Re: port-sh3/55491: pmap corruption

[Martin Husemann <martin%duskware.de@localhost>]

The following reply was made to PR port-sh3/55491; it has been noted by GNATS.

From: Martin Husemann <martin%duskware.de@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: port-sh3/55491: pmap corruption
Date: Fri, 19 Feb 2021 19:31:27 +0100

 When the endless loop in this PR happens
 
 	pmap_page_protect()
 
 is called and in the "default:" remove-all case. It loops over
 all page entries in
 
 	while ((pv = SLIST_FIRST(&pvh->pvh_head)) != NULL)
 
 and tries to pmap_remove() each VA, but in the bug case there is a VA
 in the list for which no mapping exists.
 
 I have no idea yet how this VA gets into the list (or what happened
 to it/the mapping).
 
 Martin