From: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
To: Jiri Kosina <jkosina@suse.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>,
Jason Baron <jbaron@redhat.com>,
"H. Peter Anvin" <hpa@linux.intel.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: Fri, 12 Jul 2013 09:50:28 +0900 [thread overview]
Message-ID: <51DF52D4.20500@hitachi.com> (raw)
In-Reply-To: <alpine.LNX.2.00.1307111243420.29788@pobox.suse.cz>
(2013/07/11 19:51), Jiri Kosina wrote:
>>> + * - update all but the first byte of the patched range
>>> + * - sync cores
>>> + * - replalace the first byte (int3) by the first byte of
>>> + * replacing opcode
>>> + * - sync cores
>>> + *
>>> + * Note: must be called under text_mutex.
>>> + */
>>> +void *text_poke_bp(void *addr, const void *opcode, size_t len, void *handler)
>>> +{
>>> + unsigned char int3 = 0xcc;
>>> +
>>
>> Here, you have to protect this code from others, since bp_* are
>> global.
>
> Caller is responsible for holding the text_mutex, so text_poke_bp() can't
> race with itself. And the proper consistency between text_poke_bp() and
> the notifier is achieved by the memory barriers.
Oops, right. I missed your "Note" line
>
> So what exact scenario do you have in mind here, please?
No, never mind...
Thank you,
--
Masami HIRAMATSU
IT Management Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com
next prev parent reply other threads:[~2013-07-12 0:50 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 [this message]
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
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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