Hello, sorry for delayed response, I've managed to collect and analyze a
few coredump files with valid symbols (I installed libc6-dbg and
dpkg-dev, and pointed gdb at Debian's debuginfod server, also used
apt-get source to get the sources for libc6).
It seems there are at least 3-4 distinct places it crashes at, two
places at memchr-avx2.S, one at strlen-avx2.S, and potentially one at
syscall-template.S, although that last one may be just some kind of kill
signal redirect.
Pasting all below:
Core was generated by `apt'.
Program terminated with signal SIGILL, Illegal instruction.
#0 __memchr_avx2 () at ../sysdeps/x86_64/multiarch/memchr-avx2.S:400
Download failed: Invalid argument. Continuing without source file
./string/../sysdeps/x86_64/multiarch/memchr-avx2.S.
400 ../sysdeps/x86_64/multiarch/memchr-avx2.S: No such file or
directory.
(gdb)
#######
Core was generated by `dpkg'.
Program terminated with signal SIGILL, Illegal instruction.
#0 __strlen_avx2 () at ../sysdeps/x86_64/multiarch/strlen-avx2.S:514
Download failed: Invalid argument. Continuing without source file
./string/../sysdeps/x86_64/multiarch/strlen-avx2.S.
514 ../sysdeps/x86_64/multiarch/strlen-avx2.S: No such file or
directory.
(gdb)
#######
Core was generated by `/usr/bin/perl /usr/sbin/adduser'.
Program terminated with signal SIGILL, Illegal instruction.
#0 __memchr_avx2 () at ../sysdeps/x86_64/multiarch/memchr-avx2.S:135
Download failed: Invalid argument. Continuing without source file
./string/../sysdeps/x86_64/multiarch/memchr-avx2.S.
135 ../sysdeps/x86_64/multiarch/memchr-avx2.S: No such file or
directory.
(gdb)
#######
Core was generated by `useradd'.
Program terminated with signal SIGILL, Illegal instruction.
#0 __memchr_avx2 () at ../sysdeps/x86_64/multiarch/memchr-avx2.S:135
Download failed: Invalid argument. Continuing without source file
./string/../sysdeps/x86_64/multiarch/memchr-avx2.S.
135 ../sysdeps/x86_64/multiarch/memchr-avx2.S: No such file or
directory.
(gdb)
#######
Core was generated by `passwd'.
Program terminated with signal SIGILL, Illegal instruction.
#0 __strlen_avx2 () at ../sysdeps/x86_64/multiarch/strlen-avx2.S:514
Download failed: Invalid argument. Continuing without source file
./string/../sysdeps/x86_64/multiarch/strlen-avx2.S.
514 ../sysdeps/x86_64/multiarch/strlen-avx2.S: No such file or
directory.
(gdb)
#######
Core was generated by `bash'.
Program terminated with signal SIGILL, Illegal instruction.
#0 0x00007f2006faf087 in kill () at ../sysdeps/unix/syscall-template.S:120
Download failed: Invalid argument. Continuing without source file
./signal/../sysdeps/unix/syscall-template.S.
120 ../sysdeps/unix/syscall-template.S: No such file or directory.
(gdb)
#######
Core was generated by `su'.
Program terminated with signal SIGILL, Illegal instruction.
#0 __memchr_avx2 () at ../sysdeps/x86_64/multiarch/memchr-avx2.S:135
Download failed: Invalid argument. Continuing without source file
./string/../sysdeps/x86_64/multiarch/memchr-avx2.S.
135 ../sysdeps/x86_64/multiarch/memchr-avx2.S: No such file or
directory.
(gdb)
#######
It does seem in case of this SIGILL there's no additional stack trace,
also the path containing ".." seems to cause the source code resolution
to fail, but still the debug symbols seem to show the file source and
line, so it should hopefully help see what exactly fails.
I'm yet to try rebooting with microcode package installed though (I'll
soon check it and update on whether it helps, but even if it does, one
without bootable system first won't get a chance to install it; I'm a
bit curious how these changes did trigger this, given all these years it
didn't happen to occur before)
