svn commit: r314116 - head/sys/kern

[Jonathan Looney]

On Wed, Feb 22, 2017 at 8:18 PM, Jonathan T. Looney <jtl at freebsd.org> wrote:

> Author: jtl
> Date: Thu Feb 23 01:18:47 2017
> New Revision: 314116
> URL: https://svnweb.freebsd.org/changeset/base/314116
>
> Log:
>   Fix a panic during boot caused by inadequate locking of some vt(4) driver
>   data structures.
>
>   vt_change_font() calls vtbuf_grow() to change some vt driver data
>   structures. It uses TF_MUTE to prevent the console from trying to use
> those
>   data structures while it changes them.
>
>   During the early stage of the boot process, the vt driver's tc_done
> routine
>   uses those data structures; however, it is currently called outside the
>   TF_MUTE check.
>
>   Move the tc_done routine inside the locked TF_MUTE check.
>
>   PR:           217282
>   Reviewed by:  ed, ray
>   Sponsored by: Netflix
>   Differential Revision:        https://reviews.freebsd.org/D9709


Sorry, this should also say:

MFC after: 2 weeks

The change should go back to stable/11, since EARLY_AP_STARTUP is an option
there. (It appears EARLY_AP_STARTUP is a prerequisite for hitting this bug.)

Jonathan