Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: [RFC PATCH 2/5] entry: Add calls for save/restore auxiliary pt_regs | Date | Tue, 09 Aug 2022 23:14:19 +0200 |
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On Tue, Aug 09 2022 at 20:49, Borislav Petkov wrote: > On Tue, Aug 09, 2022 at 11:38:03AM -0700, Ira Weiny wrote: >> Thomas did a lot of work to make the entry code generic. So I was >> keeping that work consistent. This also helps to ensure I did not miss >> any places. > > How about you worry about the other arches when you actually cross that > bridge?
Ira is right. If we want it for everything, then the generic code is the right place.
>> I don't believe this is correct because instrumentation is not enabled >> here. > > Why do you have to run > > arch_save_aux_pt_regs() > > with instrumentation enabled? > > Patch 5 does > > + struct pt_regs_auxiliary *aux_pt_regs = &to_extended_pt_regs(regs)->aux; > + > + aux_pt_regs->cpu = raw_smp_processor_id(); > > only? > > Why does that need to run with instrumentation enabled?
There is no reason and actually _if_ we go there then this _has_ to happen _before_ instrumentation comes into play as instrumentation might want to have access to extended pt_regs. Not necessarily the cpu number, but the other things which need to go there for a real reason.
Thanks,
tglx
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