[Crash-utility] help debug number of CPU detect failure

[Dave Anderson]

----- Original Message -----

...

> Hi Dave,
> 
> I did some more experiments and found that it is nothing to do with numa.
>
> I also found that the issue gets resolved when I insert "SYMBOL(_stext)=" into vmcoreinfo.
> Meaning sometime crash needs _stext value along with kaslr & phys_base.
>
> Thanks,
> Santosh

There is this comment in kaslr_init():

 *  Setting RELOC_AUTO will ensure that derive_kaslr_offset() is
 *  called after the sorting operation has captured the vmlinux
 *  file's "_stext" symbol value -- which it will compare to the
 *  relocated "_stext" value found in either a dumpfile's vmcoreinfo
 *  or in /proc/kallsyms on a live system.

You should report that back to the vm2core developers to fix that
half-baked ELF header.  

For example, when the KVM "virsh dump" feature is used by a KVM
host to create a dumpfile of a guest VM, they have a mechanism in
place that transfers the vmcoreinfo data from the guest back to
the host, resulting in a vmcore that is identical to a bare-metal
vmcore.

Dave