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Running the following sequence is currently broken: # tc qdisc add dev foo clsact # tc filter replace dev foo ingress prio 1 handle 1 bpf da obj bar.o # tc filter replace dev foo ingress prio 1 handle 1 bpf da obj bar.o RTNETLINK answers: Invalid argument The normal expectation on kernel side is that the second command succeeds replacing the existing program. However, what happens is in cls_bpf_change(), we bail out with err in the second run in cls_bpf_offload(). The EINVAL comes directly in cls_bpf_offload() when comparing prog vs oldprog's gen_flags. In case of above replace the new prog's gen_flags are 0, but the old ones are 8, which means TCA_CLS_FLAGS_NOT_IN_HW is set (e.g. drivers not having cls_bpf offload). Fix102740bd94("cls_bpf: fix offload assumptions after callback conversion") in the following way: gen_flags from user space passed down via netlink cannot include status flags like TCA_CLS_FLAGS_IN_HW or TCA_CLS_FLAGS_NOT_IN_HW as opposed to oldprog that we previously loaded. Therefore, it doesn't make any sense to include them in the gen_flags comparison with the new prog before we even attempt to offload. Thus, lets fix this before 4.15 goes out. Fixes:102740bd94("cls_bpf: fix offload assumptions after callback conversion") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.