On 08/24/17 at 03:11pm, Dan Carpenter wrote: > On Thu, Aug 24, 2017 at 07:56:47PM +0800, Baoquan He wrote: > > In get_domain(), 'domain' could still be NULL before it's passed to > > dma_ops_domain() to dereference. For safety, check if 'domain' is > > NULL before passing to dma_ops_domain(). > > > > Reported-by: Dan Carpenter <[email protected]> > > Signed-off-by: Baoquan He <[email protected]> > > --- > > 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 16f1e6af00b0..2e2d5e6a13b3 100644 > > --- a/drivers/iommu/amd_iommu.c > > +++ b/drivers/iommu/amd_iommu.c > > @@ -2262,7 +2262,7 @@ static struct protection_domain *get_domain(struct > > device *dev) > > domain = to_pdomain(io_domain); > > attach_device(dev, domain); > > } > > - if (!dma_ops_domain(domain)) > > + if (domain && !dma_ops_domain(domain)) > > return ERR_PTR(-EBUSY); > > > > return domain; > > This still doesn't look right. None of the callers can handle a NULL > domain.
Here the NULL domain is on purpose. In kdump kernel if iommu is pre-enabled, just stop attach the device to domain until the device driver init. So here in driver init when call get_domain(), if found get_dev_data(dev)->defer_attach is true, we just do the attachment of device to domain. Not sure if I got what you mean about 'callers'. _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
