@@ -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);
This is a note to let you know that I have just added a patch titled genirq: Prevent resend to interrupts marked IRQ_NESTED_THREAD to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.13.y-queue This patch is scheduled to be released in version 3.13.11-ckt25. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.13.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From ded36089da1159b3a9774004b5084e7d865bfd97 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner <tglx@linutronix.de> Date: Thu, 16 Jul 2015 14:10:17 +0200 Subject: genirq: Prevent resend to interrupts marked IRQ_NESTED_THREAD MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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: Kamal Mostafa <kamal@canonical.com> --- kernel/irq/resend.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) -- 1.9.1