On Tuesday 02 November 2010 15:31:22 Sheng Yang wrote: > On Tuesday 02 November 2010 15:05:51 Jan Kiszka wrote: > > From: Jan Kiszka <[email protected]> > > > > Obtail the new pgd pointer before releasing the page containing this > > value. > > > > Signed-off-by: Jan Kiszka <[email protected]> > > --- > > > > Who is taking care of this? The kvm tree? > > > > drivers/pci/intel-iommu.c | 2 +- > > 1 files changed, 1 insertions(+), 1 deletions(-) > > > > diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c > > index 4789f8e..35463dd 100644 > > --- a/drivers/pci/intel-iommu.c > > +++ b/drivers/pci/intel-iommu.c > > @@ -3627,9 +3627,9 @@ static int intel_iommu_attach_device(struct > > iommu_domain *domain, > > > > pte = dmar_domain->pgd; > > if (dma_pte_present(pte)) { > > > > - free_pgtable_page(dmar_domain->pgd); > > > > dmar_domain->pgd = (struct dma_pte *) > > > > phys_to_virt(dma_pte_addr(pte)); > > > > + free_pgtable_page(pte); > > > > } > > dmar_domain->agaw--; > > > > } > > Reviewed-by: Sheng Yang <[email protected]> > > CC iommu mailing list and David. > > OK, Jan, I got your meaning now. And it's not the exactly swap. :) > > I think the old code is safe, seems it's broken(exposed) by: > > commit 1a8bd481bfba30515b54368d90a915db3faf302f > Author: David Woodhouse <[email protected]> > Date: Tue Aug 10 01:38:53 2010 +0100 > > intel-iommu: Fix 32-bit build warning with __cmpxchg()
In fact this one shouldn't affect the result. Wrong guess... -- regards Yang, Sheng > > drivers/pci/intel-iommu.c: In function 'dma_pte_addr': > drivers/pci/intel-iommu.c:239: warning: passing argument 1 of > '__cmpxchg64' from incompatible pointer typ > > It seems that __cmpxchg64() now cares about the type of its pointer > argument, so give it a (uint64_t *) instead of a pointer to a structure > which contains only that. > > Signed-off-by: David Woodhouse <[email protected]> > > diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c > index c9171be..603cdc0 100644 > --- a/drivers/pci/intel-iommu.c > +++ b/drivers/pci/intel-iommu.c > @@ -236,7 +236,7 @@ static inline u64 dma_pte_addr(struct dma_pte *pte) > return pte->val & VTD_PAGE_MASK; > #else > /* Must have a full atomic 64-bit read */ > - return __cmpxchg64(pte, 0ULL, 0ULL) & VTD_PAGE_MASK; > + return __cmpxchg64(&pte->val, 0ULL, 0ULL) & VTD_PAGE_MASK; > #endif > } > > Seems here is the only affected code? > > -- > regards > Yang, Sheng > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
