From patchwork Sat Feb 17 15:02:24 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johan Hovold X-Patchwork-Id: 13561405 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C81A1C48BC4 for ; Sat, 17 Feb 2024 15:03:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=A4L/UiEBnFxqoxYIcS1OKsvdOAfqPcwkv9L8oR0mMTU=; b=DfCI+NsoBaB5OB Xq9mb2YWVbl3peP6gGcSC02Siq9BHSEngvIXTlkXgbHRCR1Xqwz1WIn5FmbAps3GiHCIcUlDMwqxk 9s7md/u5JewsHjo+q9miqV73fCaWhQBWm3dThYdGJSkQNwy5ydg2+KzyWHWiYyyO6oq3PO1GgxLHU CDLMPW/4+iOBsKmyfnlRFqXGcsJbaC8shi9r1QhDEv6usAADYjgAU6lP7+4OrYLutxzQBgiIdurb2 7H99EHby7FwjRfoHilfgnQsj5h+4nD7BlLk8K3sv+bdyte2mKFqLrnrlJun3CKp+S4bRnih3/eLDe tClyeihz+M8DH15kwKNQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rbMDe-00000005sjA-3pbV; Sat, 17 Feb 2024 15:03:10 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rbMDY-00000005sfj-3hHs for linux-phy@lists.infradead.org; Sat, 17 Feb 2024 15:03:07 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id DF901611BE; Sat, 17 Feb 2024 15:03:03 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 12F4AC43390; Sat, 17 Feb 2024 15:03:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1708182183; bh=UrO8iSOZ0DaThfpdYnA1yNkyhVkUZHq2oInX+0bHaNU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NaZiHiRTPIbfPSO9V0T+nG2YbfYd4RoH8ksqJQQ1dehfcWd2IBpfDfHByIOYR552k nFE6hEIT8qeuW8E1DS42blBrIgHYehI0FYTJGCYTibnUeVmyZJiOsvTtME4KgkAEe1 2DZMp8TbZu2Mg7JL+VzvP8/SC4bf+EeS4GljpXWaWwPxOIFZ7DYN71gVu5IEEVjh+w DzXELAT5AkdX51DLJnuyzx5+kHBA06WxIT15EspnGNlrpCt7XfgVUA4CP7eTv9tjWo yjnjggK8Df0jykaNcY2Dpx0NYTW6TsHn3D25leWURtAkgUtuWIOc5QR84HO7i0InVS Lg+4YkPkvcdxQ== Received: from johan by xi.lan with local (Exim 4.97.1) (envelope-from ) id 1rbMDW-000000001Vq-2fLy; Sat, 17 Feb 2024 16:03:02 +0100 From: Johan Hovold To: Bjorn Andersson , Andrzej Hajda , Neil Armstrong , Robert Foss , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , Vinod Koul Cc: Jonas Karlman , Laurent Pinchart , Jernej Skrabec , Konrad Dybcio , Kishon Vijay Abraham I , Dmitry Baryshkov , Rob Clark , Abhinav Kumar , Kuogee Hsieh , freedreno@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-phy@lists.infradead.org, Johan Hovold Subject: [PATCH 2/6] drm/bridge: aux-hpd: separate allocation and registration Date: Sat, 17 Feb 2024 16:02:24 +0100 Message-ID: <20240217150228.5788-3-johan+linaro@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240217150228.5788-1-johan+linaro@kernel.org> References: <20240217150228.5788-1-johan+linaro@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240217_070305_085433_733BD4BE X-CRM114-Status: GOOD ( 15.25 ) X-BeenThere: linux-phy@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux Phy Mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-phy" Errors-To: linux-phy-bounces+linux-phy=archiver.kernel.org@lists.infradead.org Combining allocation and registration is an anti-pattern that should be avoided. Add two new functions for allocating and registering an dp-hpd bridge with a proper 'devm' prefix so that it is clear that these are device managed interfaces. devm_drm_dp_hpd_bridge_alloc() devm_drm_dp_hpd_bridge_add() The new interface will be used to fix a use-after-free bug in the Qualcomm PMIC GLINK driver and may prevent similar issues from being introduced elsewhere. The existing drm_dp_hpd_bridge_register() is reimplemented using the above and left in place for now. Signed-off-by: Johan Hovold Reviewed-by: Bjorn Andersson Reviewed-by: Dmitry Baryshkov --- drivers/gpu/drm/bridge/aux-hpd-bridge.c | 67 +++++++++++++++++++------ include/drm/bridge/aux-bridge.h | 15 ++++++ 2 files changed, 67 insertions(+), 15 deletions(-) diff --git a/drivers/gpu/drm/bridge/aux-hpd-bridge.c b/drivers/gpu/drm/bridge/aux-hpd-bridge.c index 9e71daf95bde..6886db2d9e00 100644 --- a/drivers/gpu/drm/bridge/aux-hpd-bridge.c +++ b/drivers/gpu/drm/bridge/aux-hpd-bridge.c @@ -30,16 +30,13 @@ static void drm_aux_hpd_bridge_release(struct device *dev) kfree(adev); } -static void drm_aux_hpd_bridge_unregister_adev(void *_adev) +static void drm_aux_hpd_bridge_free_adev(void *_adev) { - struct auxiliary_device *adev = _adev; - - auxiliary_device_delete(adev); - auxiliary_device_uninit(adev); + auxiliary_device_uninit(_adev); } /** - * drm_dp_hpd_bridge_register - Create a simple HPD DisplayPort bridge + * devm_drm_dp_hpd_bridge_alloc - allocate a HPD DisplayPort bridge * @parent: device instance providing this bridge * @np: device node pointer corresponding to this bridge instance * @@ -47,11 +44,9 @@ static void drm_aux_hpd_bridge_unregister_adev(void *_adev) * DRM_MODE_CONNECTOR_DisplayPort, which terminates the bridge chain and is * able to send the HPD events. * - * Return: device instance that will handle created bridge or an error code - * encoded into the pointer. + * Return: bridge auxiliary device pointer or an error pointer */ -struct device *drm_dp_hpd_bridge_register(struct device *parent, - struct device_node *np) +struct auxiliary_device *devm_drm_dp_hpd_bridge_alloc(struct device *parent, struct device_node *np) { struct auxiliary_device *adev; int ret; @@ -82,13 +77,55 @@ struct device *drm_dp_hpd_bridge_register(struct device *parent, return ERR_PTR(ret); } - ret = auxiliary_device_add(adev); - if (ret) { - auxiliary_device_uninit(adev); + ret = devm_add_action_or_reset(parent, drm_aux_hpd_bridge_free_adev, adev); + if (ret) return ERR_PTR(ret); - } - ret = devm_add_action_or_reset(parent, drm_aux_hpd_bridge_unregister_adev, adev); + return adev; +} +EXPORT_SYMBOL_GPL(devm_drm_dp_hpd_bridge_alloc); + +static void drm_aux_hpd_bridge_del_adev(void *_adev) +{ + auxiliary_device_delete(_adev); +} + +/** + * devm_drm_dp_hpd_bridge_add - register a HDP DisplayPort bridge + * @dev: struct device to tie registration lifetime to + * @adev: bridge auxiliary device to be registered + * + * Returns: zero on success or a negative errno + */ +int devm_drm_dp_hpd_bridge_add(struct device *dev, struct auxiliary_device *adev) +{ + int ret; + + ret = auxiliary_device_add(adev); + if (ret) + return ret; + + return devm_add_action_or_reset(dev, drm_aux_hpd_bridge_del_adev, adev); +} +EXPORT_SYMBOL_GPL(devm_drm_dp_hpd_bridge_add); + +/** + * drm_dp_hpd_bridge_register - allocate and register a HDP DisplayPort bridge + * @parent: device instance providing this bridge + * @np: device node pointer corresponding to this bridge instance + * + * Return: device instance that will handle created bridge or an error pointer + */ +struct device *drm_dp_hpd_bridge_register(struct device *parent, struct device_node *np) +{ + struct auxiliary_device *adev; + int ret; + + adev = devm_drm_dp_hpd_bridge_alloc(parent, np); + if (IS_ERR(adev)) + return ERR_CAST(adev); + + ret = devm_drm_dp_hpd_bridge_add(parent, adev); if (ret) return ERR_PTR(ret); diff --git a/include/drm/bridge/aux-bridge.h b/include/drm/bridge/aux-bridge.h index c4c423e97f06..4453906105ca 100644 --- a/include/drm/bridge/aux-bridge.h +++ b/include/drm/bridge/aux-bridge.h @@ -9,6 +9,8 @@ #include +struct auxiliary_device; + #if IS_ENABLED(CONFIG_DRM_AUX_BRIDGE) int drm_aux_bridge_register(struct device *parent); #else @@ -19,10 +21,23 @@ static inline int drm_aux_bridge_register(struct device *parent) #endif #if IS_ENABLED(CONFIG_DRM_AUX_HPD_BRIDGE) +struct auxiliary_device *devm_drm_dp_hpd_bridge_alloc(struct device *parent, struct device_node *np); +int devm_drm_dp_hpd_bridge_add(struct device *dev, struct auxiliary_device *adev); struct device *drm_dp_hpd_bridge_register(struct device *parent, struct device_node *np); void drm_aux_hpd_bridge_notify(struct device *dev, enum drm_connector_status status); #else +static inline struct auxiliary_device *devm_drm_dp_hpd_bridge_alloc(struct device *parent, + struct device_node *np) +{ + return NULL; +} + +static inline int devm_drm_dp_hpd_bridge_add(struct auxiliary_device *adev) +{ + return 0; +} + static inline struct device *drm_dp_hpd_bridge_register(struct device *parent, struct device_node *np) {