Re: [PATCH v14 1/7] x86/cet/ibt: Add Kconfig option for user-mode Indirect Branch Tracking

[Yu, Yu-cheng]

On 10/12/2020 12:15 PM, Cyrill Gorcunov wrote:
> On Mon, Oct 12, 2020 at 08:45:24AM -0700, Yu-cheng Yu wrote:
> ...
> > +	  the application support it.  When this feature is enabled,
> > +	  legacy non-IBT applications continue to work, but without
> > +	  IBT protection.
> > +	  Support for this feature is only known to be present on
> > +	  processors released in 2020 or later.  CET features are also
> > +	  known to increase kernel text size by 3.7 KB.
>
> It seems the last sentence is redundant - new features always bloat
> the kernel code and precise size may differ depending on compiler
> and options. Surely this can be patched on top.

This was added after some discussion in v12 about kernel text size [1]. 
I think these few extra words can help people who have older machines 
and want to save some space.  Yes, like you said, if later we don't want 
this sentence, I will be happy to add a patch to remove it.  Thanks for 
the feedback.

Yu-cheng

[1] 
https://lore.kernel.org/linux-api/5e0a4005-45e3-3e88-e6e0-4ec31aad7eb9@xxxxxxxxx/