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From: Peter Maydell <peter.maydell@linaro.org>
To: Derrick McKee <derrick.mckee@gmail.com>
Cc: "open list:ARM" <qemu-arm@nongnu.org>,
	Richard Henderson <richard.henderson@linaro.org>,
	QEMU Developers <qemu-devel@nongnu.org>
Subject: Re: AUTIA authentication sometimes fails
Date: Mon, 29 Mar 2021 21:04:50 +0000	[thread overview]
Message-ID: <CAFEAcA8KCJTwsb2YYoU3d_PbO=KW_ytSJXHLZZTkukVX6YzCPQ@mail.gmail.com> (raw)
In-Reply-To: <CAJoBWHx5DM=zhj10j1ai5T_LO9ScAhFzUezuhGu6a73vn=4_Rg@mail.gmail.com>

On Mon, 29 Mar 2021 at 21:07, Derrick McKee <derrick.mckee@gmail.com> wrote:
>
> Hi,
>
> I am running across a scenario where a PAC signed code pointer (using
> pacia) sometimes does not successfully authenticate despite the signed
> pointer and the salt used to sign the pointer are correctly given to a
> autia instruction.  Only one particular pointer fails, while others
> are correctly authenticated.  Unfortunately, I can't provide a simple
> use case, because the behavior is part of a running kernel, and all
> the pointers involved are kernel space pointers.  An example of what I
> am seeing (not guaranteeing correct assembly, just a gist):
>
> mov x9, 0xffff800009200000
> mov x10, 0x20001
> pacia x9, x10  // x9 contains 0xff90800009200000
> ...
> mov x9, 0xff90800009200000
> mov x10 0x20001
> autia x9, x10  // x9 contains invalid pointer
>
> However, this same code with different pointer values correctly
> authenticate.  Is there something specific about the kernel and PAC
> authentication that I am missing?  Thanks.

cc'ing Richard, but I suspect you'll need to provide more detail...

thanks
-- PMM


       reply	other threads:[~2021-03-29 21:07 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CAJoBWHx5DM=zhj10j1ai5T_LO9ScAhFzUezuhGu6a73vn=4_Rg@mail.gmail.com>
2021-03-29 21:04 ` Peter Maydell [this message]
2021-03-30 19:49   ` AUTIA authentication sometimes fails Richard Henderson

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