e5c>] (dump_backtrace+0x0/0x114) from [<c01faf30>] (dump_stack+0x18/0x1c)
 r6:c781a000 r5:c0157544 r4:00000001 r3:00000000
[<c01faf18>] (dump_stack+0x0/0x1c) from [<c01e5230>] (debug_smp_processor_id+0xc4/0xf8)
[<c01e516c>] (debug_smp_processor_id+0x0/0xf8) from [<c0157544>] (__show_regs+0x18/0x234)
 r6:c781bfb0 r5:00000000 r4:c781bfb0 r3:00000000
[<c015752c>] (__show_regs+0x0/0x234) from [<c01577a0>] (show_regs+0x40/0x50)
[<c0157760>] (show_regs+0x0/0x50) from [<c015c968>] (__do_user_fault+0x5c/0xa4)
 r4:c781c000 r3:00000000
[<c015c90c>] (__do_user_fault+0x0/0xa4) from [<c015cbe0>] (do_page_fault+0x1b4/0x1e4)
 r7:00000000 r6:00010000 r5:c781bfb0 r4:c781c000
[<c015ca2c>] (do_page_fault+0x0/0x1e4) from [<c01554c8>] (do_DataAbort+0x3c/0xa0)
[<c015548c>] (do_DataAbort+0x0/0xa0) from [<c01560c4>] (ret_from_exception+0x0/0x10)
Signed-off-by: NRabin Vincent <rabin@rab.in>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

We can't request the cascade channel before it's been registered, so
move it afterwards.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This avoids races in the VFP code where the dead thread may have
state on another CPU.  By moving this code to exit_thread(), we
will be running as the thread, and therefore be running on the
current CPU.

This means that we can ensure that the only local state is accessed
in the thread notifiers.
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The Kconfigs for in-tree floating point emulation do not allow building
as modules. That leaves the Acorn FPEmulator module. I found two public
releases of this as a binary module for 2.1 and 2.2 kernels, optimized
for ARMV4.[1] If there is a resurgence of interest in this, the symbols
can always be re-exported.

This allows the EXPORT_SYMBOL_ALIAS() hack to be removed. The ulterior
motive here is that EXPORT_SYMBOL_ALIAS() makes it harder to sort the
resulting kernel symbol tables.  Sorted symbol tables will allow faster
symbol resolution during module loading.

Note that fp_send_sigs() and fp_printk() are simply aliases for existing
exports and add no obvious value.  Similarly fp_enter could easily be
renamed to kern_fp_enter at the point of definition. Therefore removing
EXPORT_SYMBOL_ALIAS will not serve as a material obstacle to re-adding
the exports should they be desired in future.

Build tested only.

[1] http://ftp.arm.linux.org.uk/pub/linux/arm/fpemulator/Signed-off-by: NAlan Jenkins <alan-jenkins@tuffmail.co.uk>
CC: Russell King <linux@arm.linux.org.uk>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Commit 023bf6f1 "linker script: unify usage of discard definition"
changed the linker scripts for all architectures except for ARM.
I can find no discussion about this ommision, so here are the changes
for ARM.

These changes are exactly parallel to the ia64 case.

"ia64 is notable because it first throws away some ia64 specific
 subsections and then include the rest of the sections into the final
 image, so those sections must be discarded before the inclusion."

Not boot-tested.  In build testing, the modified linker script generated
an identical vmlinux file.

[I would like to be able to rely on this unified discard definition.
 I want to sort the kernel symbol tables to allow faster symbol
 resolution during module loading. The simplest way appears to be
 to generate sorted versions from vmlinux.o, link them in to vmlinux,
 _and discard the original unsorted tables_.

 This work is driven by my x86 netbook, but it is implemented at a
 generic level. It is possible it will benefit some ARM systems also.]
Signed-off-by: NAlan Jenkins <alan-jenkins@tuffmail.co.uk>
Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Acked-by-without-testing: Tejun Heo <tj@kernel.org>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Convert locks which cannot be sleeping locks in preempt-rt to
raw_spinlocks.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
Acked-by: NIngo Molnar <mingo@elte.hu>

New helper - sys_mmap_pgoff(); switch syscalls to using it.
Acked-by: NDavid S. Miller <davem@davemloft.net>
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>

Since this IRQ descriptor doesn't have an action registered, it is
allowed for probing via probe_irq_on/off() and it will be disabled by
the latter function. This patch sets the IRQ_NOPROBE status bit for the
local timer descriptor.
Signed-off-by: NVarun Swara <Varun.Swara@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

This patch allows an earlyprintk console if CONFIG_DEBUG_LL is enabled,
using the printch asm function.

The patch is based on the original work by Sascha Hauer.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: NPavel Machek <pavel@ucw.cz>

This driver implements support for on-chip Embedded Tracing Macrocell and
Embedded Trace Buffer. It allows to trigger tracing of kernel execution flow
and exporting trace output to userspace via character device and a sysrq
combo.

Trace output can then be decoded by a fairly simple open source tool [1]
which is already sufficient to get the idea of what the kernel is doing.

[1]: http://github.com/virtuoso/etm2humanSigned-off-by: NAlexander Shishkin <virtuoso@slind.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This patch is mostly a straightforward translation. The primary side
effect to the resulting vmlinux should be to increase the alignment on
the initramfs to the standard PAGE_SIZE from 32 bytes.
Signed-off-by: NNelson Elhage <nelhage@ksplice.com>
Signed-off-by: NTim Abbott <tabbott@ksplice.com>
Acked-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This has the consequence of changing the section name used for head
code from ".text.head" to ".head.text".  Since this commit changes all
users in the architecture, this change should be harmless.

The .text.head output section is eliminated and the head text code is
included at the start of the .init output section.
Signed-off-by: NTim Abbott <tabbott@ksplice.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Using OABI, the call to put_user in do_signal can fail causing the
calling app to hang.

The solution is to check if put_user fails and force the app to
seg fault in that case.

Tested with multiple sleeping apps/threads (using the nanosleep syscall)
and suspend/resume.

Signed-off-by: janboe <janboe.ye at gmail.com>
Signed-off-by: NJean Pihet <jpihet@mvista.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

For consistency drop & in front of every proc_handler.  Explicity
taking the address is unnecessary and it prevents optimizations
like stubbing the proc_handlers to NULL.

Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>

Now that sys_sysctl is a generic wrapper around /proc/sys  .ctl_name
and .strategy members of sysctl tables are dead code.  Remove them.

Remove a smattering of ctl_names used in sysctl paths,
and kill the ctl_names in the recently added mach-bcmring.

mach-bcmring never should have had sysctl entries with
.ctl_name set.  The binary sysctl interface has been frozen
for a long time before that code was merged, to prevent
probmes with conflicts and lack of testing.   The sysctl_check
code would have caught this if anyone had ever tested it that way.
So I have simply dropped the binary sysctl support instead of
adding another compat entry into sysctl_binary.c.  Going through
/proc/sys/reboot/warm will still work.

Cc: Leo Chen <leochen@broadcom.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>

Use a definition for the cmpxchg SWI instead of hard-coding the number.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Acked-by: NNicolas Pitre <nico@fluxnic.net>

The existing test always failed since 'no' was always greater than
0x7ff.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

That code was refactored a long time ago, but one particular label
didn't get adjusted properly which broke the listing of supported
machines.
Signed-off-by: NNicolas Pitre <nico@marvell.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

If Linux is running in non-secure mode, this register may have been
already initialised and writing to the control register not allowed.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

ARM unwind is known to compile only with EABI and not-buggy compilers.
The problem is not the unwinding information but the -fno-frame-pointer
option added as a result of !CONFIG_FRAME_POINTER.  Now we check the
compiler and raise a #warning in case of wrong compiler.
Signed-off-by: NClaudio Scordino <claudio@evidence.eu.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The signal restarting code was placed on the user stack when OABI
compatibility is enabled.  Unfortunately, with an EABI NX executable,
this results in an attempt to run code from the non-executable stack,
which segfaults the application.

Fix this by placing the code in the vectors page, along side the
signal return code, and directing the application to that code.
Reported-by: Nsaeed bishara <saeed.bishara@gmail.com>
Tested-by: Nsaeed bishara <saeed.bishara@gmail.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Defines ELF_CORE_COPY_TASK_REGS so that CPU register information
of every thread is included in coredump. Without this, only the faulting
thread is coredumped.

Cc: Roger Quadros <ext-roger.quadros@nokia.com>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: NMika Westerberg <mika.westerberg@iki.fi>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The 32-bit wide variant of "mov pc, reg" in Thumb-2 is unpredictable
causing improper handling of the undefined instructions not caught by
the kernel. This patch adds a movw_pc macro for such situations
(currently only used in call_fpe).
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Meaning receive multiple messages, reducing the number of syscalls and
net stack entry/exit operations.

Next patches will introduce mechanisms where protocols that want to
optimize this operation will provide an unlocked_recvmsg operation.

This takes into account comments made by:

. Paul Moore: sock_recvmsg is called only for the first datagram,
  sock_recvmsg_nosec is used for the rest.

. Caitlin Bestler: recvmmsg now has a struct timespec timeout, that
  works in the same fashion as the ppoll one.

  If the underlying protocol returns a datagram with MSG_OOB set, this
  will make recvmmsg return right away with as many datagrams (+ the OOB
  one) it has received so far.

. Rémi Denis-Courmont & Steven Whitehouse: If we receive N < vlen
  datagrams and then recvmsg returns an error, recvmmsg will return
  the successfully received datagrams, store the error and return it
  in the next call.

This paves the way for a subsequent optimization, sk_prot->unlocked_recvmsg,
where we will be able to acquire the lock only at batch start and end, not at
every underlying recvmsg call.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

After m68k's task_thread_info() doesn't refer to current,
it's possible to remove sched.h from interrupt.h and not break m68k!
Many thanks to Heiko Carstens for allowing this.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>

Make die() better match x86:
- add printing of the last accessed sysfs file
- ensure console_verbose() is called under the lock
- ensure we panic outside of oops_exit()
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

dump_mem and dump_backtrace were both using multiple printk statements
to print each line.  With DEBUG_LL enabled, this causes OOPS to become
very difficult to read.  Solve this by only using one printk per line.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Instruction fault status register, IFSR, was introduced on ARMv6 to
provide status information about the last insturction fault. It
needed for proper prefetch abort handling.

Now we have three prefetch abort model:

  * legacy - for CPUs before ARMv6. They doesn't provide neither
    IFSR nor IFAR. We simulate IFSR with section translation fault
    status for them to generalize code;
  * ARMv6 - provides IFSR, but not IFAR;
  * ARMv7 - provides both IFSR and IFAR.
Signed-off-by: NKirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

From: David Brown <davidb@quicinc.com>

The ATAG_CORE is allowed to be empty.  Although this is handled
by parse_tag_core(), __vet_atags during startup rejects this tag
unless it contains data.  Allow the initial tag to be either the
full size, or empty.
Signed-off-by: NDavid Brown <davidb@quicinc.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Commit 181f817e introduced some new code to entry-common.S
Sadly, this new code uses 'bx' instruction which is available only on
ARMv5 and higher CPUs. This causes following compilation errors when
building kernel for StrongARM (ARMv4):

arch/arm/kernel/entry-common.S: Assembler messages:
arch/arm/kernel/entry-common.S:129: Error: selected processor does not
 support `bx ip'
arch/arm/kernel/entry-common.S:138: Error: selected processor does not
 support `bx ip'

Fix these errors by using 'mov pc' instead of 'bx'.
Signed-off-by: NDmitry Artamonow <mad_soft@inbox.ru>
Acked-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

do_cache_op() uses find_vma() to validate its arguments without holding
any locking.  This means that the VMA could vanish beneath us.  Fix
this by taking a read lock on mmap_sem.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Fix:

WARNING: vmlinux.o(.text+0x247c): Section mismatch in reference from the function cpu_idle() to the function .cpuexit.text:cpu_die()
The function cpu_idle() references a function in an exit section.
Often the function cpu_die() has valid usage outside the exit section
and the fix is to remove the __cpuexit annotation of cpu_die.

WARNING: vmlinux.o(.cpuexit.text+0x3c): Section mismatch in reference from the function cpu_die() to the function .cpuinit.text:secondary_start_kernel()
The function __cpuexit cpu_die() references
a function __cpuinit secondary_start_kernel().
This is often seen when error handling in the exit function
uses functionality in the init path.
The fix is often to remove the __cpuinit annotation of
secondary_start_kernel() so it may be used outside an init section.

Sam says:
> The annotation of cpu_die() is wrong.
> To be annotated __cpuexit the function shall:
> - be used in exit context and only in exit context with HOTPLUG_CPU=n
> - be used outside exit context with HOTPLUG_CPU=y

So, this also means __cpu_disable(), __cpu_die() and twd_timer_stop() are
also wrong.  However, removing __cpuexit from cpu_die() creates:

WARNING: vmlinux.o(.text+0x6834): Section mismatch in reference from the function cpu_die() to the function .cpuinit.text:secondary_start_kernel()
The function cpu_die() references
the function __cpuinit secondary_start_kernel().
This is often because cpu_die lacks a __cpuinit
annotation or the annotation of secondary_start_kernel is wrong.

so fix this using __ref.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Acked-by: NSam Ravnborg <sam@ravnborg.org>

We suffer an unfortunate combination of "features" which makes highmem
support on platforms without hardware TLB maintainence broadcast difficult:

- we need kmap_high_get() support for DMA cache coherence
- this requires kmap_high() to take a spinlock with IRQs disabled
- kmap_high() occasionally calls flush_all_zero_pkmaps() to clear
  out old mappings
- flush_all_zero_pkmaps() calls flush_tlb_kernel_range(), which
  on s/w IPI'd systems eventually calls smp_call_function_many()
- smp_call_function_many() must not be called with IRQs disabled:

WARNING: at kernel/smp.c:380 smp_call_function_many+0xc4/0x240()
Modules linked in:
Backtrace:
[<c00306f0>] (dump_backtrace+0x0/0x108) from [<c0286e6c>] (dump_stack+0x18/0x1c)
 r6:c007cd18 r5:c02ff228 r4:0000017c
[<c0286e54>] (dump_stack+0x0/0x1c) from [<c0053e08>] (warn_slowpath_common+0x50/0x80)
[<c0053db8>] (warn_slowpath_common+0x0/0x80) from [<c0053e50>] (warn_slowpath_null+0x18/0x1c)
 r7:00000003 r6:00000001 r5:c1ff4000 r4:c035fa34
[<c0053e38>] (warn_slowpath_null+0x0/0x1c) from [<c007cd18>] (smp_call_function_many+0xc4/0x240)
[<c007cc54>] (smp_call_function_many+0x0/0x240) from [<c007cec0>] (smp_call_function+0x2c/0x38)
[<c007ce94>] (smp_call_function+0x0/0x38) from [<c005980c>] (on_each_cpu+0x1c/0x38)
[<c00597f0>] (on_each_cpu+0x0/0x38) from [<c0031788>] (flush_tlb_kernel_range+0x50/0x58)
 r6:00000001 r5:00000800 r4:c05f3590
[<c0031738>] (flush_tlb_kernel_range+0x0/0x58) from [<c009c600>] (flush_all_zero_pkmaps+0xc0/0xe8)
[<c009c540>] (flush_all_zero_pkmaps+0x0/0xe8) from [<c009c6b4>] (kmap_high+0x8c/0x1e0)
[<c009c628>] (kmap_high+0x0/0x1e0) from [<c00364a8>] (kmap+0x44/0x5c)
[<c0036464>] (kmap+0x0/0x5c) from [<c0109dfc>] (cramfs_readpage+0x3c/0x194)
[<c0109dc0>] (cramfs_readpage+0x0/0x194) from [<c0090c14>] (__do_page_cache_readahead+0x1f0/0x290)
[<c0090a24>] (__do_page_cache_readahead+0x0/0x290) from [<c0090ce4>] (ra_submit+0x30/0x38)
[<c0090cb4>] (ra_submit+0x0/0x38) from [<c0089384>] (filemap_fault+0x3dc/0x438)
 r4:c1819988
[<c0088fa8>] (filemap_fault+0x0/0x438) from [<c009d21c>] (__do_fault+0x58/0x43c)
[<c009d1c4>] (__do_fault+0x0/0x43c) from [<c009e8cc>] (handle_mm_fault+0x104/0x318)
[<c009e7c8>] (handle_mm_fault+0x0/0x318) from [<c0033c98>] (do_page_fault+0x188/0x1e4)
[<c0033b10>] (do_page_fault+0x0/0x1e4) from [<c0033ddc>] (do_translation_fault+0x7c/0x84)
[<c0033d60>] (do_translation_fault+0x0/0x84) from [<c002b474>] (do_DataAbort+0x40/0xa4)
 r8:c1ff5e20 r7:c0340120 r6:00000805 r5:c1ff5e54 r4:c03400d0
[<c002b434>] (do_DataAbort+0x0/0xa4) from [<c002bcac>] (__dabt_svc+0x4c/0x60)
...

So we disable highmem support on these systems.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Commit 200b812d "Clear the exclusive monitor when returning from an
exception" broke the vast majority of ARM systems in the wild which are
still pre ARMv6.  The kernel is crashing on the first occurrence of an
exception due to the removal of the actual return instruction for them.
Let's add it back.
Signed-off-by: NNicolas Pitre <nico@marvell.com>
Acked-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* remove asm/atomic.h inclusion from linux/utsname.h --
   not needed after kref conversion
 * remove linux/utsname.h inclusion from files which do not need it

NOTE: it looks like fs/binfmt_elf.c do not need utsname.h, however
due to some personality stuff it _is_ needed -- cowardly leave ELF-related
headers and files alone.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>