Re: [PATCH v3] remoteproc: Fix NULL vs IS_ERR() checking in rproc_create_trace_file

[Mathieu Poirier <mathieu.poirier@linaro.org>]

On Wed, Jan 05, 2022 at 01:10:22PM +0000, Miaoqian Lin wrote:
> The debugfs_create_file() function doesn't return NULL.
> It returns error pointers. Fix check in rproc_create_trace_file
> and make it returns return error pointers.

s/"returns return"/return

> Fix check in rproc_handle_trace to propagate the error code.
> 
> Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
> ---
> Changes in v2:
> - return PTR_ERR(tfile) in rproc_create_trace_file
> - fix check in rproc_handle_trace()
> Changes in v3:
> - return tfile to fix incorrect return type in v2
> ---
>  drivers/remoteproc/remoteproc_core.c    | 6 ++++--
>  drivers/remoteproc/remoteproc_debugfs.c | 4 +---
>  2 files changed, 5 insertions(+), 5 deletions(-)
>

I will fix the above, add a proper "Fixes" tag and apply this patch to
rproc-next when v5.17-rc1 comes out next week.

Thanks,
Mathieu

> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index 775df165eb45..5608408f8eac 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -656,6 +656,7 @@ static int rproc_handle_trace(struct rproc *rproc, void *ptr,
>  	struct rproc_debug_trace *trace;
>  	struct device *dev = &rproc->dev;
>  	char name[15];
> +	int ret;
>  
>  	if (sizeof(*rsc) > avail) {
>  		dev_err(dev, "trace rsc is truncated\n");
> @@ -684,9 +685,10 @@ static int rproc_handle_trace(struct rproc *rproc, void *ptr,
>  
>  	/* create the debugfs entry */
>  	trace->tfile = rproc_create_trace_file(name, rproc, trace);
> -	if (!trace->tfile) {
> +	if (IS_ERR(trace->tfile)) {
> +		ret = PTR_ERR(trace->tfile);
>  		kfree(trace);
> -		return -EINVAL;
> +		return ret;
>  	}
>  
>  	list_add_tail(&trace->node, &rproc->traces);
> diff --git a/drivers/remoteproc/remoteproc_debugfs.c b/drivers/remoteproc/remoteproc_debugfs.c
> index b5a1e3b697d9..2ae59a365b7e 100644
> --- a/drivers/remoteproc/remoteproc_debugfs.c
> +++ b/drivers/remoteproc/remoteproc_debugfs.c
> @@ -390,10 +390,8 @@ struct dentry *rproc_create_trace_file(const char *name, struct rproc *rproc,
>  
>  	tfile = debugfs_create_file(name, 0400, rproc->dbg_dir, trace,
>  				    &trace_rproc_ops);
> -	if (!tfile) {
> +	if (IS_ERR(tfile))
>  		dev_err(&rproc->dev, "failed to create debugfs trace entry\n");
> -		return NULL;
> -	}
>  
>  	return tfile;
>  }
> -- 
> 2.17.1
>