Re: Early crash (was: Re: module: show version information forbuilt-in modules in sysfs)

From: Dmitry Torokhov
Date: Wed Feb 02 2011 - 19:00:01 EST


On Wed, Feb 02, 2011 at 02:52:04PM -0800, Andreas Schwab wrote:
> Dmitry Torokhov <dtor@xxxxxxxxxx> writes:
>
> > But why is it aligned on 2-byte boundary and why m64k is not happy with
> > module_version_attribute but is happy with kernel_param which is also
> > aligned similarly?
>
> struct kernel_parm doesn't contain internal padding on 32 bit
> architectures (it does on 64bit architectures though).
>
> > If we unroll module_version_attribute it woud look like this:
> >
> > struct module_version_attribute {
> >
> > struct module_attribute {
> >
> > struct attribute {
> > const char *name;
> > mode_t mode;
> > } attr;
> > ...
> >
> > } mattr;
> >
> > const char *module_name;
> > const char *version;
> > };
> >
> > So I would expect it be aligned on (char *) boundary which should be the
> > same as (void *).
>
> mode_t is a 16 bit type, thus any following member becomes aligned on an
> odd 2 byte boundary.

Even pointers? I'd expect pointers to be aligned on 4-bytes boundaries?

Thanks,

Dmitry
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