Messages in this thread | | | Date | Tue, 19 Oct 2010 00:31:40 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [PATCH] x86, irq: Check if irq is remapped before freeing irte |
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On Mon, 18 Oct 2010, Yinghai Lu wrote:
> On 10/18/2010 02:17 PM, Thomas Gleixner wrote: > > > > > > On Mon, 18 Oct 2010, Thomas Gleixner wrote: > > > >> On Mon, 18 Oct 2010, Yinghai Lu wrote: > >>> > >>> Index: linux-2.6/drivers/pci/intr_remapping.c > >>> =================================================================== > >>> --- linux-2.6.orig/drivers/pci/intr_remapping.c > >>> +++ linux-2.6/drivers/pci/intr_remapping.c > >>> @@ -60,7 +60,7 @@ int get_irte(int irq, struct irte *entry > >>> unsigned long flags; > >>> int index; > >>> > >>> - if (!entry || !irq_iommu) > >>> + if (!entry || !irq_iommu || !irq_iommu->iommu) > >>> return -1; > >> > >> Hmm, why do we need this? This is only called from > >> ir_ioapic_set_affinity() and ir_msi_set_affinity().
That does not answer that question !
> >> We should never end up there when intr_remapping=off, right ? > > > > Thinking more about it, this check is actively bogus. The call sites do: > > > > struct irte irte; > > > > if (get_irte(irq, &irte)) > > return -1; > > > > So entry _CANNOT_ be NULL. > > > > And in fact we should change get_irte() to > > > > get_irte(struct irq_2_iommu *irq_iommu, struct irte *entry) > > > > The call site already knows about it. No need to lookup irq_iommu > > based on the irq number. > > looks like all irq-irte related API could replace "int irq" to "struct irq_2_iommu *irq_iommu" > > extern int get_irte(int irq, struct irte *entry); > extern int modify_irte(int irq, struct irte *irte_modified); > extern int alloc_irte(struct intel_iommu *iommu, int irq, u16 count); > extern int set_irte_irq(int irq, struct intel_iommu *iommu, u16 index, > u16 sub_handle); > extern int map_irq_to_irte_handle(int irq, u16 *sub_handle); > extern int free_irte(int irq);
Probably, but we need to figure out which functions need which checks instead of having either redundant or superflous ones there.
Thanks,
tglx
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