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Re: [Xen-devel] Does __KERNEL_DS serve a purpose?

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From Andrew Cooper <andrew.cooper3@citrix.com>
Newsgroups linux.kernel
Subject Re: [Xen-devel] Does __KERNEL_DS serve a purpose?
Date Fri, 08 Apr 2016 10:20:02 +0200
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On 08/04/2016 01:24, Andy Lutomirski wrote:
> I can't see any reason that we need the __KERNEL_DS segment at all --
> I think that everything that uses __KERNEL_DS could use __USER_DS
> instead.  Am I missing anything?  This has been bugging me for a
> while.
>
> I mulled over this a bit when trying to understand the sysret_ss_attrs
> bug and then forgot about it.

Linux doesn't have a separate __KERNEL_SS.  For the plain data segments,
the dpl is not interesting.

However, %ss is also loaded with __KERNEL_DS, and %ss.dpl is somewhat
important.

~Andrew

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Thread

Does __KERNEL_DS serve a purpose? Andy Lutomirski <luto@kernel.org> - 2016-04-08 02:30 +0200
  Re: [Xen-devel] Does __KERNEL_DS serve a purpose? Andrew Cooper <andrew.cooper3@citrix.com> - 2016-04-08 10:20 +0200
    Re: [Xen-devel] Does __KERNEL_DS serve a purpose? Andy Lutomirski <luto@amacapital.net> - 2016-04-08 18:10 +0200
      Re: [Xen-devel] Does __KERNEL_DS serve a purpose? Paolo Bonzini <pbonzini@redhat.com> - 2016-04-08 19:20 +0200
        Re: [Xen-devel] Does __KERNEL_DS serve a purpose? Andy Lutomirski <luto@amacapital.net> - 2016-04-09 00:10 +0200
          Re: [Xen-devel] Does __KERNEL_DS serve a purpose? Andrew Cooper <andrew.cooper3@citrix.com> - 2016-04-09 00:40 +0200

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