Bug#609371: linux-image-2.6.37-trunk-sparc64: module scsi_mod: Unknown relocation: 36

From: Jesper Nilsson <jesper.nilsson@axis.com>
Date: Mon, 17 Jan 2011 10:05:57 +0100

> On Mon, Jan 17, 2011 at 07:07:55AM +0100, David Miller wrote:
>> Ugh, and I just noticed that include/linux/klist.h does this fixed
>> alignment of "4" too, where is this stuff coming from?  It's
>> wrong on 64-bit, at best.  But I can't see the impetus behind doing
>> this at all in the first place.
>> 
>> Oh, this is some CRIS thing, because it only byte aligns.  See:
>> 
>> commit c0e69a5bbc6fc74184aa043aadb9a53bc58f953b
>> Author: Jesper Nilsson <Jesper.Nilsson@axis.com>
>> Date:   Wed Jan 14 11:19:08 2009 +0100
>> 
>>     klist.c: bit 0 in pointer can't be used as flag
>> 
>> That's where the klist one comes from.
> 
> Yup, this one could instead be solved by introducing a "flags" field
> in the struct, but that was considered a too large impact fix.

Jesper, could you please review this?

--------------------
klist: Fix object alignment on 64-bit.

Commit c0e69a5bbc6fc74184aa043aadb9a53bc58f953b ("klist.c: bit 0 in
pointer can't be used as flag") intended to make sure that all klist
objects were at least pointer size aligned, but used the constant "4"
which only works on 32-bit.

Use "sizeof(void *)" which is correct in all cases.

Signed-off-by: David S. Miller <davem@davemloft.net>

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On Tue, Feb 01, 2011 at 06:11:16AM +0100, David Miller wrote:
> Jesper, could you please review this?

Looks good!

Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>

> --------------------
> klist: Fix object alignment on 64-bit.
> 
> Commit c0e69a5bbc6fc74184aa043aadb9a53bc58f953b ("klist.c: bit 0 in
> pointer can't be used as flag") intended to make sure that all klist
> objects were at least pointer size aligned, but used the constant "4"
> which only works on 32-bit.
> 
> Use "sizeof(void *)" which is correct in all cases.
> 
> Signed-off-by: David S. Miller <davem@davemloft.net>
> 
> diff --git a/include/linux/klist.h b/include/linux/klist.h
> index e91a4e5..a370ce5 100644
> --- a/include/linux/klist.h
> +++ b/include/linux/klist.h
> @@ -22,7 +22,7 @@ struct klist {
>  	struct list_head	k_list;
>  	void			(*get)(struct klist_node *);
>  	void			(*put)(struct klist_node *);
> -} __attribute__ ((aligned (4)));
> +} __attribute__ ((aligned (sizeof(void *))));
>  
>  #define KLIST_INIT(_name, _get, _put)					\
>  	{ .k_lock	= __SPIN_LOCK_UNLOCKED(_name.k_lock),		\
/^JN - Jesper Nilsson