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authorDavid Vrabel <david.vrabel@citrix.com>2015-05-19 18:40:49 +0100
committerDavid Vrabel <david.vrabel@citrix.com>2015-05-19 19:55:36 +0100
commit77bb3dfdc0d554befad58fdefbc41be5bc3ed38a (patch)
tree845e60544a5b07d4adc6beb6249997c909575c1c /drivers/tty
parentffb7dbed47da6ac4460b606a3feee295bbe4d9e2 (diff)
downloadlinux-77bb3dfdc0d554befad58fdefbc41be5bc3ed38a.tar.gz
xen/events: don't bind non-percpu VIRQs with percpu chip
A non-percpu VIRQ (e.g., VIRQ_CONSOLE) may be freed on a different
VCPU than it is bound to.  This can result in a race between
handle_percpu_irq() and removing the action in __free_irq() because
handle_percpu_irq() does not take desc->lock.  The interrupt handler
sees a NULL action and oopses.

Only use the percpu chip/handler for per-CPU VIRQs (like VIRQ_TIMER).

  # cat /proc/interrupts | grep virq
   40:      87246          0  xen-percpu-virq      timer0
   44:          0          0  xen-percpu-virq      debug0
   47:          0      20995  xen-percpu-virq      timer1
   51:          0          0  xen-percpu-virq      debug1
   69:          0          0   xen-dyn-virq      xen-pcpu
   74:          0          0   xen-dyn-virq      mce
   75:         29          0   xen-dyn-virq      hvc_console

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Cc: <stable@vger.kernel.org>
Diffstat (limited to 'drivers/tty')
-rw-r--r--drivers/tty/hvc/hvc_xen.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
index 5bab1c684bb1..7a3d146a5f0e 100644
--- a/drivers/tty/hvc/hvc_xen.c
+++ b/drivers/tty/hvc/hvc_xen.c
@@ -289,7 +289,7 @@ static int xen_initial_domain_console_init(void)
 			return -ENOMEM;
 	}
 
-	info->irq = bind_virq_to_irq(VIRQ_CONSOLE, 0);
+	info->irq = bind_virq_to_irq(VIRQ_CONSOLE, 0, false);
 	info->vtermno = HVC_COOKIE;
 
 	spin_lock(&xencons_lock);