aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
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
parentffb7dbed47da6ac4460b606a3feee295bbe4d9e2 (diff)
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>
-rw-r--r--drivers/tty/hvc/hvc_xen.c2
-rw-r--r--drivers/xen/events/events_base.c12
-rw-r--r--include/xen/events.h2
3 files changed, 10 insertions, 6 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);
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index 2b8553bd8715..38387950490e 100644
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -957,7 +957,7 @@ unsigned xen_evtchn_nr_channels(void)
}
EXPORT_SYMBOL_GPL(xen_evtchn_nr_channels);
-int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
+int bind_virq_to_irq(unsigned int virq, unsigned int cpu, bool percpu)
{
struct evtchn_bind_virq bind_virq;
int evtchn, irq, ret;
@@ -971,8 +971,12 @@ int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
if (irq < 0)
goto out;
- irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
- handle_percpu_irq, "virq");
+ if (percpu)
+ irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
+ handle_percpu_irq, "virq");
+ else
+ irq_set_chip_and_handler_name(irq, &xen_dynamic_chip,
+ handle_edge_irq, "virq");
bind_virq.virq = virq;
bind_virq.vcpu = cpu;
@@ -1062,7 +1066,7 @@ int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
{
int irq, retval;
- irq = bind_virq_to_irq(virq, cpu);
+ irq = bind_virq_to_irq(virq, cpu, irqflags & IRQF_PERCPU);
if (irq < 0)
return irq;
retval = request_irq(irq, handler, irqflags, devname, dev_id);
diff --git a/include/xen/events.h b/include/xen/events.h
index 5321cd9636e6..7d95fdf9cf3e 100644
--- a/include/xen/events.h
+++ b/include/xen/events.h
@@ -17,7 +17,7 @@ int bind_evtchn_to_irqhandler(unsigned int evtchn,
irq_handler_t handler,
unsigned long irqflags, const char *devname,
void *dev_id);
-int bind_virq_to_irq(unsigned int virq, unsigned int cpu);
+int bind_virq_to_irq(unsigned int virq, unsigned int cpu, bool percpu);
int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
irq_handler_t handler,
unsigned long irqflags, const char *devname,

Privacy Policy