On Fri, Sep 15, 2023 at 10:27 AM Alexei Starovoitov alexei.starovoitov@gmail.com wrote:
On Fri, Sep 15, 2023 at 10:24 AM Nick Desaulniers ndesaulniers@google.com wrote:
On Fri, Sep 15, 2023 at 10:22 AM Alexei Starovoitov alexei.starovoitov@gmail.com wrote:
On Fri, Sep 15, 2023 at 10:18 AM Nathan Chancellor nathan@kernel.org wrote:
On Fri, Sep 15, 2023 at 09:42:20AM -0700, Nick Desaulniers wrote:
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 Tested-by: Marcus Seyfarth m.seyfarth@gmail.com Debugged-by: Nathan Chancellor nathan@kernel.org Co-developed-by: Jiri Olsa jolsa@kernel.org Link: https://lore.kernel.org/bpf/CAEf4Bzb5KQ2_LmhN769ifMeSJaWfebccUasQOfQKaOd0nQ5... Signed-off-by: Nick Desaulniers ndesaulniers@google.com
tools/include/linux/btf_ids.h | 2 +-
Shouldn't this diff be in include/linux/btf_ids.h as well? Otherwise, I don't think it will be used by the kernel build.
D'oh!
argh. Let's do this patch as-is and another patch to update everything in tools/../btf_ids.h, since it got out of sync quite a bit.
I think I can do both in a v3? I don't see the issue (in mainline, are they out of sync in -next?)
Yes. Pls send v3 with two patches. We'll apply and flush bpf trees, so both will have all fixes in a day or so.
And please use [PATCH bpf v3] in subject, so that BPF CI can test it properly.