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From:   Sami Tolvanen <samitolvanen@google.com>
Date:   Mon, 21 Oct 2019 15:39:50 -0700
Message-ID: <CABCJKuf-tXu2ZhBMCYTHP3BU8g1i-0GGd7+YvyTDUc1kH2iZvA@mail.gmail.com>
Subject: Re: [PATCH 14/18] arm64: efi: restore x18 if it was corrupted
To:     Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc:     Will Deacon <will@kernel.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Dave Martin <Dave.Martin@arm.com>,
        Kees Cook <keescook@chromium.org>,
        Laura Abbott <labbott@redhat.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Nick Desaulniers <ndesaulniers@google.com>,
        clang-built-linux <clang-built-linux@googlegroups.com>,
        Kernel Hardening <kernel-hardening@lists.openwall.com>,
        linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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On Sun, Oct 20, 2019 at 11:20 PM Ard Biesheuvel
<ard.biesheuvel@linaro.org> wrote:
> You'll have to elaborate a bit here and explain that this is
> sufficient, given that we run EFI runtime services with interrupts
> enabled.

I can add a note about this in v2. This is called with preemption
disabled and we have a separate interrupt shadow stack, so as far as I
can tell, this should be sufficient. Did you have concerns about this?

Sami