Re: [PATCH v23 22/28] x86/cet/shstk: User-mode shadow stack support

Yu, Yu-cheng
2021-03-19T15:17:07Z

On 3/19/2021 2:28 AM, Borislav Petkov wrote:
> On Thu, Mar 18, 2021 at 12:05:58PM -0700, Yu, Yu-cheng wrote:
>> Maybe I would add comments here.
>
> Yap.
>
> Also, looking forward in the set, I see prctl_set() and that is also
> done on current so should be ok.
>
> In any case, yes, documenting the assumptions and expectations wrt
> current here is a good idea.
>
>> If vm_munmap() returns -EINTR, mmap_lock is held by something else. That
>> lock should not be held forever. For other types of error, the loop stops.
>
> Ok I guess. The subsequent WARN_ON_ONCE() looks weird too but that
> should not fire, right? :)
>
> Thx.
>

That should not fire.

Yu-cheng