Re: [PATCH AUTOSEL 5.14 04/25] cxl/pci: Introduce cdevm_file_operations

[Dan Williams]

On Mon, Sep 13, 2021 at 3:33 PM Sasha Levin <sashal@xxxxxxxxxx> wrote:
>
> From: Dan Williams <dan.j.williams@xxxxxxxxx>
>
> [ Upstream commit 9cc238c7a526dba9ee8c210fa2828886fc65db66 ]
>
> In preparation for moving cxl_memdev allocation to the core, introduce
> cdevm_file_operations to coordinate file operations shutdown relative to
> driver data release.
>
> The motivation for moving cxl_memdev allocation to the core (beyond
> better file organization of sysfs attributes in core/ and drivers in
> cxl/), is that device lifetime is longer than module lifetime. The cxl_pci
> module should be free to come and go without needing to coordinate with
> devices that need the text associated with cxl_memdev_release() to stay
> resident. The move will fix a use after free bug when looping driver
> load / unload with CONFIG_DEBUG_KOBJECT_RELEASE=y.
>
> Another motivation for passing in file_operations to the core cxl_memdev
> creation flow is to allow for alternate drivers, like unit test code, to
> define their own ioctl backends.

Hi Sasha,

Please drop this. It's not a fix, it's just a reorganization for
easing the addition of new features and capabilities.