diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2015-07-16 15:10:17 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2015-07-17 12:29:34 +0300 |
| commit | 75a06189fc508a2acf470b0b12710362ffb2c4b1 (patch) | |
| tree | af68b2120f3cba499cf8d26b6cd76cdbb1d302f2 /kernel/irq/resend.c | |
| parent | ce0d3c0a6fb1422101498ef378c0851dabbbf67f (diff) | |
| download | linux-75a06189fc508a2acf470b0b12710362ffb2c4b1.tar.xz | |
genirq: Prevent resend to interrupts marked IRQ_NESTED_THREAD
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>
Cc: stable@vger.kernel.org
Diffstat (limited to 'kernel/irq/resend.c')
| -rw-r--r-- | kernel/irq/resend.c | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/kernel/irq/resend.c b/kernel/irq/resend.c index 9065107f083e..7a5237a1bce5 100644 --- a/kernel/irq/resend.c +++ b/kernel/irq/resend.c @@ -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); |