[PATCH] xdr_array and calloc security fix

[Wolfram Gloger]

> Why not 2^32? size_t is unsigned.

Yes, however malloc can only handle chunks of a little less than 2^31
currently, so the _int_malloc later will fail anyway...  But that is
ok, having a power of two as the compared value wins against this
micro-optimisation:

> So you mean something like:
>   bytes = n * elem_size;
>   if (__builtin_expect ((a | b) >= 65536, 0)) {
>     if (bytes / elem_size != n) {
>       MALLOC_FAILURE_ACTION;
>       return 0;
>     }
>   }

Hey, nice, avoids the second comparision and ||.  Looks like we have a
winner?

Regards,
Wolfram.