On 19.08.19 12:32, Laurent Vivier wrote: > Le 17/08/2019 à 18:51, David Hildenbrand a écrit : >> On 17.08.19 18:22, Laurent Vivier wrote: >>> Le 17/08/2019 à 18:14, David Hildenbrand a écrit : >>>> On 17.08.19 17:59, David Hildenbrand wrote: >>>>> Hi everybody, >>>>> >>>>> I was just trying to run qemu-s390x (linux-user) with a very simple >>>>> binary (gzip + lib/ld64.so.1, compiled under Fedora 27). This used to >>>>> work just fine a while ago (especially when I was working on vector >>>>> instructions using QEMU v3.1). However, now I can't get past a SEGFAULT >>>>> in the dynamic library loader (I assume it is trying to locate glibc). I >>>>> tried a couple of other binaries that definitely used to work (from >>>>> Fedora 30). >>>>> >>>>> I checked QEMU v4.1, v4.0 and v3.1. All are broken for me. Which is >>>>> weird - because it used to work :/ >>>>> >>>>> I remember that I was running Fedora 29 the last time I had it running, >>>>> so my gut feeling is that this is related to some other system library >>>>> (but which?). I am running on an up-to-date Fedora 30 x86-64 now. >>>>> >>>>> Any ideas? Has this been reported already? (not sure if this is a Fedora >>>>> 30 issue) >>>>> >>>>> LANG=C ~/git/qemu/s390x-linux-user/qemu-s390x -d in_asm -L . gzip --help >>>>> >>>>> ---------------- >>>>> IN: _dl_load_cache_lookup >>>>> 0x00000040008854c2: larl %r1,0x4000895030 >>>>> 0x00000040008854c8: lg %r8,264(%r11) >>>>> 0x00000040008854ce: mvghi 0(%r1),-1 >>>>> 0x00000040008854d4: la %r3,0(%r3,%r8) >>>>> 0x00000040008854d8: l %r7,12(%r8) >>>>> 0x00000040008854dc: llgfr %r2,%r7 >>>>> 0x00000040008854e0: sllg %r1,%r2,1 >>>>> 0x00000040008854e6: agr %r1,%r2 >>>>> 0x00000040008854ea: sllg %r1,%r1,2 >>>>> 0x00000040008854f0: la %r6,16(%r1,%r8) >>>>> 0x00000040008854f4: sgr %r3,%r6 >>>>> 0x00000040008854f8: stg %r3,256(%r11) >>>>> 0x00000040008854fe: ahi %r7,-1 >>>>> 0x0000004000885502: jl 0x40008850f0 >>>>> >>>>> ---------------- >>>>> IN: _dl_load_cache_lookup >>>>> 0x0000004000885506: srak %r10,%r7,1 >>>>> 0x000000400088550c: lgfr %r2,%r10 >>>>> 0x0000004000885510: sllg %r1,%r2,1 >>>>> 0x0000004000885516: agr %r1,%r2 >>>>> 0x000000400088551a: sllg %r1,%r1,2 >>>>> 0x0000004000885520: l %r1,20(%r1,%r8) >>>>> 0x0000004000885524: clrjhe %r1,%r3,0x40008850f0 >>>>> >>>>> Segmentation fault (Speicherabzug geschrieben) >>>>> >>>>> >>>>> Core was generated by >>>>> `/home/dhildenb/git/qemu/s390x-linux-user/qemu-s390x -d in_asm -L . gzip >>>>> --help'. >>>>> Program terminated with signal SIGSEGV, Segmentation fault. >>>>> #0 0x00007fdc5d7c3232 in sigsuspend () from /lib64/libc.so.6 >>>>> [Current thread is 1 (Thread 0x7fdc5d7127c0 (LWP 31072))] >>>>> Missing separate debuginfos, use: dnf debuginfo-install >>>>> glib2-2.60.6-1.fc30.x86_64 glibc-2.29-15.fc30.x86_64 >>>>> libgcc-9.1.1-1.fc30.x86_64 libstdc++-9.1.1-1.fc30.x86_64 >>>>> pcre-8.43-2.fc30.x86_64 zlib-1.2.11-16.fc30.x86_64 >>>>> (gdb) bt >>>>> #0 0x00007fdc5d7c3232 in sigsuspend () from /lib64/libc.so.6 >>>>> #1 0x000055f826135a9c in dump_core_and_abort >>>>> (target_sig=target_sig@entry=11) >>>>> at /home/dhildenb/git/qemu/linux-user/signal.c:613 >>>>> #2 0x000055f826135e37 in handle_pending_signal >>>>> (cpu_env=cpu_env@entry=0x55f8292cec48, sig=sig@entry=11, >>>>> k=k@entry=0x55f8292d7df0) at >>>>> /home/dhildenb/git/qemu/linux-user/signal.c:877 >>>>> #3 0x000055f826136edd in process_pending_signals >>>>> (cpu_env=cpu_env@entry=0x55f8292cec48) >>>>> at /home/dhildenb/git/qemu/linux-user/signal.c:953 >>>>> #4 0x000055f82613a13a in cpu_loop (env=0x55f8292cec48) at >>>>> /home/dhildenb/git/qemu/linux-user/s390x/cpu_loop.c:150 >>>>> #5 0x000055f8260ce2ba in main (argc=<optimized out>, >>>>> argv=0x7fff587a69d8, envp=<optimized out>) >>>>> at /home/dhildenb/git/qemu/linux-user/main.c:819 >>>>> >>>>> Thanks! >>>>> >>>> >>>> CCing QEMU-devel + use my proper dev mail address (I need more coffee :)) >>>> >>> >>> I generally test qemu-s390x before my PR. Last time, I have tested with >>> Fedora 30 x86_64 but my target are always debian. >> >> What puzzles me is that it used to work just fine about 3-4 months ago. >> I still have the binaries/libs lying around that I used back then (when >> debugging a vector instruction-related issue). Whatever binary/QEMU >> version I try now, it keeps segfaulting. >> >> Via qemu-system-s390x, inside a Fedora guest, the binaries work >> perfectly fine. So I really suspect that this has to do with my host system. >> >>> >>> So I guess the problem is with the target. >>> >>> I will have a look on Monday. >> > > I'm not able to reproduce it. In a chroot or using "-L" with only > /bin/gzip, /lib64/ld64.so.1 and /lib/libc.so.6 in the directory. > > My host is Fedora 30 (updated today) and the target directory is Fedora > 30 too (from > https://download-ib01.fedoraproject.org/pub/fedora-secondary/releases/30/Container/s390x/images/Fedora-Container-Minimal-Base-30-1.2.s390x.tar.xz) > > Do you have more details?
Thanks for having a look! I just tried with the Fedora 30 target files they seem to work just fine indeed (chroot and -L after manually copying the two lib files). Now, I took the same files from RHEL8 (everything is built with z13/vector instruction support enforced under RHEL8). (I copied them from a running guest using scp) - rhel-guest-image-8.0-1854.s390x.qcow2. Trying to run them results in the reported issue. ~/git/qemu/s390x-linux-user/qemu-s390x -L . gzip Segmentation fault (Speicherabzug geschrieben) I can spot one main difference: /lib64/libc-2.28.so: ELF 64-bit MSB shared object, IBM S/390, version 1 (GNU/Linux), dynamically linked, interpreter /lib/ld64.so.1, BuildID[sha1]=f2ed86061df0bad28270244424e58eb95f60c00c, for GNU/Linux 3.2.0, not stripped, too many notes (256) /lib64/ld-2.28.so: ELF 64-bit MSB shared object, IBM S/390, version 1 (SYSV), dynamically linked, BuildID[sha1]=6a58fd6ea86ec36455655ff718509ee4320cefc2, not stripped, too many notes (256) The libraries are not completely stripped. But even when stripping, I get the same issue when trying to load them. The binaries/libraries work perfectly fine within qemu-system-s390x. -- Thanks, David / dhildenb
