Re: [PATCH 1/2] tracefs: Remove unnecessary debug_fs checks.

Greg Kroah-Hartman
2020-06-22T09:18:17Z

On Mon, Jun 22, 2020 at 10:30:18AM +0200, Peter Enderborg wrote:
> This is a preparation for debugfs restricted mode.
> We don't need debugfs to trace, the removed check stop tracefs to work
> if debugfs is not initialised. We instead tries to automount within
> debugfs and relay on it's handling. The code path is to create a
> backward compatibility from when tracefs was part of debugfs, it is now
> standalone and does not need debugfs. When debugfs is in restricted
> it is compiled in but not active and return EPERM to clients and
> tracefs wont work if it assumes it is active it is compiled in
> kernel.

I'm sorry, but I can't parse this changelog text at all. Why exactly
are you doing this?

>
> Reported-by: kernel test robot <lkp@intel.com>
> Signed-off-by: Peter Enderborg <peter.enderborg@sony.com>
> ---
> kernel/trace/trace.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index ec44b0e2a19c..34ed82364edb 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -8946,9 +8946,7 @@ struct dentry *tracing_init_dentry(void)
> if (tr->dir)
> return NULL;
>
> - if (WARN_ON(!tracefs_initialized()) ||
> - (IS_ENABLED(CONFIG_DEBUG_FS) &&
> - WARN_ON(!debugfs_initialized())))
> + if (WARN_ON(!tracefs_initialized()))
> return ERR_PTR(-ENODEV);
>

This change makes sense to me anyway, so:

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>