genirq: Fix null pointer reference in irq_set_affinity_hint()

The recent set_affinity commit by me introduced some null
pointer dereferences on driver unload, because some drivers
call this function with a NULL argument. This fixes the issue
by just checking for null before setting the affinity mask.

Fixes: e2e64a9325 ("genirq: Set initial affinity in irq_set_affinity_hint()")
Reported-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
CC: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/20150128185739.9689.84588.stgit@jbrandeb-cp2.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Jesse Brandeburg 2015-01-28 10:57:39 -08:00 коммит произвёл Ingo Molnar
Родитель fb7e7deb7f
Коммит 4fe7ffb7e1
1 изменённых файлов: 2 добавлений и 1 удалений

Просмотреть файл

@ -244,7 +244,8 @@ int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
desc->affinity_hint = m;
irq_put_desc_unlock(desc, flags);
/* set the initial affinity to prevent every interrupt being on CPU0 */
__irq_set_affinity(irq, m, false);
if (m)
__irq_set_affinity(irq, m, false);
return 0;
}
EXPORT_SYMBOL_GPL(irq_set_affinity_hint);