Re: [RFC v2 1/7] hashtable: introduce a small and naive hashtable

Tejun Heo
2012-08-03T21:48:06Z

Hello,

On Fri, Aug 03, 2012 at 11:41:34PM +0200, Sasha Levin wrote:
> I forgot to comment on that one, sorry.
>
> If we put hash entries after struct hash_table we don't take the
> bits field size into account, or did I miss something?

So, if you do the following,

struct {
struct {
int i;
long ar[];
} B;
long __ar_storage[32];
} A;

It should always be safe to dereference A.B.ar[31]. I'm not sure
whether this is something guaranteed by C tho. Maybe compilers are
allowed to put members in reverse order but I think we already depend
on the above.

Thanks.

--
tejun