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References: <20220130211838.8382-1-rick.p.edgecombe@intel.com>
 <20220130211838.8382-36-rick.p.edgecombe@intel.com> <YfxQGRV6axGQ8bBC@dell9853host>
In-Reply-To: <YfxQGRV6axGQ8bBC@dell9853host>
From:   "H.J. Lu" <hjl.tools@gmail.com>
Date:   Thu, 3 Feb 2022 14:23:43 -0800
Message-ID: <CAMe9rOqwby=p3w7L7kgDUhZPzLksYEZcyKLbWOafEYaazWgyBg@mail.gmail.com>
Subject: Re: [PATCH 35/35] x86/cpufeatures: Limit shadow stack to Intel CPUs
To:     John Allen <john.allen@amd.com>
Cc:     Rick Edgecombe <rick.p.edgecombe@intel.com>,
        "the arch/x86 maintainers" <x86@kernel.org>,
        "H . Peter Anvin" <hpa@zytor.com>,
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On Thu, Feb 3, 2022 at 1:58 PM John Allen <john.allen@amd.com> wrote:
>
> On Sun, Jan 30, 2022 at 01:18:38PM -0800, Rick Edgecombe wrote:
> > Shadow stack is supported on newer AMD processors, but the kernel
> > implementation has not been tested on them. Prevent basic issues from
> > showing up for normal users by disabling shadow stack on all CPUs except
> > Intel until it has been tested. At which point the limitation should be
> > removed.
>
> Hi Rick,
>
> I have been testing Yu-Cheng's patchsets on AMD hardware and I am
> working on testing this version now. How are you testing this new
> series? I can partially test by calling the prctl enable for shadow
> stack directly from a program, but I'm not sure how useful that's going
> to be without the glibc support. Do you have a public repo with the
> necessary glibc changes to enable shadow stack early?
>

The glibc CET branch is at

https://gitlab.com/x86-glibc/glibc/-/commits/users/hjl/cet/master

-- 
H.J.