On Fri, Dec 17, 2021 at 04:13:48PM +0100, Cezary Rojewski wrote:

On 2021-12-17 4:00 PM, Dan Carpenter wrote:

...

This code frees "graph" and then dereferences to save the error code. Save the error code first and then use gotos to unwind the allocation.

Fixes: 59716aa3f976 ("ASoC: qdsp6: Fix an IS_ERR() vs NULL bug") Signed-off-by: Dan Carpenter dan.carpenter@oracle.com

---

sound/soc/qcom/qdsp6/q6apm.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/sound/soc/qcom/qdsp6/q6apm.c b/sound/soc/qcom/qdsp6/q6apm.c index 3e007d609a9b..f424d7aa389a 100644 --- a/sound/soc/qcom/qdsp6/q6apm.c +++ b/sound/soc/qcom/qdsp6/q6apm.c @@ -615,7 +615,7 @@ struct q6apm_graph *q6apm_graph_open(struct device *dev, q6apm_cb cb, graph = kzalloc(sizeof(*graph), GFP_KERNEL); if (!graph) { ret = -ENOMEM;

• goto err;
  

• goto put_ar_graph;
  

  } graph->apm = apm;

@@ -631,13 +631,15 @@ struct q6apm_graph *q6apm_graph_open(struct device *dev, q6apm_cb cb, graph->port = gpr_alloc_port(apm->gdev, dev, graph_callback, graph); if (IS_ERR(graph->port)) {

• kfree(graph);
  

  ret = PTR_ERR(graph->port);

• goto err;
  

• goto free_graph;
  

  } return graph;

-err:

+free_graph:

• kfree(graph);

+put_ar_graph:

Hello Dan,

The patch looks good! My only suggestion is a readability improvement, but I'm unaware of the convention chosen for qcom directory so you may choose to ignore it:

Function q6apm_graph_open() has two separate return paths: a happy path ending in 'return graph' and an error path which eventually ends with 'return ERR_PTR(ret)'. Current goto label-naming convention suggests it's a happy path nonetheless.

s/free_graph/err_alloc_port/ and s/put_ar_graph/err_alloc_graph/ tells reader upfront that they are in the error path.

Generally when code is indented two tabs that's an error path. The relevant pattern is "Do error handling, not success handling". I guess the if (IS_ERR()) check means it's an error as well.

regards, dan carpenter