Ubuntu 22.04 compiles Linux 5.16.5 kernel error: FAILED: load BTF from vmlinux: Invalid argument

background

The built-in kernel version of Ubuntu22.04 is 5.15. Today I wanted to compile a higher version of the 5.16.5 kernel, but unexpectedly an error occurred during compilation:

  CALL    scripts/checksyscalls.sh
  CALL    scripts/atomic/check-atomics.sh
  DESCEND objtool

  DESCEND bpf/resolve_btfids
  CHK     include/generated/compile.h
  CHK     kernel/kheaders_data.tar.xz
  GEN     .version
  CHK     include/generated/compile.h
  UPD     include/generated/compile.h
  CC      init/version.o
  AR      init/built-in.a
  LD      vmlinux.o
  MODPOST vmlinux.symvers
  MODINFO modules.builtin.modinfo
  GEN     modules.builtin
  LD      .tmp_vmlinux.btf
  BTF     .btf.vmlinux.bin.o
  LD      .tmp_vmlinux.kallsyms1
  KSYMS   .tmp_vmlinux.kallsyms1.S
  AS      .tmp_vmlinux.kallsyms1.S
  LD      .tmp_vmlinux.kallsyms2
  KSYMS   .tmp_vmlinux.kallsyms2.S
  AS      .tmp_vmlinux.kallsyms2.S
  LD      vmlinux
  BTFIDS  vmlinux
FAILED: load BTF from vmlinux: Invalid argument
make: *** [Makefile:1161: vmlinux] Error 255
make: *** Deleting file 'vmlinux'

I searched online and said that I need to change CONFIG_DEBUG_INFO_BTF=y in the .config configuration file to CONFIG_DEBUG_INFO_BTF=n. This way the compilation will not report an error. But I want to enable this option [option related to ebpf]. Further search found that it is because the version of the program pahole is too high. The current version is 1.25.

pahole --version
v1.25

Solution

Modify the scripts/pahole-flags.sh script in the kernel source directory and add the following lines of shell code:

if [ "${pahole_ver}" -ge "124" ]; then
       # see PAHOLE_HAS_LANG_EXCLUDE
       extra_paholeopt="${extra_paholeopt} --skip_encoding_btf_enum64"
fi

problem solved.

Reference:
https://lore.kernel.org/bpf/[email protected]/t/
https:/ /bbs.archlinux.org/viewtopic.php?pid=2067555