After some investigation, I found out that failures caused by "invalid relo for insn[4].code 0x85" are due to a small typo in some headers.
That has caused LLVM to emit relocations (thinking those missing macro calls were external function calls) that are not supported by the loader. This is all in userspace, so no real kernel bugs here. We can include the typo fixup in the bionic tree, though. That led to a new failure, caused by faults when trying to read user memory from the BPF program. I will investigate further. Cascardo. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1888507 Title: [UBUNTU 18.04] BPF programs fail on Ubuntu s390x Status in Ubuntu on IBM z Systems: In Progress Status in linux package in Ubuntu: New Status in linux source package in Bionic: In Progress Bug description: We need to run BPF filters to analyse and monitor network traffic. The BPF filters are created by skydive (http://skydive.network). Currently skydive fails to install BPF filters on s390x (using Ubuntu 18.04 currently, soon moving to Ubuntu 20.04). Because of these failures, we decided to try the BPF samples that come with the kernel first. These samples also fail on s390x while they work fine on Intel. shense@boe-build:~/bionic/samples/bpf$ uname -a Linux boe-build 4.15.0-112-generic #113-Ubuntu SMP Thu Jul 9 23:40:36 UTC 2020 s390x s390x s390x GNU/Linux Example instructions: sudo apt install -y dpkg-dev clang llvm libelf-dev sudo apt-get source linux-image-unsigned-$(uname -r) cd linux-4.15.0/ make headers_install make samples/bpf/ Errors: shense@boe-build:~/bionic/samples/bpf$ sudo ./test_map_in_map [sudo] password for shense: invalid relo for insn[4].code 0x85 bpf_load_program() err=22 0: (bf) r7 = r1 1: (b7) r1 = 0 2: (63) *(u32 *)(r10 -32) = r1 3: (bf) r1 = r7 4: (85) call unknown#-1 BPF_CALL uses reserved fields 0: (bf) r7 = r1 1: (b7) r1 = 0 2: (63) *(u32 *)(r10 -32) = r1 3: (bf) r1 = r7 4: (85) call unknown#-1 BPF_CALL uses reserved fields shense@boe-build:~/bionic/samples/bpf$ sudo ./map_perf_test invalid relo for insn[22].code 0x85 bpf_load_program() err=22 0: (bf) r7 = r1 1: (18) r1 = 0x207265743a25646e 3: (7b) *(u64 *)(r10 -16) = r1 4: (18) r1 = 0x705f616c6c6f632e 6: (7b) *(u64 *)(r10 -24) = r1 7: (18) r1 = 0x5f6c72755f686d61 9: (7b) *(u64 *)(r10 -32) = r1 10: (18) r1 = 0x7420737472657373 12: (7b) *(u64 *)(r10 -40) = r1 13: (18) r1 = 0x4661696c65642061 15: (7b) *(u64 *)(r10 -48) = r1 16: (b7) r1 = 0 17: (73) *(u8 *)(r10 -8) = r1 18: (b7) r2 = 1 19: (7b) *(u64 *)(r10 -72) = r2 20: (63) *(u32 *)(r10 -76) = r1 21: (bf) r1 = r7 22: (85) call unknown#-1 BPF_CALL uses reserved fields 0: (bf) r7 = r1 1: (18) r1 = 0x207265743a25646e 3: (7b) *(u64 *)(r10 -16) = r1 4: (18) r1 = 0x705f616c6c6f632e 6: (7b) *(u64 *)(r10 -24) = r1 7: (18) r1 = 0x5f6c72755f686d61 9: (7b) *(u64 *)(r10 -32) = r1 10: (18) r1 = 0x7420737472657373 12: (7b) *(u64 *)(r10 -40) = r1 13: (18) r1 = 0x4661696c65642061 15: (7b) *(u64 *)(r10 -48) = r1 16: (b7) r1 = 0 17: (73) *(u8 *)(r10 -8) = r1 18: (b7) r2 = 1 19: (7b) *(u64 *)(r10 -72) = r2 20: (63) *(u32 *)(r10 -76) = r1 21: (bf) r1 = r7 22: (85) call unknown#-1 BPF_CALL uses reserved fields To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1888507/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
