qemu-x86_64 fails on A72 cores, but runs nice on A53 ones :)

[guannais]

I have tried to emulate a chroot for x86_64 architecture and it gave me inconsistent results, random successes and fails:

Code:

jinks /disco2/chroot/amd64 # chroot . /bin/bash
qemu: uncaught target signal 11 (Segmentation fault) - core dumped
root@jinks / # exit
exit
jinks /disco2/chroot/amd64 # chroot . /bin/bash
Instrucción ilegal
jinks /disco2/chroot/amd64 # chroot . /bin/bash
qemu: uncaught target signal 11 (Segmentation fault) - core dumped
Violación de segmento
jinks /disco2/chroot/amd64 # chroot . /bin/bash
root@jinks / # ls
Instrucción ilegal
jinks /disco2/chroot/amd64 # bin   dev  home  lib32     media  opt   root  sbin  tmp  var
boot  etc  lib   lib64  mnt    proc  run   sys   usr

jinks /disco2/chroot/amd64 #

Finally I got it to work, by forbidding to run on the last 2 cores:

Code:

jinks /disco2/chroot/amd64 # schedtool -a 0xf -e chroot . /bin/bash
jinks / # ls
bin   dev  home  lib32  media  opt   root  sbin  tmp  var
boot  etc  lib   lib64  mnt    proc  run   sys   usr
jinks / # exit
exit
jinks /disco2/chroot/amd64 #

And it is stable.

A bit more of information:

Code:

# uname -a; qemu-x86_64 --version; gcc --version
Linux jinks 4.4.154 #8 SMP Fri Oct 12 00:42:01 CEST 2018 aarch64 GNU/Linux
qemu-x86_64 version 2.12.1
Copyright (c) 2003-2017 Fabrice Bellard and the QEMU Project developers
gcc (Gentoo 7.3.0-r3 p1.4) 7.3.0
Copyright (C) 2017 Free Software Foundation, Inc. ...