Re: [PATCH] Fix NR_KEYS off-by-one error

[OGAWA Hirofumi]

Paul Jackson <pj@xxxxxxx> writes:

> -#define i (tmp.kb_index)
> -#define s (tmp.kb_table)
> -#define v (tmp.kb_value)
>  static inline int
>  do_kdsk_ioctl(int cmd, struct kbentry __user *user_kbe, int perm, struct kbd_struct *kbd)
>  {
>  	struct kbentry tmp;
>  	ushort *key_map, val, ov;
> +	unsigned char s, i;
> +	unsigned short v;
>  
>  	if (copy_from_user(&tmp, user_kbe, sizeof(struct kbentry)))
>  		return -EFAULT;
>  
> +	s = tmp.kb_table;
> +	i = tmp.kb_index;
> +	v = tmp.kb_value;

Yes, s/i/v macro is ugly.  But I think it shouldn't, because it limits
the range when struct kbentry was changed.  (I think this change is likely)

Perhaps only expand the macro... hmm..

> +	if (s >= ARRAY_SIZE(key_maps))
> +		return -EINVAL;
> +	if (i >= ARRAY_SIZE(key_map))
> +		return -EINVAL;

key_map is pointer, so ARRAY_SIZE() can't use.  Anyhow these will be
warned by gcc.

Although overhead is insignificance, I'd hated to add overhead of this
test because test is not needed right now.
-- 
OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>
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