linux.git/arch/x86/kernel/apic/vector.c, branch v4.12

x86/irq, trace: Add __irq_entry annotation to x86's platform IRQ handlers

2017-01-05T07:58:49+00:00

This patch adds the __irq_entry annotation to the default x86
platform IRQ handlers. ftrace's function_graph tracer uses the
__irq_entry annotation to notify the entry and return of IRQ
handlers.

For example, before the patch:
  354549.667252 |   3)  d..1              |  default_idle_call() {
  354549.667252 |   3)  d..1              |    arch_cpu_idle() {
  354549.667253 |   3)  d..1              |      default_idle() {
  354549.696886 |   3)  d..1              |        smp_trace_reschedule_interrupt() {
  354549.696886 |   3)  d..1              |          irq_enter() {
  354549.696886 |   3)  d..1              |            rcu_irq_enter() {

After the patch:
  366416.254476 |   3)  d..1              |    arch_cpu_idle() {
  366416.254476 |   3)  d..1              |      default_idle() {
  366416.261566 |   3)  d..1  ==========> |
  366416.261566 |   3)  d..1              |        smp_trace_reschedule_interrupt() {
  366416.261566 |   3)  d..1              |          irq_enter() {
  366416.261566 |   3)  d..1              |            rcu_irq_enter() {

KASAN also uses this annotation. The smp_apic_timer_interrupt()
was already annotated.

Signed-off-by: Daniel Bristot de Oliveira 
Acked-by: Steven Rostedt (VMware) 
Cc: Aaron Lu 
Cc: Andrew Morton 
Cc: Baoquan He 
Cc: Borislav Petkov 
Cc: Claudio Fontana 
Cc: Denys Vlasenko 
Cc: Dou Liyang 
Cc: Gu Zheng 
Cc: Hidehiro Kawai 
Cc: Linus Torvalds 
Cc: Nicolai Stange 
Cc: Peter Zijlstra (Intel) 
Cc: Steven Rostedt 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Cc: Wanpeng Li 
Cc: linux-edac@vger.kernel.org
Link: http://lkml.kernel.org/r/059fdf437c2f0c09b13c18c8fe4e69999d3ffe69.1483528431.git.bristot@redhat.com
Signed-off-by: Ingo Molnar

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

2016-10-04T11:13:47+00:00

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 
Cc: stable@vger.kernel.org # 4.4+
Link: http://lkml.kernel.org/r/20161003101708.34795-1-mika.westerberg@linux.intel.com
Signed-off-by: Thomas Gleixner

tree-wide: replace config_enabled() with IS_ENABLED()

2016-08-04T12:50:07+00:00

The use of config_enabled() against config options is ambiguous.  In
practical terms, config_enabled() is equivalent to IS_BUILTIN(), but the
author might have used it for the meaning of IS_ENABLED().  Using
IS_ENABLED(), IS_BUILTIN(), IS_MODULE() etc.  makes the intention
clearer.

This commit replaces config_enabled() with IS_ENABLED() where possible.
This commit is only touching bool config options.

I noticed two cases where config_enabled() is used against a tristate
option:

 - config_enabled(CONFIG_HWMON)
  [ drivers/net/wireless/ath/ath10k/thermal.c ]

 - config_enabled(CONFIG_BACKLIGHT_CLASS_DEVICE)
  [ drivers/gpu/drm/gma500/opregion.c ]

I did not touch them because they should be converted to IS_BUILTIN()
in order to keep the logic, but I was not sure it was the authors'
intention.

Link: http://lkml.kernel.org/r/1465215656-20569-1-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada 
Acked-by: Kees Cook 
Cc: Stas Sergeev 
Cc: Matt Redfearn 
Cc: Joshua Kinard 
Cc: Jiri Slaby 
Cc: Bjorn Helgaas 
Cc: Borislav Petkov 
Cc: Markos Chandras 
Cc: "Dmitry V. Levin" 
Cc: yu-cheng yu 
Cc: James Hogan 
Cc: Brian Gerst 
Cc: Johannes Berg 
Cc: Peter Zijlstra 
Cc: Al Viro 
Cc: Will Drewry 
Cc: Nikolay Martynov 
Cc: Huacai Chen 
Cc: "H. Peter Anvin" 
Cc: Thomas Gleixner 
Cc: Daniel Borkmann 
Cc: Leonid Yegoshin 
Cc: Rafal Milecki 
Cc: James Cowgill 
Cc: Greg Kroah-Hartman 
Cc: Ralf Baechle 
Cc: Alex Smith 
Cc: Adam Buchbinder 
Cc: Qais Yousef 
Cc: Jiang Liu 
Cc: Mikko Rapeli 
Cc: Paul Gortmaker 
Cc: Denys Vlasenko 
Cc: Brian Norris 
Cc: Hidehiro Kawai 
Cc: "Luis R. Rodriguez" 
Cc: Andy Lutomirski 
Cc: Ingo Molnar 
Cc: Dave Hansen 
Cc: "Kirill A. Shutemov" 
Cc: Roland McGrath 
Cc: Paul Burton 
Cc: Kalle Valo 
Cc: Viresh Kumar 
Cc: Tony Wu 
Cc: Huaitong Han 
Cc: Sumit Semwal 
Cc: Alexei Starovoitov 
Cc: Juergen Gross 
Cc: Jason Cooper 
Cc: "David S. Miller" 
Cc: Oleg Nesterov 
Cc: Andrea Gelmini 
Cc: David Woodhouse 
Cc: Marc Zyngier 
Cc: Rabin Vincent 
Cc: "Maciej W. Rozycki" 
Cc: David Daney 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'x86/urgent' into x86/asm, to refresh the tree

2016-04-29T09:55:04+00:00

Signed-off-by: Ingo Molnar

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

2016-04-28T07:53:06+00:00

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 
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Gleixner

x86/cpufeature: Replace cpu_has_apic with boot_cpu_has() usage

2016-04-13T09:37:41+00:00

Signed-off-by: Borislav Petkov 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: iommu@lists.linux-foundation.org
Cc: linux-pm@vger.kernel.org
Cc: oprofile-list@lists.sf.net
Link: http://lkml.kernel.org/r/1459801503-15600-8-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar

x86/irq: Cure live lock in fixup_irqs()

2016-03-18T13:51:06+00:00

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 
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1603140931430.3657@nanos
Signed-off-by: Thomas Gleixner

x86/irq: Plug vector cleanup race

2016-01-15T12:44:02+00:00

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 
Cc: stable@vger.kernel.org #4.3+
Link: http://lkml.kernel.org/r/20151231160107.207265407@linutronix.de
Signed-off-by: Thomas Gleixner

x86/irq: Call irq_force_move_complete with irq descriptor

2016-01-15T12:44:01+00:00

First of all there is no point in looking up the irq descriptor again, but we
also need the descriptor for the final cleanup race fix in the next
patch. Make that change seperate. No functional difference.

Signed-off-by: Thomas Gleixner 
Tested-by: Borislav Petkov 
Tested-by: Joe Lawrence 
Cc: Jiang Liu 
Cc: Jeremiah Mahler 
Cc: andy.shevchenko@gmail.com
Cc: Guenter Roeck 
Cc: stable@vger.kernel.org #4.3+
Link: http://lkml.kernel.org/r/20151231160107.125211743@linutronix.de
Signed-off-by: Thomas Gleixner

x86/irq: Remove outgoing CPU from vector cleanup mask

2016-01-15T12:44:01+00:00

We want to synchronize new vector assignments with a pending cleanup. Remove a
dying cpu from a pending cleanup mask.

Signed-off-by: Thomas Gleixner 
Tested-by: Borislav Petkov 
Tested-by: Joe Lawrence 
Cc: Jiang Liu 
Cc: Jeremiah Mahler 
Cc: andy.shevchenko@gmail.com
Cc: Guenter Roeck 
Cc: stable@vger.kernel.org #4.3+
Link: http://lkml.kernel.org/r/20151231160107.045961667@linutronix.de
Signed-off-by: Thomas Gleixner