>Number:         28063
>Category:       kern
>Synopsis:       free(NULL, ...) should be noted in free(9) manual page
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    kern-bug-people
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          doc-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Nov 07 06:06:00 UTC 2004
>Closed-Date:
>Last-Modified:
>Originator:     TAMURA Kent
>Release:        -current
>Organization:
>Environment:
NetBSD p4 2.99.10 NetBSD 2.99.10 (P4MP) #148: Sun Nov  7 14:55:04 JST 2004  kent@p4:/home/kent/compile/P4MP i386
>Description:
Unlike free(3), in-kernel free(9) crashes by free(NULL, ...)
call.

>How-To-Repeat:
free(NULL, M_xxx); in kernel code.

>Fix:
IMO, free(9) should accept NULL.

diff -u -r1.90 kern_malloc.c
--- kern_malloc.c       4 Sep 2004 23:30:07 -0000       1.90
+++ kern_malloc.c       7 Nov 2004 06:02:56 -0000
@@ -479,6 +479,9 @@
        long alloc, copysize;
 #endif

+       if (addr == NULL)
+               return;
+
 #ifdef MALLOC_DEBUG
        if (debug_free(addr, ksp))
                return;

The manual page of free(9) must mention behavior for NULL
regardless of crash by NULL or not.


>Release-Note:
>Audit-Trail:
>Unformatted: