From 46fb0b62ea29c0dbcb3e44f1d67aafe79bc6e045 Mon Sep 17 00:00:00 2001 From: Alan Maguire Date: Thu, 20 Jun 2024 10:17:32 +0100 Subject: kbuild,bpf: Add module-specific pahole flags for distilled base BTF Support creation of module BTF along with distilled base BTF; the latter is stored in a .BTF.base ELF section and supplements split BTF references to base BTF with information about base types, allowing for later relocation of split BTF with a (possibly changed) base. resolve_btfids detects the presence of a .BTF.base section and will use it instead of the base BTF it is passed in BTF id resolution. Modules will be built with a distilled .BTF.base section for external module build, i.e. make -C. -M=path2/module ...while in-tree module build as part of a normal kernel build will not generate distilled base BTF; this is because in-tree modules change with the kernel and do not require BTF relocation for the running vmlinux. Signed-off-by: Alan Maguire Signed-off-by: Andrii Nakryiko Reviewed-by: Eduard Zingerman Link: https://lore.kernel.org/bpf/20240620091733.1967885-6-alan.maguire@oracle.com --- scripts/Makefile.modfinal | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'scripts/Makefile.modfinal') diff --git a/scripts/Makefile.modfinal b/scripts/Makefile.modfinal index 3bec9043e4f3..1fa98b5e952b 100644 --- a/scripts/Makefile.modfinal +++ b/scripts/Makefile.modfinal @@ -41,7 +41,7 @@ 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 $@; \ + LLVM_OBJCOPY="$(OBJCOPY)" $(PAHOLE) -J $(PAHOLE_FLAGS) $(MODULE_PAHOLE_FLAGS) --btf_base vmlinux $@; \ $(RESOLVE_BTFIDS) -b vmlinux $@; \ fi; -- cgit v1.2.3