genirq: Fix cpumask check in __irq_startup_managed()

BugLink: http://bugs.launchpad.net/bugs/1721777
commit 9cb067ef8a10bb13112e4d1c0ea996ec96527422 upstream.

The result of cpumask_any_and() is invalid when result greater or equal
nr_cpu_ids. The current check is checking for greater only. Fix it.

Fixes: 761ea388e8c4 ("genirq: Handle managed irqs gracefully in irq_startup()")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Chen Yu <yu.c.chen@intel.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rui Zhang <rui.zhang@intel.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Len Brown <lenb@kernel.org>
Link: http://lkml.kernel.org/r/20170913213152.272283444@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>

diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 3675c6004f2a68c9d60493c7c46e9c46a0baa73f..75a70a2670298d04d895adcf95e57762ba85f7fb 100644 (file)
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -202,7 +202,7 @@ __irq_startup_managed(struct irq_desc *desc, struct cpumask *aff, bool force)
 
        irqd_clr_managed_shutdown(d);
 
-       if (cpumask_any_and(aff, cpu_online_mask) > nr_cpu_ids) {
+       if (cpumask_any_and(aff, cpu_online_mask) >= nr_cpu_ids) {
                /*
                 * Catch code which fiddles with enable_irq() on a managed
                 * and potentially shutdown IRQ. Chained interrupt