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From: Jarkko Sakkinen <jarkko@kernel.org>
To: kbuild-all@lists.01.org
Subject: Re: [bp:tip-x86-sgx 11/25] arch/x86/kernel/cpu/sgx/encl.h:45:19: warning: variable 'encl' set but not used
Date: Wed, 18 Nov 2020 17:01:29 +0200
Message-ID: <20201118150129.GA30164@kernel.org>
In-Reply-To: <20201118104254.GA8122@zn.tnic>
List-Id: <oe-kbuild-all.lists.linux.dev>

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On Wed, Nov 18, 2020 at 11:42:54AM +0100, Borislav Petkov wrote:
> On Wed, Nov 18, 2020 at 11:23:55AM +0800, kernel test robot wrote:
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/bp/bp.git tip-x=
86-sgx
> > head:   56e2d0eff4f8db87cf77d9c8481041878177c680
> > commit: 4b634f57cac2e1d28cfa0ca961e561362fc3f957 [11/25] x86/sgx: Add a=
n SGX misc driver interface
> > config: x86_64-allyesconfig (attached as .config)
> > compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
> > reproduce (this is a W=3D1 build):
> >         # https://git.kernel.org/pub/scm/linux/kernel/git/bp/bp.git/com=
mit/?id=3D4b634f57cac2e1d28cfa0ca961e561362fc3f957
> >         git remote add bp https://git.kernel.org/pub/scm/linux/kernel/g=
it/bp/bp.git
> >         git fetch --no-tags bp tip-x86-sgx
> >         git checkout 4b634f57cac2e1d28cfa0ca961e561362fc3f957
> >         # save the attached .config to linux build tree
> >         make W=3D1 ARCH=3Dx86_64 =

> > =

> > If you fix the issue, kindly add following tag as appropriate
> > Reported-by: kernel test robot <lkp@intel.com>
> > =

> > All warnings (new ones prefixed by >>):
> > =

> >    In file included from arch/x86/kernel/cpu/sgx/driver.c:11:
> >    arch/x86/kernel/cpu/sgx/encl.h: In function 'sgx_encl_find':
> > >> arch/x86/kernel/cpu/sgx/encl.h:45:19: warning: variable 'encl' set b=
ut not used [-Wunused-but-set-variable]
> >       45 |  struct sgx_encl *encl;
> >          |                   ^~~~
> > =

> > vim +/encl +45 arch/x86/kernel/cpu/sgx/encl.h
> > =

> >     40	=

> >     41	static inline int sgx_encl_find(struct mm_struct *mm, unsigned l=
ong addr,
> >     42					struct vm_area_struct **vma)
> >     43	{
> >     44		struct vm_area_struct *result;
> >   > 45		struct sgx_encl *encl;
> >     46	=

> >     47		result =3D find_vma(mm, addr);
> >     48		if (!result || result->vm_ops !=3D &sgx_vm_ops || addr < result=
->vm_start)
> >     49			return -EINVAL;
> >     50	=

> >     51		encl =3D result->vm_private_data;
> =

> Looks like that encl needs to go, judging by:
> =

> * Do not check !vm_private_data in sgx_encl_find(), as the enclave is
>   created at VFS open.
> =

> in patch 11.
> =

> Jarkko?

Yes, it is useless.

> -- =

> Regards/Gruss,
>     Boris.
> =

> SUSE Software Solutions Germany GmbH, GF: Felix Imend=C3=B6rffer, HRB 368=
09, AG N=C3=BCrnberg
 =


 /Jarkko
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