From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753446AbdK1PPo (ORCPT ); Tue, 28 Nov 2017 10:15:44 -0500 Received: from mail-ot0-f194.google.com ([74.125.82.194]:32863 "EHLO mail-ot0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753379AbdK1PPk (ORCPT ); Tue, 28 Nov 2017 10:15:40 -0500 X-Google-Smtp-Source: AGs4zMYJV9hxopm9s8jYZsIDGLtHZPfGI/N2TDBUOGZaP5/8OHtsISOMNALGf8c1y00BJd5iU+VTqA== Date: Tue, 28 Nov 2017 09:15:38 -0600 From: Rob Herring To: Alan Tull Cc: Frank Rowand , Pantelis Antoniou , Moritz Fischer , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fpga@vger.kernel.org Subject: Re: [RFC 1/2] of: overlay: add whitelist Message-ID: <20171128151538.2w6fjcib6my6wt5n@rob-hp-laptop> References: <1511816284-12145-1-git-send-email-atull@kernel.org> <1511816284-12145-2-git-send-email-atull@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1511816284-12145-2-git-send-email-atull@kernel.org> User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 27, 2017 at 02:58:03PM -0600, Alan Tull wrote: > Add simple whitelist. When an overlay is submitted, if any target in > the overlay is not in the whitelist, the overlay is rejected. Drivers > that support dynamic configuration can register their device node with: > > int of_add_whitelist_node(struct device_node *np) > > and remove themselves with: > > void of_remove_whitelist_node(struct device_node *np) I think these should be named for what they do, not how it is implemented. > > Signed-off-by: Alan Tull > --- > drivers/of/overlay.c | 73 ++++++++++++++++++++++++++++++++++++++++++++++++++++ > include/linux/of.h | 12 +++++++++ > 2 files changed, 85 insertions(+) > > diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c > index c150abb..5f952a1 100644 > --- a/drivers/of/overlay.c > +++ b/drivers/of/overlay.c > @@ -21,6 +21,7 @@ > #include > #include > #include > +#include > > #include "of_private.h" > > @@ -646,6 +647,74 @@ static void free_overlay_changeset(struct overlay_changeset *ovcs) > kfree(ovcs); > } > > +/* lock for adding/removing device nodes to the whitelist */ > +static spinlock_t whitelist_lock; > + > +static struct list_head whitelist_list = LIST_HEAD_INIT(whitelist_list); > + > +struct dt_overlay_whitelist { > + struct device_node *np; > + struct list_head node; > +}; Can't we just add a flags bit in device_node.flags? That would be much simpler. > + > +int of_add_whitelist_node(struct device_node *np) > +{ > + unsigned long flags; > + struct dt_overlay_whitelist *wln; > + > + wln = kzalloc(sizeof(*wln), GFP_KERNEL); > + if (!wln) > + return -ENOMEM; > + > + wln->np = np; > + > + spin_lock_irqsave(&whitelist_lock, flags); > + list_add(&wln->node, &whitelist_list); > + spin_unlock_irqrestore(&whitelist_lock, flags); > + > + return 0; > +} > +EXPORT_SYMBOL_GPL(of_add_whitelist_node); > + > +void of_remove_whitelist_node(struct device_node *np) > +{ > + struct dt_overlay_whitelist *wln; > + unsigned long flags; > + > + list_for_each_entry(wln, &whitelist_list, node) { > + if (np == wln->np) { > + spin_lock_irqsave(&whitelist_lock, flags); > + list_del(&wln->node); > + spin_unlock_irqrestore(&whitelist_lock, flags); > + kfree(wln); > + return; > + } > + } > +} > +EXPORT_SYMBOL_GPL(of_remove_whitelist_node); > + > +static int of_check_whitelist(struct overlay_changeset *ovcs) > +{ > + struct dt_overlay_whitelist *wln; > + struct device_node *target; > + int i; > + > + for (i = 0; i < ovcs->count; i++) { > + target = ovcs->fragments[i].target; > + if (!of_node_cmp(target->name, "__symbols__")) > + continue; > + > + list_for_each_entry(wln, &whitelist_list, node) > + if (target == wln->np) > + break; > + > + if (target != wln->np) > + return -ENODEV; > + } > + > + return 0; > +} > + > /** > * of_overlay_apply() - Create and apply an overlay changeset > * @tree: Expanded overlay device tree > @@ -717,6 +786,10 @@ int of_overlay_apply(struct device_node *tree, int *ovcs_id) > if (ret) > goto err_free_overlay_changeset; > > + ret = of_check_whitelist(ovcs); > + if (ret) > + goto err_free_overlay_changeset; This will break you until the next patch and breaks any other users. I think this is now just the unittest as tilcdc overlay is getting removed. You have to make this chunk the last patch in the series. Rob