Patch "x86/irq: Do not use apic_chip_data.old_domain as temporary buffer" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

x86/irq: Do not use apic_chip_data.old_domain as temporary buffer

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
x86-irq-do-not-use-apic_chip_data.old_domain-as-temporary-buffer.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Jiang Liu <[email protected]>
Date: Thu, 31 Dec 2015 16:30:46 +0000
Subject: x86/irq: Do not use apic_chip_data.old_domain as temporary buffer

From: Jiang Liu <[email protected]>

commit 8a580f70f6936ec095da217018cdeeb5835c0207 upstream.

Function __assign_irq_vector() makes use of apic_chip_data.old_domain as a temporary buffer, which is in the way of using apic_chip_data.old_domain for synchronizing the vector cleanup with the vector assignement code.

Use a proper temporary cpumask for this.

[ tglx: Renamed the mask to searched_cpumask for clarity ]

---
 arch/x86/kernel/apic/vector.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

@@ -30,7 +30,7 @@ struct apic_chip_data {
 
 struct irq_domain *x86_vector_domain;
 static DEFINE_RAW_SPINLOCK(vector_lock);
-static cpumask_var_t vector_cpumask;
+static cpumask_var_t vector_cpumask, searched_cpumask;
 static struct irq_chip lapic_controller;
 #ifdef	CONFIG_X86_IO_APIC
 static struct apic_chip_data *legacy_irq_data[NR_IRQS_LEGACY];

@@ -124,6 +124,7 @@ static int __assign_irq_vector(int irq,
 	/* Only try and allocate irqs on cpus that are present */
 	err = -ENOSPC;
 	cpumask_clear(d->old_domain);
+	cpumask_clear(searched_cpumask);
 	cpu = cpumask_first_and(mask, cpu_online_mask);
 	while (cpu < nr_cpu_ids) {
 		int new_cpu, vector, offset;

@@ -157,9 +158,9 @@ next:
 		}
 
 		if (unlikely(current_vector == vector)) {
-			cpumask_or(d->old_domain, d->old_domain,
+			cpumask_or(searched_cpumask, searched_cpumask,
 				   vector_cpumask);
-			cpumask_andnot(vector_cpumask, mask, d->old_domain);
+			cpumask_andnot(vector_cpumask, mask, searched_cpumask);
 			cpu = cpumask_first_and(vector_cpumask,
 						cpu_online_mask);
 			continue;

@@ -404,6 +405,7 @@ int __init arch_early_irq_init(void)
 	arch_init_htirq_domain(x86_vector_domain);
 
 	BUG_ON(!alloc_cpumask_var(&vector_cpumask, GFP_KERNEL));
+	BUG_ON(!alloc_cpumask_var(&searched_cpumask, GFP_KERNEL));
 
 	return arch_early_ioapic_init();
 }

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/x86-irq-validate-that-irq-descriptor-is-still-active.patch queue-4.4/x86-irq-remove-outgoing-cpu-from-vector-cleanup-mask.patch queue-4.4/x86-irq-get-rid-of-code-duplication.patch queue-4.4/genirq-validate-action-before-dereferencing-it-in-handle_irq_event_percpu.patch queue-4.4/x86-irq-remove-offline-cpus-from-vector-cleanup.patch queue-4.4/x86-irq-reorganize-the-return-path-in-assign_irq_vector.patch queue-4.4/x86-irq-copy-vectormask-instead-of-an-and-operation.patch queue-4.4/x86-irq-call-irq_force_move_complete-with-irq-descriptor.patch queue-4.4/x86-irq-call-chip-irq_set_affinity-in-proper-context.patch queue-4.4/x86-irq-plug-vector-cleanup-race.patch queue-4.4/x86-irq-do-not-use-apic_chip_data.old_domain-as-temporary-buffer.patch queue-4.4/x86-irq-reorganize-the-search-in-assign_irq_vector.patch queue-4.4/x86-irq-remove-the-cpumask-allocation-from-send_cleanup_vector.patch queue-4.4/x86-irq-fix-a-race-in-x86_vector_free_irqs.patch queue-4.4/x86-irq-check-vector-allocation-early.patch queue-4.4/x86-irq-clear-move_in_progress-before-sending-cleanup-ipi.patch