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References: <20180621211754.12757-1-h.peter.anvin@intel.com> <20180621211754.12757-8-h.peter.anvin@intel.com>
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From:   Andy Lutomirski <luto@kernel.org>
Date:   Fri, 22 Jun 2018 07:49:13 -0700
Message-ID: <CALCETrVNGjdLv4zde=qz6kJW55yZxXvLqoHxbRpQCr==gW6gBQ@mail.gmail.com>
Subject: Re: [PATCH v3 7/7] x86/ldt,ptrace: provide regset access to the LDT
To:     "H. Peter Anvin" <h.peter.anvin@intel.com>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        "H. Peter Anvin" <hpa@linux.intel.com>,
        "H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Andrew Lutomirski <luto@kernel.org>,
        "Bae, Chang Seok" <chang.seok.bae@intel.com>,
        "Metzger, Markus T" <markus.t.metzger@intel.com>
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On Thu, Jun 21, 2018 at 2:18 PM H. Peter Anvin, Intel
<h.peter.anvin@intel.com> wrote:
>
> From: "H. Peter Anvin" <hpa@linux.intel.com>
>
> Provide ptrace/regset access to the LDT, if one exists.  This
> interface provides both read and write access. The write code is
> unified with modify_ldt(); the read code doesn't have enough
> similarity so it has been kept made separate.

For this and for the GDT, you've chosen to use struct user_desc as
your format instead of using a native hardware descriptor format.  Any
particular reason why?  If nothing else, it will bloat core files a
bit more than needed.