Fwd: [perf] Build error when using LTO on 6.4

[Bagas Sanjaya]

Hi,

I notice a build regression on Bugzilla [1]. Quoting from it:

> Starting with Kernel 6.4, I see a build error when using "-flto" to build perf. This used to work fine with earlier Kernels when using either bfd or mold as linker when using GCC 13.1.1.
> 
> This is the PKGBUILD I use as my build recipe: https://github.com/ms178/archpkgbuilds/blob/main/packages/bpf/PKGBUILD
> 
> This is the konsole output I get now with Kernel 6.4.5:
> 
> [CODE]
> CFLAGS='-Wno-error=bad-function-cast -Wno-error=declaration-after-statement -Wno-error=switch-enum -Wbad-function-cast -Wdeclaration-after-statement -Wformat-security -Wformat-y2k -Winit-self -Wmissing-declarations -Wmissing-prototypes -Wno-system-headers -Wold-style-definition -Wpacked -Wredundant-decls -Wstrict-prototypes -Wswitch-default -Wswitch-enum -Wundef -Wwrite-strings -Wformat -Wno-type-limits -Wstrict-aliasing=3 -Wshadow -DHAVE_SYSCALL_TABLE_SUPPORT -DHAVE_ARCH_X86_64_SUPPORT -Iarch/x86/include/generated -DHAVE_PERF_REGS_SUPPORT -DHAVE_ARCH_REGS_QUERY_REGISTER_OFFSET -Werror -DNDEBUG=1 -O6 -fno-omit-frame-pointer -ggdb3 -funwind-tables -Wall -Wextra -std=gnu11 -fstack-protector-all -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE -I/tmp/makepkg/linux-tools/src/linux/tools/perf/util/include -I/tmp/makepkg/linux-tools/src/linux/tools/perf/arch/x86/include -I/tmp/makepkg/linux-tools/src/linux/tools/include/ -I/tmp/makepkg/linux-tools/src/linux/tools/arch/x86/include/uapi -I/tmp/makepkg/linux-tools/src/linux/tools/include/uapi -I/tmp/makepkg/linux-tools/src/linux/tools/arch/x86/include/ -I/tmp/makepkg/linux-tools/src/linux/tools/arch/x86/ -I/tmp/makepkg/linux-tools/src/linux/tools/perf/util -I/tmp/makepkg/linux-tools/src/linux/tools/perf -DHAVE_PTHREAD_ATTR_SETAFFINITY_NP -DHAVE_PTHREAD_BARRIER -DHAVE_EVENTFD_SUPPORT -DHAVE_GET_CURRENT_DIR_NAME -DHAVE_GETTID -DHAVE_FILE_HANDLE -DHAVE_DWARF_GETLOCATIONS_SUPPORT -DHAVE_AIO_SUPPORT -DHAVE_SCANDIRAT_SUPPORT -DHAVE_SCHED_GETCPU_SUPPORT -DHAVE_SETNS_SUPPORT -DHAVE_LIBELF_SUPPORT -DHAVE_ELF_GETPHDRNUM_SUPPORT -DHAVE_GELF_GETNOTE_SUPPORT -DHAVE_ELF_GETSHDRSTRNDX_SUPPORT -DHAVE_DEBUGINFOD_SUPPORT -DHAVE_DWARF_SUPPORT  -DHAVE_LIBBPF_SUPPORT -DHAVE_BPF_PROLOGUE -DHAVE_JITDUMP -DHAVE_DWARF_UNWIND_SUPPORT -DNO_LIBUNWIND_DEBUG_FRAME -DHAVE_LIBUNWIND_SUPPORT -DHAVE_LIBCRYPTO_SUPPORT -DHAVE_SLANG_SUPPORT -DNO_LIBPERL -DHAVE_TIMERFD_SUPPORT -DHAVE_LIBPYTHON_SUPPORT -DHAVE_CXA_DEMANGLE_SUPPORT -DHAVE_ZLIB_SUPPORT -DHAVE_LZMA_SUPPORT -DHAVE_ZSTD_SUPPORT -DHAVE_LIBCAP_SUPPORT -DHAVE_BACKTRACE_SUPPORT -DHAVE_LIBNUMA_SUPPORT -DHAVE_KVM_STAT_SUPPORT -DDISASM_FOUR_ARGS_SIGNATURE -DDISASM_INIT_STYLED -DHAVE_PERF_READ_VDSO32 -DHAVE_AUXTRACE_SUPPORT -DHAVE_LIBTRACEEVENT -DLIBTRACEEVENT_VERSION=66813 -I/tmp/makepkg/linux-tools/src/linux/tools/perf/libapi/include -I/tmp/makepkg/linux-tools/src/linux/tools/perf/libbpf/include -I/tmp/makepkg/linux-tools/src/linux/tools/perf/libsubcmd/include -I/tmp/makepkg/linux-tools/src/linux/tools/perf/libsymbol/include -I/tmp/makepkg/linux-tools/src/linux/tools/perf/libperf/include' LDFLAGS='-Wl,-O3,--as-needed,-Bsymbolic-functions,--sort-common,-flto=auto -fopenmp -fuse-ld=mold -march=native -mtune=native -maes -mbmi2 -mpclmul -Wl,-zmax-page-size=0x200000 -Wl,-z,noexecstack  -lunwind-x86_64 -lunwind -llzma  -L/usr/lib ' \
>   '/usr/bin/python' util/setup.py \
>   --quiet build_ext; \
> cp python_ext_build/lib/perf*.so python/
> rm -f -f /tmp/makepkg/linux-tools/src/linux/tools/perf/libbpf/libbpf.a; ar rcs /tmp/makepkg/linux-tools/src/linux/tools/perf/libbpf/libbpf.a /tmp/makepkg/linux-tools/src/linux/tools/perf/libbpf/staticobjs/libbpf-in.o
> [snip]
> gcc -Wno-error=bad-function-cast -Wno-error=declaration-after-statement -Wno-error=switch-enum -Wbad-function-cast -Wdeclaration-after-statement -Wformat-security -Wformat-y2k -Winit-self -Wmissing-declarations -Wmissing-prototypes -Wno-system-headers -Wold-style-definition -Wpacked -Wredundant-decls -Wstrict-prototypes -Wswitch-default -Wswitch-enum -Wundef -Wwrite-strings -Wformat -Wno-type-limits -Wstrict-aliasing=3 -Wshadow -DHAVE_SYSCALL_TABLE_SUPPORT -DHAVE_ARCH_X86_64_SUPPORT -Iarch/x86/include/generated -DHAVE_PERF_REGS_SUPPORT -DHAVE_ARCH_REGS_QUERY_REGISTER_OFFSET -Werror -DNDEBUG=1 -O6 -fno-omit-frame-pointer -ggdb3 -funwind-tables -Wall -Wextra -std=gnu11 -fstack-protector-all -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE -I/tmp/makepkg/linux-tools/src/linux/tools/perf/util/include -I/tmp/makepkg/linux-tools/src/linux/tools/perf/arch/x86/include -I/tmp/makepkg/linux-tools/src/linux/tools/include/ -I/tmp/makepkg/linux-tools/src/linux/tools/arch/x86/include/uapi -I/tmp/makepkg/linux-tools/src/linux/tools/include/uapi -I/tmp/makepkg/linux-tools/src/linux/tools/arch/x86/include/ -I/tmp/makepkg/linux-tools/src/linux/tools/arch/x86/ -I/tmp/makepkg/linux-tools/src/linux/tools/perf/util -I/tmp/makepkg/linux-tools/src/linux/tools/perf -DHAVE_PTHREAD_ATTR_SETAFFINITY_NP -DHAVE_PTHREAD_BARRIER -DHAVE_EVENTFD_SUPPORT -DHAVE_GET_CURRENT_DIR_NAME -DHAVE_GETTID -DHAVE_FILE_HANDLE -DHAVE_DWARF_GETLOCATIONS_SUPPORT -DHAVE_AIO_SUPPORT -DHAVE_SCANDIRAT_SUPPORT -DHAVE_SCHED_GETCPU_SUPPORT -DHAVE_SETNS_SUPPORT -DHAVE_LIBELF_SUPPORT -DHAVE_ELF_GETPHDRNUM_SUPPORT -DHAVE_GELF_GETNOTE_SUPPORT -DHAVE_ELF_GETSHDRSTRNDX_SUPPORT -DHAVE_DEBUGINFOD_SUPPORT -DHAVE_DWARF_SUPPORT  -DHAVE_LIBBPF_SUPPORT -DHAVE_BPF_PROLOGUE -DHAVE_JITDUMP -DHAVE_DWARF_UNWIND_SUPPORT -DNO_LIBUNWIND_DEBUG_FRAME -DHAVE_LIBUNWIND_SUPPORT -DHAVE_LIBCRYPTO_SUPPORT -DHAVE_SLANG_SUPPORT -DNO_LIBPERL -DHAVE_TIMERFD_SUPPORT -DHAVE_LIBPYTHON_SUPPORT -DHAVE_CXA_DEMANGLE_SUPPORT -DHAVE_ZLIB_SUPPORT -DHAVE_LZMA_SUPPORT -DHAVE_ZSTD_SUPPORT -DHAVE_LIBCAP_SUPPORT -DHAVE_BACKTRACE_SUPPORT -DHAVE_LIBNUMA_SUPPORT -DHAVE_KVM_STAT_SUPPORT -DDISASM_FOUR_ARGS_SIGNATURE -DDISASM_INIT_STYLED -DHAVE_PERF_READ_VDSO32 -DHAVE_AUXTRACE_SUPPORT -DHAVE_LIBTRACEEVENT -DLIBTRACEEVENT_VERSION=66813 -I/tmp/makepkg/linux-tools/src/linux/tools/perf/libapi/include -I/tmp/makepkg/linux-tools/src/linux/tools/perf/libbpf/include -I/tmp/makepkg/linux-tools/src/linux/tools/perf/libsubcmd/include -I/tmp/makepkg/linux-tools/src/linux/tools/perf/libsymbol/include -I/tmp/makepkg/linux-tools/src/linux/tools/perf/libperf/include -Wl,-O3,--as-needed,-Bsymbolic-functions,--sort-common,-flto=auto -fopenmp -fuse-ld=mold -march=native -mtune=native -maes -mbmi2 -mpclmul -Wl,-zmax-page-size=0x200000 -Wl,-z,noexecstack  -lunwind-x86_64 -lunwind -llzma  -L/usr/lib  \
>         perf-in.o pmu-events/pmu-events-in.o -Wl,--whole-archive /tmp/makepkg/linux-tools/src/linux/tools/perf/libapi/libapi.a /tmp/makepkg/linux-tools/src/linux/tools/perf/libperf/libperf.a /tmp/makepkg/linux-tools/src/linux/tools/perf/libsubcmd/libsubcmd.a /tmp/makepkg/linux-tools/src/linux/tools/perf/libsymbol/libsymbol.a /tmp/makepkg/linux-tools/src/linux/tools/perf/libbpf/libbpf.a  -Wl,--no-whole-archive -Wl,--start-group -lpthread -lrt -lm -ldl -lelf -ldebuginfod -ldw -lunwind-x86_64 -lunwind -llzma -lcrypto -lslang -lpython3.11 -ldl -lm -lutil -lstdc++ -lz -llzma -lzstd -lcap -lnuma -ltraceevent -Wl,--end-group -o perf
> mold: error: undefined symbol: main
>>>> referenced by /usr/lib/Scrt1.o:(.text)
>>>>               /usr/lib/Scrt1.o:(_start)
> mold: error: undefined symbol: perf_pmu__getcpuid
>>>> referenced by pmu-events.c
>>>>               pmu-events/pmu-events-in.o:(perf_pmu__find_events_table)>>>
>>>>               referenced by pmu-events.c
>>>>               pmu-events/pmu-events-in.o:(perf_pmu__find_metrics_table)
> mold: error: undefined symbol: strcmp_cpuid_str
>>>> referenced by pmu-events.c
>>>>               pmu-events/pmu-events-in.o:(perf_pmu__find_events_table)>>>
>>>>               referenced by pmu-events.c
>>>>               pmu-events/pmu-events-in.o:(perf_pmu__find_metrics_table)>>>
>>>>               referenced by pmu-events.c
>>>>               pmu-events/pmu-events-in.o:(find_core_events_table)>>>
>>>>               referenced 1 more times
> 
> mold: error: undefined symbol: _ctype
>>>> referenced by kallsyms.c
>>>>              
>>>>               /tmp/makepkg/linux-tools/src/linux/tools/perf/libsymbol/libsymbol.a(libsymbol-in.o):(__tolower)>>>
>>>>               referenced by kallsyms.c
>>>>              
>>>>               /tmp/makepkg/linux-tools/src/linux/tools/perf/libsymbol/libsymbol.a(libsymbol-in.o):(__toupper)
> mold: error: undefined symbol: strlcpy
>>>> referenced by exec-cmd.c
>>>>              
>>>>               /tmp/makepkg/linux-tools/src/linux/tools/perf/libsubcmd/libsubcmd.a(libsubcmd-in.o):(get_pwd_cwd)
> [/CODE]
> 
> I have noticed a patch series of Ian Rodgers that might adress this issue, but his reported errors were different to mine, see: https://www.spinics.net/lists/kernel/msg4872566.html
> 
> Compiler: gcc-version 13.1.1 20230714 (GCC)

See Bugzilla for the full thread.

Anyway, I'm adding this regression to regzbot:

#regzbot introduced: v6.3..v6.4.5 https://bugzilla.kernel.org/show_bug.cgi?id=217706

Thanks.

[1]: https://bugzilla.kernel.org/show_bug.cgi?id=217706

-- 
An old man doll... just what I always wanted! - Clara