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

From: Mathieu Poirier
Date: Mon Jan 17 2022 - 12:13:59 EST


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@xxxxxxxxx>
> ---
> 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
>