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From: "H. Peter Anvin" <hpa@zytor.com>
To: rostedt@goodmis.org
Cc: Jason Baron <jbaron@redhat.com>,
	linux-kernel@vger.kernel.org, mingo@elte.hu,
	mathieu.desnoyers@polymtl.ca, tglx@linutronix.de,
	andi@firstfloor.org, roland@redhat.com, rth@redhat.com,
	mhiramat@redhat.com, Arjan van de Ven <arjan@infradead.org>
Subject: Re: [RFC PATCH 2/8] jump label v4 - x86: Introduce generic jump patching without stop_machine
Date: Thu, 14 Jan 2010 07:36:58 -0800	[thread overview]
Message-ID: <4B4F3A1A.2030906@zytor.com> (raw)
In-Reply-To: <1263483139.28171.3857.camel@gandalf.stny.rr.com>

On 01/14/2010 07:32 AM, Steven Rostedt wrote:
>> +
>> +	/* Replacing 1 byte can be done atomically. */
>> +	if (unlikely(len <= 1))
>> +		return text_poke(addr, opcode, len);
> 
> This part bothers me. The text_poke just writes over the text directly
> (using a separate mapping). But if that memory is in the pipeline of
> another CPU, I think this could cause a GPF.
> 

Could you clarify why you think that?

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.


  reply	other threads:[~2010-01-14 15:42 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-01-12 16:26 [RFC PATCH 0/8] jump label v4 Jason Baron
2010-01-12 16:26 ` [RFC PATCH 1/8] jump label v4 - kprobes/x86: Cleanup RELATIVEJUMP_INSTRUCTION to RELATIVEJUMP_OPCODE Jason Baron
2010-01-12 16:26 ` [RFC PATCH 2/8] jump label v4 - x86: Introduce generic jump patching without stop_machine Jason Baron
2010-01-12 23:16   ` H. Peter Anvin
2010-01-13  2:06     ` Mathieu Desnoyers
2010-01-13  4:55       ` H. Peter Anvin
2010-01-13 14:30         ` Mathieu Desnoyers
2010-01-14  6:57           ` Masami Hiramatsu
2010-01-14 18:45           ` Masami Hiramatsu
2010-04-13 17:16             ` Mathieu Desnoyers
2010-01-13  5:38     ` Masami Hiramatsu
2010-01-14 15:32   ` Steven Rostedt
2010-01-14 15:36     ` H. Peter Anvin [this message]
2010-01-17 18:55       ` Mathieu Desnoyers
2010-01-17 19:16         ` Arjan van de Ven
2010-01-18 15:59           ` Masami Hiramatsu
2010-01-18 16:23             ` H. Peter Anvin
2010-01-18 16:52               ` Mathieu Desnoyers
2010-01-18 18:50                 ` H. Peter Anvin
2010-01-18 20:53                   ` Masami Hiramatsu
2010-01-18 21:18                     ` H. Peter Anvin
2010-01-18 21:32                   ` Mathieu Desnoyers
2010-01-18 16:31             ` Arjan van de Ven
2010-01-18 16:54               ` Mathieu Desnoyers
2010-01-18 18:21                 ` Masami Hiramatsu
2010-01-18 18:33                   ` Mathieu Desnoyers
2010-01-14 15:39     ` Mathieu Desnoyers
2010-01-14 16:23       ` Masami Hiramatsu
2010-01-14 16:42         ` Jason Baron
2010-01-12 16:26 ` [RFC PATCH 3/8] jump label v4 - move opcode definitions Jason Baron
2010-01-12 16:26 ` [RFC PATCH 4/8] jump label v4 - notifier atomic call chain notrace Jason Baron
2010-01-12 16:26 ` [RFC PATCH 5/8] jump label v4 - base patch Jason Baron
2010-01-12 16:26 ` [RFC PATCH 6/8] jump label v4 - x86 support Jason Baron
2010-01-12 16:26 ` [RFC PATCH 7/8] jump label v4 - tracepoint support Jason Baron
2010-01-12 16:26 ` [RFC PATCH 8/8] jump label v4 - add module support Jason Baron
  -- strict thread matches above, loose matches on Subject: below --
2010-01-17 22:56 [RFC PATCH 2/8] jump label v4 - x86: Introduce generic jump patching without stop_machine H. Peter Anvin

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