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0579fafd37
iavf_virtchnl_completion is called under crit_lock but when
the code for VIRTCHNL_OP_GET_OFFLOAD_VLAN_V2_CAPS is called,
this lock is released in order to obtain rtnl_lock to avoid
ABBA deadlock with unregister_netdev.
Along with the new way iavf_remove behaves, there exist
many risks related to the lock release and attmepts to regrab
it. The driver faces crashes related to races between
unregister_netdev and netdev_update_features. Yet another
risk is that the driver could already obtain the crit_lock
in order to destroy it and iavf_virtchnl_completion could
crash or block forever.
Make iavf_virtchnl_completion never relock crit_lock in it's
call paths.
Extract rtnl_lock locking logic to the driver for
unregister_netdev in order to set the netdev_registered flag
inside the lock.
Introduce a new flag that will inform adminq_task to perform
the code from VIRTCHNL_OP_GET_OFFLOAD_VLAN_V2_CAPS right after
it finishes processing messages. Guard this code with remove
flags so it's never called when the driver is in remove state.
Fixes: 5951a2b981 ("iavf: Fix VLAN feature flags after VFR")
Signed-off-by: Slawomir Laba <slawomirx.laba@intel.com>
Signed-off-by: Phani Burra <phani.r.burra@intel.com>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Mateusz Palczewski <mateusz.palczewski@intel.com>
Tested-by: Konrad Jankowski <konrad0.jankowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.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.