d396f97648
[ Upstream commit 9bb6362652f3f4d74a87d572a91ee1b38e673ef6 ]
After release of the hashbucket lock the tracking object can be modified or
freed by a concurrent thread. Using it in such a case is error prone, even
for printing the object state:
1. T1 tries to deactivate destroyed object, debugobjects detects it,
hash bucket lock is released.
2. T2 preempts T1 and frees the tracking object.
3. The freed tracking object is allocated and initialized for a
different to be tracked kernel object.
4. T1 resumes and reports error for wrong kernel object.
Create a local copy of the tracking object before releasing the hash bucket
lock and use the local copy for reporting and fixups to prevent this.
Signed-off-by: Andrzej Hajda <andrzej.hajda@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20231025-debugobjects_fix-v3-1-2bc3bf7084c2@intel.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.