This is a note to let you know that I've just added the patch titled

    genirq: Prevent resend to interrupts marked IRQ_NESTED_THREAD

to the 3.10-stable tree which can be found at:
    
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     genirq-prevent-resend-to-interrupts-marked-irq_nested_thread.patch
and it can be found in the queue-3.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.


>From 75a06189fc508a2acf470b0b12710362ffb2c4b1 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <[email protected]>
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

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: Greg Kroah-Hartman <[email protected]>

---
 kernel/irq/resend.c |   18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

--- a/kernel/irq/resend.c
+++ b/kernel/irq/resend.c
@@ -75,13 +75,21 @@ void check_irq_resend(struct irq_desc *d
                    !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);


Patches currently in stable-queue which might be from [email protected] are

queue-3.10/genirq-prevent-resend-to-interrupts-marked-irq_nested_thread.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to