Re: [PATCH 3/5] uml: Fix warning due to missing task_struct declaration

[Jan Kiszka <jan.kiszka@web.de>]

[-- Attachment #1: Type: text/plain, Size: 1652 bytes --]

Jeff Dike wrote:
> On Tue, Apr 20, 2010 at 06:09:49PM +0800, Amerigo Wang wrote:
>> On Mon, Apr 19, 2010 at 11:53:06PM +0200, Jan Kiszka wrote:
>>> We can't pull in linux/sched.h, so just declare the struct.
>>>
>> Did you meet any build error? If yes, please include it.
> 
> What does this patch fix, aside from being a bit cleaner?

  CC      arch/um/sys-i386/elfcore.o
In file included from /data/linux-2.6/include/linux/elf.h:8,
                 from /data/linux-2.6/arch/um/sys-i386/elfcore.c:2:
/data/linux-2.6/arch/um/sys-i386/asm/elf.h:78: warning: ‘struct task_struct’ declared inside parameter list
/data/linux-2.6/arch/um/sys-i386/asm/elf.h:78: warning: its scope is only this definition or declaration, which is probably not what you want

I guess not many people build against i386 hosts anymore, so this
remained widely unnoticed.

> 
> If it built before, without having a task_struct declaration, I think
> that means that the elf_core_copy_fpregs was never used.  The
> task_struct * in the declaration would become a private task_struct,
> known only to the declaration.  If the implementation or callers have
> the regular task_struct, it will be a different one, and the
> prototypes will conflict due to the different types of the first
> parameter.

This is just a forward declaration (that many arch elf header include),
so no such problem exists.

BTW, to answer the other question in this thread: We have a circular
dependency that prevents including sched.h.

I can add all these information to some v2 of this patch if it is
required to get this merged. Please let me know.

Jan



[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 257 bytes --]