We can race where we have added work to the work_list, but vhost_task_fn has passed that check but not yet set us into TASK_INTERRUPTIBLE. wake_up_process will see us in TASK_RUNNING and just return. This bug was intoduced in commit f9010dbdce91 ("fork, vhost: Use CLONE_THREAD to fix freezer/ps regression") when I moved the setting of TASK_INTERRUPTIBLE to simplfy the code and avoid get_signal from logging warnings about being in the wrong state. This moves the setting of TASK_INTERRUPTIBLE back to before we test if we need to stop the task to avoid a possible race there as well. We then have vhost_worker set TASK_RUNNING if it finds work similar to before. Fixes: f9010dbdce91 ("fork, vhost: Use CLONE_THREAD to fix freezer/ps regression") Signed-off-by: Mike Christie <michael.christie@oracle.com> Message-Id: <20230607192338.6041-3-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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.
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