tracing: Do not warn when connecting eprobe to non existing event

When the syscall trace points are not configured in, the kselftests for ftrace will try to attach an event probe (eprobe) to one of the system call trace points. This triggered a WARNING, because the failure only expects to see memory issues. But this is not the only failure. The user may attempt to attach to a non existent event, and the kernel must not warn about it. Link: https://lkml.kernel.org/r/[email protected] Fixes: 7491e2c ("tracing: Add a probe that attaches to trace events") Signed-off-by: Steven Rostedt (VMware) <[email protected]>
tadfisher · Oct 28, 2021 · 7fa598f · 7fa598f
1 parent 4e84dc4
commit 7fa598f
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
@@ -904,8 +904,8 @@ static int __trace_eprobe_create(int argc, const char *argv[])
 
 	if (IS_ERR(ep)) {
 		ret = PTR_ERR(ep);
-		/* This must return -ENOMEM, else there is a bug */
-		WARN_ON_ONCE(ret != -ENOMEM);
+		/* This must return -ENOMEM or misssing event, else there is a bug */
+		WARN_ON_ONCE(ret != -ENOMEM && ret != -ENODEV);
 		ep = NULL;
 		goto error;
 	}