Peter Lund <[EMAIL PROTECTED]> writes:

> Shifting by more than the width of the value on the left is also not allowed.

Shifting by the width of the value is not allowed as well.

> --- linux-2.6.22/lib/radix-tree.c.orig        2007-08-27 15:42:37.000000000 
> +0200
> +++ linux-2.6.22/lib/radix-tree.c     2007-08-29 13:19:19.000000000 +0200
> @@ -980,12 +980,13 @@
>  
>  static __init unsigned long __maxindex(unsigned int height)
>  {
> -     unsigned int tmp = height * RADIX_TREE_MAP_SHIFT;
> -     unsigned long index = (~0UL >> (RADIX_TREE_INDEX_BITS - tmp - 1)) >> 1;
> +     unsigned int width = height * RADIX_TREE_MAP_SHIFT;
> +     int          shift = RADIX_TREE_INDEX_BITS - width;
>  
> -     if (tmp >= RADIX_TREE_INDEX_BITS)
> -             index = ~0UL;
> -     return index;
> +     if (shift < 0)
> +             return ~0UL;
> +     else
> +             return ~0UL >> shift;

Since height can be zero, you still have undefined behaviour.

Andreas.

-- 
Andreas Schwab, SuSE Labs, [EMAIL PROTECTED]
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
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"And now for something completely different."
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