[patch v2] manual: Update signal descriptions

[Florian Weimer]

* Stefan Liebler:

> On 1/21/25 11:14, Andreas Schwab wrote:
>> On Jan 21 2025, Florian Weimer wrote:
>> 
>>> Stefan, does s390x call these notifications “ctrl-alt-del
>>> notifications”, or this there some other name for them?  Is this kernel
>>> code path really active on current systems?
>> 
>> It is also available as function key 0x020c (Boot) in the vt keyboard
>> driver, and used by various other drivers in the kernel (look for
>> kill_cad_pid and ctrl_alt_del).
>> 
>
> FYI: I've asked around in our kernel-team and the answer:
> Yes, the kernel sends SIGPWR on a machine check warning.
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/s390/kernel/nmi.c#n177
>
> Thus the description is fine.

Thanks.  Does this include the ctrl-alt-del reference?  I thought this
was about a different IBM thing. 8-)

Florian