From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Hilman Subject: Re: [PATCH] omap: resource: Fix race in register_resource() Date: Wed, 30 Sep 2009 09:44:37 -0700 Message-ID: <871vloo00a.fsf@deeprootsystems.com> References: <1253230331-701-1-git-send-email-mike@android.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-px0-f194.google.com ([209.85.216.194]:36244 "EHLO mail-px0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752678AbZI3Qoi (ORCPT ); Wed, 30 Sep 2009 12:44:38 -0400 Received: by pxi32 with SMTP id 32so5613200pxi.4 for ; Wed, 30 Sep 2009 09:44:42 -0700 (PDT) In-Reply-To: <1253230331-701-1-git-send-email-mike@android.com> (Mike Chan's message of "Thu\, 17 Sep 2009 16\:32\:11 -0700") Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Mike Chan Cc: linux-omap@vger.kernel.org Mike Chan writes: > Checking if the resource is already registered and adding to the list > must be atomic or bad things can happen. > > Signed-off-by: Mike Chan Thanks, this one applies. Pushing to PM branch and pm-2.6.29. Kevin > --- > arch/arm/plat-omap/resource.c | 13 ++++++++----- > 1 files changed, 8 insertions(+), 5 deletions(-) > > diff --git a/arch/arm/plat-omap/resource.c b/arch/arm/plat-omap/resource.c > index 111020a..4631912 100644 > --- a/arch/arm/plat-omap/resource.c > +++ b/arch/arm/plat-omap/resource.c > @@ -255,6 +255,7 @@ int resource_refresh(void) > */ > int resource_register(struct shared_resource *resp) > { > + int ret = 0; > if (!resp) > return -EINVAL; > > @@ -262,12 +263,13 @@ int resource_register(struct shared_resource *resp) > return -EINVAL; > > /* Verify that the resource is not already registered */ > - if (resource_lookup(resp->name)) > - return -EEXIST; > + down(&res_mutex); > + if (_resource_lookup(resp->name)) > + ret = -EEXIST; > + goto out; > > INIT_LIST_HEAD(&resp->users_list); > > - down(&res_mutex); > /* Add the resource to the resource list */ > list_add(&resp->node, &res_list); > > @@ -275,10 +277,11 @@ int resource_register(struct shared_resource *resp) > if (resp->ops->init) > resp->ops->init(resp); > > - up(&res_mutex); > pr_debug("resource: registered %s\n", resp->name); > > - return 0; > +out: > + up(&res_mutex); > + return ret; > } > EXPORT_SYMBOL(resource_register); > > -- > 1.5.4.5