Re: [RFC 2.6.10 3/22] xfrm: Add offload management routines

["David S. Miller" <davem@xxxxxxxxxxxxx>]

On Thu, 30 Dec 2004 03:48:35 -0500
David Dillow <dave@xxxxxxxxxxxxxx> wrote:

> +static inline struct xfrm_offload *
> +xfrm_offload_alloc(int sizeof_priv, struct net_device *dev)

This whole scheme looks buggy.  The intent is to 8-byte align
the object, but look at what the code is actually doing.

Whatever kmalloc() returns to xfrm_offload_alloc() is directly
used as the xfrm_offload pointer, and the members are initialized.

Then xfrm_offload_priv() does the alignments.

It is clear that kmalloc() is always giving you 8-byte aligned
data else the first time xfrm_offload_priv() is used you'd
get a bogus pointer since xfrm_offload_alloc() initialized
the object without first aligning the pointer.

We do something similar when we allocate netdevs, so have a look
at how net/core/dev.c:alloc_netdev() works.