Re: [PATCH v11 09/12] x86: Enable User-Mode Instruction Prevention at runtime

2017-11-08 Thread Ricardo Neri
On Wed, Nov 08, 2017 at 10:52:59AM +0100, Ingo Molnar wrote: > > * Ricardo Neri wrote: > > > User-Mode Instruction Prevention (UMIP) is enabled by setting/clearing a > > bit in %cr4. > > > > It makes sense to enable UMIP at some point while booting, before user > > spaces come up. Like SMAP and

Re: [PATCH v11 09/12] x86: Enable User-Mode Instruction Prevention at runtime

2017-11-08 Thread Ingo Molnar
* Ricardo Neri wrote: > User-Mode Instruction Prevention (UMIP) is enabled by setting/clearing a > bit in %cr4. > > It makes sense to enable UMIP at some point while booting, before user > spaces come up. Like SMAP and SMEP, is not critical to have it enabled > very early during boot. This is b

[PATCH v11 09/12] x86: Enable User-Mode Instruction Prevention at runtime

2017-11-05 Thread Ricardo Neri
User-Mode Instruction Prevention (UMIP) is enabled by setting/clearing a bit in %cr4. It makes sense to enable UMIP at some point while booting, before user spaces come up. Like SMAP and SMEP, is not critical to have it enabled very early during boot. This is because UMIP is relevant only when the