tracing/probe: Fix to allow user to enable events on unloaded modules (44d00dc7) · Commits · e / devices / android_kernel_fairphone_FP5

Fix to allow user to enable probe events on unloaded modules. This operations was allowed before commit ("tracing/probe: Split trace_event related data from trace_probe"), because if users need to probe module init functions, they have to enable those probe events before loading module. Link: http://lkml.kernel.org/r/156879693733.31056.9331322616994665167.stgit@devnote2 Cc: stable@vger.kernel.org Fixes: ("tracing/probe: Split trace_event related data from trace_probe") Signed-off-by:

Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by:

Steven Rostedt (VMware) <rostedt@goodmis.org>

kernel/trace/trace_kprobe.c

+5 −12

Original line number	Diff line number	Diff line
		@@ -371,31 +371,24 @@ static int enable_trace_kprobe(struct trace_event_call *call,
		if (enabled)
		return 0;

		enabled = false;
		list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
		tk = container_of(pos, struct trace_kprobe, tp);
		if (trace_kprobe_has_gone(tk))
		continue;
		ret = __enable_trace_kprobe(tk);
		if (ret) {
		if (enabled) {
		__disable_trace_kprobe(tp);
		enabled = false;
		}
		if (ret)
		break;
		}
		enabled = true;
		}

		if (!enabled) {
		/* No probe is enabled. Roll back */
		if (ret) {
		/* Failed to enable one of them. Roll back all */
		if (enabled)
		__disable_trace_kprobe(tp);
		if (file)
		trace_probe_remove_file(tp, file);
		else
		trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
		if (!ret)
		/* Since all probes are gone, this is not available */
		ret = -EADDRNOTAVAIL;
		}

		return ret;