Re: CVS commit: src/sys/dev

[Paul Goyette <paul%whooppee.com@localhost>]

> On Wed, 27 Jul 2016, coypu%SDF.ORG@localhost wrote:
>
> > > Log Message:
> > > If we're going to check for a NULL pointer, do the check before we
> > > dereference it (to get the lock address).
> > >
> > >
> > > To generate a diff of this commit:
> > > cvs rdiff -u -r1.76 -r1.77 src/sys/dev/md.c
> > >
> > > Please note that diffs are not public domain; they are subject to the
> > > copyright notices on the relevant files.
> >
> > > Modified files:
> > >
> > > Index: src/sys/dev/md.c
> > > diff -u src/sys/dev/md.c:1.76 src/sys/dev/md.c:1.77
> > > --- src/sys/dev/md.c:1.76	Mon Jan  4 16:24:52 2016
> > > +++ src/sys/dev/md.c	Wed Jul 27 01:09:44 2016
> > > @@ -1,4 +1,4 @@
> > > -/*	$NetBSD: md.c,v 1.76 2016/01/04 16:24:52 hannken Exp $	*/
> > > +/*	$NetBSD: md.c,v 1.77 2016/07/27 01:09:44 pgoyette Exp $	*/
> > >
> > >  /*
> > >   * Copyright (c) 1995 Gordon W. Ross, Leo Weppelman.
> > > @@ -40,7 +40,7 @@
> > >   */
> > >
> > >  #include <sys/cdefs.h>
> > > -__KERNEL_RCSID(0, "$NetBSD: md.c,v 1.76 2016/01/04 16:24:52 hannken Exp 
> > > $");
> > > +__KERNEL_RCSID(0, "$NetBSD: md.c,v 1.77 2016/07/27 01:09:44 pgoyette Exp 
> > > $");
> > >
> > >  #ifdef _KERNEL_OPT
> > >  #include "opt_md.h"
> > > @@ -414,13 +414,13 @@ mdstrategy(struct buf *bp)
> > >
> > >  	sc = device_lookup_private(&md_cd, MD_UNIT(bp->b_dev));
> > >
> > > -	mutex_enter(&sc->sc_lock);
> > > -
> > >  	if (sc == NULL || sc->sc_type == MD_UNCONFIGURED) {
> > >  		bp->b_error = ENXIO;
> > >  		goto done;
> > >  	}
> > >
> > > +	mutex_enter(&sc->sc_lock);
> > > +
> > >  	switch (sc->sc_type) {
> > >  #if MEMORY_DISK_SERVER
> > >  	case MD_UMEM_SERVER:
> >
> > goto done; will exit mutex not entered now, I think.
>
> Yup - already fixed.

Well, I had fixed it in my localcount branch, but not on HEAD.  It 
should be fixed everywhere now.

Thanks for pointing this out.


+------------------+--------------------------+------------------------+
| Paul Goyette     | PGP Key fingerprint:     | E-mail addresses:      |
| (Retired)        | FA29 0E3B 35AF E8AE 6651 | paul at whooppee.com   |
| Kernel Developer | 0786 F758 55DE 53BA 7731 | pgoyette at netbsd.org |
+------------------+--------------------------+------------------------+