linux/kernel/irq
Lukas Wunner 792ea6a074 genirq: Remove WARN_ON_ONCE() in generic_handle_domain_irq()
Since commit 0953fb2637 ("irq: remove handle_domain_{irq,nmi}()"),
generic_handle_domain_irq() warns if called outside hardirq context, even
though the function calls down to handle_irq_desc(), which warns about the
same, but conditionally on handle_enforce_irqctx().

The newly added warning is a false positive if the interrupt originates
from any other irqchip than x86 APIC or ARM GIC/GICv3.  Those are the only
ones for which handle_enforce_irqctx() returns true.  Per commit
c16816acd0 ("genirq: Add protection against unsafe usage of
generic_handle_irq()"):

 "In general calling generic_handle_irq() with interrupts disabled from non
  interrupt context is harmless. For some interrupt controllers like the
  x86 trainwrecks this is outright dangerous as it might corrupt state if
  an interrupt affinity change is pending."

Examples for interrupt chips where the warning is a false positive are
USB-attached GPIO controllers such as drivers/gpio/gpio-dln2.c:

  USB gadgets are incapable of directly signaling an interrupt because they
  cannot initiate a bus transaction by themselves.  All communication on
  the bus is initiated by the host controller, which polls a gadget's
  Interrupt Endpoint in regular intervals.  If an interrupt is pending,
  that information is passed up the stack in softirq context, from which a
  hardirq is synthesized via generic_handle_domain_irq().

Remove the warning to eliminate such false positives.

Fixes: 0953fb2637 ("irq: remove handle_domain_{irq,nmi}()")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Jakub Kicinski <kuba@kernel.org>
CC: Linus Walleij <linus.walleij@linaro.org>
Cc: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: Octavian Purdila <octavian.purdila@nxp.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220505113207.487861b2@kernel.org
Link: https://lore.kernel.org/r/20220506203242.GA1855@wunner.de
Link: https://lore.kernel.org/r/c3caf60bfa78e5fdbdf483096b7174da65d1813a.1652168866.git.lukas@wunner.de
2022-05-11 02:22:52 +02:00
..
affinity.c genirq/affinity: Consider that CPUs on nodes can be unbalanced 2022-04-11 09:58:03 +02:00
autoprobe.c genirq: Delay deactivation in free_irq() 2019-07-03 10:12:28 +02:00
chip.c genirq: Allow irq_chip registration functions to take a const irq_chip 2022-02-15 11:10:21 +00:00
cpuhotplug.c sched/isolation: Use single feature type while referring to housekeeping cpumask 2022-02-16 15:57:55 +01:00
debug.h
debugfs.c genirq/debugfs: Use irq_print_chip() when provided by irqchip 2022-02-15 11:22:34 +00:00
devres.c
dummychip.c irq: Fix typos in comments 2021-03-22 04:23:14 +01:00
generic-chip.c genirq/generic_chip: Constify irq_generic_chip_ops 2021-12-01 00:15:07 +01:00
handle.c irq: remove unused flags argument from __handle_irq_event_percpu() 2022-01-07 00:25:25 +01:00
internals.h genirq: Synchronize interrupt thread startup 2022-05-05 11:54:05 +02:00
ipi.c genirq: Fix kernel-doc warnings in pm.c, msi.c and ipi.c 2021-08-11 14:33:35 +02:00
irq_sim.c The usual updates from the irq departement: 2021-04-26 09:43:16 -07:00
irqdesc.c genirq: Remove WARN_ON_ONCE() in generic_handle_domain_irq() 2022-05-11 02:22:52 +02:00
irqdomain.c irqdomain: Let irq_domain_set_{info,hwirq_and_chip} take a const irq_chip 2022-02-15 11:10:21 +00:00
Kconfig Merge branch irq/irq_cpu_offline into irq/irqchip-next 2021-10-28 13:34:57 +01:00
Makefile
manage.c genirq: Synchronize interrupt thread startup 2022-05-05 11:54:05 +02:00
matrix.c genirq/matrix: Fix kernel doc warnings for irq_matrix_alloc_managed() 2021-08-10 22:50:07 +02:00
migration.c genirq: Fix typos and misspellings in comments 2021-03-16 15:08:29 +01:00
msi.c genirq/msi: Populate sysfs entry only once 2022-01-10 19:22:10 +01:00
pm.c genirq: Fix kernel-doc warnings in pm.c, msi.c and ipi.c 2021-08-11 14:33:35 +02:00
proc.c proc: remove PDE_DATA() completely 2022-01-22 08:33:37 +02:00
resend.c genirq: Fix typos and misspellings in comments 2021-03-16 15:08:29 +01:00
settings.h genirq: Add a IRQF_NO_DEBUG flag 2021-05-17 20:01:35 +02:00
spurious.c genirq: Disable irqfixup/poll on PREEMPT_RT. 2021-09-19 23:01:15 +02:00
timings.c Updates to the interrupt core and driver subsystems: 2021-08-30 14:38:37 -07:00