2620e92ae6
Execute the following command and exit, then execute it again, the following error will be reported: $ sudo ./samples/bpf/xdpsock -i ens4f2 -M ^C $ sudo ./samples/bpf/xdpsock -i ens4f2 -M libbpf: elf: skipping unrecognized data section(16) .eh_frame libbpf: elf: skipping relo section(17) .rel.eh_frame for section(16) .eh_frame libbpf: Kernel error message: XDP program already attached ERROR: link set xdp fd failed Commitc9d27c9e8d("samples: bpf: Do not unload prog within xdpsock") removed the unloading prog code because of the presence of bpf_link. This is fine if XDP_SHARED_UMEM is disabled, but if it is enabled, unloading the prog is still needed. Fixes:c9d27c9e8d("samples: bpf: Do not unload prog within xdpsock") Signed-off-by: Wang Hai <wanghai38@huawei.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Cc: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Link: https://lore.kernel.org/bpf/20210628091815.2373487-1-wanghai38@huawei.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.