This folder contains examples for eunomia-bpf.
Tools are expected to follow a simple naming convention:
- .bpf.c contains BPF C code, which gets compiled into
package.json - .h can optionally contain types exported to userspace through pref event or ring buffer
- .bpf.h can optionally contain any types and constants, shared by both BPF and userspace sides of a tool.
libbpf probes to see if your sys fs exports the file /sys/kernel/btf/vmlinux (from Kernel 5.5+) or if you have the ELF version in your system code
Please note the ELF file could exist without the BTF info in it. Your Kconfig should contain the options below
- Compile options
CONFIG_DEBUG_INFO_BTF=y
CONFIG_DEBUG_INFO=y
- Also, make sure that you have pahole 1.13 (or preferably 1.16+) during the kernel build (it comes from dwarves package). Without it, BTF won't be generated, and on older kernels you'd get only warning, but still would build kernel successfully
It's possible to run some tools in kernels that don't expose
/sys/kernel/btf/vmlinux. For those cases,
BTFGen
and BTFHub can be used to
generate small BTF files for the most popular Linux distributions that
are shipped with the tools in order to provide the needed information to
perform the CO-RE relocations when loading the eBPF programs.
Most codes come from:
- libbpf-tools: https://github.com/iovisor/bcc/tree/master/libbpf-tools
- libbpf-bootstrap: https://github.com/libbpf/libbpf-bootstrap/tree/master/examples/c