Re: [PATCH v11 25/25] x86/cet/shstk: Add arch_prctl functions for shadow stack

Yu, Yu-cheng
2020-09-01T17:58:32Z

On 9/1/2020 10:50 AM, Florian Weimer wrote:
> * Yu-cheng Yu:
>
>> Like other arch_prctl()'s, this parameter was 'unsigned long'
>> earlier. The idea was, since this arch_prctl is only implemented for
>> the 64-bit kernel, we wanted it to look as 64-bit only. I will change
>> it back to 'unsigned long'.
>
> What about x32? In general, long is rather problematic for x32.

The problem is the size of 'long', right?
Because this parameter is passed in a register, and only the lower bits
are used, x32 works as well.