Re: [PATCH 02/30] x86-64: Use explicit sizes in sigcontext.h, preparefor x32

From: H. Peter Anvin
Date: Wed Feb 22 2012 - 16:55:38 EST


On 02/22/2012 01:23 PM, Arnd Bergmann wrote:
>
> Depends on how you want to do it. In some cases, the easiest answer
> would be to change the data structure to use __u64 and be compatible
> with i386. Once there are distros built using data structure with
> padding around a long long, you have to use a run-time conditional
> in the compat handler.
>

That we'd like to avoid, but as you said, they'd be broken or might
already be broken.

> I'd say we should fix at least the ones that are easy to spot because
> they already use compat_u64 or have an #ifdef CONFIG_X86_64 in compat
> code. I've looked at everything I could find that fits into that category
> and found only two locations. My expectation is that all other data
> structures that would fall into this category are already broken
> for 32 bit emulation on x86.
>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
>
> diff --git a/include/drm/drm.h b/include/drm/drm.h
> index 49d94ed..73b7c33 100644
> --- a/include/drm/drm.h
> +++ b/include/drm/drm.h
> @@ -438,7 +438,7 @@ struct drm_update_draw {
> drm_drawable_t handle;
> unsigned int type;
> unsigned int num;
> - unsigned long long data;
> + __u64 data;
> };
>
> /**
> diff --git a/include/sound/asound.h b/include/sound/asound.h
> index a2e4ff5..a17e96c 100644
> --- a/include/sound/asound.h
> +++ b/include/sound/asound.h
> @@ -824,8 +824,8 @@ struct snd_ctl_elem_value {
> long *value_ptr; /* obsoleted */
> } integer;
> union {
> - long long value[64];
> - long long *value_ptr; /* obsoleted */
> + __s64 value[64];
> + __s64 *value_ptr; /* obsoleted */
> } integer64;
> union {
> unsigned int item[128];
> Arnd

Right, those are good starts.

-hpa

--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.

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