Commit-ID: 5a0d9050db4d1147722b42afef9011251b2651ee Gitweb: http://git.kernel.org/tip/5a0d9050db4d1147722b42afef9011251b2651ee Author: Masami Hiramatsu <mhiramat@xxxxxxxxxx> AuthorDate: Mon, 14 Sep 2009 16:49:37 -0400 Committer: Frederic Weisbecker <fweisbec@xxxxxxxxx> 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 <mhiramat@xxxxxxxxxx> Acked-by: Steven Rostedt <rostedt@xxxxxxxxxxx> Cc: Jim Keniston <jkenisto@xxxxxxxxxx> Cc: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxx> Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx> Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx> Cc: Frank Ch. Eigler <fche@xxxxxxxxxx> Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx> Cc: H. Peter Anvin <hpa@xxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxx> Cc: Jason Baron <jbaron@xxxxxxxxxx> Cc: K.Prasad <prasad@xxxxxxxxxxxxxxxxxx> Cc: Lai Jiangshan <laijs@xxxxxxxxxxxxxx> Cc: Li Zefan <lizf@xxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx> Cc: Tom Zanussi <tzanussi@xxxxxxxxx> LKML-Reference: <20090914204937.18779.59422.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx> Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx> --- 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-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html