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Subject: Re: [PATCH v3 16/51] x86/32: put real return address on stack in
 entry code
To: Josh Poimboeuf <jpoimboe@redhat.com>,
        Andy Lutomirski <luto@amacapital.net>
References: <cover.1471011425.git.jpoimboe@redhat.com>
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 <CALCETrU8m-tAj52gidFjxZTeTHQoqXHNa0ERDnXDUn92tQ35xw@mail.gmail.com>
 <20160815150941.nilwkrkszj5mm5ka@treble>
Cc: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@kernel.org>,
        X86 ML <x86@kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Steven Rostedt <rostedt@goodmis.org>, Brian Gerst <brgerst@gmail.com>,
        Kees Cook <keescook@chromium.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Frederic Weisbecker <fweisbec@gmail.com>,
        Byungchul Park <byungchul.park@lge.com>,
        Nilay Vaish <nilayvaish@gmail.com>
From: "H. Peter Anvin" <hpa@zytor.com>
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Date: Mon, 15 Aug 2016 11:04:42 -0700
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On 08/15/16 08:09, Josh Poimboeuf wrote:
> On Sun, Aug 14, 2016 at 12:31:47AM -0700, Andy Lutomirski wrote:
>> On Fri, Aug 12, 2016 at 7:28 AM, Josh Poimboeuf <jpoimboe@redhat.com> wrote:
>>> This standardizes the stacks of idle tasks to be consistent with other
>>> tasks on 32-bit.
>>
>> It might be nice to stick a ud2 or 1: hlt; jmp 1b or similar
>> afterwards to make it clear that initial_code can't return.
> 
> Yeah, I'll do something like that.
> 

"Standardizing the stack" how?  A zero on the stack terminates the stack
trace.

	-hpa