From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 27997C433E2 for ; Mon, 14 Sep 2020 12:56:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E5F87208E4 for ; Mon, 14 Sep 2020 12:56:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726577AbgINM4P (ORCPT ); Mon, 14 Sep 2020 08:56:15 -0400 Received: from relay10.mail.gandi.net ([217.70.178.230]:43219 "EHLO relay10.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726376AbgINMv4 (ORCPT ); Mon, 14 Sep 2020 08:51:56 -0400 Received: from uno.localdomain (93-34-118-233.ip49.fastwebnet.it [93.34.118.233]) (Authenticated sender: jacopo@jmondi.org) by relay10.mail.gandi.net (Postfix) with ESMTPSA id 0C83D24000C; Mon, 14 Sep 2020 12:51:35 +0000 (UTC) Date: Mon, 14 Sep 2020 14:55:26 +0200 From: Jacopo Mondi To: Laurent Pinchart Cc: linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org, Jacopo Mondi , Kieran Bingham , Niklas =?utf-8?Q?S=C3=B6derlund?= , Ramesh Shanmugasundaram , Sakari Ailus , Steve Longerbeam Subject: Re: [PATCH 5/5] media: i2c: max9286: Allocate v4l2_async_subdev dynamically Message-ID: <20200914125526.kukq5pir7jgamekv@uno.localdomain> References: <20200811205939.19550-1-laurent.pinchart+renesas@ideasonboard.com> <20200811205939.19550-6-laurent.pinchart+renesas@ideasonboard.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200811205939.19550-6-laurent.pinchart+renesas@ideasonboard.com> Sender: linux-renesas-soc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-renesas-soc@vger.kernel.org Hi Laurent, On Tue, Aug 11, 2020 at 11:59:39PM +0300, Laurent Pinchart wrote: > v4l2_async_notifier_add_subdev() requires the asd to be allocated > dynamically, but the max9286 driver embeds it in the max9286_source > structure. This causes memory corruption when the notifier is destroyed > at remove time with v4l2_async_notifier_cleanup(). > > Fix this issue by registering the asd with > v4l2_async_notifier_add_fwnode_subdev(), which allocates it dynamically > internally. A new max9286_asd structure is introduced, to store a > pointer to the corresonding max9286_source that needs to be accessed > from bound and unbind callbacks. There's no need to take an extra > explicit reference to the fwnode anymore as > v4l2_async_notifier_add_fwnode_subdev() does so internally. > > While at it, use %u instead of %d to print the unsigned index in the > error message from the v4l2_async_notifier_add_fwnode_subdev() error > path. > > Fixes: 66d8c9d2422d ("media: i2c: Add MAX9286 driver") > Signed-off-by: Laurent Pinchart > --- > drivers/media/i2c/max9286.c | 38 +++++++++++++++++++------------------ > 1 file changed, 20 insertions(+), 18 deletions(-) > > diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c > index 47f280518fdb..5d890dddb376 100644 > --- a/drivers/media/i2c/max9286.c > +++ b/drivers/media/i2c/max9286.c > @@ -135,13 +135,19 @@ > #define MAX9286_SRC_PAD 4 > > struct max9286_source { > - struct v4l2_async_subdev asd; > struct v4l2_subdev *sd; > struct fwnode_handle *fwnode; > }; > > -#define asd_to_max9286_source(_asd) \ > - container_of(_asd, struct max9286_source, asd) > +struct max9286_asd { > + struct v4l2_async_subdev base; > + struct max9286_source *source; > +}; > + > +static inline struct max9286_asd *to_max9286_asd(struct v4l2_async_subdev *asd) > +{ > + return container_of(asd, struct max9286_asd, base); > +} > > struct max9286_priv { > struct i2c_client *client; > @@ -480,7 +486,7 @@ static int max9286_notify_bound(struct v4l2_async_notifier *notifier, > struct v4l2_async_subdev *asd) > { > struct max9286_priv *priv = sd_to_max9286(notifier->sd); > - struct max9286_source *source = asd_to_max9286_source(asd); > + struct max9286_source *source = to_max9286_asd(asd)->source; > unsigned int index = to_index(priv, source); > unsigned int src_pad; > int ret; > @@ -544,7 +550,7 @@ static void max9286_notify_unbind(struct v4l2_async_notifier *notifier, > struct v4l2_async_subdev *asd) > { > struct max9286_priv *priv = sd_to_max9286(notifier->sd); > - struct max9286_source *source = asd_to_max9286_source(asd); > + struct max9286_source *source = to_max9286_asd(asd)->source; > unsigned int index = to_index(priv, source); > > source->sd = NULL; > @@ -569,23 +575,19 @@ static int max9286_v4l2_notifier_register(struct max9286_priv *priv) > > for_each_source(priv, source) { > unsigned int i = to_index(priv, source); > + struct v4l2_async_subdev *asd; > > - source->asd.match_type = V4L2_ASYNC_MATCH_FWNODE; > - source->asd.match.fwnode = source->fwnode; > - > - ret = v4l2_async_notifier_add_subdev(&priv->notifier, > - &source->asd); > - if (ret) { > - dev_err(dev, "Failed to add subdev for source %d", i); > + asd = v4l2_async_notifier_add_fwnode_subdev(&priv->notifier, > + source->fwnode, > + sizeof(*asd)); This should be sizeof(struct max9286_asd), but suprisingly, it doesn't fail at runtime :) I'll send a patch for this in the meantime. Thanks j > + if (IS_ERR(asd)) { > + dev_err(dev, "Failed to add subdev for source %u: %ld", > + i, PTR_ERR(asd)); > v4l2_async_notifier_cleanup(&priv->notifier); > - return ret; > + return PTR_ERR(asd); > } > > - /* > - * Balance the reference counting handled through > - * v4l2_async_notifier_cleanup() > - */ > - fwnode_handle_get(source->fwnode); > + to_max9286_asd(asd)->source = source; > } > > priv->notifier.ops = &max9286_notify_ops; > -- > Regards, > > Laurent Pinchart >