From 4fb56e82d939eb949bfa6b142cf54b394b7514a6 Mon Sep 17 00:00:00 2001 From: Nick Desaulniers Date: Fri, 15 Sep 2023 10:34:28 -0700 Subject: [PATCH] bpf: Fix BTF_ID symbol generation collision in tools/ commit c0bb9fb0e52a64601d38b3739b729d9138d4c8a1 upstream. 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 :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 Reported-by: Marcus Seyfarth Closes: https://github.com/ClangBuiltLinux/linux/issues/1913 Debugged-by: Nathan Chancellor Co-developed-by: Jiri Olsa Link: https://lore.kernel.org/bpf/CAEf4Bzb5KQ2_LmhN769ifMeSJaWfebccUasQOfQKaOd0nQ51tw@mail.gmail.com/ Signed-off-by: Nick Desaulniers Link: https://lore.kernel.org/r/20230915-bpf_collision-v3-2-263fc519c21f@google.com Signed-off-by: Alexei Starovoitov Signed-off-by: Greg Kroah-Hartman --- tools/include/linux/btf_ids.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/include/linux/btf_ids.h b/tools/include/linux/btf_ids.h index 71e54b1..2f882d5 100644 --- a/tools/include/linux/btf_ids.h +++ b/tools/include/linux/btf_ids.h @@ -38,7 +38,7 @@ asm( \ ____BTF_ID(symbol) #define __ID(prefix) \ - __PASTE(prefix, __COUNTER__) + __PASTE(__PASTE(prefix, __COUNTER__), __LINE__) /* * The BTF_ID defines unique symbol for each ID pointing -- 2.7.4