On 10/24/19 9:04 AM, Ilya Leoshkevich wrote: >> Am 23.10.2019 um 03:35 schrieb Prabhakar Kushwaha <prabhakar.pkin@xxxxxxxxx>: >> >> >> Adding other mailing list, folks... >> >> Hi All, >> >> I am trying to build kselftest on Linux-5.4 on ubuntu 18.04. I installed >> LLVM-9.0.0 and Clang-9.0.0 from below links after following steps from >> [1] because of discussion [2] >> >> https://urldefense.proofpoint.com/v2/url?u=https-3A__releases.llvm.org_9.0.0_llvm-2D9.0.0.src.tar.xz&d=DwIFAg&c=5VD0RTtNlTh3ycd41b3MUw&r=DA8e1B5r073vIqRrFz7MRA&m=se8pV6OlDAeF2g5iEAvSB2qhLBJGPaHADv3NQVNFx6U&s=IzBxNhAvcILfAD_XcSB7t0s6-B-wFY3TBoVGH6WhRK8&e= >> https://urldefense.proofpoint.com/v2/url?u=https-3A__releases.llvm.org_9.0.0_clang-2Dtools-2Dextra-2D9.0.0.src.tar.xz&d=DwIFAg&c=5VD0RTtNlTh3ycd41b3MUw&r=DA8e1B5r073vIqRrFz7MRA&m=se8pV6OlDAeF2g5iEAvSB2qhLBJGPaHADv3NQVNFx6U&s=KkjCjWm_q2iMfFh50rTKtFqQEMbRBVhT9Oh8KMfgwW4&e= >> https://urldefense.proofpoint.com/v2/url?u=https-3A__releases.llvm.org_9.0.0_cfe-2D9.0.0.src.tar.xz&d=DwIFAg&c=5VD0RTtNlTh3ycd41b3MUw&r=DA8e1B5r073vIqRrFz7MRA&m=se8pV6OlDAeF2g5iEAvSB2qhLBJGPaHADv3NQVNFx6U&s=TvkN9sb5rSB5BNxJP27UmCsfNHsRQdaVeAnBa1TkyjM&e= >> >> Now, i am trying with llc -march=bpf, with this segmentation fault is >> coming as below: >> >> gcc -g -Wall -O2 -I../../../include/uapi -I../../../lib >> -I../../../lib/bpf -I../../../../include/generated -DHAVE_GENHDR >> -I../../../include -Dbpf_prog_load=bpf_prog_test_load >> -Dbpf_load_program=bpf_test_load_program test_flow_dissector.c >> /usr/src/tovards/linux/tools/testing/selftests/bpf/test_stub.o >> /usr/src/tovards/linux/tools/testing/selftests/bpf/libbpf.a -lcap -lelf >> -lrt -lpthread -o >> /usr/src/tovards/linux/tools/testing/selftests/bpf/test_flow_dissector >> gcc -g -Wall -O2 -I../../../include/uapi -I../../../lib >> -I../../../lib/bpf -I../../../../include/generated -DHAVE_GENHDR >> -I../../../include -Dbpf_prog_load=bpf_prog_test_load >> -Dbpf_load_program=bpf_test_load_program >> test_tcp_check_syncookie_user.c >> /usr/src/tovards/linux/tools/testing/selftests/bpf/test_stub.o >> /usr/src/tovards/linux/tools/testing/selftests/bpf/libbpf.a -lcap -lelf >> -lrt -lpthread -o >> /usr/src/tovards/linux/tools/testing/selftests/bpf/test_tcp_check_syncookie_user >> gcc -g -Wall -O2 -I../../../include/uapi -I../../../lib >> -I../../../lib/bpf -I../../../../include/generated -DHAVE_GENHDR >> -I../../../include -Dbpf_prog_load=bpf_prog_test_load >> -Dbpf_load_program=bpf_test_load_program test_lirc_mode2_user.c >> /usr/src/tovards/linux/tools/testing/selftests/bpf/test_stub.o >> /usr/src/tovards/linux/tools/testing/selftests/bpf/libbpf.a -lcap -lelf >> -lrt -lpthread -o >> /usr/src/tovards/linux/tools/testing/selftests/bpf/test_lirc_mode2_user >> (clang -I. -I./include/uapi -I../../../include/uapi >> -I/usr/src/tovards/linux/tools/testing/selftests/bpf/../usr/include >> -D__TARGET_ARCH_arm64 -g -idirafter /usr/local/include -idirafter >> /usr/local/lib/clang/9.0.0/include -idirafter >> /usr/include/aarch64-linux-gnu -idirafter /usr/include >> -Wno-compare-distinct-pointer-types -O2 -target bpf -emit-llvm \ >> -c progs/test_core_reloc_arrays.c -o - || echo "clang failed") | \ >> llc -march=bpf -mcpu=probe -filetype=obj -o >> /usr/src/tovards/linux/tools/testing/selftests/bpf/test_core_reloc_arrays.o >> Stack dump: >> 0. Program arguments: llc -march=bpf -mcpu=probe -filetype=obj -o >> /usr/src/tovards/linux/tools/testing/selftests/bpf/test_core_reloc_arrays.o >> 1. Running pass 'Function Pass Manager' on module '<stdin>'. >> 2. Running pass 'BPF Assembly Printer' on function '@test_core_arrays' >> #0 0x0000aaaac618db08 llvm::sys::PrintStackTrace(llvm::raw_ostream&) >> (/usr/local/bin/llc+0x152eb08) >> Segmentation fault > > Hi, > > FWIW I can confirm that this is happening on s390 too with llvm-project > commit 950b800c451f. > > Here is the reduced sample that triggers this (with -march=bpf > -mattr=+alu32): > > struct b { > int e; > } c; > int f() { > return __builtin_preserve_field_info(c.e, 0); > } > > This is compiled into: > > 0B bb.0 (%ir-block.0): > 16B %0:gpr = LD_imm64 @"b:0:0$0:0" > 32B $w0 = COPY %0:gpr, debug-location !17; 1-E.c:5:3 > 48B RET implicit killed $w0, debug-location !17; 1-E.c:5:3 > > and then BPFInstrInfo::copyPhysReg chokes on COPY, since $w0 and %0 are > in different register classes. Ilya, Thanks for reporting. I can reproduce the issue with latest trunk. I will investigate and fix the problem soon. Yonghong > > I'm currently bisecting, and also checking whether supporting asymmetric > copies (like X86 does in CopyToFromAsymmetricReg) would resolve that. > > Best regards, > Ilya >
