Date: Fri, 24 Jul 2015 12:28:26 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>, X86 ML <x86@kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Willy Tarreau <w@1wt.eu>, Borislav Petkov <bp@alien8.de>,
        Thomas Gleixner <tglx@linutronix.de>,
        Steven Rostedt <rostedt@goodmis.org>, Brian Gerst <brgerst@gmail.com>
Subject: Re: Dealing with the NMI mess
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On Thu, Jul 23, 2015 at 02:59:46PM -0700, Andy Lutomirski wrote:
> OK, new proposal:
> 
> In do_debug, if we trip an instruction breakpoint while
> !user_mode(regs) && ((regs->flags & X86_EFLAGS_IF) == 0), then disarm
> *that breakpoint*.

Doesn't !IF already imply that it must be kernel space? AFAIK user space
cannot clear IF.
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