From: Jiaxing Wang Date: Fri, 6 Nov 2015 08:04:16 +0000 (+0800) Subject: tracing: Make tracing work when debugfs is not configured in X-Git-Tag: v4.4-rc1~23^2~2 X-Git-Url: https://git.kernelconcepts.de/?a=commitdiff_plain;h=8b1291994d8e5e621a8af7e165b106e50d04bbf1;p=karo-tx-linux.git tracing: Make tracing work when debugfs is not configured in Currently tracing_init_dentry() returns -ENODEV when debugfs is not configured in, which causes tracefs not populated with tracing files and directories, so we will get an empty directory even after we manually mount tracefs. We can make tracing_init_dentry() return NULL if debugfs is not configured in and can manually mount tracefs. But return -ENODEV if debugfs is configured in but not initialized or failed to create automount point as that would break backward compatibility with older tools. Link: http://lkml.kernel.org/r/1446797056-11683-1-git-send-email-hello.wjx@gmail.com Signed-off-by: Jiaxing Wang Signed-off-by: Steven Rostedt --- diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 2198a630ef58..08af79c106e1 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -6847,7 +6847,9 @@ struct dentry *tracing_init_dentry(void) if (tr->dir) return NULL; - if (WARN_ON(!debugfs_initialized())) + if (WARN_ON(!tracefs_initialized()) || + (IS_ENABLED(CONFIG_DEBUG_FS) && + WARN_ON(!debugfs_initialized()))) return ERR_PTR(-ENODEV); /*