linux/kernel/irq
Thomas Gleixner 753649dbc4 genirq: Force MSI irq handlers to run with interrupts disabled
Network folks reported that directing all MSI-X vectors of their multi
queue NICs to a single core can cause interrupt stack overflows when
enough interrupts fire at the same time.

This is caused by the fact that we run interrupt handlers by default
with interrupts enabled unless the driver reuqests the interrupt with
the IRQF_DISABLED set. The NIC handlers do not set this flag, so
simultaneous interrupts can nest unlimited and cause the stack
overflow.

The only safe counter measure is to run the interrupt handlers with
interrupts disabled. We can't switch to this mode in general right
now, but it is safe to do so for MSI interrupts.

Force IRQF_DISABLED for MSI interrupt handlers.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Linus Torvalds <torvalds@osdl.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: David Miller <davem@davemloft.net>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: stable@kernel.org
2010-03-31 15:48:38 +02:00
..
autoprobe.c genirq: Convert irq_desc.lock to raw_spinlock 2009-12-14 23:55:33 +01:00
chip.c Merge branch 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-03-26 15:09:06 -07:00
devres.c devres/irq: Fix devm_irq_match comment 2010-02-11 16:01:02 +01:00
handle.c sparseirq: Use radix_tree instead of ptrs array 2010-02-17 17:27:20 -08:00
internals.h sparseirq: Change irq_desc_ptrs to static 2010-02-17 17:27:03 -08:00
Makefile x86/irq: use move_irq_desc() in create_irq_nr() 2009-05-01 19:01:12 +02:00
manage.c genirq: Force MSI irq handlers to run with interrupts disabled 2010-03-31 15:48:38 +02:00
migration.c genirq: Convert irq_desc.lock to raw_spinlock 2009-12-14 23:55:33 +01:00
numa_migrate.c sparseirq: Change irq_desc_ptrs to static 2010-02-17 17:27:03 -08:00
pm.c genirq: Convert irq_desc.lock to raw_spinlock 2009-12-14 23:55:33 +01:00
proc.c genirq: Convert irq_desc.lock to raw_spinlock 2009-12-14 23:55:33 +01:00
resend.c irq: Remove superfluous NULL pointer check in check_irq_resend() 2009-08-09 12:44:29 +02:00
spurious.c genirq: Convert irq_desc.lock to raw_spinlock 2009-12-14 23:55:33 +01:00