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

From: Thomas Gleixner
Date: Sun Jun 24 2018 - 03:13:14 EST


On Sun, 24 Jun 2018, Ingo Molnar wrote:
> * Borislav Petkov <bp@xxxxxxxxx> wrote:
>
> > Lemme send a proper patch now...
> >
> > ---
> > From: Borislav Petkov <bp@xxxxxxx>
> > Date: Sun, 17 Jun 2018 13:57:42 +0200
> > Subject: [PATCH] x86/crypto: Add missing RETs
> >
> > 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. When applying the patch
> please don't include the SHA1 of the non-upstream (and probably never-upstream)
> commit.

We should really have something like that exactly to catch cases like this.

Thanks,

tglx