Re: [PATCH] x86/crypto: Add missing RETs

From: Ingo Molnar
Date: Mon Jun 25 2018 - 03:24:50 EST



* 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.

Thanks,

Ingo