linux/arch/x86/kernel/apic
Thomas Gleixner df4393424a x86/ioapic: Prevent inconsistent state when moving an interrupt
There is an issue with threaded interrupts which are marked ONESHOT
and using the fasteoi handler:

  if (IS_ONESHOT())
    mask_irq();
  ....
  cond_unmask_eoi_irq()
    chip->irq_eoi();
      if (setaffinity_pending) {
         mask_ioapic();
         ...
	 move_affinity();
	 unmask_ioapic();
      }

So if setaffinity is pending the interrupt will be moved and then
unconditionally unmasked at the ioapic level, which is wrong in two
aspects:

 1) It should be kept masked up to the point where the threaded handler
    finished.

 2) The physical chip state and the software masked state are inconsistent

Guard both the mask and the unmask with a check for the software masked
state. If the line is marked masked then the ioapic line is also masked, so
both mask_ioapic() and unmask_ioapic() can be skipped safely.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Fixes: 3aa551c9b4 ("genirq: add threaded interrupt handler support")
Link: https://lkml.kernel.org/r/20191017101938.321393687@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-24 12:09:21 +02:00
..
apic_common.c x86/apic: Fix signedness bug in APIC ID validity checks 2018-04-10 16:46:39 +02:00
apic_flat_64.c x86/apic/flat64: Remove the IPI shorthand decision logic 2019-07-25 16:12:02 +02:00
apic_noop.c x86/apic: Cleanup the include maze 2019-07-25 16:11:57 +02:00
apic_numachip.c x86/apic: Consolidate the apic local headers 2019-07-25 16:11:58 +02:00
apic.c Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-09-17 12:04:39 -07:00
bigsmp_32.c Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-09-17 12:04:39 -07:00
hw_nmi.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
io_apic.c x86/ioapic: Prevent inconsistent state when moving an interrupt 2019-10-24 12:09:21 +02:00
ipi.c x86/apic: Share common IPI helpers 2019-07-25 16:12:02 +02:00
local.h x86/apic/x2apic: Implement IPI shorthands support 2019-07-25 16:12:02 +02:00
Makefile x86/PCI: Remove unused HyperTransport interrupt support 2017-11-23 20:18:18 +01:00
msi.c x86/hpet: Move clockevents into channels 2019-06-28 00:57:24 +02:00
probe_32.c Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-09-17 12:04:39 -07:00
probe_64.c x86/apic/flat64: Remove the IPI shorthand decision logic 2019-07-25 16:12:02 +02:00
vector.c x86/apic/vector: Warn when vector space exhaustion breaks affinity 2019-08-28 14:44:08 +02:00
x2apic_cluster.c x86/apic/x2apic: Fix a NULL pointer deref when handling a dying cpu 2019-10-15 10:57:09 +02:00
x2apic_phys.c x86/apic/x2apic: Implement IPI shorthands support 2019-07-25 16:12:02 +02:00
x2apic_uv_x.c x86/apic/uv: Make x2apic_extra_bits static 2019-07-25 16:11:58 +02:00