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Date: Mon, 15 Aug 2016 10:34:58 -0500
From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@kernel.org>,
        "H . Peter Anvin" <hpa@zytor.com>, X86 ML <x86@kernel.org>,
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        Kees Cook <keescook@chromium.org>,
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        Frederic Weisbecker <fweisbec@gmail.com>,
        Byungchul Park <byungchul.park@lge.com>,
        Nilay Vaish <nilayvaish@gmail.com>
Subject: Re: [PATCH v3 32/51] x86/dumpstack: simplify in_exception_stack()
Message-ID: <20160815153458.7lochdewklrev3lz@treble>
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On Sun, Aug 14, 2016 at 12:48:15AM -0700, Andy Lutomirski wrote:
> On Fri, Aug 12, 2016 at 7:28 AM, Josh Poimboeuf <jpoimboe@redhat.com> wrote:
> > in_exception_stack() does some bad, bad things just so the unwinder can
> > print different values for different areas of the debug exception stack.
> >
> > There's no need to clarify where exactly on the stack it is.  Just print
> > "#DB" and be done with it.
> 
> I'm okay with the printing part, but you're also using this to prevent
> infinite looping.  Will this cause the unwind to fail if we go debug
> -> page fault -> debug or similar?

Yes, but that behavior already existed.  This patch doesn't change that;
it just makes it clearer what's going on.

-- 
Josh