Re: [RFC] [PATCH] Fix b43 driver build for arm

From: Michael Buesch
Date: Sat Feb 23 2008 - 10:59:31 EST


On Saturday 23 February 2008 11:14:23 Gordon Farquharson wrote:
> On Fri, Feb 22, 2008 at 10:51 PM, Michael Buesch <mb@xxxxxxxxx> wrote:
> > A big fat comment is something like that:
> >
> > /* Explicit padding to support a broken sanity check in file2alias.c.
> > * The check will compare the size of the structure in the kernel
> > * object file to the userspace the kernel is compiled on.
> > * This breaks on cross-compilation. This padding is a workaround
> > * for this. */
>
> ---
>
> Align the members of the SSB device structure to a 32 bit boundary so
> that the b43 driver can be built for arm using a cross compiler. This
> alignment is required so that the test in scripts/mod/file2alias.c
> that checks that the size of the device ID type against the size of
> the section in the object file succeeds (see comment and
> http://lkml.org/lkml/2008/2/18/481 for explanation).
>
> Signed-off-by: Gordon Farquharson <gordonfarquharson@xxxxxxxxx>

Acked-by: Michael Buesch <mb@xxxxxxxxx>

> ---
>
> diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
> index 139d49d..208d49a 100644
> --- a/include/linux/mod_devicetable.h
> +++ b/include/linux/mod_devicetable.h
> @@ -351,7 +351,13 @@ struct sdio_device_id {
> struct ssb_device_id {
> __u16 vendor;
> __u16 coreid;
> - __u8 revision;
> + /* Explicit padding to support a broken sanity check in file2alias.c.
> + * The check compares the size of the structure in the kernel
> + * object file to the size of the structure reported in userspace for
> + * the system on which the kernel is compiled. The check breaks on
> + * cross-compilation, and the padding is a workaround for this. */
> + __u8 revision
> + __attribute__((aligned(sizeof(__u32))));
> };
> #define SSB_DEVICE(_vendor, _coreid, _revision) \
> { .vendor = _vendor, .coreid = _coreid, .revision = _revision, }
>



--
Greetings Michael.
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