By having a BTF_BASE variable defaulting to using vmlinux as base BTF, we allow module builders to build standalone BTF such that it is generated independently and not de-duplicated with core vmlinux BTF. This allows such modules to be more resilient to changes in vmlinux BTF if they occur, as would happen if a change resulted in a different vmlinux BTF id mapping. Opt-out of split BTF is done via make BTF_BASE= M=path/2/module Signed-off-by: Alan Maguire <alan.maguire@xxxxxxxxxx> --- scripts/Makefile.btf | 3 +++ scripts/Makefile.modfinal | 4 ++-- 2 files changed, 5 insertions(+), 2 deletions(-) diff --git a/scripts/Makefile.btf b/scripts/Makefile.btf index f8ce33d7f9bb..352271a10fb5 100644 --- a/scripts/Makefile.btf +++ b/scripts/Makefile.btf @@ -19,3 +19,6 @@ pahole-flags-$(call test-ge, $(pahole-ver), 125) += --skip_encoding_btf_inconsis pahole-flags-$(call test-ge, $(pahole-ver), 126) = -j --lang_exclude=rust --btf_features=encode_force,var,float,decl_tag,type_tag,enum64,optimized_func,consistent_func,crc,kind_layout export PAHOLE_FLAGS := $(pahole-flags-y) + +# Allow opt-out of split BTF by overriding BTF_BASE +export BTF_BASE := --btf_base vmlinux diff --git a/scripts/Makefile.modfinal b/scripts/Makefile.modfinal index 8568d256d6fb..3400d1a72127 100644 --- a/scripts/Makefile.modfinal +++ b/scripts/Makefile.modfinal @@ -39,8 +39,8 @@ quiet_cmd_btf_ko = BTF [M] $@ if [ ! -f vmlinux ]; then \ printf "Skipping BTF generation for %s due to unavailability of vmlinux\n" $@ 1>&2; \ else \ - LLVM_OBJCOPY="$(OBJCOPY)" $(PAHOLE) -J $(PAHOLE_FLAGS) --btf_base vmlinux $@; \ - $(RESOLVE_BTFIDS) -b vmlinux $@; \ + LLVM_OBJCOPY="$(OBJCOPY)" $(PAHOLE) -J $(PAHOLE_FLAGS) $(BTF_BASE) $@; \ + $(RESOLVE_BTFIDS) $(BTF_BASE) $@; \ fi; # Same as newer-prereqs, but allows to exclude specified extra dependencies -- 2.31.1
