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From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Fri, 15 Mar 2024 07:34:26 -0700
Message-ID: <CAMe9rOrgAtQvA=Tj0=T095JmdoRZ8pLuNOY3sT_RwwnznJN2Ow@mail.gmail.com>
Subject: Re: [PATCH] x86/shstk: Enable shadow stack for x32
To: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, "x86@kernel.org" <x86@kernel.org>
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On Fri, Mar 15, 2024 at 7:20=E2=80=AFAM Edgecombe, Rick P
<rick.p.edgecombe@intel.com> wrote:
>
> On Fri, 2024-03-15 at 07:04 -0700, H.J. Lu wrote:
> > 1. Add shadow stack support to x32 signal.
> > 2. Use the 64-bit map_shadow_stack syscall for x32.
> > 3. Set up shadow stack for x32.
> >
> > Tested with shadow stack enabled x32 glibc on Intel Tiger Lake.
> >
> > Cc: Rick P Edgecombe <rick.p.edgecombe@intel.com>
> > Tested-by: H.J. Lu <hjl.tools@gmail.com>
> > Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
>
> How many people do you think will use this?
>
> I would have thought it would require more changes for basic x32

This is all needed.

> operation. What was the testing exactly?

I configured x32 glibc with --enable-cet, build glibc and
run all glibc tests with shadow stack enabled.  There are
no regressions.  I verified that shadow stack is enabled
via /proc/pid/status.

--=20
H.J.