Re: [PATCH 10/11] x86/fpu: prepare copy_fpstate_to_sigframe for TIF_LOAD_FPU

2018-11-02 Thread Sebastian Andrzej Siewior
On 2018-10-12 12:40:19 [-0700], Dave Hansen wrote: > On 10/04/2018 07:05 AM, Sebastian Andrzej Siewior wrote: > > From: Rik van Riel > > > > If TIF_LOAD_FPU is set, then the registers are saved (not loaded). In that > > case > > we skip the saving part. > > This sentence hurts my brain. > >

Re: [PATCH 10/11] x86/fpu: prepare copy_fpstate_to_sigframe for TIF_LOAD_FPU

2018-11-02 Thread Sebastian Andrzej Siewior
On 2018-10-15 17:24:31 [+0200], Borislav Petkov wrote: > On Fri, Oct 12, 2018 at 12:40:19PM -0700, Dave Hansen wrote: > > > + __fpregs_changes_end(); > > > > Do we really need the __fpregs_changes_*() abstraction for this single > > call site? > > Yap, I'm staring at those in patch 2, there's no

Re: [PATCH 10/11] x86/fpu: prepare copy_fpstate_to_sigframe for TIF_LOAD_FPU

2018-10-15 Thread Borislav Petkov
On Fri, Oct 12, 2018 at 12:40:19PM -0700, Dave Hansen wrote: > > + __fpregs_changes_end(); > > Do we really need the __fpregs_changes_*() abstraction for this single > call site? Yap, I'm staring at those in patch 2, there's no documentation there what they're supposed to do, only the commit me

Re: [PATCH 10/11] x86/fpu: prepare copy_fpstate_to_sigframe for TIF_LOAD_FPU

2018-10-12 Thread Dave Hansen
On 10/04/2018 07:05 AM, Sebastian Andrzej Siewior wrote: > From: Rik van Riel > > If TIF_LOAD_FPU is set, then the registers are saved (not loaded). In that > case > we skip the saving part. This sentence hurts my brain. "If TIF_LOAD_FPU is set the registers are ... not loaded" I thin