Re: [RFC][PATCH 04/10] x86/espfix: use kernel-default PTE mask

2018-02-22 Thread Dave Hansen
On 02/22/2018 01:59 PM, Andy Lutomirski wrote: >> I think it's good practice to just expose only the *minimal* amount of >> data necessary. It's easier to audit and less likely to expose things >> accidentall. > But espfix64 is geniunely global. I'm confused. I'm the confused one. In my

Re: [RFC][PATCH 04/10] x86/espfix: use kernel-default PTE mask

2018-02-22 Thread Dave Hansen
On 02/22/2018 01:59 PM, Andy Lutomirski wrote: >> I think it's good practice to just expose only the *minimal* amount of >> data necessary. It's easier to audit and less likely to expose things >> accidentall. > But espfix64 is geniunely global. I'm confused. I'm the confused one. In my

Re: [RFC][PATCH 04/10] x86/espfix: use kernel-default PTE mask

2018-02-22 Thread Andy Lutomirski
On Thu, Feb 22, 2018 at 9:30 PM, Dave Hansen wrote: > On 02/22/2018 01:27 PM, Nadav Amit wrote: >> Dave Hansen wrote: >>> From: Dave Hansen >>> In creating its page tables, the espfix code masks its

Re: [RFC][PATCH 04/10] x86/espfix: use kernel-default PTE mask

2018-02-22 Thread Andy Lutomirski
On Thu, Feb 22, 2018 at 9:30 PM, Dave Hansen wrote: > On 02/22/2018 01:27 PM, Nadav Amit wrote: >> Dave Hansen wrote: >>> From: Dave Hansen >>> In creating its page tables, the espfix code masks its PGTABLE_PROT >>> value with the supported mask: __supported_pte_mask. This ensures >>> that

Re: [RFC][PATCH 04/10] x86/espfix: use kernel-default PTE mask

2018-02-22 Thread Dave Hansen
On 02/22/2018 01:27 PM, Nadav Amit wrote: > Dave Hansen wrote: >> From: Dave Hansen >> In creating its page tables, the espfix code masks its PGTABLE_PROT >> value with the supported mask: __supported_pte_mask. This ensures >> that

Re: [RFC][PATCH 04/10] x86/espfix: use kernel-default PTE mask

2018-02-22 Thread Dave Hansen
On 02/22/2018 01:27 PM, Nadav Amit wrote: > Dave Hansen wrote: >> From: Dave Hansen >> In creating its page tables, the espfix code masks its PGTABLE_PROT >> value with the supported mask: __supported_pte_mask. This ensures >> that unsupported bits are not set in the final PTE. But, it also >>

Re: [RFC][PATCH 04/10] x86/espfix: use kernel-default PTE mask

2018-02-22 Thread Nadav Amit
Dave Hansen wrote: > > From: Dave Hansen > > In creating its page tables, the espfix code masks its PGTABLE_PROT > value with the supported mask: __supported_pte_mask. This ensures > that unsupported bits are not set in the final PTE.

Re: [RFC][PATCH 04/10] x86/espfix: use kernel-default PTE mask

2018-02-22 Thread Nadav Amit
Dave Hansen wrote: > > From: Dave Hansen > > In creating its page tables, the espfix code masks its PGTABLE_PROT > value with the supported mask: __supported_pte_mask. This ensures > that unsupported bits are not set in the final PTE. But, it also > sets _PAGE_GLOBAL which we do not want

[RFC][PATCH 04/10] x86/espfix: use kernel-default PTE mask

2018-02-22 Thread Dave Hansen
From: Dave Hansen In creating its page tables, the espfix code masks its PGTABLE_PROT value with the supported mask: __supported_pte_mask. This ensures that unsupported bits are not set in the final PTE. But, it also sets _PAGE_GLOBAL which we do not want for PTE.

[RFC][PATCH 04/10] x86/espfix: use kernel-default PTE mask

2018-02-22 Thread Dave Hansen
From: Dave Hansen In creating its page tables, the espfix code masks its PGTABLE_PROT value with the supported mask: __supported_pte_mask. This ensures that unsupported bits are not set in the final PTE. But, it also sets _PAGE_GLOBAL which we do not want for PTE. Use