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Date:   Wed, 11 Jul 2018 10:27:39 +0200
From:   Pavel Machek <pavel@ucw.cz>
To:     Yu-cheng Yu <yu-cheng.yu@intel.com>
Cc:     x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
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Subject: Re: [RFC PATCH v2 05/27] Documentation/x86: Add CET description
Message-ID: <20180711082739.GA18919@amd>
References: <20180710222639.8241-1-yu-cheng.yu@intel.com>
 <20180710222639.8241-6-yu-cheng.yu@intel.com>
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On Tue 2018-07-10 15:26:17, Yu-cheng Yu wrote:
> Explain how CET works and the no_cet_shstk/no_cet_ibt kernel
> parameters.
>=20

> --- /dev/null
> +++ b/Documentation/x86/intel_cet.txt
> @@ -0,0 +1,250 @@
> +=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> +Control Flow Enforcement Technology (CET)
> +=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D

We normally use .rst for this kind of formatted text.


> +[6] The implementation of the SHSTK
> +=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> +
> +SHSTK size
> +----------
> +
> +A task's SHSTK is allocated from memory to a fixed size that can
> +support 32 KB nested function calls; that is 256 KB for a 64-bit
> +application and 128 KB for a 32-bit application.  The system admin
> +can change the default size.

How does admin change that? We already have ulimit for stack size,
should those be somehow tied together?

$ ulimit -a
=2E..
stack size              (kbytes, -s) 8192


--=20
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo=
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