On Tue, Sep 14, 2021 at 08:42:04AM -0700, Dan Williams wrote:
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.
I'll drop it, but just to satisfy my curiousity: the description says it
fixes a use-after-free bug in the existing code, is it not the case?
--
Thanks,
Sasha
