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

From: Matthieu CASTET
Date: Fri Feb 22 2008 - 08:13:46 EST


Sam Ravnborg <sam <at> ravnborg.org> writes:

>
> In at least 99% of the cases this is OK and the check has found
> several bugs where things would not have worked due to different
> alignmnet between kernel and userland. Just think about the
> issues in a mixed 32/64 bit world.
>
I don't see how this check is supposed to work.
For some arch userspace can have different alignement depending on compilation
option :
- x86_64 : 32 or 64 bits mode
- arm : 32 bits or thumb mode
- mips : 32 bits or mips16 mode
[...]

The check is done only for one case ?


> In this particular case you _could_ be right that it would work
> on ARM userland. But the only way to be sure is to pad the
> structure so it become 8 byte in size.
> Or as was recently done in the m68k case to tell the
> compiler to specifically align it to 8 byte boundary.
An easy way to fix this is just to issue a warning but not an error. So it could
ignored on cross compilation case.

Matthieu

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