Messages in this thread | | | Subject | Re: [PATCH] x86/cpufeatures: make bits in cpu_caps_cleared[] and cpu_cpus_set[] exclusive | From | Xiaoyao Li <> | Date | Wed, 18 Mar 2020 20:57:58 +0800 |
| |
On 3/18/2020 6:32 PM, Borislav Petkov wrote: > On Wed, Mar 18, 2020 at 02:16:24PM +0800, Xiaoyao Li wrote: >> In apply_forced_caps(), cpu_caps_set[] overrides cpu_caps_cleared[], so >> that setup_clear_cpu_cap() cannot clear one cap if setup_force_cpu_cap() >> sets the cap before it. > > Context pls: what is the observation, what are you trying to do, > reproducer, etc?
Well. I use setup_force_cup_cap(XXX) to set one flag, XXX, during early boot. And use setup_clear_cpu_cap(XXX) to clear this flag when something wrong later. However, it turns out that the flag is still set when I use cpu_has(c, XXX) to check when init each AP. I have to clear the flag XXX explicitly using clear_cpu_cap(c, XXX). However, in /proc/cpuinfo, this XXX flag still presents on every CPU.
> Thx. >
| |