[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <CABCJKueVVJNV2MibRkQGPbmpenK_b007kkHOoxfBHf1Wen2ENw@mail.gmail.com>
Date: Thu, 31 Oct 2019 10:42:17 -0700
From: Sami Tolvanen <samitolvanen@...gle.com>
To: Nick Desaulniers <ndesaulniers@...gle.com>
Cc: Will Deacon <will@...nel.org>, Catalin Marinas <catalin.marinas@....com>,
Steven Rostedt <rostedt@...dmis.org>, Masami Hiramatsu <mhiramat@...nel.org>,
Ard Biesheuvel <ard.biesheuvel@...aro.org>, Dave Martin <Dave.Martin@....com>,
Kees Cook <keescook@...omium.org>, Laura Abbott <labbott@...hat.com>,
Mark Rutland <mark.rutland@....com>, Jann Horn <jannh@...gle.com>,
Miguel Ojeda <miguel.ojeda.sandonis@...il.com>,
Masahiro Yamada <yamada.masahiro@...ionext.com>,
clang-built-linux <clang-built-linux@...glegroups.com>,
Kernel Hardening <kernel-hardening@...ts.openwall.com>,
Linux ARM <linux-arm-kernel@...ts.infradead.org>, LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v3 13/17] arm64: preserve x18 when CPU is suspended
On Thu, Oct 31, 2019 at 10:35 AM Nick Desaulniers
<ndesaulniers@...gle.com> wrote:
>
> On Thu, Oct 31, 2019 at 10:27 AM Sami Tolvanen <samitolvanen@...gle.com> wrote:
> >
> > On Thu, Oct 31, 2019 at 10:18 AM Nick Desaulniers
> > <ndesaulniers@...gle.com> wrote:
> > > > +#ifdef CONFIG_SHADOW_CALL_STACK
> > > > + ldr x18, [x0, #96]
> > > > + str xzr, [x0, #96]
> > >
> > > How come we zero out x0+#96, but not for other offsets? Is this str necessary?
> >
> > It clears the shadow stack pointer from the sleep state buffer, which
> > is not strictly speaking necessary, but leaves one fewer place to find
> > it.
>
> That sounds like a good idea. Consider adding comments or to the
> commit message so that the str doesn't get removed accidentally in the
> future.
Sure, I'll add a comment in the next version.
Sami
Powered by blists - more mailing lists
Confused about mailing lists and their use?
Read about mailing lists on Wikipedia
and check out these
guidelines on proper formatting of your messages.
