From: Greg KH <gregkh@linuxfoundation.org>
To: Zhang Zekun <zhangzekun11@huawei.com>
Cc: dan.j.williams@intel.com, linux-kernel@vger.kernel.org,
rafael.j.wysocki@intel.com, regressions@lists.linux.dev,
tj@kernel.org, alex.williamson@redhat.com, chenjun102@huawei.com
Subject: Re: Possible hungtask issue will be introduced with device_lock() in uevent_show()
Date: Tue, 31 Dec 2024 09:26:49 +0100 [thread overview]
Message-ID: <2024123128-monetize-outtakes-3260@gregkh> (raw)
In-Reply-To: <20241231075608.84009-1-zhangzekun11@huawei.com>
On Tue, Dec 31, 2024 at 03:56:08PM +0800, Zhang Zekun wrote:
> Hi, Dan, Greg,
>
> We have found a potential tungtask issue has been introduce by commit 9a71892cbcdb ("Revert "driver core: Fix uevent_show() vs driver detach race""), which revert the rcu in device_uevent but reintroduce the device_lock() in uevent_show(). The reproduce procedure is quite simple:
The revert just puts the original logic back in place, so this is not
anything new that has been introduced, right? It's just that the
attempted fix didn't work, so a different fix needs to happen.
If you could help debug the original fix, that would be most appreciated
as none of us here are arguing that there isn't a bug present, only that
the fix caused different problems which required it to be reverted.
thanks,
greg k-h
next prev parent reply other threads:[~2024-12-31 8:27 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-02 21:54 [PATCH v2] driver core: Fix userspace expectations of uevent_show() as a probe barrier Dan Williams
2024-10-07 9:39 ` kernel test robot
2024-10-08 0:26 ` Dan Williams
2024-10-13 15:00 ` Greg KH
2024-10-28 9:08 ` Thorsten Leemhuis
2024-10-28 22:57 ` Dan Williams
2024-10-29 0:21 ` Greg KH
2024-12-31 7:56 ` Possible hungtask issue will be introduced with device_lock() in uevent_show() Zhang Zekun
2024-12-31 8:26 ` Greg KH [this message]
2025-01-04 6:02 ` zhangzekun (A)
2025-01-04 8:14 ` Greg KH
2025-01-23 2:07 ` Dan Williams
2025-01-27 3:27 ` zhangzekun (A)
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