x86/irq: Fix a race in x86_vector_free_irqs()

[firefly-linux-kernel-4.4.55.git] / arch / x86 / kernel / apic / vector.c

diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c
index 861bc59c8f2564eac7b87193e7cd250571e1fbf4..6bd9cb941bfaa2ba8dc8648676ae0f28ffc58f23 100644 (file)
--- a/arch/x86/kernel/apic/vector.c
+++ b/arch/x86/kernel/apic/vector.c
@@ -224,10 +224,8 @@ static int assign_irq_vector_policy(int irq, int node,
 static void clear_irq_vector(int irq, struct apic_chip_data *data)
 {
        struct irq_desc *desc;
-       unsigned long flags;
        int cpu, vector;
 
-       raw_spin_lock_irqsave(&vector_lock, flags);
        BUG_ON(!data->cfg.vector);
 
        vector = data->cfg.vector;
@@ -237,10 +235,8 @@ static void clear_irq_vector(int irq, struct apic_chip_data *data)
        data->cfg.vector = 0;
        cpumask_clear(data->domain);
 
-       if (likely(!data->move_in_progress)) {
-               raw_spin_unlock_irqrestore(&vector_lock, flags);
+       if (likely(!data->move_in_progress))
                return;
-       }
 
        desc = irq_to_desc(irq);
        for_each_cpu_and(cpu, data->old_domain, cpu_online_mask) {
@@ -253,7 +249,6 @@ static void clear_irq_vector(int irq, struct apic_chip_data *data)
                }
        }
        data->move_in_progress = 0;
-       raw_spin_unlock_irqrestore(&vector_lock, flags);
 }
 
 void init_irq_alloc_info(struct irq_alloc_info *info,
@@ -274,19 +269,24 @@ void copy_irq_alloc_info(struct irq_alloc_info *dst, struct irq_alloc_info *src)
 static void x86_vector_free_irqs(struct irq_domain *domain,
                                 unsigned int virq, unsigned int nr_irqs)
 {
+       struct apic_chip_data *apic_data;
        struct irq_data *irq_data;
+       unsigned long flags;
        int i;
 
        for (i = 0; i < nr_irqs; i++) {
                irq_data = irq_domain_get_irq_data(x86_vector_domain, virq + i);
                if (irq_data && irq_data->chip_data) {
+                       raw_spin_lock_irqsave(&vector_lock, flags);
                        clear_irq_vector(virq + i, irq_data->chip_data);
-                       free_apic_chip_data(irq_data->chip_data);
+                       apic_data = irq_data->chip_data;
+                       irq_domain_reset_irq_data(irq_data);
+                       raw_spin_unlock_irqrestore(&vector_lock, flags);
+                       free_apic_chip_data(apic_data);
 #ifdef CONFIG_X86_IO_APIC
                        if (virq + i < nr_legacy_irqs())
                                legacy_irq_data[virq + i] = NULL;
 #endif
-                       irq_domain_reset_irq_data(irq_data);
                }
        }
 }