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

[David Hildenbrand]

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!