binutils: add support for dumping BTF info
Adds an --btf option to objdump for displaying BTF section contents in a text format compatible with bpftool.
This patch introduces the --btf[=SECTION] option to objdump, enabling it to display the contents of a specified BTF section. The output format is designed to be compatible with the Linux kernel’s bpftool utility. This enhancement allows developers to inspect BTF debug information directly using objdump.
- maintainer
LGTMs the patch, reiterating the previous comment about BTF's relation to BPF.
“This patch also LGTM. Same remark than about the other email: Assuming that BTF falls within the BPF realm (which I think it is a fair assumption, but please wait for a day or so in case some global maintainer has some objection) this patch is OK. Thanks!”
- proposer
Submits a patch to add an objdump option for dumping BTF section contents.
“This patch adds a new command line option --btf[=SECTION] to objdump to dump a textual representation of the BTF data stored in section SECTION. If no section name is given, then the default of .BTF is used. The textual representation is the same as used by the Linux kernel bpftool utility.”
Technical Tradeoffs
- Adds new functionality to objdump, increasing its complexity.
In Details
This change adds a new command-line option to objdump for parsing and displaying the contents of BTF (BPF Type Format) sections. BTF is a metadata format used by eBPF and increasingly by the kernel, often residing in a .BTF section. This patch enables objdump to decode this section and present it in a human-readable text format, aligning with the output of the bpftool utility for consistency.
- objdump
- A common utility in binutils for displaying information from object files, including disassembly.
- BTF
- BPF Type Format, a compact debugging data format used for eBPF programs and increasingly in the Linux kernel and userspace.
- bpftool
- A Linux utility used to interact with eBPF programs and related kernel features, capable of dumping BTF information.
- section
- A part of an object file or executable that contains specific types of data, such as code (.text), initialized data (.data), or debugging information (.BTF, .debug_info).