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authorDaniel Borkmann2018-12-18 01:12:00 +0100
committerDaniel Borkmann2018-12-18 01:12:01 +0100
commit37c7b1caeaf60c8d3bc3cedc9ff4b9cc2f015d7e (patch)
tree0e68981876d990fcdb98e6b1d2e6a6645e52a6ae /tools/lib/bpf/libbpf.c
parentbpf: remove useless version check for prog load (diff)
parenttools: bpftool: support pretty print with kind_flag set (diff)
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Merge branch 'bpf-btf-type-fixes'
Yonghong Song says: ==================== Commit 69b693f0aefa ("bpf: btf: Introduce BPF Type Format (BTF)") introduced BTF, a debug info format for BTF. The original design has a couple of issues though. First, the bitfield size is only encoded in int type. If the struct member bitfield type is enum, pahole ([1]) or llvm is forced to replace enum with int type. As a result, the original type information gets lost. Second, the original BTF design does not envision the possibility of BTF=>header_file conversion ([2]), hence does not encode "struct" or "union" info for a forward type. Such information is necessary to convert BTF to a header file. This patch set fixed the issue by introducing kind_flag, using one bit in type->info. When kind_flag, the struct/union btf_member->offset will encode both bitfield_size and bit_offset, covering both int and enum base types. The kind_flag is also used to indicate whether the forward type is a union (when set) or a struct. Patch #1 refactors function btf_int_bits_seq_show() so Patch #2 can reuse part of the function. Patch #2 implemented kind_flag support for struct/union/fwd types. Patch #3 added kind_flag support for cgroup local storage map pretty print. Patch #4 syncs kernel uapi btf.h to tools directory. Patch #5 added unit tests for kind_flag. Patch #6 added tests for kernel bpffs based pretty print with kind_flag. Patch #7 refactors function btf_dumper_int_bits() so Patch #8 can reuse part of the function. Patch #8 added bpftool support of pretty print with kind_flag set. [1] https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=b18354f64cc215368c3bc0df4a7e5341c55c378c [2] https://lwn.net/SubscriberLink/773198/fe3074838f5c3f26/ Change logs: v2 -> v3: . Relocated comments about bitfield_size/bit_offset interpretation of the "offset" field right before the "offset" struct member. . Added missing byte alignment checking for non-bitfield enum member of a struct with kind_flag set. . Added two test cases in unit tests for struct type, kind_flag set, non-bitfield int/enum member, not-byte aligned bit offsets. . Added comments to help understand there is no overflow for total_bits_offset in bpftool function btf_dumper_int_bits(). . Added explanation of typedef type dumping fix in Patch #8 commit message. v1 -> v2: . If kind_flag is set for a structure, ensure an int member, whether it is a bitfield or not, is a regular int type. . Added support so cgroup local storage map pretty print works with kind_flag. ==================== Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'tools/lib/bpf/libbpf.c')
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