Re: [REGRESSION] 4.2-rc2: early boot memory corruption from FPU rework

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From	Linus Torvalds <torvalds@linux-foundation.org>
Newsgroups	linux.kernel
Subject	Re: [REGRESSION] 4.2-rc2: early boot memory corruption from FPU rework
Date	Thu, 16 Jul 2015 05:00:01 +0200
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On Wed, Jul 15, 2015 at 5:34 PM, Dave Hansen
<dave.hansen@linux.intel.com> wrote:
>
> I understand why you were misled by it, but the old "xsave_hdr_struct"
> was wrong.  Fenghua even posted patches to remove it before the FPU
> rework (you were cc'd):
>
>         https://lkml.org/lkml/2015/4/18/164

Oh, and that patch looks like a good idea.

I wish there was some way to make sure sizeof() fail on it so that
we'd enforce that nobody allocates that thing as-is. I had this dim
memory that an unsized array at the end would do that, but I was
clearly wrong. It's just the array itself you can't do sizeof on, not
the structure that contains it. Is there some magic trick that I'm
forgetting?

                      Linus
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Thread

4.2-rc2: early boot memory corruption from FPU rework Dave Hansen <dave.hansen@linux.intel.com> - 2015-07-14 21:50 +0200
  Re: 4.2-rc2: early boot memory corruption from FPU rework "H. Peter Anvin" <hpa@zytor.com> - 2015-07-15 03:30 +0200
  Re: 4.2-rc2: early boot memory corruption from FPU rework Ingo Molnar <mingo@kernel.org> - 2015-07-15 13:10 +0200
    [REGRESSION] 4.2-rc2: early boot memory corruption from FPU rework Dave Hansen <dave.hansen@linux.intel.com> - 2015-07-16 02:40 +0200
      Re: [REGRESSION] 4.2-rc2: early boot memory corruption from FPU rework Linus Torvalds <torvalds@linux-foundation.org> - 2015-07-16 04:40 +0200
      Re: [REGRESSION] 4.2-rc2: early boot memory corruption from FPU rework Linus Torvalds <torvalds@linux-foundation.org> - 2015-07-16 05:00 +0200
      Re: [REGRESSION] 4.2-rc2: early boot memory corruption from FPU  rework Ingo Molnar <mingo@kernel.org> - 2015-07-17 09:50 +0200
        Re: [REGRESSION] 4.2-rc2: early boot memory corruption from FPU  rework Ingo Molnar <mingo@kernel.org> - 2015-07-17 11:00 +0200

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