• Martin KaFai Lau's avatar
    bpf: Prepare btf_ctx_access for non raw_tp use case · 38207291
    Martin KaFai Lau authored
    This patch makes a few changes to btf_ctx_access() to prepare
    it for non raw_tp use case where the attach_btf_id is not
    necessary a BTF_KIND_TYPEDEF.
    
    It moves the "btf_trace_" prefix check and typedef-follow logic to a new
    function "check_attach_btf_id()" which is called only once during
    bpf_check().  btf_ctx_access() only operates on a BTF_KIND_FUNC_PROTO
    type now. That should also be more efficient since it is done only
    one instead of every-time check_ctx_access() is called.
    
    "check_attach_btf_id()" needs to find the func_proto type from
    the attach_btf_id.  It needs to store the result into the
    newly added prog->aux->attach_func_proto.  func_proto
    btf type has no name, so a proper name should be stored into
    "attach_func_name" also.
    
    v2:
    - Move the "btf_trace_" check to an earlier verifier phase (Alexei)
    Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
    Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
    Link: https://lore.kernel.org/bpf/20191025001811.1718491-1-kafai@fb.com
    38207291
bpf_trace.c 40.3 KB