Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933317AbeAAOrI (ORCPT + 1 other); Mon, 1 Jan 2018 09:47:08 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:46888 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933284AbeAAOrF (ORCPT ); Mon, 1 Jan 2018 09:47:05 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Thierry Reding , Johan Hovold , Kishon Vijay Abraham I Subject: [PATCH 4.14 135/146] phy: tegra: fix device-tree node lookups Date: Mon, 1 Jan 2018 15:38:46 +0100 Message-Id: <20180101140143.302027142@linuxfoundation.org> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20180101140123.743014891@linuxfoundation.org> References: <20180101140123.743014891@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Johan Hovold commit 046046737bd35bed047460f080ea47e186be731e upstream. Fix child-node lookups during probe, which ended up searching the whole device tree depth-first starting at the parents rather than just matching on their children. To make things worse, some parent nodes could end up being being prematurely freed (by tegra_xusb_pad_register()) as of_find_node_by_name() drops a reference to its first argument. Fixes: 53d2a715c240 ("phy: Add Tegra XUSB pad controller support") Cc: Thierry Reding Signed-off-by: Johan Hovold Signed-off-by: Kishon Vijay Abraham I Signed-off-by: Greg Kroah-Hartman --- drivers/phy/tegra/xusb.c | 60 +++++++++++++++++++++++------------------------ 1 file changed, 30 insertions(+), 30 deletions(-) --- a/drivers/phy/tegra/xusb.c +++ b/drivers/phy/tegra/xusb.c @@ -75,14 +75,14 @@ MODULE_DEVICE_TABLE(of, tegra_xusb_padct static struct device_node * tegra_xusb_find_pad_node(struct tegra_xusb_padctl *padctl, const char *name) { - /* - * of_find_node_by_name() drops a reference, so make sure to grab one. - */ - struct device_node *np = of_node_get(padctl->dev->of_node); + struct device_node *pads, *np; - np = of_find_node_by_name(np, "pads"); - if (np) - np = of_find_node_by_name(np, name); + pads = of_get_child_by_name(padctl->dev->of_node, "pads"); + if (!pads) + return NULL; + + np = of_get_child_by_name(pads, name); + of_node_put(pads); return np; } @@ -90,16 +90,16 @@ tegra_xusb_find_pad_node(struct tegra_xu static struct device_node * tegra_xusb_pad_find_phy_node(struct tegra_xusb_pad *pad, unsigned int index) { - /* - * of_find_node_by_name() drops a reference, so make sure to grab one. - */ - struct device_node *np = of_node_get(pad->dev.of_node); + struct device_node *np, *lanes; - np = of_find_node_by_name(np, "lanes"); - if (!np) + lanes = of_get_child_by_name(pad->dev.of_node, "lanes"); + if (!lanes) return NULL; - return of_find_node_by_name(np, pad->soc->lanes[index].name); + np = of_get_child_by_name(lanes, pad->soc->lanes[index].name); + of_node_put(lanes); + + return np; } static int @@ -195,7 +195,7 @@ int tegra_xusb_pad_register(struct tegra unsigned int i; int err; - children = of_find_node_by_name(pad->dev.of_node, "lanes"); + children = of_get_child_by_name(pad->dev.of_node, "lanes"); if (!children) return -ENODEV; @@ -444,21 +444,21 @@ static struct device_node * tegra_xusb_find_port_node(struct tegra_xusb_padctl *padctl, const char *type, unsigned int index) { - /* - * of_find_node_by_name() drops a reference, so make sure to grab one. - */ - struct device_node *np = of_node_get(padctl->dev->of_node); + struct device_node *ports, *np; + char *name; + + ports = of_get_child_by_name(padctl->dev->of_node, "ports"); + if (!ports) + return NULL; - np = of_find_node_by_name(np, "ports"); - if (np) { - char *name; - - name = kasprintf(GFP_KERNEL, "%s-%u", type, index); - if (!name) - return ERR_PTR(-ENOMEM); - np = of_find_node_by_name(np, name); - kfree(name); + name = kasprintf(GFP_KERNEL, "%s-%u", type, index); + if (!name) { + of_node_put(ports); + return ERR_PTR(-ENOMEM); } + np = of_get_child_by_name(ports, name); + kfree(name); + of_node_put(ports); return np; } @@ -847,7 +847,7 @@ static void tegra_xusb_remove_ports(stru static int tegra_xusb_padctl_probe(struct platform_device *pdev) { - struct device_node *np = of_node_get(pdev->dev.of_node); + struct device_node *np = pdev->dev.of_node; const struct tegra_xusb_padctl_soc *soc; struct tegra_xusb_padctl *padctl; const struct of_device_id *match; @@ -855,7 +855,7 @@ static int tegra_xusb_padctl_probe(struc int err; /* for backwards compatibility with old device trees */ - np = of_find_node_by_name(np, "pads"); + np = of_get_child_by_name(np, "pads"); if (!np) { dev_warn(&pdev->dev, "deprecated DT, using legacy driver\n"); return tegra_xusb_padctl_legacy_probe(pdev);