From: Sasha Levin <sashal@kernel.org>
To: Dan Williams <dan.j.williams@intel.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
stable <stable@vger.kernel.org>,
Ben Widawsky <ben.widawsky@intel.com>,
Jonathan Cameron <Jonathan.Cameron@huawei.com>,
linux-cxl@vger.kernel.org
Subject: Re: [PATCH AUTOSEL 5.14 04/25] cxl/pci: Introduce cdevm_file_operations
Date: Tue, 14 Sep 2021 13:01:17 -0400 [thread overview]
Message-ID: <YUDVXV8egoZP05SF@sashalap> (raw)
In-Reply-To: <CAPcyv4i5OHv2wHTO1Pdjz+qzAAWEha-7HdDdt42VyO_FasLSEA@mail.gmail.com>
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
next prev parent reply other threads:[~2021-09-14 17:01 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20210913223339.435347-1-sashal@kernel.org>
2021-09-13 22:33 ` [PATCH AUTOSEL 5.14 03/25] cxl: Move cxl_core to new directory Sasha Levin
2021-09-14 8:56 ` Jonathan Cameron
2021-09-14 8:57 ` Jonathan Cameron
2021-09-14 15:05 ` Ben Widawsky
2021-09-14 15:40 ` Dan Williams
2021-09-14 17:00 ` Sasha Levin
2021-09-13 22:33 ` [PATCH AUTOSEL 5.14 04/25] cxl/pci: Introduce cdevm_file_operations Sasha Levin
2021-09-14 15:42 ` Dan Williams
2021-09-14 17:01 ` Sasha Levin [this message]
2021-09-14 17:46 ` Dan Williams
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