We can't assume that if we execute the unwinder code and the unwinder
was already running that it has faulted. Clearly two kernel threads can
invoke the unwinder at the same time and may be running simultaneously.

The previous approach used BUG() and BUG_ON() in the unwinder code to
detect whether the unwinder was incapable of unwinding the stack, and
that the next available unwinder should be used instead. A better
approach is to explicitly invoke a trap handler to switch unwinders when
the current unwinder cannot continue.
Signed-off-by: Matt Fleming <matt@console-pimps.org>

The handling of DW_CFA_val_offset ops was incorrectly using the
DWARF_REG_OFFSET flag but the register's value cannot be calculated
using the DWARF_REG_OFFSET method. Create a new flag to indicate that a
different method must be used to calculate the register's value even
though there is no implementation for DWARF_VAL_OFFSET yet; it's mainly
just a place holder.
Signed-off-by: Matt Fleming <matt@console-pimps.org>

Plug a memory leak in dwarf_unwinder_dump() where we didn't free the
memory that we had previously allocated for the DWARF frames and DWARF
registers.

Now is also a opportune time to implement our own mempool and kmem
cache. It's a good idea to have a certain number of frame and register
objects in reserve at all times, so that we are guaranteed to have our
allocation satisfied even when memory is scarce. Since we have pools to
allocate from we can implement the registers for each frame as a linked
list as opposed to a sparsely populated array. Whilst it's true that the
lookup time for a linked list is larger than for arrays, there's only
usually a maximum of 8 registers per frame. So the overhead isn't that
much of a concern.
Signed-off-by: Matt Fleming <matt@console-pimps.org>

This moves the initialization over to an early_initcall(). This fixes up
some lockdep interaction issues. At the same time, kill off some
superfluous locking in the init path.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

Also, remove the "fix" to DW_CFA_def_cfa_register where we reset the
frame's cfa_offset to 0. This action is incorrect when handling
DW_CFA_def_cfa_register as the DWARF spec specifically states that the
previous contents of cfa_offset should be used with the new
register. The reason that I thought cfa_offset should be reset to 0 was
because it was being assigned a bogus value prior to executing the
DW_CFA_def_cfa_register op. It turns out that the bogus cfa_offset value
came from interpreting .cfi_escape pseudo-ops (those used by the GNU
extensions) as CFA_DW_def_cfa ops.
Signed-off-by: Matt Fleming <matt@console-pimps.org>

The previous hack for calculating the return address for the first frame
we unwind (dwarf_unwinder_dump) didn't always work. The problem was that
it assumed once it read the rule for calculating the return address,
there would be no new rules for calculating it. This isn't true because
the way in which the CFA is calculated can change as you progress
through a function and the return address is figured out using the
CFA. Therefore, the way to calculate the return address can change.

So, instead of using some offset from the beginning of
dwarf_unwind_stack which is just a flakey approach, and instead of
executing instructions from the FDE until the return address is setup,
we now figure out the pc in dwarf_unwind_stack() just before we call
dwarf_cfa_execute_insns().
Signed-off-by: Matt Fleming <matt@console-pimps.org>

This uses the BITS export as per x86 in order to allow the same Makefile
to be used.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This patch updates the SuperH Mobile sleep assembly code with
support for DBSC memory controller found in the sh7724 processor.

Without this fix the memory hooked up to the sh7724 processor
will never enter self-refresh mode before suspending to ram. The
effect of this is that the memory contents most likeley will be
lost upon resume which may or may not be what you want.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This patch updates the Solution Engine 7724 board code to use
in-SoC KEYSC resources for the keyboard platform device. Using
the in-SoC key scan controller fixes a crash-during-resume issue.

Without this patch the KEYSC hardware block located in the board
specific FPGA is used together with an external IRQ which is
routed through the FPGA and handled by some board specific demux
code. This board specific FPGA interrupt code does not implement
desc->set_wake() so the enable_irq_wake() call in the sh_keysc
driver will fail at suspend-to-ram time and the disable_irq_wake()
will bomb out when resuming.

Changing the platform data to use the in-SoC KEYSC hardware makes
the se7724 board support code less special which is a good thing.
Also, the board specific KEYSC pin setup code selects in-SoC pin
functions already which makes the current FPGA platform device data
look like a typo.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This patch updates the SuperH CMT driver with suspend and resume
callbacks for the suspend-to-ram case. This patch stops the CMT
channel at suspend time to avoid unwanted wake up events.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This patch updates the SuperH Mobile LCDC driver to skip
over disabled channels. Without this patch suspend-to-ram
operation will crash if deferred io is enabled.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

The way that the CFA is calculated can change as we progress through a
function. If we see a DW_CFA_def_cfa_register op we need to reset the
frame's cfa_offset value which may have been previously setup.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This implements EXPMASK initialization code for SH-4A parts, where it is
possible to disable compat features that will go away in newer cores.
Presently this includes disabling support for non-nop instructions in the
rte delay slot, as well as a sleep instruction being placed in a delay
slot (neither of which the kernel does any longer). As a result of this,
any future offenders will have illegal slot exceptions generated for
them.

Associative writes for the memory-mapped cache array are still left
enabled, until such a point that special cache operations for SH-4A are
provided to move off of the current (and rather dated) SH-4 versions.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

Future SH parts do not support any instruction but a nop in the rte delay
slot, so make the change for all offending parts. SH-5 is excluded from
this, and already has its own set of restrictions with regards to rte
delay slot handling.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This inserts a ULONG_MAX entry at the end of the valid entries in the
stack trace buffer so the default code doesn't need to scan to the end of
available slots. This also makes the trace buffer termination behaviour
consistent with the other architectures.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This flags the default unwinder as reliable, as it tends to be reliable
enough for the purposes of the stacktrace buffer. We leave the unreliable
cases for the unwind methods that we know to be completely broken.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This adopts the reliability checks from the x86 stacktrace code so known
bad addresses are not recorded in the stack trace buffer.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

save_stack_trace_tsk() and friends can be called from atomic context (as
triggered by latencytop), and subsequently hit two problematic allocation
points that were using GFP_KERNEL (these were dwarf_unwind_stack() and
dwarf_frame_alloc_regs()). Convert these over to GFP_ATOMIC and get
latencytop working with the DWARF unwinder.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

free_irq() can remove an irqaction while the corresponding interrupt
is in progress, but free_irq() sets action->thread to NULL
unconditionally, which might lead to a NULL pointer dereference in
handle_IRQ_event() when the hard interrupt context tries to wake up
the handler thread.

Prevent this by moving the thread stop after synchronize_irq(). No
need to set action->thread to NULL either as action is going to be
freed anyway.

This fixes a boot crash reported against preempt-rt which uses the
mainline irq threads code to implement full irq threading.

[ tglx: removed local irqthread variable ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Trying to figure out the best value for DWARF_ARCH_UNWIND_OFFSET is
tricky at best. Various things can change the size (and offset from the
beginning of the function) of the prologue. Notably, turning on ftrace
adds calls to mcount at the beginning of functions, thereby pushing the
prologue further into the function.

So replace DWARF_ARCH_UNWIND_OFFSET with some code that continues to
execute CFA instructions until the value of return address register is
defined. This is safe to do because we know that the return address must
have been pushed onto the frame before our first function call; we just
can't figure out where at compile-time.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This is no longer used, kill it off.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

Merge branch 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf_counter: Report the cloning task as parent on perf_counter_fork()
  perf_counter: Fix an ipi-deadlock
  perf: Rework/fix the whole read vs group stuff
  perf_counter: Fix swcounter context invariance
  perf report: Don't show unresolved DSOs and symbols when -S/-d is used
  perf tools: Add a general option to enable raw sample records
  perf tools: Add a per tracepoint counter attribute to get raw sample
  perf_counter: Provide hw_perf_counter_setup_online() APIs
  perf list: Fix large list output by using the pager
  perf_counter, x86: Fix/improve apic fallback
  perf record: Add missing -C option support for specifying profile cpu
  perf tools: Fix dso__new handle() to handle deleted DSOs
  perf tools: Fix fallback to cplus_demangle() when bfd_demangle() is not available
  perf report: Show the tid too in -D
  perf record: Fix .tid and .pid fill-in when synthesizing events
  perf_counter, x86: Fix generic cache events on P6-mobile CPUs
  perf_counter, x86: Fix lapic printk message

Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  futex: Fix handling of bad requeue syscall pairing
  futex: Fix compat_futex to be same as futex for REQUEUE_PI
  locking, sched: Give waitqueue spinlocks their own lockdep classes
  futex: Update futex_q lock_ptr on requeue proxy lock

Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Fix oops in identify_cpu() on CPUs without CPUID
  x86: Clear incorrectly forced X86_FEATURE_LAHF_LM flag
  x86, mce: therm_throt - change when we print messages
  x86: Add reboot quirk for every 5 series MacBook/Pro

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2: (22 commits)
  ocfs2: Fix possible deadlock when extending quota file
  ocfs2: keep index within status_map[]
  ocfs2: Initialize the cluster we're writing to in a non-sparse extend
  ocfs2: Remove redundant BUG_ON in __dlm_queue_ast()
  ocfs2/quota: Release lock for error in ocfs2_quota_write.
  ocfs2: Define credit counts for quota operations
  ocfs2: Remove syncjiff field from quota info
  ocfs2: Fix initialization of blockcheck stats
  ocfs2: Zero out padding of on disk dquot structure
  ocfs2: Initialize blocks allocated to local quota file
  ocfs2: Mark buffer uptodate before calling ocfs2_journal_access_dq()
  ocfs2: Make global quota files blocksize aligned
  ocfs2: Use ocfs2_rec_clusters in ocfs2_adjust_adjacent_records.
  ocfs2: Fix deadlock on umount
  ocfs2: Add extra credits and access the modified bh in update_edge_lengths.
  ocfs2: Fail ocfs2_get_block() immediately when a block needs allocation
  ocfs2: Fix error return in ocfs2_write_cluster()
  ocfs2: Fix compilation warning for fs/ocfs2/xattr.c
  ocfs2: Initialize count in aio_write before generic_write_checks
  ocfs2: log the actual return value of ocfs2_file_aio_write()
  ...

The destination address might be unaligned, so set it with
put_unaligned() for safety. This restores the previous behaviour, albeit
through the proper API.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

* 'for-linus' of git://neil.brown.name/md:
  md: allow upper limit for resync/reshape to be set when array is read-only
  md/raid5: Properly remove excess drives after shrinking a raid5/6
  md/raid5: make sure a reshape restarts at the correct address.
  md/raid5: allow new reshape modes to be restarted in the middle.
  md: never advance 'events' counter by more than 1.
  Remove deadlock potential in md_open

* 'sh/for-2.6.31' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6:
  sh: fix i2c init order on ap325rxa V2
  sh: fix i2c init order on Migo-R V2
  sh: convert processor device setup functions to arch_initcall()

kernel_sendpage() does the proper default case handling for when the
socket doesn't have a native sendpage implementation.

Now, arguably this might be something that we could instead solve by
just specifying that all protocols should do it themselves at the
protocol level, but we really only care about the common protocols.
Does anybody really care about sendpage on something like Appletalk? Not
likely.
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Julien TINNES <julien@cr0.org>
Acked-by: Tavis Ormandy <taviso@sdf.lonestar.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This was using internal symbols for unaligned accesses, bypassing the
exposed interface for variable sized safe accesses. This converts all of
the __get_unaligned_cpuXX() users over to get_unaligned() directly,
relying on the cast to select the proper internal routine.

Additionally, the __put_unaligned_cpuXX() case is superfluous given that
the destination address is aligned in all of the current cases, so just
drop that outright.

Furthermore, this switches to the asm/unaligned.h header instead of the
asm-generic version, which was silently bypassing the SH-4A optimized
unaligned ops.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

Annotate various assembly code paths with CFI assembler directives so
that DWARF unwind info is available for the unwinder.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

In order to use DWARF unwinder info the frame register has to contain a
valid value. Whilst GCC takes care of this for C code, we have to do it
ourselves for assembly.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This is a first cut at a generic DWARF unwinder for the kernel. It's
still lacking DWARF64 support and the DWARF expression support hasn't
been tested very well but it is generating proper stacktraces on SH for
WARN_ON() and NULL dereferences.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

A bug in (9f498cc5: perf_counter: Full task tracing) makes
profiling multi-threaded apps it go belly up.

[ output as: (PID:TID):(PPID:PTID) ]

 # ./perf report -D | grep FORK
0x4b0 [0x18]: PERF_EVENT_FORK: (3237:3237):(3236:3236)
0xa10 [0x18]: PERF_EVENT_FORK: (3237:3238):(3236:3236)
0xa70 [0x18]: PERF_EVENT_FORK: (3237:3239):(3236:3236)
0xad0 [0x18]: PERF_EVENT_FORK: (3237:3240):(3236:3236)
0xb18 [0x18]: PERF_EVENT_FORK: (3237:3241):(3236:3236)

Shows us that the test (27d028de perf report: Update for the new
FORK/EXIT events) in builtin-report.c:

        /*
         * A thread clone will have the same PID for both
         * parent and child.
         */
        if (thread == parent)
                return 0;

Will clearly fail.

The problem is that perf_counter_fork() reports the actual
parent, instead of the cloning thread.

Fixing that (with the below patch), yields:

 # ./perf report -D | grep FORK
0x4c8 [0x18]: PERF_EVENT_FORK: (1590:1590):(1589:1589)
0xbd8 [0x18]: PERF_EVENT_FORK: (1590:1591):(1590:1590)
0xc80 [0x18]: PERF_EVENT_FORK: (1590:1592):(1590:1590)
0x3338 [0x18]: PERF_EVENT_FORK: (1590:1593):(1590:1590)
0x66b0 [0x18]: PERF_EVENT_FORK: (1590:1594):(1590:1590)

Which both makes more sense and doesn't confuse perf report
anymore.
Reported-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: paulus@samba.org
Cc: Anton Blanchard <anton@samba.org>
Cc: Arjan van de Ven <arjan@infradead.org>
LKML-Reference: <1250172882.5241.62.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

perf_pending_counter() is called from IRQ context and will call
perf_counter_disable(), however perf_counter_disable() uses
smp_call_function_single() which doesn't fancy being used with
IRQs disabled due to IPI deadlocks.

Fix this by making it use the local __perf_counter_disable()
call and teaching the counter_sched_out() code about pending
disables as well.

This should cover the case where a counter migrates before the
pending queue gets processed.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Corey J Ashford <cjashfor@us.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: stephane eranian <eranian@googlemail.com>
LKML-Reference: <20090813103655.244097721@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Replace PERF_SAMPLE_GROUP with PERF_SAMPLE_READ and introduce
PERF_FORMAT_GROUP to deal with group reads in a more generic
way.

This allows you to get group reads out of read() as well.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Corey J Ashford <cjashfor@us.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: stephane eranian <eranian@googlemail.com>
LKML-Reference: <20090813103655.117411814@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Instead of implementing our own stack unwinder via dump_trace() we
should use the new stack unwinder API because it is more modular. This
change allows us to decouple the interface for generating stacktraces
from the implementation of a stack unwinder.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>