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From: Andy Lutomirski <luto@amacapital.net>
Date: Thu, 13 Aug 2015 11:25:02 -0700
Message-ID: <CALCETrV9YsdR561=YmQbjGCoC1LSHBwO=n05AZiQC_WiQPtaHw@mail.gmail.com>
Subject: Re: [regression] x86/signal/64: Fix SS handling for signals delivered
 to 64-bit programs breaks dosemu
To: Stas Sergeev <stsp@list.ru>
Cc: Ingo Molnar <mingo@kernel.org>, X86 ML <x86@kernel.org>,
        Linux kernel <linux-kernel@vger.kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        "H. Peter Anvin" <hpa@zytor.com>, Thomas Gleixner <tglx@linutronix.de>,
        Brian Gerst <brgerst@gmail.com>, Borislav Petkov <bp@alien8.de>,
        Stas Sergeev <stsp@users.sourceforge.net>
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On Thu, Aug 13, 2015 at 11:19 AM, Stas Sergeev <stsp@list.ru> wrote:

> It is more about selecting the right field for such a flag.
> You can select the right field now, and introduce some flag
> to it, like SIG_SAVE_SS or whatever. This will fix a regression.
> Then, when the TLS time will code, you'll just add SIG_SAVE_FS
> flag to the same field, so that they can be ORed.

Oh.

I think the field is obvious: uc_flags.  I also thing that all of the
saving should happen automatically, since I still don't see how
anything will break if the kernel starts saving more things.  It's the
restore part that's problematic.

--Andy

-- 
Andy Lutomirski
AMA Capital Management, LLC