Return-Path: linux-nfs-owner@vger.kernel.org Received: from fieldses.org ([174.143.236.118]:53468 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751952AbaGQUQu (ORCPT ); Thu, 17 Jul 2014 16:16:50 -0400 Date: Thu, 17 Jul 2014 16:16:50 -0400 From: "J. Bruce Fields" To: Jeff Layton Cc: linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] nfsd: silence sparse warning about accessing credentials Message-ID: <20140717201649.GF30442@fieldses.org> References: <1405443576-28348-1-git-send-email-jlayton@primarydata.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1405443576-28348-1-git-send-email-jlayton@primarydata.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Tue, Jul 15, 2014 at 12:59:36PM -0400, Jeff Layton wrote: > sparse says: > > fs/nfsd/auth.c:31:38: warning: incorrect type in argument 1 (different address spaces) > fs/nfsd/auth.c:31:38: expected struct cred const *cred > fs/nfsd/auth.c:31:38: got struct cred const [noderef] *real_cred > > Add a new accessor for the ->real_cred and use that to fetch the > pointer. Accessing current->real_cred directly is actually quite safe > since we know that they can't go away so this is mostly a cosmetic fixup > to silence sparse. Thanks, applying, absent any objections. --b. > > Signed-off-by: Jeff Layton > --- > fs/nfsd/auth.c | 2 +- > include/linux/cred.h | 9 +++++++++ > 2 files changed, 10 insertions(+), 1 deletion(-) > > diff --git a/fs/nfsd/auth.c b/fs/nfsd/auth.c > index 72f44823adbb..9d46a0bdd9f9 100644 > --- a/fs/nfsd/auth.c > +++ b/fs/nfsd/auth.c > @@ -28,7 +28,7 @@ int nfsd_setuser(struct svc_rqst *rqstp, struct svc_export *exp) > validate_process_creds(); > > /* discard any old override before preparing the new set */ > - revert_creds(get_cred(current->real_cred)); > + revert_creds(get_cred(current_real_cred())); > new = prepare_creds(); > if (!new) > return -ENOMEM; > diff --git a/include/linux/cred.h b/include/linux/cred.h > index f61d6c8f5ef3..b2d0820837c4 100644 > --- a/include/linux/cred.h > +++ b/include/linux/cred.h > @@ -259,6 +259,15 @@ static inline void put_cred(const struct cred *_cred) > rcu_dereference_protected(current->cred, 1) > > /** > + * current_real_cred - Access the current task's objective credentials > + * > + * Access the objective credentials of the current task. RCU-safe, > + * since nobody else can modify it. > + */ > +#define current_real_cred() \ > + rcu_dereference_protected(current->real_cred, 1) > + > +/** > * __task_cred - Access a task's objective credentials > * @task: The task to query > * > -- > 1.9.3 >