# Re: net/sctp/sm\_make\_chunk.c alignment problems on parisc64

- From: David S. Miller \<hidden\>
- Date: 2003-09-19 02:55:25 
- List: netdev
- Page: https://ratatoskr.run/netdev/2003/09/10736748
- Thread: https://ratatoskr.run/netdev/2003/09/10736582/t.md

```text
On Wed, 17 Sep 2003 16:06:18 -0700 (PDT)
Sridhar Samudrala [ref] wrote:

> I don't see this problem on i386, ia64 or ppc64. Can someone
> familiar with parisc64 provide more details or submit a a patch to
> fix this problem?

As an example, if you have an structure member of type "char":

struct foo {
	char	a;
	char	b[4];
};

And then try to do something like this:

	struct foo *p;
	unsigned int *v;

	v = (unsigned int *) (&p->b[0]);
	*v = 0;

The build is going to explode on parisc because this simply is not
allowed.  You cannot access a structure member as an object which
has larger alignment than is guarenteed for the type that member
has.

In the above example we're trying to access with 'unsigned int'
alignment a member which is only guarenteed to have the alignment
for a 'char'.
```