2024-01-30 23:05 UTC+0000 ~ Bryce Kahle <git@xxxxxxxxxxxxxx> > From: Bryce Kahle <bryce.kahle@xxxxxxxxxxxxx> > > Enables a user to generate minimized kernel module BTF. > > If an eBPF program probes a function within a kernel module or uses > types that come from a kernel module, split BTF is required. The split > module BTF contains only the BTF types that are unique to the module. > It will reference the base/vmlinux BTF types and always starts its type > IDs at X+1 where X is the largest type ID in the base BTF. > > Minimization allows a user to ship only the types necessary to do > relocations for the program(s) in the provided eBPF object file(s). A > minimized module BTF will still not contain vmlinux BTF types, so you > should always minimize the vmlinux file first, and then minimize the > kernel module file. > > Example: > > bpftool gen min_core_btf vmlinux.btf vm-min.btf prog.bpf.o > bpftool -B vm-min.btf gen min_core_btf mod.btf mod-min.btf prog.bpf.o > > v3->v4: > - address style nit about start_id initialization > - rename base to src_base_btf (base_btf is a global var) > - copy src_base_btf so new BTF is not modifying original vmlinux BTF > > Signed-off-by: Bryce Kahle <bryce.kahle@xxxxxxxxxxxxx> Looks good, thank you! Reviewed-by: Quentin Monnet <quentin@xxxxxxxxxxxxx>
