[PATCH][GIT PULL][v2.6.35] perf/tracing: Fix regression of perf losing kprobe events
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From: Steven Rostedt on 10 Jun 2010 21:00 Ingo, Please pull the latest tip/perf/urgent tree, which can be found at: git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git tip/perf/urgent Steven Rostedt (1): perf/tracing: Fix regression of perf losing kprobe events ---- kernel/trace/trace_event_perf.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-) --------------------------- commit a8fb2608053547bc3152ea61a5ec7cdfce5d942c Author: Steven Rostedt <srostedt(a)redhat.com> Date: Thu Jun 10 14:53:16 2010 -0400 perf/tracing: Fix regression of perf losing kprobe events With the addition of the code to shrink the kernel tracepoint infrastructure, we lost kprobes being traced by perf. The reason is that I tested if the "tp_event->class->perf_probe" existed before enabling it. This prevents "ftrace only" events (like the function trace events) from being enabled by perf. Unfortunately, kprobe events do not use perf_probe. This causes kprobes to be missed by perf. To fix this, we add the test to see if "tp_event->class->reg" exists as well as perf_probe. Normal trace events have only "perf_probe" but no "reg" function, and kprobes and syscalls have the "reg" but no "perf_probe". The ftrace unique events do not have either, so this is a valid test. If a kprobe or syscall is not to be probed by perf, the "reg" function is called anyway, and will return a failure and prevent perf from probing it. Reported-by: Srikar Dronamraju <srikar(a)linux.vnet.ibm.com> Tested-by: Srikar Dronamraju <srikar(a)linux.vnet.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra(a)chello.nl> Signed-off-by: Steven Rostedt <rostedt(a)goodmis.org> diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c index e6f6588..8a2b73f 100644 --- a/kernel/trace/trace_event_perf.c +++ b/kernel/trace/trace_event_perf.c @@ -96,7 +96,9 @@ int perf_trace_init(struct perf_event *p_event) mutex_lock(&event_mutex); list_for_each_entry(tp_event, &ftrace_events, list) { if (tp_event->event.type == event_id && - tp_event->class && tp_event->class->perf_probe && + tp_event->class && + (tp_event->class->perf_probe || + tp_event->class->reg) && try_module_get(tp_event->mod)) { ret = perf_trace_event_init(tp_event, p_event); break; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |