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Date: Tue, 12 Oct 2004 15:19:50 -0700
From: Alfred Perlstein <alfred@freebsd.org>
To: Don Lewis <truckman@FreeBSD.org>
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Subject: Re: cvs commit: src/sys/kern kern_subr.c
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* Don Lewis <truckman@FreeBSD.org> [041012 15:17] wrote:
> On 12 Oct, Alfred Perlstein wrote:
> > I like this, my only concern is that there may be places that
> > call this with locks held but with the kernel/user buffer wired
> > so that it can't fault.
> > 
> > Are you sure this isn't the case?  (specifically for some sysctls)
> 
> There are a number of sysctl handlers where I added code to wire the
> buffer so that there was no danger of sleeping while a mutex is held.
> Allocating a kernel buffer and doing an extra copy would be ugly.

Yup.  Maybe an auxilliary uio_move_wired() that doesn't do this
check?

> 
> > * John Baldwin <jhb@FreeBSD.org> [041012 11:27] wrote:
> >> jhb         2004-10-12 18:27:14 UTC
> >> 
> >>   FreeBSD src repository
> >> 
> >>   Modified files:
> >>     sys/kern             kern_subr.c 
> >>   Log:
> >>   Add a WITNESS_WARN() to uiomove() to whine if locks are held when this
> >>   function is called.
> >>   
> >>   MFC after:      1 month
> >>   
> >>   Revision  Changes    Path
> >>   1.89      +2 -0      src/sys/kern/kern_subr.c
> > 

-- 
- Alfred Perlstein
- Research Engineering Development Inc.
- email: bright@mu.org cell: 408-480-4684