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From:   Keno Fischer <keno@juliacomputing.com>
Date:   Sun, 31 May 2020 12:13:18 -0400
Message-ID: <CABV8kRyHo+EAWaMUzGA220z=HJRBCpH6UWiYGb84uSL3h8HQHw@mail.gmail.com>
Subject: Re: arm64: Register modification during syscall entry/exit stop
To:     Will Deacon <will@kernel.org>
Cc:     Dave Martin <Dave.Martin@arm.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Kyle Huey <khuey@pernos.co>, Oleg Nesterov <oleg@redhat.com>,
        linux-arm-kernel@lists.infradead.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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> Keno -- are you planning to send out a patch? You previously spoke about
> implementing this using PTRACE_SETOPTIONS.

Yes, I'll have a patch for you. Though I've come to the conclusion
that introducing a new regset is probably a better way to solve it.
We can then also expose orig_x0 at the same time and give it sane semantics
(there's some problems with the way it works currently - I'll write it up
together with the patch).


Keno