svn commit: r357055 - head/sys/sparc64/sparc64

[Jeff Roberson]

On Thu, 23 Jan 2020, Mark Johnston wrote:

> Author: markj
> Date: Thu Jan 23 17:18:58 2020
> New Revision: 357055
> URL: https://svnweb.freebsd.org/changeset/base/357055
>
> Log:
>  sparc64: Busy the TSB page before freeing it in pmap_release().
>
>  This is now required by vm_page_free().
>
>  PR:	243534
>  Reported and tested by:	Michael Reim <kraileth at elderlinux.org>
>
> Modified:
>  head/sys/sparc64/sparc64/pmap.c
>
> Modified: head/sys/sparc64/sparc64/pmap.c
> ==============================================================================
> --- head/sys/sparc64/sparc64/pmap.c	Thu Jan 23 17:08:33 2020	(r357054)
> +++ head/sys/sparc64/sparc64/pmap.c	Thu Jan 23 17:18:58 2020	(r357055)
> @@ -1302,6 +1302,7 @@ pmap_release(pmap_t pm)
> 		m = TAILQ_FIRST(&obj->memq);
> 		m->md.pmap = NULL;
> 		vm_page_unwire_noq(m);
> +		vm_page_xbusy(m);

vm_page_xbusy() is unsafe long-term and I will be removing it as soon as I 
get patches into drm.  It technically 'works' now but not for great 
reasons.

Thanks,
Jeff

> 		vm_page_free_zero(m);
> 	}
> 	VM_OBJECT_WUNLOCK(obj);
>