From 547cd9eacd1c699c8d1fa77c95c6cdb33b2eba6a Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Mon, 5 Nov 2018 18:00:15 +0900 Subject: [PATCH] tracing/uprobes: Add busy check when cleanup all uprobes Add a busy check loop in cleanup_all_probes() before trying to remove all events in uprobe_events, the same way that kprobe_events does. Without this change, writing null to uprobe_events will try to remove events but if one of them is enabled, it will stop there leaving some events cleared and others not clceared. With this change, writing null to uprobe_events makes sure all events are not enabled before removing events. So, it clears all events, or returns an error (-EBUSY) with keeping all events. Link: http://lkml.kernel.org/r/154140841557.17322.12653952888762532401.stgit@devbox Reviewed-by: Tom Zanussi Tested-by: Tom Zanussi Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- 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; }