Messages in this thread | | | Subject | Re: [PATCH v5 03/10] swiotlb: Map the buffer if it was unmapped by XPFO | From | Dave Hansen <> | Date | Wed, 20 Sep 2017 09:19:56 -0700 |
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On 08/09/2017 01:07 PM, Tycho Andersen wrote: > --- a/lib/swiotlb.c > +++ b/lib/swiotlb.c > @@ -420,8 +420,9 @@ static void swiotlb_bounce(phys_addr_t orig_addr, phys_addr_t tlb_addr, > { > unsigned long pfn = PFN_DOWN(orig_addr); > unsigned char *vaddr = phys_to_virt(tlb_addr); > + struct page *page = pfn_to_page(pfn); > > - if (PageHighMem(pfn_to_page(pfn))) { > + if (PageHighMem(page) || xpfo_page_is_unmapped(page)) { > /* The buffer does not have a mapping. Map it in and copy */ > unsigned int offset = orig_addr & ~PAGE_MASK; > char *buffer;
This is a little scary. I wonder how many more of these are in the kernel, like:
> static inline void *skcipher_map(struct scatter_walk *walk) > { > struct page *page = scatterwalk_page(walk); > > return (PageHighMem(page) ? kmap_atomic(page) : page_address(page)) + > offset_in_page(walk->offset); > }
Is there any better way to catch these? Like, can we add some debugging to check for XPFO pages in __va()?
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