Messages in this thread | | | Date | Tue, 14 Sep 2021 13:01:17 -0400 | From | Sasha Levin <> | Subject | Re: [PATCH AUTOSEL 5.14 04/25] cxl/pci: Introduce cdevm_file_operations |
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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@kernel.org> wrote: >> >> From: Dan Williams <dan.j.williams@intel.com> >> >> [ 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
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