Re: [PATCH] tracing: fix incorrect tracer freeing when opening tracing pipe

[Steven Rostedt]

On Wed, 13 Feb 2019 20:29:06 +0800
"zhangyi (F)" <yi.zhang@xxxxxxxxxx> wrote:

> Commit d716ff71dd12 ("tracing: Remove taking of trace_types_lock in
> pipe files") use the current tracer instead of the copy in
> tracing_open_pipe(), but it forget to remove the freeing sentence in
> the error path.
> 
> Fixes: d716ff71dd12 ("tracing: Remove taking of trace_types_lock in pipe files")

Thanks.

As this is harmless (frees to NULL is ok, and iter is allocated with
kzalloc()), I'm going to just add this for the next merge window.

-- Steve

> Signed-off-by: zhangyi (F) <yi.zhang@xxxxxxxxxx>
> ---
>  kernel/trace/trace.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index c521b73..b583ff7 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -5624,7 +5624,6 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp)
>  	return ret;
>  
>  fail:
> -	kfree(iter->trace);
>  	kfree(iter);
>  	__trace_array_put(tr);
>  	mutex_unlock(&trace_types_lock);