Issue with libxdp and LLVM 16?
simosund opened this issue · 4 comments
simosund commented
Hi,
Recently when I tried to build the project on a testbed (or pping specifically) I ran into an issue where libxdp failed to compile (with clang/llc 16), see below.
$ ./configure
clang: 16.0.0 (++20221208053009+4f7e5d22060e-1~exp1~20221208173118.471)
libmnl support: yes
libbpf support: submodule
ELF support: yes
zlib support: yes
libxdp support: submodule
Configuring libxdp to use our libbpf submodule
Found clang binary 'clang' with version 16 (from 'Ubuntu clang version 16.0.0 (++20221208053009+4f7e5d22060e-1~exp1~20221208173118.471)')
libbpf support: custom v1.0.0
perf_buffer__consume support: yes
btf__load_from_kernel_by_id support: yes
btf__type_cnt support: yes
bpf_object__next_map support: yes
bpf_object__next_program support: yes
bpf_program__insn_cnt support: yes
bpf_map_create support: yes
perf_buffer__new_raw support: yes
bpf_xdp_attach support: yes
zlib support: yes
ELF support: yes
pcap support: yes
secure_getenv support: yes
$ cd pping/
$ make
libbpf
CC install/lib/libbpf.a
INSTALL install/lib/libbpf.a
libxdp
CC install/lib/libxdp.a
xdp-dispatcher.ll:10:40: warning: ptr type is only supported in -opaque-pointers mode
@dispatcher_version = dso_local global ptr null, section "xdp_metadata", align 8, !dbg !21
^
llc: error: llc: xdp-dispatcher.ll:10:40: error: expected type
@dispatcher_version = dso_local global ptr null, section "xdp_metadata", align 8, !dbg !21
^
make[4]: *** [Makefile:140: xdp-dispatcher.o] Error 1
make[3]: *** [Makefile:20: libxdp] Error 2
make[2]: *** [Makefile:28: libxdp] Error 2
make[1]: *** [Makefile:68: install/lib/libxdp.a] Error 2
make: *** [../lib/common.mk:66: ../lib/install/lib/libxdp.a] Error 2
This issue did not occur if I compiled libxdp with clang-14 instead (clang-15 was not installed on the testbed at the time). Have no really spent much time trying to figure this out yet, but thought I would report it while I still remembered.
zzxgzgz commented
Looks like we are having the same issue:
➜ bpf-examples git:(master) ✗ sudo ./configure
clang: 15.0.6
libmnl support: yes
libbpf support: submodule
ELF support: yes
zlib support: yes
libxdp support: submodule
Configuring libxdp to use our libbpf submodule
Found clang binary 'clang' with version 15 (from 'Ubuntu clang version 15.0.6')
libbpf support: custom v1.0.0
perf_buffer__consume support: yes
btf__load_from_kernel_by_id support: yes
btf__type_cnt support: yes
bpf_object__next_map support: yes
bpf_object__next_program support: yes
bpf_program__insn_cnt support: yes
bpf_map_create support: yes
perf_buffer__new_raw support: yes
bpf_xdp_attach support: yes
zlib support: yes
ELF support: yes
pcap support: yes
secure_getenv support: yes
➜ bpf-examples git:(master) ✗ sudo make
lib
libxdp
CC install/lib/libxdp.a
llc: xdp-dispatcher.ll:10:40: error: expected type
@dispatcher_version = dso_local global ptr null, section "xdp_metadata", align 8, !dbg !21
^
make[4]: *** [xdp-dispatcher.o] Error 1
make[3]: *** [libxdp] Error 2
make[2]: *** [libxdp] Error 2
Makefile:67: recipe for target 'install/lib/libxdp.a' failed
make[1]: *** [install/lib/libxdp.a] Error 2
Makefile:34: recipe for target 'lib' failed
make: *** [lib] Error 2
tohojo commented
This usually happens if there's a version mismatch between clang and
llc; can you please check config.mk and see which binaries the configure script
picked up for each?
zzxgzgz commented
This usually happens if there's a version mismatch between clang and llc; can you please check config.mk and see which binaries the configure script picked up for each?
I think you're right, there's a mistach between the clang version and the llvm version:
➜ bpf-examples git:(master) ✗ which llc
/usr/bin/llc
➜ bpf-examples git:(master) ✗ llc --version
LLVM (http://llvm.org/):
LLVM version 6.0.0
Optimized build.
Default target: x86_64-pc-linux-gnu
Host CPU: skylake-avx512
Registered Targets:
aarch64 - AArch64 (little endian)
aarch64_be - AArch64 (big endian)
amdgcn - AMD GCN GPUs
arm - ARM
arm64 - ARM64 (little endian)
armeb - ARM (big endian)
bpf - BPF (host endian)
bpfeb - BPF (big endian)
bpfel - BPF (little endian)
hexagon - Hexagon
lanai - Lanai
mips - Mips
mips64 - Mips64 [experimental]
mips64el - Mips64el [experimental]
mipsel - Mipsel
msp430 - MSP430 [experimental]
nvptx - NVIDIA PTX 32-bit
nvptx64 - NVIDIA PTX 64-bit
ppc32 - PowerPC 32
ppc64 - PowerPC 64
ppc64le - PowerPC 64 LE
r600 - AMD GPUs HD2XXX-HD6XXX
sparc - Sparc
sparcel - Sparc LE
sparcv9 - Sparc V9
systemz - SystemZ
thumb - Thumb
thumbeb - Thumb (big endian)
x86 - 32-bit X86: Pentium-Pro and above
x86-64 - 64-bit X86: EM64T and AMD64
xcore - XCore
➜ bpf-examples git:(master) ✗ which clang
/usr/bin/clang
➜ bpf-examples git:(master) ✗ clang --version
Ubuntu clang version 15.0.6
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
I upgraded my Linux to 20.04, and re-installed clang and llvm, and I'm now able to configure/make the project.
Thank you @tohojo !