From: Jiri Olsa jolsa@kernel.org
Marcus and Satya reported an issue where BTF_ID macro generates same symbol in separate objects and that breaks final vmlinux link.
ld.lld: error: ld-temp.o <inline asm>:14577:1: symbol '__BTF_ID__struct__cgroup__624' is already defined
This can be triggered under specific configs when __COUNTER__ happens to be the same for the same symbol in two different translation units, which is already quite unlikely to happen.
Add __LINE__ number suffix to make BTF_ID symbol more unique, which is not a complete fix, but it would help for now and meanwhile we can work on better solution as suggested by Andrii.
Cc: stable@vger.kernel.org Reported-by: Satya Durga Srinivasu Prabhala quic_satyap@quicinc.com Reported-by: Marcus Seyfarth m.seyfarth@gmail.com Closes: https://github.com/ClangBuiltLinux/linux/issues/1913 Debugged-by: Nathan Chancellor nathan@kernel.org Link: https://lore.kernel.org/bpf/CAEf4Bzb5KQ2_LmhN769ifMeSJaWfebccUasQOfQKaOd0nQ5... Signed-off-by: Jiri Olsa jolsa@kernel.org Signed-off-by: Nick Desaulniers ndesaulniers@google.com --- include/linux/btf_ids.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/btf_ids.h b/include/linux/btf_ids.h index a3462a9b8e18..a9cb10b0e2e9 100644 --- a/include/linux/btf_ids.h +++ b/include/linux/btf_ids.h @@ -49,7 +49,7 @@ word \ ____BTF_ID(symbol, word)
#define __ID(prefix) \ - __PASTE(prefix, __COUNTER__) + __PASTE(__PASTE(prefix, __COUNTER__), __LINE__)
/* * The BTF_ID defines unique symbol for each ID pointing