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genirq: Prevent resend to interrupts marked IRQ_NESTED_THREAD 

commit 75a06189fc508a2acf470b0b12710362ffb2c4b1 upstream.

The resend mechanism happily calls the interrupt handler of interrupts
which are marked IRQ_NESTED_THREAD from softirq context. This can
result in crashes because the interrupt handler is not the proper way
to invoke the device handlers. They must be invoked via
handle_nested_irq.

Prevent the resend even if the interrupt has no valid parent irq
set. Its better to have a lost interrupt than a crashing machine.

Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Thomas Gleixner 2015-07-16 14:10:17 +02:00 committed by Greg Kroah-Hartman
parent 508a750fe6
commit dcc2305a48
1 changed files with 13 additions and 5 deletions
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18
kernel/irq/resend.c
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@ -75,13 +75,21 @@ void check_irq_resend(struct irq_desc *desc, unsigned int irq)
!desc->irq_data.chip->irq_retrigger(&desc->irq_data)) {
#ifdef CONFIG_HARDIRQS_SW_RESEND
/*
* If the interrupt has a parent irq and runs
* in the thread context of the parent irq,
* retrigger the parent.
* If the interrupt is running in the thread
* context of the parent irq we need to be
* careful, because we cannot trigger it
* directly.
*/
if (desc->parent_irq &&
irq_settings_is_nested_thread(desc))
if (irq_settings_is_nested_thread(desc)) {
/*
* If the parent_irq is valid, we
* retrigger the parent, otherwise we
* do nothing.
*/
if (!desc->parent_irq)
return;
irq = desc->parent_irq;
}
/* Set it pending and activate the softirq: */
set_bit(irq, irqs_resend);
tasklet_schedule(&resend_tasklet);