Re: net/sctp/sm_make_chunk.c alignment problems on parisc64

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

On Wed, 17 Sep 2003 16:06:18 -0700 (PDT)
Sridhar Samudrala <sri@xxxxxxxxxx> 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'.