Re: memremap: change devm_memremap_pages interface to use struct dev_pagemap

[Dan Williams]

On Sat, Jun 30, 2018 at 2:11 PM, Colin Ian King
<colin.king@xxxxxxxxxxxxx> wrote:
> Hi,
>
> static analysis with CoverityScan detected an issue with the following
> commit:
>
> commit e8d5134833006a46fcbefc5f4a84d0b62bd520e7
> Author: Christoph Hellwig <hch@xxxxxx>
> Date:   Fri Dec 29 08:54:05 2017 +0100
>
>     memremap: change devm_memremap_pages interface to use struct dev_pagemap
>
>
> 247        }
> 248
>    CID 1464431 (#1 of 1): Unchecked return value (CHECKED_RETURN)
> check_return: Calling devm_add_action without checking return value (as
> is done elsewhere 33 out of 35 times).
>
> 249        devm_add_action(dev, devm_memremap_pages_release, pgmap);
> 250
> 251        return __va(res->start);
>
> devm_add_action can fail and return -ENOMEM because it calls
> devres_alloc which can fail in an out of memory situation. So I believe
> it may be pertinent to add a -ENOMEM check and clean up appropriately.
> I'm not sure of the correct way to perform the error clean up, so I'm
> sending this report instead of a fix.

Thanks for this. We have a fix pending here looking to go through Andrew's tree.

    https://patchwork.kernel.org/patch/10473317/