kern/55327: !cpu_intr_p() assertion failure in DDB

[rokuyama.rk%gmail.com@localhost]

>Number:         55327
>Category:       kern
>Synopsis:       !cpu_intr_p() assertion failure in DDB
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun May 31 13:25:00 +0000 2020
>Originator:     Rin Okuyama
>Release:        9.99.64
>Organization:
Department of Physics, Meiji University
>Environment:
Should be MI problem, but,
NetBSD obs266 9.99.64 NetBSD 9.99.64 (OBS266) #214: Sun May 31 18:33:52 JST 2020  rin@latipes:/usr/src/sys/arch/evbppc/compile/OBS266 evbppc
>Description:
DDB can be running in the interrupt context, when, e.g., activated from
console. This results in !cpu_intr_p() assertion failure here and there.

Recently, I've hacked db_alloc() and friends to use kmem_intr_alloc(9),
instead of malloc(9). But, still, kill command at least triggers that
assertion failure:

~Stopped in pid 0.2 (system) at  netbsd:comintr+0x82c:   stw     r25, 0x6c(r27)
db> ps
PID    LID S CPU     FLAGS       STRUCT LWP *               NAME WAIT
1663  1663 3   0        80            77949c0                 sh ttyraw
...
db> kill 67f
panic: kernel diagnostic assertion "!cpu_intr_p()" failed: file "../../../../kern/kern_sig.c", line 1308
...
>How-To-Repeat:
Enable DIAGNOSTIC, enter DDB from console, then, kill some process.
>Fix:
No idea at the moment...