From: Frederic Weisbecker <fweisbec@gmail.com>
To: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>,
Ananth N Mavinakayanahalli <ananth@in.ibm.com>,
lkml <linux-kernel@vger.kernel.org>,
systemtap <systemtap@sources.redhat.com>,
DLE <dle-develop@lists.sourceforge.net>,
Jim Keniston <jkenisto@us.ibm.com>,
Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
Christoph Hellwig <hch@infradead.org>,
Steven Rostedt <rostedt@goodmis.org>,
"H. Peter Anvin" <hpa@zytor.com>,
Anders Kaseorg <andersk@ksplice.com>,
Tim Abbott <tabbott@ksplice.com>,
Andi Kleen <andi@firstfloor.org>,
Jason Baron <jbaron@redhat.com>,
Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Subject: Re: [PATCH -tip v5 03/10] kprobes: Introduce kprobes jump optimization
Date: Tue, 24 Nov 2009 03:31:00 -0000 [thread overview]
Message-ID: <20091124033135.GE6752@nowhere> (raw)
In-Reply-To: <20091124024417.GA6752@nowhere>
On Tue, Nov 24, 2009 at 03:44:19AM +0100, Frederic Weisbecker wrote:
> On Mon, Nov 23, 2009 at 06:21:41PM -0500, Masami Hiramatsu wrote:
> > +static void kprobe_optimizer(struct work_struct *work);
> > +static DECLARE_DELAYED_WORK(optimizing_work, kprobe_optimizer);
> > +#define OPTIMIZE_DELAY 5
> > +
> > +/* Kprobe jump optimizer */
> > +static __kprobes void kprobe_optimizer(struct work_struct *work)
> > +{
> > + struct optimized_kprobe *op, *tmp;
> > +
> > + /* Lock modules while optimizing kprobes */
> > + mutex_lock(&module_mutex);
> > + mutex_lock(&kprobe_mutex);
> > + if (kprobes_all_disarmed)
> > + goto end;
> > +
> > + /* Wait quiesence period for ensuring all interrupts are done */
> > + synchronize_sched();
>
>
>
> It's not clear to me why you are doing that.
> Is this waiting for pending int 3 kprobes handlers
> to complete? If so, why, and what does that prevent?
I _might_ have understood.
You have set up the optimized flags, then you wait for
any old-style int 3 kprobes to complete and route
to detour buffer so that you can patch the jump
safely in the dead code? (and finish with first byte
by patching the int 3 itself)
next prev parent reply other threads:[~2009-11-24 3:31 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-23 23:18 [PATCH -tip v5 00/10] kprobes: Kprobes jump optimization support Masami Hiramatsu
2009-11-23 23:18 ` [PATCH -tip v5 01/10] kprobes/x86: Cleanup RELATIVEJUMP_INSTRUCTION to RELATIVEJUMP_OPCODE Masami Hiramatsu
2009-11-23 23:18 ` [PATCH -tip v5 02/10] kprobes: Introduce generic insn_slot framework Masami Hiramatsu
2009-11-23 23:19 ` [PATCH -tip v5 09/10] [RFC] x86: Introduce generic jump patching without stop_machine Masami Hiramatsu
2009-11-23 23:19 ` [PATCH -tip v5 08/10] kprobes: Add documents of jump optimization Masami Hiramatsu
2009-11-23 23:19 ` [PATCH -tip v5 10/10] [RFC] kprobes/x86: Use text_poke_fixup() for " Masami Hiramatsu
2009-11-23 23:19 ` [PATCH -tip v5 06/10] kprobes/x86: Cleanup save/restore registers Masami Hiramatsu
2009-11-24 2:51 ` Frederic Weisbecker
2009-11-24 15:36 ` Masami Hiramatsu
2009-11-24 20:19 ` Frederic Weisbecker
2009-11-24 15:40 ` Frank Ch. Eigler
2009-11-24 20:20 ` Frederic Weisbecker
2009-11-23 23:19 ` [PATCH -tip v5 03/10] kprobes: Introduce kprobes jump optimization Masami Hiramatsu
2009-11-24 2:44 ` Frederic Weisbecker
2009-11-24 3:31 ` Frederic Weisbecker [this message]
2009-11-24 15:32 ` Masami Hiramatsu
2009-11-24 20:14 ` Frederic Weisbecker
2009-11-24 20:59 ` Masami Hiramatsu
2009-11-25 21:09 ` Steven Rostedt
2009-11-25 21:30 ` Masami Hiramatsu
2009-11-24 21:12 ` H. Peter Anvin
2009-11-24 15:31 ` Masami Hiramatsu
2009-11-24 19:45 ` Frederic Weisbecker
2009-11-24 21:15 ` Masami Hiramatsu
2009-11-23 23:19 ` [PATCH -tip v5 07/10] kprobes/x86: Support kprobes jump optimization on x86 Masami Hiramatsu
2009-11-24 3:15 ` Frederic Weisbecker
2009-11-24 16:27 ` Jason Baron
2009-11-24 17:46 ` Masami Hiramatsu
2009-11-25 16:12 ` Masami Hiramatsu
2009-11-24 16:42 ` H. Peter Anvin
2009-11-24 17:01 ` Masami Hiramatsu
2009-11-23 23:19 ` [PATCH -tip v5 05/10] kprobes/x86: Boost probes when reentering Masami Hiramatsu
2009-11-23 23:19 ` [PATCH -tip v5 04/10] kprobes: Jump optimization sysctl interface Masami Hiramatsu
2009-11-24 2:03 ` [PATCH -tip v5 00/10] kprobes: Kprobes jump optimization support Frederic Weisbecker
2009-11-24 3:20 ` Frederic Weisbecker
2009-11-24 7:53 ` Ingo Molnar
2009-11-24 16:03 ` Masami Hiramatsu
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20091124033135.GE6752@nowhere \
--to=fweisbec@gmail.com \
--cc=ananth@in.ibm.com \
--cc=andersk@ksplice.com \
--cc=andi@firstfloor.org \
--cc=dle-develop@lists.sourceforge.net \
--cc=hch@infradead.org \
--cc=hpa@zytor.com \
--cc=jbaron@redhat.com \
--cc=jkenisto@us.ibm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mathieu.desnoyers@polymtl.ca \
--cc=mhiramat@redhat.com \
--cc=mingo@elte.hu \
--cc=rostedt@goodmis.org \
--cc=srikar@linux.vnet.ibm.com \
--cc=systemtap@sources.redhat.com \
--cc=tabbott@ksplice.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).