Yes, thank you for your advice. The new patch's been sent. On Thu, May 31, 2018 at 2:44 AM, Joerg Roedel <j...@8bytes.org> wrote:
> Hi Yizhuo Zhai, > > thanks for your patch, but I think there is a better way to fix that. > Please see below. > > On Wed, May 30, 2018 at 11:02:54PM -0700, Yizhuo Zhai wrote: > > Variable "unmap_size" is supposed to be initialized in function > fetch_pte. > > However, it's uninitialized if fetch_pte returns NULL. And "unmap_size" > is used > > outside the return check. > > > > From 377ccb647d3c6c6747f20a242b035bafc775c3be Mon Sep 17 00:00:00 2001 > > > > Signed-off-by: From: "yzhai...@ucr.edu" <yzhai...@ucr.edu> > > --- > > drivers/iommu/amd_iommu.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c > > index 8fb8c73..774e057 100644 > > --- a/drivers/iommu/amd_iommu.c > > +++ b/drivers/iommu/amd_iommu.c > > @@ -1500,7 +1500,7 @@ static unsigned long iommu_unmap_page(struct > > protection_domain *dom, > > unsigned long page_size) > > { > > unsigned long long unmapped; > > - unsigned long unmap_size; > > + unsigned long unmap_size = 0; > > That is not sufficient because fetch_pte is called in a loop, and when > it returns NULL then unmap_size keeps the value of the previous > invocation. > > So from looking at the code, it is better to set page_size=0 in > fetch_pte at the very beginning, before the function can return NULL. > > > Thanks, > > Joerg > > -- Kind Regards, *Yizhuo Zhai* *Computer Science, Graduate Student* *University of California, Riverside *
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