Re: [PATCH -mm] Taskstats fix the structure members alignment issue

From: Andrew Morton
Date: Fri Apr 20 2007 - 15:16:20 EST


On Fri, 20 Apr 2007 22:13:41 +0530
Balbir Singh <balbir@xxxxxxxxxx> wrote:

>
> We broke the the alignment of members of taskstats to the 8 byte boundary
> with the CSA patches. In the current kernel, the taskstats structure is
> not suitable for use by 32 bit applications in a 64 bit kernel.
>

ugh, that was bad of us.

> ...
> The patch adds an __attribute__((aligned(8))) to the
> taskstats structure members so that 32 bit applications using taskstats
> can work with a 64 bit kernel.

But there might be 32-bit applications out there which are using the
present wrong structure?

otoh, I assume that those applications would be using taskstats.h and would
hence encounter this bug and we would have heard about it, is that correct?

otoh^2, 32-bit applications running under 32-bit kernels will presently be
functioning correctly, and your change will require that those applications
be recompiled, I think?


This patch looks like 2.6.20 and 2.6.21 material, but very carefully...
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