Re: [RFC PATCH v2 05/27] Documentation/x86: Add CET description

[Yu-cheng Yu]

On Wed, 2018-07-11 at 10:27 +0200, Pavel Machek wrote:
> On Tue 2018-07-10 15:26:17, Yu-cheng Yu wrote:
> > 
> > Explain how CET works and the no_cet_shstk/no_cet_ibt kernel
> > parameters.
> > 
> > 
> > --- /dev/null
> > +++ b/Documentation/x86/intel_cet.txt
> > @@ -0,0 +1,250 @@
> > +=========================================
> > +Control Flow Enforcement Technology (CET)
> > +=========================================
> We normally use .rst for this kind of formatted text.

I will change this to a .rst file.

> 
> 
> > 
> > +[6] The implementation of the SHSTK
> > +===================================
> > +
> > +SHSTK size
> > +----------
> > +
> > +A task's SHSTK is allocated from memory to a fixed size that can
> > +support 32 KB nested function calls; that is 256 KB for a 64-bit
> > +application and 128 KB for a 32-bit application.ÂÂThe system admin
> > +can change the default size.
> How does admin change that? We already have ulimit for stack size,
> should those be somehow tied together?
> 
> $ ulimit -a
> ...
> stack sizeÂÂÂÂÂÂÂÂÂÂÂÂÂÂ(kbytes, -s) 8192
> 

We can do that. ÂThis makes sense to me.

Yu-cheng