[PATCH v2] ARM: imx: fix error handling

walter harms
2014-05-16T11:49:10Z

Am 16.05.2014 13:16, schrieb Emil Goode:
> Hello Walter,
>
> On Fri, May 16, 2014 at 12:40:19PM +0200, walter harms wrote:
>>
>>
>> Am 16.05.2014 11:54, schrieb Emil Goode:
>>> If we fail to allocate struct platform_device pdev we
>>> dereference it after the goto label err.
>>>
>>> I have rearranged the error handling a bit to fix the issue
>>> and also make it more clear.
>>>
>>> Signed-off-by: Emil Goode <emilgoode@gmail.com>
>>> ---
>>> v2: Changed to return -ENOMEM instead of ret where possible and
>>> updated the subject line.
>>>
>>> arch/arm/mach-imx/devices/platform-ipu-core.c | 22 +++++++++++++---------
>>> 1 file changed, 13 insertions(+), 9 deletions(-)
>>>
>>> diff --git a/arch/arm/mach-imx/devices/platform-ipu-core.c b/arch/arm/mach-imx/devices/platform-ipu-core.c
>>> index fc4dd7c..68f2a4a 100644
>>> --- a/arch/arm/mach-imx/devices/platform-ipu-core.c
>>> +++ b/arch/arm/mach-imx/devices/platform-ipu-core.c
>>> @@ -77,34 +77,38 @@ struct platform_device *__init imx_alloc_mx3_camera(
>>>
>>> pdev = platform_device_alloc("mx3-camera", 0);
>>> if (!pdev)
>>> - goto err;
>>> + return ERR_PTR(-ENOMEM);
>>>
>>> pdev->dev.dma_mask = kmalloc(sizeof(*pdev->dev.dma_mask), GFP_KERNEL);
>>> if (!pdev->dev.dma_mask)
>>> - goto err;
>>> + goto put_pdev;
>>>
>>> *pdev->dev.dma_mask = DMA_BIT_MASK(32);
>>> pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
>>>
>>> ret = platform_device_add_resources(pdev, res, ARRAY_SIZE(res));
>>> if (ret)
>>> - goto err;
>>> + goto free_dma_mask;
>>>
>>> if (pdata) {
>>> struct mx3_camera_pdata *copied_pdata;
>>>
>>> ret = platform_device_add_data(pdev, pdata, sizeof(*pdata));
>>> - if (ret) {
>>> -err:
>>> - kfree(pdev->dev.dma_mask);
>>> - platform_device_put(pdev);
>>> - return ERR_PTR(-ENODEV);
>>> - }
>>> + if (ret)
>>> + goto free_dma_mask;
>>> +
>>> copied_pdata = dev_get_platdata(&pdev->dev);
>>> copied_pdata->dma_dev = &imx_ipu_coredev->dev;
>>
>>
>> the patch is fine, but what use is this copied_pdata ?
>> It scope ends next line ?
>>
>> re,
>> wh
>
> I also thought that looked a bit odd, but copied_pdata is a temporary
> pointer to platform_data of the dev struct.
>
> dev_get_platdata looks like this:
>
> static inline void *dev_get_platdata(const struct device *dev)
> {
> return dev->platform_data;
> }
>
> So I believe it's a more compact way of writing:
>
> pdev->dev->platform_data->dma_dev = &imx_ipu_coredev->dev;

ok i see ...

Both ways are horrible to read, but the second is at least
understandable. fortunately i am not the maintainer.

thx,

re,
wh

> Best regards,
>
> Emil Goode
>
>>
>>> }
>>>
>>> return pdev;
>>> +
>>> +free_dma_mask:
>>> + kfree(pdev->dev.dma_mask);
>>> +put_pdev:
>>> + platform_device_put(pdev);
>>> +
>>> + return ERR_PTR(ret);
>>> }
>>>
>>> struct platform_device *__init imx_add_mx3_sdc_fb(
>