[Bugfix 1/5] x86/irq: Do not reuse struct apic_chip_data.old_domain as temporary buffer

[Jiang Liu]

Function __assign_irq_vector() makes use of apic_chip_data.old_domain
as a temporary buffer, which causes trouble to rollback logic in case of
failure. So use a dedicated temporary buffer for __assign_irq_vector().

Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx>
---
 arch/x86/kernel/apic/vector.c |    9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c
index 861bc59c8f25..d6ec36b4461e 100644
--- a/arch/x86/kernel/apic/vector.c
+++ b/arch/x86/kernel/apic/vector.c
@@ -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, used_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, struct apic_chip_data *d,
 	/* Only try and allocate irqs on cpus that are present */
 	err = -ENOSPC;
 	cpumask_clear(d->old_domain);
+	cpumask_clear(used_cpumask);
 	cpu = cpumask_first_and(mask, cpu_online_mask);
 	while (cpu < nr_cpu_ids) {
 		int new_cpu, vector, offset;
@@ -157,9 +158,8 @@ next:
 		}
 
 		if (unlikely(current_vector == vector)) {
-			cpumask_or(d->old_domain, d->old_domain,
-				   vector_cpumask);
-			cpumask_andnot(vector_cpumask, mask, d->old_domain);
+			cpumask_or(used_cpumask, used_cpumask, vector_cpumask);
+			cpumask_andnot(vector_cpumask, mask, used_cpumask);
 			cpu = cpumask_first_and(vector_cpumask,
 						cpu_online_mask);
 			continue;
@@ -404,6 +404,7 @@ 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(&used_cpumask, GFP_KERNEL));
 
 	return arch_early_ioapic_init();
 }
-- 
1.7.10.4

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