misc/38425: savecore confused if getbootfile(3) fails

[Simon Burge <simonb%NetBSD.org@localhost>]

>Number:         38425
>Category:       misc
>Synopsis:       savecore confused if getbootfile(3) fails
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    misc-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Apr 14 04:40:00 +0000 2008
>Originator:     Simon Burge
>Release:        NetBSD current, any time after 2008/01/15
>Organization:
>Environment:
  Architecture: all ?
  Machine: all ?
>Description:
        If you try to boot a non-root-owned kernel that isn't called
        'netbsd', getbootfile() fails and savecore will try to use
        /netbsd anyway.  The KREAD in kmem_setup() that fetches the
        'dumpcdev' value will then read some random garbage value.  In
        my case, that reads a "0".  find_dev() then searches for dev_t
        0, returns "/dev/console" and any further operations that
        try to read from "kernel" memory now block waiting for console
        input (!!).

>How-To-Repeat:
        Boot from a non-root-owned kernel that isn't called 'netbsd'

>Fix:
        Not sure..  Better error checking in kmem_setup()?