Messages in this thread | | | Date | Tue, 17 Nov 2015 09:44:10 +0000 | From | Matt Fleming <> | Subject | Re: [PATCH v2 1/5] x86/mm/pageattr: Ensure cpa->pfn only contains page frame numbers |
| |
On Mon, 16 Nov, at 07:56:17AM, Dave Hansen wrote: > I'm glad you're looking at this. It obviously needed some love. :) > > On 11/14/2015 02:00 PM, Matt Fleming wrote: > > + npages = (_end - _text) >> PAGE_SHIFT; > > + text = __pa(_text); > > + pfn = text >> PAGE_SHIFT; > > + > > + if (kernel_map_pages_in_pgd(pgd, pfn, text, npages, 0)) { > > + pr_err("Failed to map kernel text 1:1\n"); > > + return 1; > > + } > > Are _end and _text guaranteed to be aligned? If not, I think the > calculation might be wrong. Just for fun, imagine that _end=0xfff and > _text=0x1001. npages would be 0.
Bugger. Good catch, thanks.
> Some other code like set_kernel_text_rw() does alignment on _text. > > One nit is that there's quite a bit going on here, like rearranging the > phys_stack arithmetic ordering that is far beyond just simplifying the > paddr vs. pfn issue, but that isn't called out in the changelog at all.
Yeah, the phys_stack hunk actually slipped into this patch by accident. It ensures the stack is mapped into the EFI page tables. I'll split this out.
> Your fixes all look correct to me, fwiw.
Thanks! If you could respond to the next version with an ACK or Reviewed-by tag, that'd be great.
| |