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

[John Baldwin]

On Tuesday, August 31, 2010 2:11:50 pm Dimitry Andric wrote:
> 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;
>  }

Perhaps replace '(p + 0x594 - 0x401)' with just 'PTOV(0x594)'?

I would actually find it cleaner to remove 'p' altogether perhaps:

	return (*(u_char *)PTOV(0x401) * 128 * 1024 +
	    *(uint16_t *)PTOV(0x594) * 1024 * 1024);

-- 
John Baldwin