Implemented as https://reviews.freebsd.org/D38933.

In D39507#899652, @dchagin wrote:

well, the part after a dash is not standart, depends on a distributive, so we can put here any information, and it would be nice to print p_osrel of the current process here.
However, I would propose completely remove the pr_osrelease from struct linux_prison as we have pr_osrel and due to the pr_osrelease was intended to map into the vdso page at the Note section. But its not possible due to jails and can be removed now.

In D38933#897702, @mjg wrote:

I strongly suspect the right way is to have linux binaries auto chrooted to /compat/linux or whatever you are looking up against and then have nullfs mounts inside for /home, /tmp and whatever else which makes sense to share. This avoids any suspicious lookups like failing to find a file in Linux because it is missing when it should not and trying to pick up the FreeBSD one. This also avoids adding any complexity to the kernel.

Hah, I've been working on something similar, although from a somewhat different, CHERI-related, angle :)

Only tangentially related, but I wonder if this constant shouldn't be defined for arm64 too?

My first thought about ENODEV was something about GEOM. ENOENT, on the other hand, would make it obvious what's going on: the root device node is simply not there.

I've been burned by this in the past, but I've assumed it's just me. This time, though, there was another person involved, and this made me reconsider. In this case it's not even that it's a remote machine: this is for a homebrew remote management mechanism; essentially we have BeagleBone Blacks hooked up to the actual machines (mechanically they are inside the machines), which provide remote console and virtual media, and halting one of those by mistake - for example when you fail to notice the cu(1) to the "real" machine has been disconnected - results in having to power cycle the whole thing, which is one thing our BBB-based remote management does not provide.

Linux, it’s a Linux core file :-) The easiest way is to use debootstrap port to bootstrap an Ubuntu Bionic userland, then chroot there and do “apt install gdb”. See https://wiki.freebsd.org/LinuxJails.

I’m not opposed to this patch, but isn’t this what core files are for?

Fix sc_fpstate.

It's gonna be two weeks soon, can I assume a timeout for releng?

Few more nits - most from Pau, but there's also two grammar fixes
I've noticed.

Nice! This cleanup was long overdue. A few nits though.

Rebase (the mechanical change got committed) and reword
things a bit to make them bit less src-centric; point
at {contributing} instead.