Re: ARM: Section mismatch warnings

From: Sam Ravnborg
Date: Mon May 28 2007 - 14:35:48 EST


>
> > o-arm-neponset/log.out:WARNING: arch/arm/mach-sa1100/built-in.o(.text+0x1748):
> Section mismatch: reference to .init.text:sa1110_mb_disable
> (between 'neponset_init' and 'neponset_resume')
>
> This one looks quite bogus. sa1110_mb_disable() is marked __init, and
> it's called from neponset_init() which is also marked __init.

Created a neponset.i file - output:

static int neponset_init(void)
{
platform_driver_register(&neponset_device_driver);

So we loose the __init marker during preprocessing.
Which is due the the buggy part of my path that adds __devinit.

There was a reason I noted the devinit markers should be reviewed carefully -
this one seems wrong.


>
> > o-arm-neponset/log.out:WARNING: arch/arm/mach-sa1100/built-in.o(.text+0x17ac):
> Section mismatch: reference to .init.data:devices
> (between 'neponset_init' and 'neponset_resume')
>
> No reference to 'devices' (marked __initdata) in neponset_resume but there
> is in neponset_init(), which is the only reference to it, and it is marked
> __init. Another false positive?
It is between the symbols so the rference will never be in the latter function.
In this case it is due to my wrong __devinit marking (again).

>
> > o-arm-s3c2410/log.out:WARNING: arch/arm/mach-s3c2410/built-in.o(.text+0x80):
> Section mismatch: reference to .init.data:s3c2410_dma_order
> (between 's3c2410_dma_add' and 's3c2410_pm_add')
>
> Don't know enough about s3c stuff, but this one looks like a false positive
> as well - it's registering a sysdev driver at boot time, and the class
> and sysdev is only ever also registered at boot time and never unregistered.
> Adding __init to s3c2410_dma_add would probably be the right thing to do
> but will move the problem to be a reference to s3c2410_dma_add from
> s3c2410_dma_driver instead.
>
> Once that's done, might need an annotation of some sort? Not sure.
modpost allows references to .init.text from variables named *_driver - so that
would work out.
And it is not a 'false positive' in the sense that there is indeed a
reference from a .text section to a .init.text section - so the calling
function ougth to be marked __init.


So conclusion is that most of these were caused by a wrong marking from my side.
But at least I had requested special attention to that part in my patch
submission because I knew I was not sure.

I did not see any wrong-doings by modpost.

Sam
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