x86, x2apic: fix lock ordering during IRQ migration
Impact: fix potential deadlock on x2apic fix "hard-safe -> hard-unsafe lock order detected" with irq_2_ir_lock On x2apic enabled system: [ INFO: hard-safe -> hard-unsafe lock order detected ] 2.6.27-03151-g4480f15b #1 ------------------------------------------------------ swapper/1 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: (irq_2_ir_lock){--..}, at: [<ffffffff8038ebc0>] get_irte+0x2f/0x95 and this task is already holding: (&irq_desc_lock_class){+...}, at: [<ffffffff802649ed>] setup_irq+0x67/0x281 which would create a new lock dependency: (&irq_desc_lock_class){+...} -> (irq_2_ir_lock){--..} but this new dependency connects a hard-irq-safe lock: (&irq_desc_lock_class){+...} ... which became hard-irq-safe at: [<ffffffffffffffff>] 0xffffffffffffffff to a hard-irq-unsafe lock: (irq_2_ir_lock){--..} ... which became hard-irq-unsafe at: ... [<ffffffff802547b5>] __lock_acquire+0x571/0x706 [<ffffffff8025499f>] lock_acquire+0x55/0x71 [<ffffffff8062f2c4>] _spin_lock+0x2c/0x38 [<ffffffff8038ee50>] alloc_irte+0x8a/0x14b [<ffffffff8021f733>] setup_IO_APIC_irq+0x119/0x30e [<ffffffff8090860e>] setup_IO_APIC+0x146/0x6e5 [<ffffffff809058fc>] native_smp_prepare_cpus+0x24e/0x2e9 [<ffffffff808f982c>] kernel_init+0x5a/0x176 [<ffffffff8020c289>] child_rip+0xa/0x11 [<ffffffffffffffff>] 0xffffffffffffffff Fix this theoretical lock order issue by using spin_lock_irqsave() instead of spin_lock() Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This commit is contained in:
Suresh Siddha
H. Peter Anvin
Родитель
0ca0f16fd1
Коммит
4c5502b1c5
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@ -117,21 +117,22 @@ int get_irte(int irq, struct irte *entry)
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{
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int index;
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struct irq_2_iommu *irq_iommu;
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unsigned long flags;
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if (!entry)
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return -1;
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spin_lock(&irq_2_ir_lock);
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spin_lock_irqsave(&irq_2_ir_lock, flags);
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irq_iommu = valid_irq_2_iommu(irq);
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if (!irq_iommu) {
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spin_unlock(&irq_2_ir_lock);
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spin_unlock_irqrestore(&irq_2_ir_lock, flags);
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return -1;
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}
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index = irq_iommu->irte_index + irq_iommu->sub_handle;
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*entry = *(irq_iommu->iommu->ir_table->base + index);
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spin_unlock(&irq_2_ir_lock);
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spin_unlock_irqrestore(&irq_2_ir_lock, flags);
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return 0;
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}
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@ -141,6 +142,7 @@ int alloc_irte(struct intel_iommu *iommu, int irq, u16 count)
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struct irq_2_iommu *irq_iommu;
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u16 index, start_index;
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unsigned int mask = 0;
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unsigned long flags;
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int i;
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if (!count)
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@ -170,7 +172,7 @@ int alloc_irte(struct intel_iommu *iommu, int irq, u16 count)
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return -1;
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}
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spin_lock(&irq_2_ir_lock);
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spin_lock_irqsave(&irq_2_ir_lock, flags);
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do {
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for (i = index; i < index + count; i++)
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if (table->base[i].present)
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@ -182,7 +184,7 @@ int alloc_irte(struct intel_iommu *iommu, int irq, u16 count)
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index = (index + count) % INTR_REMAP_TABLE_ENTRIES;
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if (index == start_index) {
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spin_unlock(&irq_2_ir_lock);
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spin_unlock_irqrestore(&irq_2_ir_lock, flags);
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printk(KERN_ERR "can't allocate an IRTE\n");
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return -1;
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}
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@ -193,7 +195,7 @@ int alloc_irte(struct intel_iommu *iommu, int irq, u16 count)
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irq_iommu = irq_2_iommu_alloc(irq);
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if (!irq_iommu) {
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spin_unlock(&irq_2_ir_lock);
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spin_unlock_irqrestore(&irq_2_ir_lock, flags);
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printk(KERN_ERR "can't allocate irq_2_iommu\n");
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return -1;
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}
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@ -203,7 +205,7 @@ int alloc_irte(struct intel_iommu *iommu, int irq, u16 count)
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irq_iommu->sub_handle = 0;
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irq_iommu->irte_mask = mask;
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spin_unlock(&irq_2_ir_lock);
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spin_unlock_irqrestore(&irq_2_ir_lock, flags);
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return index;
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}
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@ -223,30 +225,32 @@ int map_irq_to_irte_handle(int irq, u16 *sub_handle)
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{
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int index;
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struct irq_2_iommu *irq_iommu;
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unsigned long flags;
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spin_lock(&irq_2_ir_lock);
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spin_lock_irqsave(&irq_2_ir_lock, flags);
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irq_iommu = valid_irq_2_iommu(irq);
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if (!irq_iommu) {
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spin_unlock(&irq_2_ir_lock);
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spin_unlock_irqrestore(&irq_2_ir_lock, flags);
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return -1;
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}
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*sub_handle = irq_iommu->sub_handle;
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index = irq_iommu->irte_index;
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spin_unlock(&irq_2_ir_lock);
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spin_unlock_irqrestore(&irq_2_ir_lock, flags);
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return index;
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}
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int set_irte_irq(int irq, struct intel_iommu *iommu, u16 index, u16 subhandle)
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{
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struct irq_2_iommu *irq_iommu;
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unsigned long flags;
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spin_lock(&irq_2_ir_lock);
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spin_lock_irqsave(&irq_2_ir_lock, flags);
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irq_iommu = irq_2_iommu_alloc(irq);
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if (!irq_iommu) {
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spin_unlock(&irq_2_ir_lock);
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spin_unlock_irqrestore(&irq_2_ir_lock, flags);
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printk(KERN_ERR "can't allocate irq_2_iommu\n");
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return -1;
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}
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@ -256,7 +260,7 @@ int set_irte_irq(int irq, struct intel_iommu *iommu, u16 index, u16 subhandle)
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irq_iommu->sub_handle = subhandle;
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irq_iommu->irte_mask = 0;
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spin_unlock(&irq_2_ir_lock);
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spin_unlock_irqrestore(&irq_2_ir_lock, flags);
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return 0;
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}
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@ -264,11 +268,12 @@ int set_irte_irq(int irq, struct intel_iommu *iommu, u16 index, u16 subhandle)
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int clear_irte_irq(int irq, struct intel_iommu *iommu, u16 index)
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{
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struct irq_2_iommu *irq_iommu;
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unsigned long flags;
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spin_lock(&irq_2_ir_lock);
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spin_lock_irqsave(&irq_2_ir_lock, flags);
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irq_iommu = valid_irq_2_iommu(irq);
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if (!irq_iommu) {
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spin_unlock(&irq_2_ir_lock);
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spin_unlock_irqrestore(&irq_2_ir_lock, flags);
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return -1;
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}
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@ -277,7 +282,7 @@ int clear_irte_irq(int irq, struct intel_iommu *iommu, u16 index)
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irq_iommu->sub_handle = 0;
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irq_2_iommu(irq)->irte_mask = 0;
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spin_unlock(&irq_2_ir_lock);
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spin_unlock_irqrestore(&irq_2_ir_lock, flags);
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return 0;
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}
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@ -289,11 +294,12 @@ int modify_irte(int irq, struct irte *irte_modified)
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struct irte *irte;
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struct intel_iommu *iommu;
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struct irq_2_iommu *irq_iommu;
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unsigned long flags;
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spin_lock(&irq_2_ir_lock);
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spin_lock_irqsave(&irq_2_ir_lock, flags);
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irq_iommu = valid_irq_2_iommu(irq);
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if (!irq_iommu) {
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spin_unlock(&irq_2_ir_lock);
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spin_unlock_irqrestore(&irq_2_ir_lock, flags);
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return -1;
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}
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@ -306,7 +312,7 @@ int modify_irte(int irq, struct irte *irte_modified)
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__iommu_flush_cache(iommu, irte, sizeof(*irte));
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rc = qi_flush_iec(iommu, index, 0);
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spin_unlock(&irq_2_ir_lock);
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spin_unlock_irqrestore(&irq_2_ir_lock, flags);
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return rc;
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}
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@ -317,11 +323,12 @@ int flush_irte(int irq)
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int index;
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struct intel_iommu *iommu;
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struct irq_2_iommu *irq_iommu;
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unsigned long flags;
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spin_lock(&irq_2_ir_lock);
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spin_lock_irqsave(&irq_2_ir_lock, flags);
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irq_iommu = valid_irq_2_iommu(irq);
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if (!irq_iommu) {
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spin_unlock(&irq_2_ir_lock);
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spin_unlock_irqrestore(&irq_2_ir_lock, flags);
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return -1;
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}
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@ -330,7 +337,7 @@ int flush_irte(int irq)
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index = irq_iommu->irte_index + irq_iommu->sub_handle;
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rc = qi_flush_iec(iommu, index, irq_iommu->irte_mask);
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spin_unlock(&irq_2_ir_lock);
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spin_unlock_irqrestore(&irq_2_ir_lock, flags);
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return rc;
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}
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@ -363,11 +370,12 @@ int free_irte(int irq)
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struct irte *irte;
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struct intel_iommu *iommu;
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struct irq_2_iommu *irq_iommu;
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unsigned long flags;
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spin_lock(&irq_2_ir_lock);
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spin_lock_irqsave(&irq_2_ir_lock, flags);
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irq_iommu = valid_irq_2_iommu(irq);
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if (!irq_iommu) {
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spin_unlock(&irq_2_ir_lock);
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spin_unlock_irqrestore(&irq_2_ir_lock, flags);
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return -1;
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}
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@ -387,7 +395,7 @@ int free_irte(int irq)
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irq_iommu->sub_handle = 0;
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irq_iommu->irte_mask = 0;
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spin_unlock(&irq_2_ir_lock);
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spin_unlock_irqrestore(&irq_2_ir_lock, flags);
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return rc;
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}
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