https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106773
--- Comment #8 from David Faust <david.faust at oracle dot com> --- (In reply to James Hilliard from comment #5) > (In reply to David Faust from comment #4) > > Created attachment 53993 [details] > > proposed patch > > > > Should fix the remaining issues with 'extern' linkage and the missing > > 'const' modifier (and includes the earlier partial fixes in this bug) > > Fixes the reported test failure but some others(unclear if related to this > bug) are still failing such as tailcall_bpf2bpf3.c: Thanks for testing and confirming. > $ /home/buildroot/bpf-next/tools/testing/selftests/bpf/tools/sbin/bpftool > --debug gen object > /home/buildroot/bpf-next/tools/testing/selftests/bpf/bpf_gcc/ > tailcall_bpf2bpf3.bpf.linked1.o > /home/buildroot/bpf-next/tools/testing/selftests/bpf/bpf_gcc/ > tailcall_bpf2bpf3.bpf.o > libbpf: linker: adding object file > '/home/buildroot/bpf-next/tools/testing/selftests/bpf/bpf_gcc/ > tailcall_bpf2bpf3.bpf.o'... > libbpf: failed to find BTF info for global/extern symbol 'llvm.bpf.load.word' > Error: failed to link > https://github.com/torvalds/linux/blob/v6.1-rc7/tools/testing/selftests/bpf/bpf_legacy.h unsigned long long load_word(void *skb, unsigned long long off) asm("llvm.bpf.load.word"); Looks like LLVM-specific inline asm to use their llvm.bpf.load.word intrinsic. GCC has equivalent __builtin_load_{byte,half,word} target builtins. > There's also this error during skeleton generation for kfunc_call_test.c: > ... > libbpf: failed to find BTF for extern 'bpf_kfunc_call_test2': -22 Hm, looks like we are OK for extern variables but are mis-generating something (or missing something) for extern funcs still. Will look into this.
