[src/trunk]: src/sys/kern The file being closed is (fdp->fd_lastfile - i), no...

[wrstuden <wrstuden%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/9fded5737436
branches:  trunk
changeset: 581023:9fded5737436
user:      wrstuden <wrstuden%NetBSD.org@localhost>
date:      Fri May 20 16:13:00 2005 +0000

description:
The file being closed is (fdp->fd_lastfile - i), not i. So compare
(fdp->fd_lastfile - i) against fd_knlistsize. Otherwise we can
call knote_fdclose() on a file descriptor that doesn't have a knote.

This issue explains random panics I have had on process exit over the
past few years.

diffstat:

 sys/kern/kern_descrip.c |  6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diffs (27 lines):

diff -r ea0b9bec757e -r 9fded5737436 sys/kern/kern_descrip.c
--- a/sys/kern/kern_descrip.c   Fri May 20 15:09:45 2005 +0000
+++ b/sys/kern/kern_descrip.c   Fri May 20 16:13:00 2005 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_descrip.c,v 1.131 2005/02/26 21:34:55 perry Exp $ */
+/*     $NetBSD: kern_descrip.c,v 1.132 2005/05/20 16:13:00 wrstuden Exp $      */
 
 /*
  * Copyright (c) 1982, 1986, 1989, 1991, 1993
@@ -37,7 +37,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_descrip.c,v 1.131 2005/02/26 21:34:55 perry Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_descrip.c,v 1.132 2005/05/20 16:13:00 wrstuden Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -1285,7 +1285,7 @@
                        *fpp = NULL;
                        simple_lock(&fp->f_slock);
                        FILE_USE(fp);
-                       if (i < fdp->fd_knlistsize)
+                       if ((fdp->fd_lastfile - i) < fdp->fd_knlistsize)
                                knote_fdclose(p, fdp->fd_lastfile - i);
                        (void) closef(fp, p);
                }