[src/trunk]: src/sys/kern crfree(): add DIAGNOSTIC sanity check of cr_ref; un...

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

details:   https://anonhg.NetBSD.org/src/rev/f6d6612f45bb
branches:  trunk
changeset: 518277:f6d6612f45bb
user:      jdolecek <jdolecek%NetBSD.org@localhost>
date:      Tue Nov 27 07:30:03 2001 +0000

description:
crfree(): add DIAGNOSTIC sanity check of cr_ref; unfortunately, if the memory
is freed prematurely the check won't be triggered immediatelly, probably
since the memory is likely to be reused fast; but it _would_ be triggered
eventually

diffstat:

 sys/kern/kern_prot.c |  13 +++++++++++--
 1 files changed, 11 insertions(+), 2 deletions(-)

diffs (34 lines):

diff -r 5dcea8523c70 -r f6d6612f45bb sys/kern/kern_prot.c
--- a/sys/kern/kern_prot.c      Tue Nov 27 05:42:24 2001 +0000
+++ b/sys/kern/kern_prot.c      Tue Nov 27 07:30:03 2001 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_prot.c,v 1.65 2001/11/12 15:25:14 lukem Exp $     */
+/*     $NetBSD: kern_prot.c,v 1.66 2001/11/27 07:30:03 jdolecek Exp $  */
 
 /*
  * Copyright (c) 1982, 1986, 1989, 1990, 1991, 1993
@@ -45,7 +45,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_prot.c,v 1.65 2001/11/12 15:25:14 lukem Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_prot.c,v 1.66 2001/11/27 07:30:03 jdolecek Exp $");
 
 #include "opt_compat_43.h"
 
@@ -687,6 +687,15 @@
        struct ucred *cr;
 {
 
+#ifdef DIAGNOSTIC
+       /*
+        * This check is not too reliable - the memory is likely
+        * to be reused fast.
+        */
+       if (cr->cr_ref == 0)
+               panic("crfree: ucred already free");
+#endif
+
        if (--cr->cr_ref == 0)
                FREE((caddr_t)cr, M_CRED);
 }