On Mon, 5 Nov 2018 18:00:15 +0900 Masami Hiramatsu <[email protected]> wrote:
> Add a busy check loop in cleanup_all_probes() before > trying to remove all events in uprobe_events as same as > kprobe_events does. > > Without this change, writing null to uprobe_events will > try to remove events but if one of them is enabled, it > stopped there but some of events are already cleared. > > With this change, writing null to uprobe_events make > sure all events are not enabled before removing events. > So, it clears all events, or return an error (-EBUSY) > with keeping all events. > Hmm, should this patch be marked as stable? -- Steve > Signed-off-by: Masami Hiramatsu <[email protected]> > --- > kernel/trace/trace_uprobe.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c > index 31ea48eceda1..b708e4ff7ea7 100644 > --- a/kernel/trace/trace_uprobe.c > +++ b/kernel/trace/trace_uprobe.c > @@ -587,12 +587,19 @@ static int cleanup_all_probes(void) > int ret = 0; > > mutex_lock(&uprobe_lock); > + /* Ensure no probe is in use. */ > + list_for_each_entry(tu, &uprobe_list, list) > + if (trace_probe_is_enabled(&tu->tp)) { > + ret = -EBUSY; > + goto end; > + } > while (!list_empty(&uprobe_list)) { > tu = list_entry(uprobe_list.next, struct trace_uprobe, list); > ret = unregister_trace_uprobe(tu); > if (ret) > break; > } > +end: > mutex_unlock(&uprobe_lock); > return ret; > }
