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Date: Wed, 27 May 2009 13:48:12 +0800
From: Amerigo Wang <amwang@redhat.com>
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To: Rusty Russell <rusty@rustcorp.com.au>
CC: linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org,
       akpm@linux-foundation.org, jdike@addtoit.com, mingo@elte.hu,
       sparclinux@vger.kernel.org, linux-ia64@vger.kernel.org
Subject: Re: [Patch 4/4] module: trim exception table in module_free()
References: <20090526083717.5050.32719.sendpatchset@localhost.localdomain> <200905271151.28045.rusty@rustcorp.com.au> <4A1CAF44.7000002@redhat.com> <200905271453.51914.rusty@rustcorp.com.au>
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Rusty Russell wrote:
> __ex_table ends up with two entries:
>
> Contents of section __ex_table:
>  0000 0c000000 00000000 0e000000 00000000  ................
>  0010 10000000 0a000000 12000000 0a000000  ................
>
> The first is for the __put_user in .text (extable_not_init()) and the second is 
> for the one in .init.text (init()).
>
> Depending on how the module gets allocated, the one referring to .init.text 
> may be first or last.
>   

Hmm, I understand now. The problem is that we don't know which entries
are for __init, and which are not...

> (You can see here why we haven't fixed this: exceptions in __init in modules 
> are rare, perhaps non-existent).
>   
Agreed.
Is it possible to put extable for __init in a separate section?

Thanks for your explanation!