Re: [PATCH v2 06/20] x86/alternative: use temporary mm for text poking
From: Peter Zijlstra
Date: Tue Feb 05 2019 - 08:25:21 EST
On Tue, Feb 05, 2019 at 01:35:33PM +0100, Borislav Petkov wrote:
> On Tue, Feb 05, 2019 at 12:31:46PM +0100, Peter Zijlstra wrote:
> > ...
> > So while in general I agree with BUG_ON() being undesirable, I think
> > liberal sprinking in text_poke() is fine; you really _REALLY_ want this
> > to work or fail loudly. Text corruption is just painful.
> Ok. It would be good to have the gist of this sentiment in a comment
> above it so that it is absolutely clear why we're doing it.
> And since text_poke() can't fail, then it doesn't need a retval too.
> AFAICT, nothing is actually using it.
See patch 12, that removes the return value (after fixing the few users
that currently 'rely' on it).