Re: [PATCH RFC 2/4] x86/arch_prctl: add ARCH_GET_NOPTI and ARCH_SET_NOPTI to enable/disable PTI

[Willy Tarreau]

On Mon, Jan 08, 2018 at 05:49:00PM +0100, Peter Zijlstra wrote:
> On Mon, Jan 08, 2018 at 05:12:17PM +0100, Willy Tarreau wrote:
> > +		if (doit) {
> > +			if (arg2)
> > +				task_thread_info(task)->flags |= _TIF_NOPTI;
> > +			else
> > +				task_thread_info(task)->flags &= ~_TIF_NOPTI;
> 
> {set,clear}_thread_flag() please, the above is not SMP safe.

Oops, thank you. I initially thought about it initially but didn't
know the names of the functions to use, and have left it there
thinking I'd fix it later. Usual source of bugs :-/

Bah and I left my debugging printk() in the patch as well! I'll
rework this a bit.

Thanks,
Willy