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  • Daniel Borkmann's avatar
    net: filter: get rid of BPF_S_* enum · 34805931
    Daniel Borkmann authored
    This patch finally allows us to get rid of the BPF_S_* enum.
    Currently, the code performs unnecessary encode and decode
    workarounds in seccomp and filter migration itself when a filter
    is being attached in order to overcome BPF_S_* encoding which
    is not used anymore by the new interpreter resp. JIT compilers.
    Keeping it around would mean that also in future we would need
    to extend and maintain this enum and related encoders/decoders.
    We can get rid of all that and save us these operations during
    filter attaching. Naturally, also JIT compilers need to be updated
    by this.
    Before JIT conversion is being done, each compiler checks if A
    is being loaded at startup to obtain information if it needs to
    emit instructions to clear A first. Since BPF extensions are a
    subset of BPF_LD | BPF_{W,H,B} | BPF_ABS variants, case statements
    for extensions can be removed at that point. To ease and minimalize
    code changes in the classic JITs, we have introduced bpf_anc_helper().
    Tested with test_bpf on x86_64 (JIT, int), s390x (JIT, int),
    arm (JIT, int), i368 (int), ppc64 (JIT, int); for sparc we
    unfortunately didn't have access, but changes are analogous to
    the rest.
    Joint work with Alexei Starovoitov.
    Signed-off-by: default avatarDaniel Borkmann <>
    Signed-off-by: default avatarAlexei Starovoitov <>
    Cc: Benjamin Herrenschmidt <>
    Cc: Martin Schwidefsky <>
    Cc: Mircea Gherzan <>
    Cc: Kees Cook <>
    Acked-by: default avatarChema Gonzalez <>
    Signed-off-by: default avatarDavid S. Miller <>