linsysfs on /usr/src/sys (linsysfs, local)

From: Graham Perrin <grahamperrin_at_freebsd.org>
Date: Mon, 07 Nov 2022 03:03:25 UTC 
On 29/10/2022 21:30, Graham Perrin wrote:

> Subject: poudriere jail update from source: syscall.mk does not exist

> After updating to yesterday's 
> aba921bd9e1869dae9ae4cc6e0c048f997401034, I aimed for a routine update 
> of the jail that I used for poudriere.
>
>
> poudriere jail -u -J 1 -j main
> …
> ===> lib/libc (install)
> make[5]: "/usr/src/lib/libc/sys/Makefile.inc" line 9: Cannot open 
> /usr/src/sys/sys/syscall.mk
> make[5]: Fatal errors encountered -- cannot continue
> make[5]: stopped in /usr/src/lib/libc
> *** Error code 1
> …


bdrewery and others in IRC helped me to realise an offending mount.


With linux_enable: YES,

root@mowa219-gjp4-8570p-freebsd:~ # mount | grep sys
linsysfs on /usr/src/sys (linsysfs, local)
root@mowa219-gjp4-8570p-freebsd:~ # exit
logout
% grep linsysfs /etc/fstab
# linsysfs      /compat/linux/sys       linsysfs 
rw                         0     0
# linsysfs        /compat/ubuntu/sys      linsysfs 
rw,late                    0     0
%


After linux_enable: NO and a reboot,

% sysrc -f /etc/rc.conf linux_enable
linux_enable: NO
% mount | grep sys
% date ; uname -aKU
Wed 2 Nov 2022 19:06:01 GMT
FreeBSD mowa219-gjp4-8570p-freebsd 14.0-CURRENT FreeBSD 14.0-CURRENT #24 
main-n258900-aba921bd9e18: Sat Oct 29 14:39:59 BST 2022 
grahamperrin@mowa219-gjp4-8570p-freebsd:/usr/obj/usr/src/amd64.amd64/sys/GENERIC-NODEBUG 
amd64 1400073 1400073
% sudo service linux onestart
grahamperrin's password:
kldload: an error occurred while loading module linux. Please check 
dmesg(8) for more details.
/etc/rc.d/linux: WARNING: Unable to load kernel module linux
kldload: an error occurred while loading module linux64. Please check 
dmesg(8) for more details.
/etc/rc.d/linux: WARNING: Unable to load kernel module linux64
% mount | grep sys
linsysfs on /compat/linux/sys (linsysfs, local)
% sudo sysrc linux_enable="YES"
linux_enable: NO -> YES
%


With linux_enable: YES (re-enabled) and a reboot, the clobber of 
/usr/src/sys recurred.

----

Resolved through an OS update on 3rd November:

% uname -aKU
FreeBSD mowa219-gjp4-8570p-freebsd 14.0-CURRENT FreeBSD 14.0-CURRENT #25 
main-n259004-2c10be9e06d4: Thu Nov  3 00:14:52 GMT 2022 
grahamperrin@mowa219-gjp4-8570p-freebsd:/usr/obj/usr/src/amd64.amd64/sys/GENERIC-NODEBUG 
amd64 1400073 1400073