Subject: Re: kernel mappings of shared-library pages
To: None <>
From: Chuck Silvers <>
List: tech-kern
Date: 10/15/2001 09:37:09
most likely this is coming from UBC mappings, which are always writable.

all of the other VAC pmaps look at whether multiple mappings will actually
use different cache lines rather than whether any of the mappings are
writable.  you should make the arm pmap do this too.


On Sat, Oct 13, 2001 at 09:51:06AM +0100, Richard Earnshaw wrote:
> While working on a fix for pr/13998 I noticed that several (maybe many) 
> shared library pages seem to be permanently mapped into the kernel.  This 
> is bad news on a VAC machine since such mappings tend to be always 
> writable, so we must leave all such mappings of that page uncached (all 
> user-space mappings are read-only).
> Is this correct behaviour (that the kernel should keep a mapping of such 
> pages)?
> If not, any idea where they may be being entered?
> R.