Messages in this thread | | | Date | Tue, 10 Nov 2015 09:43:03 -0800 | Subject | Re: [PATCH 4/4] iommu/vt-d: Do access checks before calling handle_mm_fault() | From | Linus Torvalds <> |
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On Tue, Nov 10, 2015 at 5:26 AM, Joerg Roedel <joro@8bytes.org> wrote: > + > +static bool access_error(struct vm_area_struct *vma, struct page_req_dsc *req) > +{ > + return !((req->rd_req && (vma->vm_flags & VM_READ)) || > + (req->wr_req && (vma->vm_flags & VM_WRITE)) || > + (req->exe_req && (vma->vm_flags & VM_EXEC))); > +}
This seems odd.
Shouldn't it be
return ((req->rd_req && !(vma->vm_flags & VM_READ)) || (req->wr_req && !(vma->vm_flags & VM_WRITE)) || (req->exe_req && !(vma->vm_flags & VM_EXEC)));
instead?
Of course, if you just used the VM_xyz flags internally itself, this would all be easier, and you'd end up with something like
/* Do we have requested bits that aren't in the allowed set? */ return (requested & ~vma->vm_flags) != 0;
instead..
Linus
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