Re: [PATCH 08/10] Use __kernel_ulong_t in struct msqid64_ds

From: H. Peter Anvin
Date: Fri May 18 2012 - 18:08:50 EST


On 05/18/2012 02:58 PM, Arnd Bergmann wrote:
>
> But why do you think it's wrong the way it is? I see the idea of putting
> padding in varying places depending on the endianess as a failed experiment
> and defining a structure that is always the same as the logical conclusion
> from that, even if it's a bit silly to have any padding in it at all.
>

The *whole point* is to make the structure the same across modes, to
make the compat layer's job easier.

> Being consistent seems more important here than following the intent
> of whoever came up with the concept of the ipc64 data structures
> and was consequently ignored by most people after him.

So you're saying because some architectures introduced a bug, we should
*CONTINUE* to introduce the same bug?? WTF??

> If we really wanted the data structures to be compatible between 32 and
> 64 bit mode, we'd have to use __u64 here but that would mean having to
> change all bits of user code that already rely on the existing x86
> compatible layout.

x86 is doing it right. Some bigendian architectures blindly copied what
x86 was doing without thinking. That's a bug on their part, period.

-hpa


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