sparc32, leon: Check for existent irq_map entry in leon_handle_ext_irq

If an irq is being unlinked concurrently with leon_handle_ext_irq,
irq_map[eirq] might be null in leon_handle_ext_irq. Make sure that
this is not dereferenced.

Signed-off-by: Andreas Larsson <andreas@gaisler.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Andreas Larsson 2012-10-30 00:09:46 +00:00 committed by David S. Miller
parent 5cf8f7db82
commit 20424d85f8

View File

@ -56,11 +56,13 @@ static inline unsigned int leon_eirq_get(int cpu)
static void leon_handle_ext_irq(unsigned int irq, struct irq_desc *desc)
{
unsigned int eirq;
struct irq_bucket *p;
int cpu = sparc_leon3_cpuid();
eirq = leon_eirq_get(cpu);
if ((eirq & 0x10) && irq_map[eirq]->irq) /* bit4 tells if IRQ happened */
generic_handle_irq(irq_map[eirq]->irq);
p = irq_map[eirq];
if ((eirq & 0x10) && p && p->irq) /* bit4 tells if IRQ happened */
generic_handle_irq(p->irq);
}
/* The extended IRQ controller has been found, this function registers it */