From: Borislav Petkov <bp@alien8.de>
To: "H. Peter Anvin" <hpa@linux.intel.com>
Cc: Jiri Kosina <jkosina@suse.cz>,
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: Wed, 10 Jul 2013 23:48:48 +0200 [thread overview]
Message-ID: <20130710214848.GB14879@pd.tnic> (raw)
In-Reply-To: <51DDD3E9.6090601@linux.intel.com>
On Wed, Jul 10, 2013 at 02:36:41PM -0700, H. Peter Anvin wrote:
> I'm wondering if it would be easier/more general to just return to the
> instruction. The "more general" bit would allow this to be used for
> other things, like alternatives, and perhaps eventually dynamic call
> patching.
Well, the aspect of not using stop_machine in alternatives is a don't
care because there we do text_poke_early on the BSP anyway. However,
there we toggle interrupts so it would probably be interesting to see
whether a non-interrupt-disabling variant would be faster.
> Returning to the instruction will, in effect, be a busy-wait for
> the faulted CPU until the patch is complete; more or less what
> stop_machine would do, but only for a CPU which actually strays into
> the affected region.
Oh, something like we patch in a two-byte jump first:
1:
jmp 1b
until we finish patching the rest? Ha, interesting :).
--
Regards/Gruss,
Boris.
Sent from a fat crate under my desk. Formatting is fine.
--
next prev parent reply other threads:[~2013-07-10 21:49 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 [this message]
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
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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