This series changes resolve_btfids and kernel build scripts to enable
BTF transformations in resolve_btfids. Main motivation for enhancing
resolve_btfids is to reduce dependency of the kernel build on pahole
capabilities [1] and enable BTF features and optimizations [2][3]
particular to the kernel.
Patches #1-#3 in the series are non-functional refactoring in
resolve_btfids.
Patch #4 changes minimum version of pahole required for
CONFIG_DEBUG_INFO_BTF to v1.22
Patch #5 makes a small prep change in selftests/bpf build.
The last patch (#6) makes significant changes in resolve_btfids and
introduces scripts/gen-btf.sh. See implementation details in the patch
description.
Successful CI run: https://github.com/kernel-patches/bpf/actions/runs/19976024062?pr=10438
[1] https://lore.kernel.org/dwarves/ba1650aa-fafd-49a8-bea4-bdddee7c38c9@linux.dev/
[2] https://lore.kernel.org/bpf/20251029190113.3323406-1-ihor.solodrai@linux.dev/
[3] https://lore.kernel.org/bpf/20251119031531.1817099-1-dolinux.peng@gmail.com/
---
v2->v3:
- add patch #4 bumping minimum pahole version (Andrii, Alan)
- add patch #5 pre-fixing resolve_btfids test (Donglin)
- add GEN_BTF var and assemble RESOLVE_BTFIDS_FLAGS in Makefile.btf (Alan)
- implement --distill_base flag in resolve_btfids, set it depending
on KBUILD_EXTMOD in Makefile.btf (Eduard)
- various implementation nits, see the v2 thread for details (Andrii, Eduard)
v2: https://lore.kernel.org/bpf/20251127185242.3954132-1-ihor.solodrai@linux.dev/
v1->v2:
- gen-btf.sh and other shell script fixes (Donglin)
- update selftests build (Donglin)
- generate .BTF.base only when KBUILD_EXTMOD is set (Alan)
- proper endianness handling for cross-compilation
- change elf_begin mode from ELF_C_RDWR_MMAP to ELF_C_READ_MMAP_PRIVATE
- remove compressed_section_fix()
- nit NULL check in patch #3 (suggested by AI)
v1: https://lore.kernel.org/bpf/20251126012656.3546071-1-ihor.solodrai@linux.dev/
Ihor Solodrai (6):
resolve_btfids: Rename object btf field to btf_path
resolve_btfids: Factor out load_btf()
resolve_btfids: Introduce enum btf_id_kind
lib/Kconfig.debug: Set the minimum required pahole version to v1.22
selftests/bpf: Run resolve_btfids only for relevant .test.o objects
resolve_btfids: change in-place update with raw binary output
MAINTAINERS | 1 +
lib/Kconfig.debug | 13 +-
scripts/Makefile.btf | 26 +-
scripts/Makefile.modfinal | 5 +-
scripts/Makefile.vmlinux | 2 +-
scripts/gen-btf.sh | 157 ++++++++
scripts/link-vmlinux.sh | 46 +--
tools/bpf/resolve_btfids/main.c | 355 ++++++++++++------
tools/sched_ext/README.md | 1 -
tools/testing/selftests/bpf/.gitignore | 3 +
tools/testing/selftests/bpf/Makefile | 11 +-
.../selftests/bpf/prog_tests/resolve_btfids.c | 4 +-
12 files changed, 434 insertions(+), 190 deletions(-)
create mode 100755 scripts/gen-btf.sh
--
2.52.0