From: "H. Peter Anvin" <hpa@linux.intel.com>
To: Jiri Kosina <jkosina@suse.cz>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>,
Steven Rostedt <rostedt@goodmis.org>,
Jason Baron <jbaron@redhat.com>,
Borislav Petkov <bpetkov@suse.de>,
linux-kernel@vger.kernel.org
Subject: Re: [RFC] [PATCH 1/2 v2] x86: introduce int3-based instruction patching
Date: Thu, 11 Jul 2013 13:51:05 -0700 [thread overview]
Message-ID: <51DF1AB9.2010405@linux.intel.com> (raw)
In-Reply-To: <alpine.LNX.2.00.1307112127530.29788@pobox.suse.cz>
On 07/11/2013 12:29 PM, Jiri Kosina wrote:
> On Thu, 11 Jul 2013, H. Peter Anvin wrote:
>
>>>> + * The way it is done:
>>>> + * - add a int3 trap to the address that will be patched
>>>> + * - sync cores
>>>
>>> You don't need this "sync cores". (and your code didn't) :)
>>
>> I believe you do, lest you get "Frankenstructions". I believe you don't
>> need the second one, however. I should dig up my notes on this.
>
> I found this post from 2010 from you:
>
> http://lkml.indiana.edu/hypermail/linux/kernel/1001.1/01530.html
>
> If it's still valid and you guys at Intel haven't discovered any reason
> why that procedure would be invalid, I'll send out v3 with that'd be using
> exactly this ordering of syncing of the cores.
>
Just a note on that: in that post "In fact, if a suitable int3 handler
is left permanently in place then step 5 is unnecessary as well" should
obviously have been "the synchronization in step 4" rather than "step 5".
-hpa
next prev parent reply other threads:[~2013-07-11 20:51 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-10 20:25 [RFC] [PATCH 0/2] x86: make jump labels use int3-based breakpoint instead of stop_machine() Jiri Kosina
2013-07-10 20:25 ` [RFC] [PATCH 1/2] x86: introduce int3-based instruction patching Jiri Kosina
2013-07-10 21:31 ` [RFC] [PATCH 1/2 v2] " Jiri Kosina
2013-07-10 21:36 ` H. Peter Anvin
2013-07-10 21:48 ` Borislav Petkov
2013-07-10 21:56 ` H. Peter Anvin
2013-07-10 22:14 ` Borislav Petkov
2013-07-10 22:39 ` Jiri Kosina
2013-07-11 3:29 ` Masami Hiramatsu
2013-07-11 10:09 ` Jiri Kosina
2013-07-11 10:54 ` Jiri Kosina
2013-07-11 16:31 ` H. Peter Anvin
2013-07-11 16:46 ` Steven Rostedt
2013-07-11 19:21 ` Jiri Kosina
2013-07-12 1:00 ` Masami Hiramatsu
2013-07-11 14:35 ` Steven Rostedt
2013-07-11 14:47 ` Jason Baron
2013-07-10 21:46 ` Joe Perches
2013-07-11 10:23 ` Masami Hiramatsu
2013-07-11 10:51 ` Jiri Kosina
2013-07-12 0:50 ` Masami Hiramatsu
2013-07-11 16:10 ` H. Peter Anvin
2013-07-11 19:29 ` Jiri Kosina
2013-07-11 20:49 ` H. Peter Anvin
2013-07-11 20:51 ` H. Peter Anvin [this message]
2013-07-11 15:57 ` Steven Rostedt
2013-07-11 19:43 ` Jiri Kosina
2013-07-11 19:52 ` Steven Rostedt
2013-07-10 20:25 ` [RFC] [PATCH 2/2] x86: make jump_label use int3-based patching Jiri Kosina
2013-07-10 22:26 ` [RFC] [PATCH 0/2] x86: make jump labels use int3-based breakpoint instead of stop_machine() Jason Baron
2013-07-11 0:04 ` Jiri Kosina
2013-07-11 16:42 ` Steven Rostedt
2013-07-11 19:23 ` Jiri Kosina
2013-07-11 19:54 ` Steven Rostedt
2013-07-11 2:21 ` Masami Hiramatsu
2013-07-11 20:26 ` [PATCH 2/2 v3] x86: make jump_label use int3-based patching Jiri Kosina
2013-07-12 2:12 ` Steven Rostedt
2013-07-12 5:44 ` Masami Hiramatsu
2013-07-11 20:26 ` [PATCH 1/2 v3] x86: introduce int3-based instruction patching Jiri Kosina
2013-07-11 20:53 ` H. Peter Anvin
2013-07-11 21:04 ` Borislav Petkov
2013-07-11 21:36 ` H. Peter Anvin
2013-07-12 7:57 ` Borislav Petkov
2013-07-17 3:59 ` H. Peter Anvin
2013-07-11 22:31 ` Jiri Kosina
2013-07-12 2:09 ` Steven Rostedt
2013-07-11 23:01 ` Joe Perches
2013-07-12 2:07 ` Steven Rostedt
2013-07-12 2:40 ` Masami Hiramatsu
2013-07-12 9:21 ` [PATCH 1/2 v4] " Jiri Kosina
2013-07-17 1:18 ` [tip:x86/jumplabel] x86: Introduce int3 (breakpoint) -based " tip-bot for Jiri Kosina
2013-07-12 9:22 ` [PATCH 2/2 v4] x86: make jump_label use int3-based patching Jiri Kosina
2013-07-17 1:18 ` [tip:x86/jumplabel] x86: Make " tip-bot for Jiri Kosina
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