This patch series fixes unwanted stripping of kernel kfuncs during linker optimization, as indicated by build warnings from resolve_btfids e.g. "WARN: resolve_btfids: unresolved symbol ...". This can happen because the __bpf_kfunc macro annotating kfunc declarations is ignored during linking. Patch 1 adds support for the compiler attribute "__retain__", used to avoid linker garbage cleanup. Patch 2 then updates __bpf_kfunc to use this attribute when LTO builds are enabled. Tony Ambardar (2): Compiler Attributes: Add __retain macro bpf: Harden __bpf_kfunc tag against linker kfunc removal include/linux/btf.h | 2 +- include/linux/compiler_attributes.h | 14 ++++++++++++++ 2 files changed, 15 insertions(+), 1 deletion(-) -- 2.34.1
