[PATCH] dma-buf: Release module reference on creation failure

[Sumit Semwal]

Hi Chris,

On 18 July 2016 at 17:40, Daniel Vetter <daniel at ffwll.ch> wrote:
> On Mon, Jul 18, 2016 at 12:16:22PM +0100, Chris Wilson wrote:
>> If we fail to create the anon file, we need to remember to release the
>> module reference on the owner.
>>
Thanks for the patch.

>> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
>> Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
>> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
>> Cc: Sumit Semwal <sumit.semwal at linaro.org>
>> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
>> Cc: linux-media at vger.kernel.org
>> Cc: dri-devel at lists.freedesktop.org
>> Cc: linaro-mm-sig at lists.linaro.org
>> ---
>>  drivers/dma-buf/dma-buf.c | 15 +++++++++++----
>>  1 file changed, 11 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
>> index 20ce0687b111..ddaee60ae52a 100644
>> --- a/drivers/dma-buf/dma-buf.c
>> +++ b/drivers/dma-buf/dma-buf.c
>> @@ -334,6 +334,7 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
>>       struct reservation_object *resv = exp_info->resv;
>>       struct file *file;
>>       size_t alloc_size = sizeof(struct dma_buf);
>> +     int ret;
>
> Not sure this really helps readability, but meh. Will apply to drm-misc,
> with a cc: stable.
Daniel, fwiw, please feel free to add
Acked-by: Sumit Semwal <sumit.semwal at linaro.org>

> -Daniel

BR,
~Sumit.
>
>>
>>       if (!exp_info->resv)
>>               alloc_size += sizeof(struct reservation_object);
>> @@ -357,8 +358,8 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
>>
>>       dmabuf = kzalloc(alloc_size, GFP_KERNEL);
>>       if (!dmabuf) {
>> -             module_put(exp_info->owner);
>> -             return ERR_PTR(-ENOMEM);
>> +             ret = -ENOMEM;
>> +             goto err_module;
>>       }
>>
>>       dmabuf->priv = exp_info->priv;
>> @@ -379,8 +380,8 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
>>       file = anon_inode_getfile("dmabuf", &dma_buf_fops, dmabuf,
>>                                       exp_info->flags);
>>       if (IS_ERR(file)) {
>> -             kfree(dmabuf);
>> -             return ERR_CAST(file);
>> +             ret = PTR_ERR(file);
>> +             goto err_dmabuf;
>>       }
>>
>>       file->f_mode |= FMODE_LSEEK;
>> @@ -394,6 +395,12 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
>>       mutex_unlock(&db_list.lock);
>>
>>       return dmabuf;
>> +
>> +err_dmabuf:
>> +     kfree(dmabuf);
>> +err_module:
>> +     module_put(exp_info->owner);
>> +     return ERR_PTR(ret);
>>  }
>>  EXPORT_SYMBOL_GPL(dma_buf_export);
>>
>> --
>> 2.8.1
>>
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch



-- 
Thanks and regards,

Sumit Semwal
Linaro Mobile Group - Kernel Team Lead
Linaro.org │ Open source software for ARM SoCs