Subject: Re: kern/21107: genfs_putpages modifies page tables without proper locking
To: Brian Buhrow <>
From: Manuel Bouyer <>
List: netbsd-bugs
Date: 04/12/2003 19:34:57
On Fri, Apr 11, 2003 at 11:55:17PM -0700, Brian Buhrow wrote:
> >Description:
> 	/usr/src/sys/miscfs/genfs/genfs_vnops.c:genfs_putpages() attempts to
> clean pages with the pmap_clear_modify() routine without locking the uvm
> page queues.  On some systems, including I386 and Sparc architectures, this
> results in intermittent illegal page faults which panic the system.

Hum, shouldn't the pmap_clear_modify() call in ufs/lfs/lfs_vnops.c be
protected the same way ?
uvn_findpages() also calls pmap_clear_modify() without pageq locking,
so I guess uvn_findpages() has to be called with the pageq locked.
uvn_findpages() is called at various places in genfs_vnops.c (and only there).

Manuel Bouyer <>
     NetBSD: 24 ans d'experience feront toujours la difference