kern/55407: fstat cannot display descriptors of chrooted processes

[mlelstv%serpens.de@localhost]

>Number:         55407
>Category:       kern
>Synopsis:       fstat cannot display descriptors of chrooted processes
>Confidential:   no
>Severity:       serious
>Priority:       low
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Jun 22 13:20:00 +0000 2020
>Originator:     Michael van Elst
>Release:        NetBSD 9.0_STABLE
>Organization:
-- 
                                Michael van Elst
Internet: mlelstv%serpens.de@localhost
                                "A potential Snark may lurk in every tree."
>Environment:
	
	
System: NetBSD victory.netbsd.org 9.0_STABLE NetBSD 9.0_STABLE (GENERIC64) #0: Tue Mar 3 18:56:34 UTC 2020 mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/evbarm/compile/GENERIC64 evbarm
Architecture: aarch64
Machine: evbarm
>Description:

fstat only prints errors for chrooted processes. E.g.

# fstat -p 25353
USER     CMD          PID   FD MOUNT       INUM MODE         SZ|DV R/W
fstat: can't read filedesc at 0xffff009c4e849600 for pid 25353

The failure is present also when fstat is run within the same chroot.
procfs shows all descriptors.


This seems to be no problem on amd64, i386 or arm.

>How-To-Repeat:

Run fstat on a system using chrooted processes on aarch64.

>Fix:
	

>Unformatted: