Re: [PATCH] x86/crypto: Add missing RETs
From: Josh Poimboeuf
Date: Mon Jun 25 2018 - 09:19:44 EST
On Mon, Jun 25, 2018 at 09:24:38AM +0200, Ingo Molnar wrote:
>
> * Alexey Dobriyan <adobriyan@xxxxxxxxx> wrote:
>
> > On Sun, Jun 24, 2018 at 09:11:05AM +0200, Ingo Molnar wrote:
> > > > Add explicit RETs to the tail calls of AEGIS and MORUS crypto algorithms
> > > > otherwise they run into INT3 padding due to
> > > >
> > > > 51bad67ffbce ("x86/asm: Pad assembly functions with INT3 instructions")
> > > >
> > > > leading to spurious debug exceptions.
> > > >
> > > > Mike Galbraith <efault@xxxxxx> took care of all the remaining callsites.
> > >
> > > Note that 51bad67ffbce has been zapped because it caused too many problems like
> > > this, but the explicit RETs make sense nevertheless.
> >
> > So commit which found real bug(s) was zapped.
> >
> > OK
>
> No, what happened is that the commit was first moved into WIP.x86/debug showing
> its work-in-progress status, because it was incomplete and caused bugs:
>
> https://lore.kernel.org/lkml/20180518073644.GA8593@xxxxxxxxx/T/#u
>
> ... and finally, after weeks of inaction I zapped it because I didn't see progress
> and you didn't answer my question.
>
> If a fixed patch with updated tooling to detect these crashes before they occur on
> live systems is submitted we'll reconsider - it didn't get NAK-ed, it's just
> incomplete in the current form.
Hm, what happened to the objtool patch to detect these at build time?
Did it not work?
https://lore.kernel.org/lkml/20180517134934.eog2fgoby5azq5a7@treble
--
Josh