Messages in this thread | | | Subject | Re: [PATCH 26/26] x86, pkeys: Documentation | From | Dave Hansen <> | Date | Wed, 7 Oct 2015 13:24:00 -0700 |
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On 10/03/2015 01:17 AM, Ingo Molnar wrote: > Right now the native x86 PTE format allows two protection related bits for > user-space pages: > > _PAGE_BIT_RW: if 0 the page is read-only, if 1 then it's read-write > _PAGE_BIT_NX: if 0 the page is executable, if 1 then it's not executable > > As discussed previously, pkeys allows 'true execute only (--x)' mappings. > > Another possibility would be 'true write-only (-w-)' mappings.
How would those work?
Protection Keys has a Write-Disable and an Access-Disable bit. But, Access-Disable denies _all_ data access to the region. There's no way to allow only writes.
Or am I missing something?
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