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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AA17DC71153 for ; Mon, 4 Sep 2023 09:29:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347221AbjIDJ3E (ORCPT ); Mon, 4 Sep 2023 05:29:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49468 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229747AbjIDJ3E (ORCPT ); Mon, 4 Sep 2023 05:29:04 -0400 Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.136]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 58D56CC for ; Mon, 4 Sep 2023 02:29:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1693819740; x=1725355740; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=hSEf9AtIpa1+Qo/iru9dpm+rlzezvLKZKvW79Pi0lXc=; b=fXYG1QNNWFMuTpppbGpzOpyKnGccEMAP+8gp5D8Lb+2M/GZdhhytoasS nAln2Paqb/Ueya557QxxUF94Vb8VUq795P8VtOegP0NE7qyr4hNgdbEcv iaNKjmo/oNoLbMs4RR5uFhj3Kw706U+T6njPmvBGJa3QfXihV0wCrydjV 1oQZ+SipNja93PCkSwqP8LX/ef7CIT+Kgp9shyksGuqwfR1FIgHaL9Xgn W+oaygtmbH09hjhGtrboDcBG+2pmkuXHVriAwOZ8kad8ehrtPEFAjngPS j/FWmRv7Enndg8lZeABZ9alCsu3xC5R65ZZdJX1oaOMZh1W8cXiifcDez w==; X-IronPort-AV: E=McAfee;i="6600,9927,10822"; a="356055681" X-IronPort-AV: E=Sophos;i="6.02,226,1688454000"; d="scan'208";a="356055681" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Sep 2023 02:28:59 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10822"; a="855548971" X-IronPort-AV: E=Sophos;i="6.02,226,1688454000"; d="scan'208";a="855548971" Received: from joe-255.igk.intel.com (HELO localhost) ([10.91.220.57]) by fmsmga002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Sep 2023 02:28:58 -0700 Date: Mon, 4 Sep 2023 11:28:55 +0200 From: Stanislaw Gruszka To: Jeffrey Hugo Cc: quic_carlv@quicinc.com, quic_pkanojiy@quicinc.com, linux-arm-msm@vger.kernel.org, ogabbay@kernel.org, dri-devel@lists.freedesktop.org Subject: Re: [PATCH] accel/qaic: Use devm_drm_dev_alloc() instead of drm_dev_alloc() Message-ID: <20230904092855.GC184247@linux.intel.com> References: <20230901161236.8371-1-quic_jhugo@quicinc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230901161236.8371-1-quic_jhugo@quicinc.com> Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On Fri, Sep 01, 2023 at 10:12:36AM -0600, Jeffrey Hugo wrote: > From: Pranjal Ramajor Asha Kanojiya > > Since drm_dev_alloc() is deprecated it is recommended to use > devm_drm_dev_alloc() instead. Update the driver to start using > devm_drm_dev_alloc(). > > Signed-off-by: Pranjal Ramajor Asha Kanojiya > Reviewed-by: Carl Vanderlip > Reviewed-by: Jeffrey Hugo > Signed-off-by: Jeffrey Hugo > + /* > + * drm_dev_unregister() sets the driver data to NULL and > + * drm_dev_register() does not update the driver data. During a SOC > + * reset drm dev is unregistered and registered again leaving the > + * driver data to NULL. > + */ > + dev_set_drvdata(to_accel_kdev(qddev), drm->accel); Yeah, explicitly nullified in drm_minor_unregister() with ' /* safety belt */ comment. I think in long term goal would be device reset not require unregister/register. > + drm_dev_get(drm); > + drm_dev_unregister(drm); That looks odd. I guess there is use-after-free problem if you just do drm_dev_unregister(). Additional drm_dev_get() does not seems to be right solution, but I'm not 100% sure, so ... Reviewed-by: Stanislaw Gruszka Regards Stanislaw 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 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 8FF15C83F2C for ; Mon, 4 Sep 2023 09:29:04 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id A1A3B10E315; Mon, 4 Sep 2023 09:29:03 +0000 (UTC) Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.136]) by gabe.freedesktop.org (Postfix) with ESMTPS id AF23110E315 for ; Mon, 4 Sep 2023 09:29:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1693819740; x=1725355740; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=hSEf9AtIpa1+Qo/iru9dpm+rlzezvLKZKvW79Pi0lXc=; b=fXYG1QNNWFMuTpppbGpzOpyKnGccEMAP+8gp5D8Lb+2M/GZdhhytoasS nAln2Paqb/Ueya557QxxUF94Vb8VUq795P8VtOegP0NE7qyr4hNgdbEcv iaNKjmo/oNoLbMs4RR5uFhj3Kw706U+T6njPmvBGJa3QfXihV0wCrydjV 1oQZ+SipNja93PCkSwqP8LX/ef7CIT+Kgp9shyksGuqwfR1FIgHaL9Xgn W+oaygtmbH09hjhGtrboDcBG+2pmkuXHVriAwOZ8kad8ehrtPEFAjngPS j/FWmRv7Enndg8lZeABZ9alCsu3xC5R65ZZdJX1oaOMZh1W8cXiifcDez w==; X-IronPort-AV: E=McAfee;i="6600,9927,10822"; a="356055684" X-IronPort-AV: E=Sophos;i="6.02,226,1688454000"; d="scan'208";a="356055684" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Sep 2023 02:28:59 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10822"; a="855548971" X-IronPort-AV: E=Sophos;i="6.02,226,1688454000"; d="scan'208";a="855548971" Received: from joe-255.igk.intel.com (HELO localhost) ([10.91.220.57]) by fmsmga002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Sep 2023 02:28:58 -0700 Date: Mon, 4 Sep 2023 11:28:55 +0200 From: Stanislaw Gruszka To: Jeffrey Hugo Subject: Re: [PATCH] accel/qaic: Use devm_drm_dev_alloc() instead of drm_dev_alloc() Message-ID: <20230904092855.GC184247@linux.intel.com> References: <20230901161236.8371-1-quic_jhugo@quicinc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230901161236.8371-1-quic_jhugo@quicinc.com> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: quic_pkanojiy@quicinc.com, linux-arm-msm@vger.kernel.org, quic_carlv@quicinc.com, ogabbay@kernel.org, dri-devel@lists.freedesktop.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Fri, Sep 01, 2023 at 10:12:36AM -0600, Jeffrey Hugo wrote: > From: Pranjal Ramajor Asha Kanojiya > > Since drm_dev_alloc() is deprecated it is recommended to use > devm_drm_dev_alloc() instead. Update the driver to start using > devm_drm_dev_alloc(). > > Signed-off-by: Pranjal Ramajor Asha Kanojiya > Reviewed-by: Carl Vanderlip > Reviewed-by: Jeffrey Hugo > Signed-off-by: Jeffrey Hugo > + /* > + * drm_dev_unregister() sets the driver data to NULL and > + * drm_dev_register() does not update the driver data. During a SOC > + * reset drm dev is unregistered and registered again leaving the > + * driver data to NULL. > + */ > + dev_set_drvdata(to_accel_kdev(qddev), drm->accel); Yeah, explicitly nullified in drm_minor_unregister() with ' /* safety belt */ comment. I think in long term goal would be device reset not require unregister/register. > + drm_dev_get(drm); > + drm_dev_unregister(drm); That looks odd. I guess there is use-after-free problem if you just do drm_dev_unregister(). Additional drm_dev_get() does not seems to be right solution, but I'm not 100% sure, so ... Reviewed-by: Stanislaw Gruszka Regards Stanislaw