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

Sumit Semwal
2016-07-18T13:04:12Z

Hi Chris,

On 18 July 2016 at 17:40, Daniel Vetter <daniel@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@chris-wilson.co.uk>
>> Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
>> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
>> Cc: Sumit Semwal <sumit.semwal@linaro.org>
>> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
>> Cc: linux-media@vger.kernel.org
>> Cc: dri-devel@lists.freedesktop.org
>> Cc: linaro-mm-sig@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@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