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Use synchronize_rcu to wait until the XSK wakeup function finishes before destroying the resources it uses: 1. ixgbe_down already calls synchronize_rcu after setting __IXGBE_DOWN. 2. After switching the XDP program, call synchronize_rcu to let ixgbe_xsk_wakeup exit before the XDP program is freed. 3. Changing the number of channels brings the interface down. 4. Disabling UMEM sets __IXGBE_TX_DISABLED before closing hardware resources and resetting xsk_umem. Check that bit in ixgbe_xsk_wakeup to avoid using the XDP ring when it's already destroyed. synchronize_rcu is called from ixgbe_txrx_ring_disable. Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com> Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191217162023.16011-5-maximmi@mellanox.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.