Eric Lee / smarc-fsl-linux-kernel

30 Oct, 2016

1 commit

  • 96a8eb1ee   bpf: fix samples to add fake KBUILD_MODNAME ... Browse Code »

    Some of the sample files are causing issues when they are loaded with tc
    and cls_bpf, meaning tc bails out while trying to parse the resulting ELF
    file as program/map/etc sections are not present, which can be easily
    spotted with readelf(1).

    Currently, BPF samples are including some of the kernel headers and mid
    term we should change them to refrain from this, really. When dynamic
    debugging is enabled, we bail out due to undeclared KBUILD_MODNAME, which
    is easily overlooked in the build as clang spills this along with other
    noisy warnings from various header includes, and llc still generates an
    ELF file with mentioned characteristics. For just playing around with BPF
    examples, this can be a bit of a hurdle to take.

    Just add a fake KBUILD_MODNAME as a band-aid to fix the issue, same is
    done in xdp*_kern samples already.

    Fixes: 65d472fb007d ("samples/bpf: add 'pointer to packet' tests")
    Fixes: 6afb1e28b859 ("samples/bpf: Add tunnel set/get tests.")
    Fixes: a3f74617340b ("cgroup: bpf: Add an example to do cgroup checking in BPF")
    Reported-by: Chandrasekar Kannan
    Signed-off-by: Daniel Borkmann
    Acked-by: Alexei Starovoitov
    Signed-off-by: David S. Miller

    Daniel Borkmann
     

07 May, 2016

1 commit

  • 65d472fb0   samples/bpf: add 'pointer to packet' tests ... Browse Code »

    parse_simple.c - packet parser exapmle with single length check that
    filters out udp packets for port 9

    parse_varlen.c - variable length parser that understand multiple vlan headers,
    ipip, ipip6 and ip options to filter out udp or tcp packets on port 9.
    The packet is parsed layer by layer with multitple length checks.

    parse_ldabs.c - classic style of packet parsing using LD_ABS instruction.
    Same functionality as parse_simple.

    simple = 24.1Mpps per core
    varlen = 22.7Mpps
    ldabs = 21.4Mpps

    Parser with LD_ABS instructions is slower than full direct access parser
    which does more packet accesses and checks.

    These examples demonstrate the choice bpf program authors can make between
    flexibility of the parser vs speed.

    Signed-off-by: Alexei Starovoitov
    Signed-off-by: David S. Miller

    Alexei Starovoitov