RE: [PING][PATCH 0/15] arm: Enables return address verification and branch target identification on Cortex-M

[Kyrylo Tkachov <Kyrylo.Tkachov@arm.com>]

Hi Andrea,

> -----Original Message-----
> From: Gcc-patches <gcc-patches-
> bounces+kyrylo.tkachov=arm.com@gcc.gnu.org> On Behalf Of Andrea
> Corallo via Gcc-patches
> Sent: Monday, December 5, 2022 2:11 PM
> To: Andrea Corallo via Gcc-patches <gcc-patches@gcc.gnu.org>
> Cc: Richard Earnshaw <Richard.Earnshaw@arm.com>; nd <nd@arm.com>
> Subject: Re: [PING][PATCH 0/15] arm: Enables return address verification and
> branch target identification on Cortex-M
> 
> Andrea Corallo via Gcc-patches <gcc-patches@gcc.gnu.org> writes:
> 
> > Hi all,
> >
> > ping^2 for patches 9/15 7/15 11/15 12/15 and 10/15 V2 of this series.
> >
> >   Andrea
> 
> Hello all,
> 
> PING^3 for:
> [PATCH 6/12 V2] arm: Add pointer authentication for stack-unwinding
> runtime
> [PATCH 9/15] arm: Set again stack pointer as CFA reg when popping if
> necessary
> [PATCH 10/15 V4] arm: Implement cortex-M return signing address codegen
> [PATCH 12/15 V3] arm: implement bti injection
> 
> which I believe are still pending for review.

Thanks for pinging these, it helps keep track of the patches needing attention.

> 
> Other option would be to declare the arm backend as unmaintained.

Apologies for the delays in this patch series. For patches such as PACBTI in particular it is important to be extra thorough in the review,
as this functionality has important security implications and as it will be deployed in deeply embedded M-profile systems
it would be hard to address bugs and vulnerabilities effectively after the fact. See, for example the many PAC and BTI bug reports we've had over the years for AArch64.
There are many things that can go wrong 😊

So it's important to get this right the first time.
Thank you for your patience.
Kyrill

> 
> Thanks
> 
>   Andrea