Re: [Qemu-devel] [qemu-s390x] linux-user: s390x issue on Fedora 30 (dynamic library loader?)

[Laurent Vivier]

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.

So I guess the problem is with the target.

I will have a look on Monday.

Thanks,
Laurent