Re: [PATCH][RFC] err.h: silence sparse warning: dereference of noderef expression

[Jeff Layton]

On Wed, 11 Jun 2014 16:11:46 +0300
Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote:

> On Wed, Jun 11, 2014 at 07:06:32AM -0400, Jeff Layton wrote:
> > $ rpm -q sparse
> > sparse-0.5.0-1.fc20.x86_64
> >
> > I see it all over the tree, but an easy example is fs/locks.c:
> > 
> > $ make fs/locks.o C=1
> > make[1]: Nothing to be done for `all'.
> > make[1]: Nothing to be done for `relocs'.
> >   CHK     include/config/kernel.release
> >   CHK     include/generated/uapi/linux/version.h
> >   CHK     include/generated/utsrelease.h
> >   CALL    scripts/checksyscalls.sh
> >   CHECK   fs/locks.c
> > include/linux/err.h:35:16: warning: dereference of noderef expression
> > include/linux/err.h:30:23: warning: dereference of noderef expression
> > include/linux/err.h:35:16: warning: dereference of noderef expression
> > include/linux/err.h:30:23: warning: dereference of noderef expression
> >   CC      fs/locks.o
> > 
> > It has two IS_ERR calls and two PTR_ERR calls, and each generates the
> > warning.
> >
> 
> I downloaded the Fedora SRPM and built the binary but I still wasn't
> able to reproduce the bug.
> 
> dcarpenter@speke:~/progs/kernel/devel$ /tmp/sparse/sparse-0.5.0/sparse --version
> 0.5.0
> dcarpenter@speke:~/progs/kernel/devel$ make C=2 CHECK=/tmp/sparse/sparse-0.5.0/sparse fs/locks.o
>   CHK     include/config/kernel.release
>   CHK     include/generated/uapi/linux/version.h
>   CHK     include/generated/utsrelease.h
>   CALL    scripts/checksyscalls.sh
> <stdin>:1226:2: warning: #warning syscall finit_module not implemented [-Wcpp]
> <stdin>:1229:2: warning: #warning syscall sched_setattr not implemented [-Wcpp]
> <stdin>:1232:2: warning: #warning syscall sched_getattr not implemented [-Wcpp]
> <stdin>:1235:2: warning: #warning syscall renameat2 not implemented [-Wcpp]
>   CHECK   scripts/mod/empty.c
>   CHECK   fs/locks.c
> dcarpenter@speke:~/progs/kernel/devel$
> 
> I'm on today's linux-next.  I can't think of a kernel configuration
> issue which would cause this...
> 
> regards,
> dan carpenter

Could it be arch-specific then? What arch are you using? I'm on x86_64.
I know that quite a few other people have mentioned seeing these
warnings as well, so I'm pretty sure it's not just me.

-- 
Jeff Layton <jlayton@xxxxxxxxxxxxxxx>
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