That field will contain internal state information which is not going
to be exposed to anything outside the core code - except via accessor
functions. I'm tired of everyone fiddling in irq_desc.status.

core_internal_state__do_not_mess_with_it is clear enough, annoying to
type and easy to grep for. Offenders will be tracked down and slapped
with stinking trouts.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

All archs implement show_interrupts() in more or less the same
way. That's tons of duplicated code with different bugs with no
value. Implement a generic version and deprecate show_interrupts()

Unfortunately we need some ifdeffery for !GENERIC_HARDIRQ archs.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Now that all core users are converted one layer can go.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

It's safe to drop the IRQ_INPROGRESS flag between action chain walks
as we are protected by desc->lock.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Core code replacement for the ugly camel case. It contains all the
code which is shared in all handlers.

     clear status flags
     set INPROGRESS flag
     unlock
     call action chain
     note_interrupt
     lock
     clr INPROGRESS flag
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

IRQ_MASKED is set in mask_ack_irq() anyway. Remove it from
handle_edge_irq() to allow simpler ab^HHreuse of that function.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20110202212551.918484270@linutronix.de>

Handle IRQ_DISABLED consistent.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Now that everything uses the wrappers, we can remove the default
functions. None of those functions is performance critical.

That makes the IRQ_MASKED flag tracking fully consistent.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Create irq_disable/enable and use them to keep the flags consistent.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Aside of duplicated code some of the startup/shutdown sites do not
handle the MASKED/DISABLED flags and the depth field at all. Move that
to a helper function and take care of it there.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20110202212551.787481468@linutronix.de>

The if (chip->irq_shutdown) check will always evaluate to true, as we
fill in chip->irq_shutdown with default_shutdown in
irq_chip_set_defaults() if the chip does not provide its own function.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20110202212551.667607458@linutronix.de>

Soleley used in core code.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

With the chip.end() function gone we might run into a situation where
a poll call runs and the real interrupt comes in, sees IRQ_INPROGRESS
and disables the line. That might be a perfect working one, which will
then be masked forever.

So mark them polled while the poll runs. When the real handler sees
IRQ_INPROGRESS it checks the poll flag and waits for the polling to
complete. Add the necessary amount of sanity checks to it to avoid
deadlocks.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

No point in running concurrent pollers which confuse each other by
setting PENDING.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

There is no point in polling disabled lines.

percpu does not make sense at all because we only poll on the cpu
we're currently running on. Also polling per_cpu interrupts is racy as
hell. The handler runs without locking so we might get a huge
surprise.

If the timer interrupt needs polling, then we wont get there anyway.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

try_one_irq() contains redundant code and lots of useless checks for
shared interrupts. Check for shared before setting IRQ_INPROGRESS and
then call handle_IRQ_event() while pending. Shorter version with the
same functionality.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

We run all handlers with interrupts disabled and expect them not to
enable them. Warn when we catch one who does.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

We cannot walk the action chain unlocked. Even if IRQ_INPROGRESS is
set an action can be removed and we follow a null pointer. It's safe
to take the lock there, because the code which removes the action will
call synchronize_irq() which waits unlocked for IRQ_INPROGRESS going
away.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Thread affinity is already set by setup_affinity().
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

While rumaging through arch code I found that there are a few
workarounds which deal with the fact that the initial affinity setting
from request_irq() copies the mask into irq_data->affinity before the
chip code is called. In the normal path we unconditionally copy the
mask when the chip code returns 0.

Copy after the code is called and add a return code
IRQ_SET_MASK_OK_NOCOPY for the chip functions, which prevents the
copy. That way we see the real mask when the chip function decided to
truncate it further as some arches do. IRQ_SET_MASK_OK is 0, which is
the current behaviour.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

If the affinity had been set by the user, then a later request_irq()
will honour that setting. But online cpus can have changed. So apply
the online mask and for this case as well.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

IRQ_NO_BALANCING is already checked in irq_can_set_affinity() above,
no need to check it again.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

There is lot of #ifdef CONFIG_GENERIC_PENDING_IRQ along with
duplicated code in the irq core. Move the #ifdeffery into one place
and cleanup the code so it's readable. No functional change.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

The irq namespace has become quite convoluted. My bad.  Clean it up
and deprecate the old functions. All new functions follow the scheme:

irq number based:
    irq_set/get/xxx/_xxx(unsigned int irq, ...)

irq_data based:
	 irq_data_set/get/xxx/_xxx(struct irq_data *d, ....)

irq_desc based:
	 irq_desc_get_xxx(struct irq_desc *desc)
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

chips behind a slow bus cannot update the chip under desc->lock, but
we miss the chip_buslock/chip_bus_sync_unlock() calls around the set
type and set wake functions.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

We face more and more the requirement to expand nr_irqs at
runtime. The reason are irq expanders which can not be detected in the
early boot stage. So we speculate nr_irqs to have enough room. Further
Xen needs extra irq numbers and we really want to avoid adding more
"detection" code into the early boot. There is no real good reason why
we need to limit nr_irqs at early boot.

Allow the allocation code to expand nr_irqs. We have already 8k extra
number space in the allocation bitmap, so lets use it.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

With CONFIG_SHIRQ_DEBUG=y we call a newly installed interrupt handler
in request_threaded_irq().

The original implementation (commit a304e1b8) called the handler
_BEFORE_ it was installed, but that caused problems with handlers
calling disable_irq_nosync(). See commit 377bf1e4.

It's braindead in the first place to call disable_irq_nosync in shared
handlers, but ....

Moving this call after we installed the handler looks innocent, but it
is very subtle broken on SMP.

Interrupt handlers rely on the fact, that the irq core prevents
reentrancy.

Now this debug call violates that promise because we run the handler
w/o the IRQ_INPROGRESS protection - which we cannot apply here because
that would result in a possibly forever masked interrupt line.

A concurrent real hardware interrupt on a different CPU results in
handler reentrancy and can lead to complete wreckage, which was
unfortunately observed in reality and took a fricking long time to
debug.

Leave the code here for now. We want this debug feature, but that's
not easy to fix. We really should get rid of those
disable_irq_nosync() abusers and remove that function completely.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Anton Vorontsov <avorontsov@ru.mvista.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: stable@kernel.org # .28 -> .37

Lars-Peter Clausen pointed out:

   I stumbled upon this while looking through the existing archs using
   SPARSE_IRQ.  Even with SPARSE_IRQ the NR_IRQS is still the upper
   limit for the number of IRQs.

   Both PXA and MMP set NR_IRQS to IRQ_BOARD_START, with
   IRQ_BOARD_START being the number of IRQs used by the core.

   In various machine files the nr_irqs field of the ARM machine
   defintion struct is then set to "IRQ_BOARD_START + NR_BOARD_IRQS".

   As a result "nr_irqs" will greater then NR_IRQS which then again
   causes the "allocated_irqs" bitmap in the core irq code to be
   accessed beyond its size overwriting unrelated data.

The core code really misses a sanity check there.

This went unnoticed so far as by chance the compiler/linker places
data behind that bitmap which gets initialized later on those affected
platforms.

So the obvious fix would be to add a sanity check in early_irq_init()
and break all affected platforms. Though that check wants to be
backported to stable as well, which will require to fix all known
problematic platforms and probably some more yet not known ones as
well. Lots of churn.

A way simpler solution is to allocate a slightly larger bitmap and
avoid the whole churn w/o breaking anything. Add a few warnings when
an arch returns utter crap.
Reported-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: stable@kernel.org # .37
Cc: Haojian Zhuang <haojian.zhuang@marvell.com>
Cc: Eric Miao <eric.y.miao@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>

Currently we return 0 in swsusp_alloc() when alloc_image_page() fails.
Fix that.  Also remove unneeded "error" variable since the only
useful value of error is -ENOMEM.

[rjw: Fixed up the changelog and changed subject.]
Signed-off-by: NStanislaw Gruszka <stf_xl@wp.pl>
Cc: stable@kernel.org
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

MAYDAY_INITIAL_TIMEOUT is defined as HZ / 100 and depending on
configuration may end up 0 or 1.  Even when it's 1, depending on when
the mayday timer is added in the current jiffy interval, it may expire
way before a jiffy has passed.

Make sure MAYDAY_INITIAL_TIMEOUT is at least two to guarantee that at
least a full jiffy has passed before calling rescuers.
Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: NRay Jui <rjui@broadcom.com>
Cc: stable@kernel.org

There are two spellings in use for 'freeze' + 'able' - 'freezable' and
'freezeable'.  The former is the more prominent one.  The latter is
mostly used by workqueue and in a few other odd places.  Unify the
spelling to 'freezable'.
Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: NAlan Stern <stern@rowland.harvard.edu>
Acked-by: N"Rafael J. Wysocki" <rjw@sisk.pl>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Acked-by: NDmitry Torokhov <dtor@mail.ru>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Alex Dubov <oakad@yahoo.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Steven Whitehouse <swhiteho@redhat.com>

After executing the matching works, a rescuer leaves the gcwq whether
there are more pending works or not.  This may decrease the
concurrency level to zero and stall execution until a new work item is
queued on the gcwq.

Make rescuer wake up a regular worker when it leaves a gcwq if there
are more works to execute, so that execution isn't stalled.
Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: NRay Jui <rjui@broadcom.com>
Cc: stable@kernel.org

In the continuing effort to avoid kernel addresses leaking to
unprivileged users, this patch switches to %pK for
/proc/timer_list reporting.
Signed-off-by: NKees Cook <kees.cook@canonical.com>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Dan Rosenberg <drosenberg@vsecurity.com>
Cc: Eugene Teo <eugeneteo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <20110212032125.GA23571@outflux.net>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The wake_up_process() call in ptrace_detach() is spurious and not
interlocked with the tracee state.  IOW, the tracee could be running or
sleeping in any place in the kernel by the time wake_up_process() is
called.  This can lead to the tracee waking up unexpectedly which can be
dangerous.

The wake_up is spurious and should be removed but for now reduce its
toxicity by only waking up if the tracee is in TRACED or STOPPED state.

This bug can possibly be used as an attack vector.  I don't think it
will take too much effort to come up with an attack which triggers oops
somewhere.  Most sleeps are wrapped in condition test loops and should
be safe but we have quite a number of places where sleep and wakeup
conditions are expected to be interlocked.  Although the window of
opportunity is tiny, ptrace can be used by non-privileged users and with
some loading the window can definitely be extended and exploited.
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: NRoland McGrath <roland@redhat.com>
Acked-by: NOleg Nesterov <oleg@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>