[PATCH 4.9 017/102] genirq: Use cpumask_available() for check of cpumask variable

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Matthias Kaehlcke <mka@xxxxxxxxxxxx>

commit d170fe7dd992b313d4851ae5ab77ee7a51ed8c72 upstream.

This fixes the following clang warning when CONFIG_CPUMASK_OFFSTACK=n:

kernel/irq/manage.c:839:28: error: address of array
'desc->irq_common_data.affinity' will always evaluate to 'true'
[-Werror,-Wpointer-bool-conversion]

Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
Cc: Grant Grundler <grundler@xxxxxxxxxxxx>
Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Cc: Greg Hackmann <ghackmann@xxxxxxxxxx>
Cc: Michael Davidson <md@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/20170412182030.83657-2-mka@xxxxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Nathan Chancellor <natechancellor@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 kernel/irq/manage.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -850,7 +850,7 @@ irq_thread_check_affinity(struct irq_des
 	 * This code is triggered unconditionally. Check the affinity
 	 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
 	 */
-	if (desc->irq_common_data.affinity)
+	if (cpumask_available(desc->irq_common_data.affinity))
 		cpumask_copy(mask, desc->irq_common_data.affinity);
 	else
 		valid = false;