kern/106646: [patch] Pointer incorrectly cast to ulong

[Peter Jeremy]

>Number:         106646
>Category:       kern
>Synopsis:       [patch] Pointer incorrectly cast to ulong
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Tue Dec 12 18:20:02 GMT 2006
>Closed-Date:
>Last-Modified:
>Originator:     Peter Jeremy
>Release:        FreeBSD 6.2-PRERELEASE amd64
>Organization:
n/a
>Environment:
System: FreeBSD turion.vk2pj.dyndns.org 6.2-PRERELEASE FreeBSD 6.2-PRERELEASE #23: Fri Oct 27 09:36:46 EST 2006 root at turion.vk2pj.dyndns.org:/usr/obj/usr/src/sys/turion amd64

The problem also appears in the latest 7-current source

>Description:
	sys/nfs/nfs_common.h defines a macro nfsm_aligned()
	to test if a particular address is sufficiently aligned
	for the architecture.  It does this by casting the address
	to u_long.  For portability, it should cast to intptr_t.

	The existing code will fail on an architecture with strict
	alignment where sizeof(void *) > sizeof(u_long)

>How-To-Repeat:
	Code inspection
>Fix:

	The following (untested) patch should work
Index: sys/nfs/nfs_common.h
===================================================================
RCS file: /usr/ncvs/src/sys/nfs/nfs_common.h,v
retrieving revision 1.38
diff -u -r1.38 nfs_common.h
--- sys/nfs/nfs_common.h	14 Jul 2005 20:08:26 -0000	1.38
+++ sys/nfs/nfs_common.h	12 Dec 2006 18:02:19 -0000
@@ -130,7 +130,7 @@
 #ifdef __NO_STRICT_ALIGNMENT
 #define nfsm_aligned(p, t)	1
 #else
-#define nfsm_aligned(p, t)	((((u_long)(p)) & (sizeof(t) - 1)) == 0)
+#define nfsm_aligned(p, t)	((((intptr_t)(p)) & (sizeof(t) - 1)) == 0)
 #endif
 
 #endif


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