Hi, This set adds a new command BPF_BTF_GET_NEXT_ID to the bpf() system call, adds the relevant API function in libbpf, and uses it in bpftool to list all BTF objects loaded on the system (and to dump the ids of maps and programs associated with them, if any). The main motivation of listing BTF objects is introspection and debugging purposes. By getting BPF program and map information, it should already be possible to list all BTF objects associated to at least one map or one program. But there may be unattached BTF objects, held by a file descriptor from a user space process only, and we may want to list them too. As a side note, it also turned useful for examining the BTF objects attached to offloaded programs, which would not show in program information because the BTF id is not copied when retrieving such info. A fix is in progress on that side. Quentin Monnet (5): bpf: add new BPF_BTF_GET_NEXT_ID syscall command tools: bpf: synchronise BPF UAPI header with tools libbpf: refactor bpf_*_get_next_id() functions libbpf: add bpf_btf_get_next_id() to cycle through BTF objects tools: bpftool: implement "bpftool btf show|list" include/linux/bpf.h | 3 + include/uapi/linux/bpf.h | 1 + kernel/bpf/btf.c | 4 +- kernel/bpf/syscall.c | 4 + .../bpf/bpftool/Documentation/bpftool-btf.rst | 7 + tools/bpf/bpftool/bash-completion/bpftool | 20 +- tools/bpf/bpftool/btf.c | 342 +++++++++++++++++- tools/include/uapi/linux/bpf.h | 1 + tools/lib/bpf/Makefile | 2 +- tools/lib/bpf/bpf.c | 24 +- tools/lib/bpf/bpf.h | 1 + tools/lib/bpf/libbpf.map | 5 + 12 files changed, 393 insertions(+), 21 deletions(-) -- 2.17.1
