linux-toradex.git/arch/x86/kernel/apic, branch v4.4.86

x86/ioapic: Pass the correct data to unmask_ioapic_irq()

2017-07-27T22:06:07+00:00

commit e708e35ba6d89ff785b225cd07dcccab04fa954a upstream.

One of the rarely executed code pathes in check_timer() calls
unmask_ioapic_irq() passing irq_get_chip_data(0) as argument.

That's wrong as unmask_ioapic_irq() expects a pointer to the irq data of
interrupt 0. irq_get_chip_data(0) returns NULL, so the following
dereference in unmask_ioapic_irq() causes a kernel panic.

The issue went unnoticed in the first place because irq_get_chip_data()
returns a void pointer so the compiler cannot do a type check on the
argument. The code path was added for machines with broken configuration,
but it seems that those machines are either not running current kernels or
simply do not longer exist.

Hand in irq_get_irq_data(0) as argument which provides the correct data.

[ tglx: Rewrote changelog ]

Fixes: 4467715a44cc ("x86/irq: Move irq_cfg.irq_2_pin into io_apic.c")
Signed-off-by: Seunghun Han 
Signed-off-by: Thomas Gleixner 
Link: http://lkml.kernel.org/r/1500369644-45767-1-git-send-email-kkamagui@gmail.com
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

x86/ioapic: Restore IO-APIC irq_chip retrigger callback

2017-05-14T11:32:55+00:00

commit a9b4f08770b415f30f2fb0f8329a370c8f554aa3 upstream.

commit d32932d02e18 removed the irq_retrigger callback from the IO-APIC
chip and did not add it to the new IO-APIC-IR irq chip.

There is no harm because the interrupts are resent in software when the
retrigger callback is NULL, but it's less efficient. So restore them.

[ tglx: Massaged changelog ]

Fixes: d32932d02e18  ("x86/irq: Convert IOAPIC to use hierarchical irqdomain interfaces")
Signed-off-by: Ruslan Ruslichenko 
Cc: xe-linux-external@cisco.com
Link: http://lkml.kernel.org/r/1484662432-13580-1-git-send-email-rruslich@cisco.com
Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

Revert "x86/ioapic: Restore IO-APIC irq_chip retrigger callback"

2017-02-14T23:22:50+00:00

commit d966564fcdc19e13eb6ba1fbe6b8101070339c3d upstream.

This reverts commit 020eb3daaba2857b32c4cf4c82f503d6a00a67de.

Gabriel C reports that it causes his machine to not boot, and we haven't
tracked down the reason for it yet.  Since the bug it fixes has been
around for a longish time, we're better off reverting the fix for now.

Gabriel says:
 "It hangs early and freezes with a lot RCU warnings.

  I bisected it down to :

  > Ruslan Ruslichenko (1):
  >       x86/ioapic: Restore IO-APIC irq_chip retrigger callback

  Reverting this one fixes the problem for me..

  The box is a PRIMERGY TX200 S5 , 2 socket , 2 x E5520 CPU(s) installed"

and Ruslan and Thomas are currently stumped.

Reported-and-bisected-by: Gabriel C 
Cc: Ruslan Ruslichenko 
Cc: Thomas Gleixner 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

x86/irq: Make irq activate operations symmetric

2017-02-09T07:02:47+00:00

commit aaaec6fc755447a1d056765b11b24d8ff2b81366 upstream.

The recent commit which prevents double activation of interrupts unearthed
interesting code in x86. The code (ab)uses irq_domain_activate_irq() to
reconfigure an already activated interrupt. That trips over the prevention
code now.

Fix it by deactivating the interrupt before activating the new configuration.

Fixes: 08d85f3ea99f1 "irqdomain: Avoid activating interrupts more than once"
Reported-and-tested-by: Mike Galbraith 
Reported-and-tested-by: Borislav Petkov 
Signed-off-by: Thomas Gleixner 
Cc: Andrey Ryabinin 
Cc: Marc Zyngier 
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1701311901580.3457@nanos
Signed-off-by: Greg Kroah-Hartman

x86/ioapic: Restore IO-APIC irq_chip retrigger callback

2017-01-26T07:23:48+00:00

commit 020eb3daaba2857b32c4cf4c82f503d6a00a67de upstream.

commit d32932d02e18 removed the irq_retrigger callback from the IO-APIC
chip and did not add it to the new IO-APIC-IR irq chip.

Unfortunately the software resend fallback is not enabled on X86, so edge
interrupts which are received during the lazy disabled state of the
interrupt line are not retriggered and therefor lost.

Restore the callbacks.

[ tglx: Massaged changelog ]

Fixes: d32932d02e18  ("x86/irq: Convert IOAPIC to use hierarchical irqdomain interfaces")
Signed-off-by: Ruslan Ruslichenko 
Cc: xe-linux-external@cisco.com
Link: http://lkml.kernel.org/r/1484662432-13580-1-git-send-email-rruslich@cisco.com
Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

x86/irq: Prevent force migration of irqs which are not in the vector domain

2016-10-16T15:36:15+00:00

commit db91aa793ff984ac048e199ea1c54202543952fe upstream.

When a CPU is about to be offlined we call fixup_irqs() that resets IRQ
affinities related to the CPU in question. The same thing is also done when
the system is suspended to S-states like S3 (mem).

For each IRQ we try to complete any on-going move regardless whether the
IRQ is actually part of x86_vector_domain. For each IRQ descriptor we fetch
its chip_data, assume it is of type struct apic_chip_data and manipulate it
by clearing old_domain mask etc. For irq_chips that are not part of the
x86_vector_domain, like those created by various GPIO drivers, will find
their chip_data being changed unexpectly.

Below is an example where GPIO chip owned by pinctrl-sunrisepoint.c gets
corrupted after resume:

  # cat /sys/kernel/debug/gpio
  gpiochip0: GPIOs 360-511, parent: platform/INT344B:00, INT344B:00:
   gpio-511 (                    |sysfs               ) in  hi

  # rtcwake -s10 -mmem
  <10 seconds passes>

  # cat /sys/kernel/debug/gpio
  gpiochip0: GPIOs 360-511, parent: platform/INT344B:00, INT344B:00:
   gpio-511 (                    |sysfs               ) in  ?

Note '?' in the output. It means the struct gpio_chip ->get function is
NULL whereas before suspend it was there.

Fix this by first checking that the IRQ belongs to x86_vector_domain before
we try to use the chip_data as struct apic_chip_data.

Reported-and-tested-by: Sakari Ailus 
Signed-off-by: Mika Westerberg 
Link: http://lkml.kernel.org/r/20161003101708.34795-1-mika.westerberg@linux.intel.com
Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

x86/apic: Do not init irq remapping if ioapic is disabled

2016-09-15T06:27:53+00:00

commit 2e63ad4bd5dd583871e6602f9d398b9322d358d9 upstream.

native_smp_prepare_cpus
  -> default_setup_apic_routing
    -> enable_IR_x2apic
      -> irq_remapping_prepare
        -> intel_prepare_irq_remapping
          -> intel_setup_irq_remapping

So IR table is setup even if "noapic" boot parameter is added. As a result we
crash later when the interrupt affinity is set due to a half initialized
remapping infrastructure.

Prevent remap initialization when IOAPIC is disabled.

Signed-off-by: Wanpeng Li 
Cc: Peter Zijlstra 
Cc: Joerg Roedel 
Link: http://lkml.kernel.org/r/1471954039-3942-1-git-send-email-wanpeng.li@hotmail.com
Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

x86/apic: Handle zero vector gracefully in clear_vector_irq()

2016-05-04T21:48:49+00:00

commit 1bdb8970392a68489b469c3a330a1adb5ef61beb upstream.

If x86_vector_alloc_irq() fails x86_vector_free_irqs() is invoked to cleanup
the already allocated vectors. This subsequently calls clear_vector_irq().

The failed irq has no vector assigned, which triggers the BUG_ON(!vector) in
clear_vector_irq().

We cannot suppress the call to x86_vector_free_irqs() for the failed
interrupt, because the other data related to this irq must be cleaned up as
well. So calling clear_vector_irq() with vector == 0 is legitimate.

Remove the BUG_ON and return if vector is zero,

[ tglx: Massaged changelog ]

Fixes: b5dc8e6c21e7 "x86/irq: Use hierarchical irqdomain to manage CPU interrupt vectors"
Signed-off-by: Keith Busch 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

x86/irq: Cure live lock in fixup_irqs()

2016-04-12T16:08:37+00:00

commit 551adc60573cb68e3d55cacca9ba1b7437313df7 upstream.

Harry reported, that he's able to trigger a system freeze with cpu hot
unplug. The freeze turned out to be a live lock caused by recent changes in
irq_force_complete_move().

When fixup_irqs() and from there irq_force_complete_move() is called on the
dying cpu, then all other cpus are in stop machine an wait for the dying cpu
to complete the teardown. If there is a move of an interrupt pending then
irq_force_complete_move() sends the cleanup IPI to the cpus in the old_domain
mask and waits for them to clear the mask. That's obviously impossible as
those cpus are firmly stuck in stop machine with interrupts disabled.

I should have known that, but I completely overlooked it being concentrated on
the locking issues around the vectors. And the existance of the call to
__irq_complete_move() in the code, which actually sends the cleanup IPI made
it reasonable to wait for that cleanup to complete. That call was bogus even
before the recent changes as it was just a pointless distraction.

We have to look at two cases:

1) The move_in_progress flag of the interrupt is set

   This means the ioapic has been updated with the new vector, but it has not
   fired yet. In theory there is a race:

   set_ioapic(new_vector) <-- Interrupt is raised before update is effective,
   			      i.e. it's raised on the old vector.

   So if the target cpu cannot handle that interrupt before the old vector is
   cleaned up, we get a spurious interrupt and in the worst case the ioapic
   irq line becomes stale, but my experiments so far have only resulted in
   spurious interrupts.

   But in case of cpu hotplug this should be a non issue because if the
   affinity update happens right before all cpus rendevouz in stop machine,
   there is no way that the interrupt can be blocked on the target cpu because
   all cpus loops first with interrupts enabled in stop machine, so the old
   vector is not yet cleaned up when the interrupt fires.

   So the only way to run into this issue is if the delivery of the interrupt
   on the apic/system bus would be delayed beyond the point where the target
   cpu disables interrupts in stop machine. I doubt that it can happen, but at
   least there is a theroretical chance. Virtualization might be able to
   expose this, but AFAICT the IOAPIC emulation is not as stupid as the real
   hardware.

   I've spent quite some time over the weekend to enforce that situation,
   though I was not able to trigger the delayed case.

2) The move_in_progress flag is not set and the old_domain cpu mask is not
   empty.

   That means, that an interrupt was delivered after the change and the
   cleanup IPI has been sent to the cpus in old_domain, but not all CPUs have
   responded to it yet.

In both cases we can assume that the next interrupt will arrive on the new
vector, so we can cleanup the old vectors on the cpus in the old_domain cpu
mask.

Fixes: 98229aa36caa "x86/irq: Plug vector cleanup race"
Reported-by: Harry Junior 
Tested-by: Tony Luck 
Signed-off-by: Thomas Gleixner 
Cc: Peter Zijlstra 
Cc: Joe Lawrence 
Cc: Borislav Petkov 
Cc: Ben Hutchings 
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1603140931430.3657@nanos
Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

x86/irq: Plug vector cleanup race

2016-03-03T23:07:32+00:00

commit 98229aa36caa9c769b13565523de9b813013c703 upstream.

We still can end up with a stale vector due to the following:

CPU0                          CPU1                      CPU2
lock_vector()
data->move_in_progress=0
sendIPI()
unlock_vector()
                              set_affinity()
                              assign_irq_vector()
                              lock_vector()             handle_IPI
                              move_in_progress = 1      lock_vector()
                              unlock_vector()
                                                        move_in_progress == 1

So we need to serialize the vector assignment against a pending cleanup. The
solution is rather simple now. We not only check for the move_in_progress flag
in assign_irq_vector(), we also check whether there is still a cleanup pending
in the old_domain cpumask. If so, we return -EBUSY to the caller and let him
deal with it. Though we have to be careful in the cpu unplug case. If the
cleanout has not yet completed then the following setaffinity() call would
return -EBUSY. Add code which prevents this.

Full context is here: http://lkml.kernel.org/r/5653B688.4050809@stratus.com

Reported-and-tested-by: Joe Lawrence 
Signed-off-by: Thomas Gleixner 
Tested-by: Borislav Petkov 
Cc: Jiang Liu 
Cc: Jeremiah Mahler 
Cc: andy.shevchenko@gmail.com
Cc: Guenter Roeck 
Link: http://lkml.kernel.org/r/20151231160107.207265407@linutronix.de
Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman