svn commit: r212064 - head/sys/boot/pc98/boot2

[Dimitry Andric]

Author: dim
Date: Tue Aug 31 18:11:50 2010
New Revision: 212064
URL: http://svn.freebsd.org/changeset/base/212064

Log:
  Avoid directly manipulating a NULL pointer (which could result in
  undefined behaviour) in sys/boot/pc98/boot2/boot2.c.
  
  Reviewed by:	nyan
  Approved by:	rpaulo (mentor)

Modified:
  head/sys/boot/pc98/boot2/boot2.c

Modified: head/sys/boot/pc98/boot2/boot2.c
==============================================================================
--- head/sys/boot/pc98/boot2/boot2.c	Tue Aug 31 17:43:47 2010	(r212063)
+++ head/sys/boot/pc98/boot2/boot2.c	Tue Aug 31 18:11:50 2010	(r212064)
@@ -187,9 +187,9 @@ xfsread(ino_t inode, void *buf, size_t n
 static inline uint32_t
 memsize(void)
 {
-    u_char *p = (u_char *)PTOV(0);
+    u_char *p = (u_char *)PTOV(0x401);
 
-    return *(p + 0x401) * 128 * 1024 + *(u_int16_t *)(p + 0x594) * 1024 * 1024;
+    return *p * 128 * 1024 + *(u_int16_t *)(p + (0x594 - 0x401)) * 1024 * 1024;
 }
 
 static inline void