gdb says "Unexpected size of section `.reg-xstate/...` in core file

[Zbigniew Jędrzejewski-Szmek]

Hi,

I'm not sure if this is a bug and if it is, where it is...

$ coredumpctl gdb
...
Using host libthread_db library "/lib64/libthread_db.so.1".
Core was generated by `/usr/lib/systemd/systemd-oomd'.
Program terminated with signal SIGABRT, Aborted.

warning: Unexpected size of section `.reg-xstate/59286' in core file.
#0  0x00007f552f8b3b95 in raise () from /lib64/libc.so.6
(gdb)

Is this gcc, gdb, binutils, something else?

Zbyszek

[J. Scheurich]

> I'm not sure if this is a bug and if it is, where it is...
>
> $ coredumpctl gdb
> ...
> Using host libthread_db library "/lib64/libthread_db.so.1".
> Core was generated by `/usr/lib/systemd/systemd-oomd'.
> Program terminated with signal SIGABRT, Aborted.
>
> warning: Unexpected size of section `.reg-xstate/59286' in core file.
> #0  0x00007f552f8b3b95 in raise () from /lib64/libc.so.6
> (gdb)

coredumpctl gdb is a command for systemd to unhide and debug
the last core file.
Do you have a crash/core file ?
Otherwise this output may mean "no core file found" ?

so long
MUFTI

[Jan Kratochvil]

On Sat, 11 Jul 2020 16:52:41 +0200, Zbigniew Jędrzejewski-Szmek wrote:
> warning: Unexpected size of section `.reg-xstate/59286' in core file.
> #0  0x00007f552f8b3b95 in raise () from /lib64/libc.so.6
> (gdb)
>
> Is this gcc, gdb, binutils, something else?

gdb is older than kernel and you have too new CPU.
    https://stackoverflow.com/a/62866856/2995591

You did not say versions + CPU you use.

Jan

[Zbigniew Jędrzejewski-Szmek]

On Mon, Jul 13, 2020 at 10:25:36AM +0200, Jan Kratochvil wrote:
> On Sat, 11 Jul 2020 16:52:41 +0200, Zbigniew Jędrzejewski-Szmek wrote:
> > warning: Unexpected size of section `.reg-xstate/59286' in core file.
> > #0  0x00007f552f8b3b95 in raise () from /lib64/libc.so.6
> > (gdb)
> >
> > Is this gcc, gdb, binutils, something else?
>
> gdb is older than kernel and you have too new CPU.
>    https://stackoverflow.com/a/62866856/2995591

Thanks, that looks promising.
> You did not say versions + CPU you use.

It's a VM (libvirt, kvm, uefi). /proc/cpuinfo shows xsave is present:

vendor_id  : GenuineIntel
cpu family : 6
model	     : 94
model name   : Intel Core Processor (Skylake, IBRS)
stepping     : 3
microcode    : 0x1
cpu MHz	       : 2591.998
cache size     : 16384 KB
physical id    : 0
siblings : 1
core id	   : 0
cpu cores  : 1
apicid	     : 0
initial apicid : 0
fpu	       : yes
fpu_exception  : yes
cpuid level    : 13
wp    	       : yes
flags	       	 : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss syscall nx pdpe1gb rdtscp lm constant_tsc rep_good nopl xtopology cpuid tsc_known_freq pni pclmulqdq vmx ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch cpuid_fault invpcid_single pti ssbd ibrs ibpb stibp tpr_shadow vnmi flexpriority ept vpid ept_ad fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid mpx rdseed adx smap clflushopt xsaveopt xsavec xgetbv1 xsaves arat umip md_clear arch_capabilities
vmx flags	 : vnmi preemption_timer invvpid ept_x_only ept_ad ept_1gb flexpriority tsc_offset vtpr mtf vapic ept vpid unrestricted_guest shadow_vmcs pml
bugs		   : cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf mds swapgs itlb_multihit srbds
bogomips	   : 5183.99
clflush size	   : 64
cache_alignment	   : 64
address sizes	   : 40 bits physical, 48 bits virtual

The guest is 5.8.0-0.rc2.20200622git625d3449788f.1.fc33.x86_64, and has
gdb-9.2-2.fc33.x86_64 which is the latest rawhide build... Does gdb need updating?

Zbyszek

[Jan Kratochvil]

On Mon, 13 Jul 2020 18:32:10 +0200, Zbigniew Jędrzejewski-Szmek wrote:
> gdb-9.2-2.fc33.x86_64 which is the latest rawhide build... Does gdb need updating?

You may rather ask at gdb -at - sourceware.org.

Jan

[Kevin Buettner]

On Sat, 11 Jul 2020 14:52:41 +0000
Zbigniew J__drzejewski-Szmek  wrote:
> I'm not sure if this is a bug and if it is, where it is...
>
> $ coredumpctl gdb
> ...
> Using host libthread_db library "/lib64/libthread_db.so.1".
> Core was generated by `/usr/lib/systemd/systemd-oomd'.
> Program terminated with signal SIGABRT, Aborted.
>
> warning: Unexpected size of section `.reg-xstate/59286' in core file.
> #0  0x00007f552f8b3b95 in raise () from /lib64/libc.so.6
> (gdb)
>
> Is this gcc, gdb, binutils, something else?

I think this is the same problem that I encountered recently.  If
so, it turned out to be a kernel bug.

See:

https://bugzilla.redhat.com/show_bug.cgi?id=1858645

Kevin