Re: [PATCH v7 24/26] x86: Enable User-Mode Instruction Prevention

2017-07-27 Thread Borislav Petkov
On Tue, Jul 25, 2017 at 05:44:08PM -0700, Ricardo Neri wrote: > On Fri, 2017-06-09 at 18:10 +0200, Borislav Petkov wrote: > > On Fri, May 05, 2017 at 11:17:22AM -0700, Ricardo Neri wrote: > > > User_mode Instruction Prevention (UMIP) is enabled by setting/clearing a > > > bit in %cr4. > > > > > >

Re: [PATCH v7 24/26] x86: Enable User-Mode Instruction Prevention

2017-07-25 Thread Ricardo Neri
On Fri, 2017-06-09 at 18:10 +0200, Borislav Petkov wrote: > On Fri, May 05, 2017 at 11:17:22AM -0700, 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 >

Re: [PATCH v7 24/26] x86: Enable User-Mode Instruction Prevention

2017-06-09 Thread Borislav Petkov
On Fri, May 05, 2017 at 11:17:22AM -0700, 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

[PATCH v7 24/26] x86: Enable User-Mode Instruction Prevention

2017-05-05 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