kern/57712: crash/savecore truncates the kernel image in /var/crash

[paul%whooppee.com@localhost]

>Number:         57712
>Category:       kern
>Synopsis:       crash/savecore truncates the kernel image in /var/crash
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Nov 20 14:20:00 +0000 2023
>Originator:     Paul Goyette
>Release:        NetBSD 10.99.10
>Organization:
+---------------------+--------------------------+----------------------+
| Paul Goyette (.sig) | PGP Key fingerprint:     | E-mail addresses:    |
| (Retired)           | 1B11 1849 721C 56C8 F63A | paul%whooppee.com@localhost    |
| Software Developer  | 6E2E 05FD 15CE 9F2D 5102 | pgoyette%netbsd.org@localhost  |
| & Network Engineer  |                          | pgoyette99%gmail.com@localhost |
+---------------------+--------------------------+----------------------+
>Environment:
	
	
System: NetBSD speedy.whooppee.com 10.99.10 NetBSD 10.99.10 (SPEEDY 2023-11-20 00:19:14 UTC) #0: Mon Nov 20 03:50:56 UTC 2023 paul%speedy.whooppee.com@localhost:/build/netbsd-local/obj/amd64/sys/arch/amd64/compile/SPEEDY amd64
Architecture: x86_64
Machine: amd64
>Description:
Twice recently I have had a system crash.  Both times, the correct
amount of RAM is saved in the crash file (on the swap device), and
when the system reboots, savecore(8) copies the appropriate amount
to the core-dump file in /var/crash.

HOWEVER, on both recent occassions, the copy of the kernel has been
truncated.  A kernel from this system should be about 16megabytes,
but only 1.5megabytes were written to the /var/crash/<kernel> copy.

This isn't really critical to normal operations, but it could make 
it much more difficult for us to support users, so I think it should
be a 'blocker' for the upcoming netbsd-10 release.
	
>How-To-Repeat:
See above - crash-and-dump-core
	
>Fix:
please
	

>Unformatted: