Date: Fri, 18 Nov 2016 13:38:38 +0100
From: Borislav Petkov <bp@alien8.de>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Ingo Molnar <mingo@kernel.org>, X86 ML <x86@kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [RFC PATCH] x86/debug: Dump more detailed segfault info
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On Thu, Nov 17, 2016 at 03:33:21PM -0800, Andy Lutomirski wrote:
> Huh, go figure.  How about access_ok() instead?  There's also
> pagefault_disable() + copy_from_user().

Ah, you don't want to have another #PF during the first one.

How about copy_from_user_nmi()?

It already does __range_not_ok() which is basically access_ok() and
disables #PF around __copy_from_user_inatomic().

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.