Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753485AbZJQKC4 (ORCPT ); Sat, 17 Oct 2009 06:02:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753281AbZJQKCz (ORCPT ); Sat, 17 Oct 2009 06:02:55 -0400 Received: from hera.kernel.org ([140.211.167.34]:36528 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753178AbZJQKCy (ORCPT ); Sat, 17 Oct 2009 06:02:54 -0400 Date: Sat, 17 Oct 2009 10:01:55 GMT From: tip-bot for Masami Hiramatsu Cc: mingo@redhat.com, peterz@infradead.org, fweisbec@gmail.com, rostedt@goodmis.org, ak@linux.intel.com, jbaron@redhat.com, tglx@linutronix.de, laijs@cn.fujitsu.com, mhiramat@redhat.com, linux-kernel@vger.kernel.org, hpa@zytor.com, fche@redhat.com, jkenisto@us.ibm.com, tzanussi@gmail.com, lizf@cn.fujitsu.com, hch@infradead.org, ananth@in.ibm.com, srikar@linux.vnet.ibm.com, mingo@elte.hu, prasad@linux.vnet.ibm.com Reply-To: mingo@redhat.com, peterz@infradead.org, fweisbec@gmail.com, rostedt@goodmis.org, ak@linux.intel.com, jbaron@redhat.com, tglx@linutronix.de, laijs@cn.fujitsu.com, mhiramat@redhat.com, linux-kernel@vger.kernel.org, hpa@zytor.com, fche@redhat.com, jkenisto@us.ibm.com, tzanussi@gmail.com, lizf@cn.fujitsu.com, hch@infradead.org, ananth@in.ibm.com, srikar@linux.vnet.ibm.com, mingo@elte.hu, prasad@linux.vnet.ibm.com In-Reply-To: <20090914204937.18779.59422.stgit@dhcp-100-2-132.bos.redhat.com> References: <20090914204937.18779.59422.stgit@dhcp-100-2-132.bos.redhat.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/probes] tracing/kprobes: Disable kprobe events by default after creation Message-ID: Git-Commit-ID: 5a0d9050db4d1147722b42afef9011251b2651ee X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Sat, 17 Oct 2009 10:01:56 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3616 Lines: 90 Commit-ID: 5a0d9050db4d1147722b42afef9011251b2651ee Gitweb: http://git.kernel.org/tip/5a0d9050db4d1147722b42afef9011251b2651ee Author: Masami Hiramatsu AuthorDate: Mon, 14 Sep 2009 16:49:37 -0400 Committer: Frederic Weisbecker CommitDate: Thu, 17 Sep 2009 04:04:01 +0200 tracing/kprobes: Disable kprobe events by default after creation Disable newly created kprobe events by default, not to disturb another user using ftrace. "Disturb" means when someone is using ftrace and another user tries to use perf-tools, (in near future) if he defines new kprobe event via perf-tools, then new events will mess up the frace buffer. Fix this to allow proper and transparent kprobes events concurrent usage between ftrace users and perf users. Signed-off-by: Masami Hiramatsu Acked-by: Steven Rostedt Cc: Jim Keniston Cc: Ananth N Mavinakayanahalli Cc: Andi Kleen Cc: Christoph Hellwig Cc: Frank Ch. Eigler Cc: Frederic Weisbecker Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Jason Baron Cc: K.Prasad Cc: Lai Jiangshan Cc: Li Zefan Cc: Peter Zijlstra Cc: Srikar Dronamraju Cc: Tom Zanussi LKML-Reference: <20090914204937.18779.59422.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Frederic Weisbecker --- Documentation/trace/kprobetrace.txt | 11 +++++++++-- kernel/trace/trace_kprobe.c | 4 ++-- 2 files changed, 11 insertions(+), 4 deletions(-) diff --git a/Documentation/trace/kprobetrace.txt b/Documentation/trace/kprobetrace.txt index 6521681..9b8f7c6 100644 --- a/Documentation/trace/kprobetrace.txt +++ b/Documentation/trace/kprobetrace.txt @@ -122,8 +122,15 @@ print fmt: "(%lx) dfd=%lx filename=%lx flags=%lx mode=%lx", REC->ip, REC->dfd, R echo > /sys/kernel/debug/tracing/kprobe_events - This clears all probe points. and you can see the traced information via -/sys/kernel/debug/tracing/trace. + This clears all probe points. + + Right after definition, each event is disabled by default. For tracing these +events, you need to enable it. + + echo 1 > /sys/kernel/debug/tracing/events/kprobes/myprobe/enable + echo 1 > /sys/kernel/debug/tracing/events/kprobes/myretprobe/enable + + And you can see the traced information via /sys/kernel/debug/tracing/trace. cat /sys/kernel/debug/tracing/trace # tracer: nop diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index d8db935..f6821f1 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -383,7 +383,7 @@ static int register_trace_probe(struct trace_probe *tp) goto end; } - tp->flags = TP_FLAG_TRACE; + tp->rp.kp.flags |= KPROBE_FLAG_DISABLED; if (probe_is_return(tp)) ret = register_kretprobe(&tp->rp); else @@ -1298,7 +1298,7 @@ static int register_probe_event(struct trace_probe *tp) call->id = register_ftrace_event(&tp->event); if (!call->id) return -ENODEV; - call->enabled = 1; + call->enabled = 0; call->regfunc = probe_event_enable; call->unregfunc = probe_event_disable; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/