Commit 57ea2a34 authored Jul 25, 2018 by Artem Savkov Committed by Steven Rostedt (VMware) Jul 25, 2018

tracing/kprobes: Fix trace_probe flags on enable_trace_kprobe() failure

If enable_trace_kprobe fails to enable the probe in enable_k(ret)probe
it returns an error, but does not unset the tp flags it set previously.
This results in a probe being considered enabled and failures like being
unable to remove the probe through kprobe_events file since probes_open()
expects every probe to be disabled.

Link: http://lkml.kernel.org/r/20180725102826.8300-1-asavkov@redhat.com
Link: http://lkml.kernel.org/r/20180725142038.4765-1-asavkov@redhat.com



Cc: Ingo Molnar <mingo@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 41a7dd42 ("tracing/kprobes: Support ftrace_event_file base multibuffer")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

parent 82f4f3e6

kernel/trace/trace_kprobe.c

+11 −2

Original line number	Diff line number	Diff line
		@@ -400,11 +400,10 @@ static struct trace_kprobe find_trace_kprobe(const char event,
		static int
		enable_trace_kprobe(struct trace_kprobe tk, struct trace_event_file file)
		{
		struct event_file_link *link;
		int ret = 0;

		if (file) {
		struct event_file_link *link;

		link = kmalloc(sizeof(*link), GFP_KERNEL);
		if (!link) {
		ret = -ENOMEM;
		@@ -424,6 +423,16 @@ enable_trace_kprobe(struct trace_kprobe tk, struct trace_event_file file)
		else
		ret = enable_kprobe(&tk->rp.kp);
		}

		if (ret) {
		if (file) {
		list_del_rcu(&link->list);
		kfree(link);
		tk->tp.flags &= ~TP_FLAG_TRACE;
		} else {
		tk->tp.flags &= ~TP_FLAG_PROFILE;
		}
		}
		out:
		return ret;
		}