kern/53143: NetBSD 8 panic probably related to procfs

[dmb%yenn.ulegend.net@localhost]

>Number:         53143
>Category:       kern
>Synopsis:       NetBSD 8 panic probably related to procfs
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Mar 30 08:55:00 +0000 2018
>Originator:     Dominik Bialy
>Release:        NetBSD 8.0_BETA
>Organization:
Underlegend Networks
>Environment:
System: NetBSD yenn 8.0_BETA NetBSD 8.0_BETA (YENN) #0: Mon Mar 19 07:56:58 CET 2018 dominik@dominik-Inspiron-5567:/builds/netbsd-8/amd64/obj/sys/arch/amd64/compile/YENN amd64
Architecture: x86_64
Machine: amd64
>Description:
	The NetBSD 8 kernel panics when procfs and htop(1) are used.

	This is the dmesg after the crash:

uvm_fault(0xfffffe81296925d0, 0x0, 1) -> e
fatal page fault in supervisor mode
trap type 6 code 0 rip 0xffffffff8090c7da cs 0x8 rflags 0x10282 cr2 0x801 ilevel 0x8 rsp 0xffff800048f856d0
curlwp 0xfffffe81161485a0 pid 16549.1 lowest kstack 0xffff800048f832c0
panic: trap
cpu1: Begin traceback...
vpanic() at netbsd:vpanic+0x140
snprintf() at netbsd:snprintf
startlwp() at netbsd:startlwp
alltraps() at netbsd:alltraps+0x96
lwp_trylock() at netbsd:lwp_trylock+0x17
turnstile_block() at netbsd:turnstile_block+0x173
mutex_vector_enter() at netbsd:mutex_vector_enter+0x34e
uvmspace_free() at netbsd:uvmspace_free+0x1c
procfs_do_pid_stat() at netbsd:procfs_do_pid_stat+0x131
procfs_rw() at netbsd:procfs_rw+0x2ef
VOP_READ() at netbsd:VOP_READ+0x37
vn_read() at netbsd:vn_read+0x94
dofileread() at netbsd:dofileread+0x8f
sys_read() at netbsd:sys_read+0x5f
syscall() at netbsd:syscall+0x1bc
--- syscall (number 3) ---
79409643e22a:
cpu1: End traceback...

	The kernel is custom, but there aren't much differences
	with GENERIC, except for altq(9) turned on.

>How-To-Repeat:
	I left htop(1) from pkgsrc running for the night.  In the morning
	the machine was reboot after crash.
>Fix:
	I don't know, I'm not a developer.  I just umounted procfs
	for now.