Message-ID: <54DCA7AC.3080602@suse.cz>
Date: Thu, 12 Feb 2015 14:16:28 +0100
From: Jiri Slaby <jslaby@suse.cz>
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To: Peter Zijlstra <peterz@infradead.org>,
        Josh Poimboeuf <jpoimboe@redhat.com>
CC: Ingo Molnar <mingo@redhat.com>,
        Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>,
        live-patching@vger.kernel.org, linux-kernel@vger.kernel.org,
        Seth Jennings <sjenning@redhat.com>, Jiri Kosina <jkosina@suse.cz>,
        Vojtech Pavlik <vojtech@suse.cz>
Subject: Re: [RFC PATCH 6/9] livepatch: create per-task consistency model
References: <cover.1423499826.git.jpoimboe@redhat.com> <2c3d1e685dae5cccc2dfdb1b24c241b2f1c89348.1423499826.git.jpoimboe@redhat.com> <20150212032121.GA18578@treble.redhat.com> <20150212115628.GL2896@worktop.programming.kicks-ass.net> <20150212125149.GB18578@treble.redhat.com> <20150212130817.GV23123@twins.programming.kicks-ass.net>
In-Reply-To: <20150212130817.GV23123@twins.programming.kicks-ass.net>
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Hi,

On 02/12/2015, 02:08 PM, Peter Zijlstra wrote:
> How can one task run new and another task old functions?

because this is how it is designed to work in one of the consistency models.

> Once you patch
> any indirect function pointer any task will see the new call.

It does not patch any pointers. Callees' fentrys are "patched" using ftrace.

> And what's wrong with using known good spots like the freezer?

This was already discussed too. Please STA.

thanks,
-- 
js
suse labs
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