3.13.11-ckt25 -stable review patch. If anyone has any objections, please let me know.
------------------ From: Thomas Gleixner <[email protected]> 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 <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Signed-off-by: Kamal Mostafa <[email protected]> --- kernel/irq/resend.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/kernel/irq/resend.c b/kernel/irq/resend.c index 9065107..7a5237a 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); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
