git: 811e27fa3c44 - main - jail: Add PD_KILL to remove a prison in prison_deref().

[James Gritton]

On 2021-02-24 21:29, Kyle Evans wrote:
> On Tue, Feb 23, 2021 at 7:16 AM Alexander Richardson
> <arichardson at freebsd.org> wrote:
>> 
>> On Mon, 22 Feb 2021 at 20:28, Jamie Gritton <jamie at freebsd.org> wrote:
>> >
>> > The branch main has been updated by jamie:
>> >
>> > URL: https://cgit.FreeBSD.org/src/commit/?id=811e27fa3c445664e36071a7d08228fc7fb85676
>> >
>> > commit 811e27fa3c445664e36071a7d08228fc7fb85676
>> > Author:     Jamie Gritton <jamie at FreeBSD.org>
>> > AuthorDate: 2021-02-22 20:27:44 +0000
>> > Commit:     Jamie Gritton <jamie at FreeBSD.org>
>> > CommitDate: 2021-02-22 20:27:44 +0000
>> >
>> >     jail: Add PD_KILL to remove a prison in prison_deref().
>> >
>> >     Add the PD_KILL flag that instructs prison_deref() to take steps
>> >     to actively kill a prison and its descendents, namely marking it
>> >     PRISON_STATE_DYING, clearing its PR_PERSIST flag, and killing any
>> >     attached processes.
>> >
>> >     This replaces a similar loop in sys_jail_remove(), bringing the
>> >     operation under the same single hold on allprison_lock that it already
>> >     has. It is also used to clean up failed jail (re-)creations in
>> >     kern_jail_set(), which didn't generally take all the proper steps.
>> >
>> >     Differential Revision:  https://reviews.freebsd.org/D28473
>> 
>> Hi Jamie,
>> 
>> After this commit running cd /usr/tests/lib/libc/sys && kyua test
>> cpuset_test renders the entire system unusable: all exec calls
>> afterwards seem to fail. In Jenkins it's triggering a kernel panic:
>> https://ci.freebsd.org/job/FreeBSD-main-amd64-test/17630/consoleFull
>> Reverting this commit fixes the issue.
>> 
> 
> Based on the backtrace and a wild stab in the dark, the last
> prison_deref() in do_jail_attach() prior to successful return should
> explicitly clear the PD_KILL flag from drflags.
> 
> Thanks,
> 
> Kyle Evans

Yep, that's what's doing it.  Actually, PD_KILL has no business being 
passed to do_jail_attach in the first place.  Running a test on that 
right now.

- Jamie