[systemd-devel] Illegal CPUID instruction causes systemd core dump

[Lennart Poettering]

On Do, 28.12.17 14:07, tedheadster (tedheadster at gmail.com) wrote:

> I am doing regression testing on old hardware. systemd-233 just
> generated the following error on startup:
> 
> traps:systemd[1] trap invalid opcode ip:b7d97361 sp:bfa2f6bc error:0
> in libsystemd-shared-233.so[b7d3e000+1cc000]
> systemd[1]: Caught <ILL>, dumped core as pid 78.
> systemd[1]: Freezing execution
> 
> I believe it is getting an illegal instruction trap on this first
> generation 486 because it is calling "cpuid" in detect_vm_cpuid()
> without first checking if the hardware supports it; it doesn't in this
> case.
> 
> The gcc compiler provides a workaround in the cpuid.h header file. You
> can call __get_cpuid_max() first and check the return value > 0.
> 
> https://stackoverflow.com/questions/14266772/how-do-i-call-cpuid-in-linux#14266932
> 
> The Linux kernel still supports the 486 so we have to code around this
> case, even if it is ancient hardware.

Please send a patch for this. We lack the relevant hardware and
can't test this. In fact, for most such portability support for
less-than-mainsrtream systems we rely on external patches.

Lennart

-- 
Lennart Poettering, Red Hat