Messages in this thread | | | Date | Wed, 7 Feb 2018 13:06:51 +0100 | From | Jiri Olsa <> | Subject | Re: [PATCH 01/18] tracing: Add function based events |
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On Tue, Feb 06, 2018 at 10:09:17PM -0500, Steven Rostedt wrote: > On Mon, 5 Feb 2018 10:00:50 -0500 > Steven Rostedt <rostedt@goodmis.org> wrote: > > > On Mon, 5 Feb 2018 09:24:23 +0100 > > Jiri Olsa <jolsa@redhat.com> wrote: > > > > > > > should this be done under 'func_event_mutex' ? > > > > Probably. > > I think we only need to add the list.
yep, seems enough
jirka
> > > > > > > > > I tried and crashed the system by running 2 scripts with: > > > > > > echo 'ip_rcv(u64 skb, u64 dev)' > /sys/kernel/debug/tracing/function_events > > > echo 'SyS_openat(int dfd, string buf, x32 flags, x32 mode)' >> /sys/kernel/debug/tracing/function_events > > > echo 'SyS_open(x8[32] buf, x32 flags, x32 mode)' >> /sys/kernel/debug/tracing/function_events > > > > > > > There's no reason that we can't have more than one function event > attached to the same function. I'm adding this: > > diff --git a/kernel/trace/trace_event_ftrace.c b/kernel/trace/trace_event_ftrace.c > index b145639eac45..928168fc2025 100644 > --- a/kernel/trace/trace_event_ftrace.c > +++ b/kernel/trace/trace_event_ftrace.c > @@ -1275,12 +1275,6 @@ static int create_function_event(int argc, char **argv) > if (state != FUNC_STATE_END) > goto fail; > > - ret = -EALREADY; > - list_for_each_entry(fe, &func_events, list) { > - if (strcmp(fe->func, func_event->func) == 0) > - goto fail; > - } > - > ret = ftrace_set_filter(&func_event->ops, func_event->func, > strlen(func_event->func), 0); > if (ret < 0) > @@ -1290,7 +1284,9 @@ static int create_function_event(int argc, char **argv) > if (ret < 0) > goto fail; > > + mutex_lock(&func_event_mutex); > list_add_tail(&func_event->list, &func_events); > + mutex_unlock(&func_event_mutex); > return 0; > fail: > free_func_event(func_event); > > -- Steve
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