Re: PROBLEM: kernel 2.6.22.9-cfs-v22 compile warnings

From: Ahmed S. Darwish
Date: Mon Oct 08 2007 - 14:11:55 EST


Hi Konstantin,

On Mon, Oct 08, 2007 at 03:34:24PM +0300, Konstantin Oshovskij wrote:
>
> Hello,
> i have encountered 2.6.22.9 compile warnings. This is the first time i
> decided to report them. I had various compile warnings with earlier
> kernel versions, its just i didnt had courage to report them :) I'm
> using instructions from REPORTING-BUGS file as template so please bear
> with me :)
>

The "may be used uninitialized" errors are false positives from GCC. Mostly
this happens from code paths like:

int x, y;
set_method(&x);
y = x;

> fs/xfs/xfs_bmap.c: In function 'xfs_bmap_rtalloc':
> fs/xfs/xfs_bmap.c:2650: warning: 'rtx' is used uninitialized in this
> function
>

Hidden by uninitialized_var() macro in latest pull. This macro silence
the gcc by using the trick: #define uninitialized_var(x) x = x

> function
> ipc/msg.c:390: warning: 'setbuf.mode' may be used uninitialized in
> this function
> CC ipc/sem.o
> ipc/sem.c: In function 'sys_semctl':
> ipc/sem.c:861: warning: 'setbuf.uid' may be used uninitialized in this
> function
> ipc/sem.c:861: warning: 'setbuf.gid' may be used uninitialized in this
> function
> ipc/sem.c:861: warning: 'setbuf.mode' may be used uninitialized in
> this function
>

Already hidden now by the uninitialized_var() macro.

> drivers/pci/search.c: In function 'pci_find_slot':
> drivers/pci/search.c:99: warning: 'pci_find_device' is deprecated
> (declared at include/linux/pci.h:477)

pci_find_slot is using pci_find_device on purpose here (equivalent to the
safe pci_get_slot method).

> drivers/pci/search.c: At top level:
> drivers/pci/search.c:434: warning: 'pci_find_device' is deprecated
> (declared at drivers/pci/search.c:241)
> drivers/pci/search.c:434: warning: 'pci_find_device' is deprecated
> (declared at drivers/pci/search.c:241)
>

False positives from function definition and from the innocent EXPORT_SYMBOL
macro (It makes the method available to kernel modules).

Regards,

--
Ahmed S. Darwish
HomePage: http://darwish.07.googlepages.com
Blog: http://darwish-07.blogspot.com
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