[PATCH] media: atomisp: Fix error handling in probe

[PATCH] media: atomisp: Fix error handling in probe

[Evgeny Novikov]

There were several issues with handling errors in lm3554_probe():
- Probe did not set the error code when v4l2_ctrl_handler_init() failed.
- It intermixed gotos for handling errors of v4l2_ctrl_handler_init()
  and media_entity_pads_init().
- Probe did not free resources in case of failures of
  atomisp_register_i2c_module().

The patch fixes all these issues.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Evgeny Novikov <novikov@ispras.ru>
---
 .../media/atomisp/i2c/atomisp-lm3554.c        | 28 +++++++++++++------
 1 file changed, 19 insertions(+), 9 deletions(-)

diff --git a/drivers/staging/media/atomisp/i2c/atomisp-lm3554.c b/drivers/staging/media/atomisp/i2c/atomisp-lm3554.c
index 362ed44b4eff..1e9432d6ec0c 100644
--- a/drivers/staging/media/atomisp/i2c/atomisp-lm3554.c
+++ b/drivers/staging/media/atomisp/i2c/atomisp-lm3554.c
@@ -835,7 +835,6 @@ static int lm3554_probe(struct i2c_client *client)
 	int err = 0;
 	struct lm3554 *flash;
 	unsigned int i;
-	int ret;
 
 	flash = kzalloc(sizeof(*flash), GFP_KERNEL);
 	if (!flash)
@@ -852,12 +851,12 @@ static int lm3554_probe(struct i2c_client *client)
 	flash->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
 	flash->mode = ATOMISP_FLASH_MODE_OFF;
 	flash->timeout = LM3554_MAX_TIMEOUT / LM3554_TIMEOUT_STEPSIZE - 1;
-	ret =
+	err =
 	    v4l2_ctrl_handler_init(&flash->ctrl_handler,
 				   ARRAY_SIZE(lm3554_controls));
-	if (ret) {
+	if (err) {
 		dev_err(&client->dev, "error initialize a ctrl_handler.\n");
-		goto fail3;
+		goto fail2;
 	}
 
 	for (i = 0; i < ARRAY_SIZE(lm3554_controls); i++)
@@ -873,7 +872,7 @@ static int lm3554_probe(struct i2c_client *client)
 	err = media_entity_pads_init(&flash->sd.entity, 0, NULL);
 	if (err) {
 		dev_err(&client->dev, "error initialize a media entity.\n");
-		goto fail2;
+		goto fail3;
 	}
 
 	flash->sd.entity.function = MEDIA_ENT_F_FLASH;
@@ -884,12 +883,23 @@ static int lm3554_probe(struct i2c_client *client)
 
 	err = lm3554_gpio_init(client);
 	if (err) {
-		dev_err(&client->dev, "gpio request/direction_output fail");
-		goto fail3;
+		dev_err(&client->dev, "gpio request/direction_output fail.\n");
+		goto fail4;
 	}
-	return atomisp_register_i2c_module(&flash->sd, NULL, LED_FLASH);
-fail3:
+
+	err = atomisp_register_i2c_module(&flash->sd, NULL, LED_FLASH);
+	if (err) {
+		dev_err(&client->dev, "fail to register atomisp i2c module.\n");
+		goto fail5;
+	}
+
+	return 0;
+
+fail5:
+	lm3554_gpio_uninit(client);
+fail4:
 	media_entity_cleanup(&flash->sd.entity);
+fail3:
 	v4l2_ctrl_handler_free(&flash->ctrl_handler);
 fail2:
 	v4l2_device_unregister_subdev(&flash->sd);
-- 
2.26.2

Re: [PATCH] media: atomisp: Fix error handling in probe

[Sakari Ailus]

On Tue, Aug 10, 2021 at 02:53:03PM +0300, Evgeny Novikov wrote:
> There were several issues with handling errors in lm3554_probe():
> - Probe did not set the error code when v4l2_ctrl_handler_init() failed.
> - It intermixed gotos for handling errors of v4l2_ctrl_handler_init()
>   and media_entity_pads_init().
> - Probe did not free resources in case of failures of
>   atomisp_register_i2c_module().
> 
> The patch fixes all these issues.
> 
> Found by Linux Driver Verification project (linuxtesting.org).
> 
> Signed-off-by: Evgeny Novikov <novikov@ispras.ru>

Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>

-- 
Sakari Ailus

Re: [PATCH] media: atomisp: Fix error handling in probe

[Dan Carpenter]

On Tue, Aug 10, 2021 at 02:53:03PM +0300, Evgeny Novikov wrote:
> There were several issues with handling errors in lm3554_probe():
> - Probe did not set the error code when v4l2_ctrl_handler_init() failed.
> - It intermixed gotos for handling errors of v4l2_ctrl_handler_init()
>   and media_entity_pads_init().
> - Probe did not free resources in case of failures of
>   atomisp_register_i2c_module().
> 
> The patch fixes all these issues.
> 
> Found by Linux Driver Verification project (linuxtesting.org).

This patch is good, but two things:

1) Please can you rename all the labels to say what the goto does?

err_uninit:
	lm3554_gpio_uninit(client);
cleanup_media:
 	media_entity_cleanup(&flash->sd.entity);
free_handler:
 	v4l2_ctrl_handler_free(&flash->ctrl_handler);
unregister_subdev:
 	v4l2_device_unregister_subdev(&flash->sd);

2) There is a missing error code still:

drivers/staging/media/atomisp/i2c/atomisp-lm3554.c
   858          if (ret) {
   859                  dev_err(&client->dev, "error initialize a ctrl_handler.\n");
   860                  goto fail3;
   861          }
   862  
   863          for (i = 0; i < ARRAY_SIZE(lm3554_controls); i++)
   864                  v4l2_ctrl_new_custom(&flash->ctrl_handler, &lm3554_controls[i],
   865                                       NULL);
   866  
   867          if (flash->ctrl_handler.error) {
   868                  dev_err(&client->dev, "ctrl_handler error.\n");
   869                  goto fail3;
                        ^^^^^^^^^^
	err = flash->ctrl_handler.error;

   870          }
   871  
   872          flash->sd.ctrl_handler = &flash->ctrl_handler;
   873          err = media_entity_pads_init(&flash->sd.entity, 0, NULL);
   874          if (err) {
   875                  dev_err(&client->dev, "error initialize a media entity.\n");
   876                  goto fail2;
   877          }

regards,
dan carpenter

Re: [PATCH] media: atomisp: Fix error handling in probe

[Evgeny Novikov]

Hi Dan,

Thank you for these suggestions. I will resend the patch.

Best regards,
Evgeny Novikov

On 10.08.2021 18:14, Dan Carpenter wrote:
> On Tue, Aug 10, 2021 at 02:53:03PM +0300, Evgeny Novikov wrote:
>> There were several issues with handling errors in lm3554_probe():
>> - Probe did not set the error code when v4l2_ctrl_handler_init() failed.
>> - It intermixed gotos for handling errors of v4l2_ctrl_handler_init()
>>    and media_entity_pads_init().
>> - Probe did not free resources in case of failures of
>>    atomisp_register_i2c_module().
>>
>> The patch fixes all these issues.
>>
>> Found by Linux Driver Verification project (linuxtesting.org).
> This patch is good, but two things:
>
> 1) Please can you rename all the labels to say what the goto does?
>
> err_uninit:
> 	lm3554_gpio_uninit(client);
> cleanup_media:
>   	media_entity_cleanup(&flash->sd.entity);
> free_handler:
>   	v4l2_ctrl_handler_free(&flash->ctrl_handler);
> unregister_subdev:
>   	v4l2_device_unregister_subdev(&flash->sd);
>
> 2) There is a missing error code still:
>
> drivers/staging/media/atomisp/i2c/atomisp-lm3554.c
>     858          if (ret) {
>     859                  dev_err(&client->dev, "error initialize a ctrl_handler.\n");
>     860                  goto fail3;
>     861          }
>     862
>     863          for (i = 0; i < ARRAY_SIZE(lm3554_controls); i++)
>     864                  v4l2_ctrl_new_custom(&flash->ctrl_handler, &lm3554_controls[i],
>     865                                       NULL);
>     866
>     867          if (flash->ctrl_handler.error) {
>     868                  dev_err(&client->dev, "ctrl_handler error.\n");
>     869                  goto fail3;
>                          ^^^^^^^^^^
> 	err = flash->ctrl_handler.error;
>
>     870          }
>     871
>     872          flash->sd.ctrl_handler = &flash->ctrl_handler;
>     873          err = media_entity_pads_init(&flash->sd.entity, 0, NULL);
>     874          if (err) {
>     875                  dev_err(&client->dev, "error initialize a media entity.\n");
>     876                  goto fail2;
>     877          }
>
> regards,
> dan carpenter
>