From patchwork Thu Dec 12 19:02:25 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Paul X-Patchwork-Id: 11289285 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2EB836C1 for ; Thu, 12 Dec 2019 19:03:07 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 0E3132073B for ; Thu, 12 Dec 2019 19:03:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=poorly.run header.i=@poorly.run header.b="dEA4zMNn" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0E3132073B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=poorly.run Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 654C16E147; Thu, 12 Dec 2019 19:02:49 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mail-yb1-xb41.google.com (mail-yb1-xb41.google.com [IPv6:2607:f8b0:4864:20::b41]) by gabe.freedesktop.org (Postfix) with ESMTPS id B4B436E145 for ; Thu, 12 Dec 2019 19:02:44 +0000 (UTC) Received: by mail-yb1-xb41.google.com with SMTP id d34so877906yba.10 for ; Thu, 12 Dec 2019 11:02:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=poorly.run; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=ZvNOwIquqfbZ0FAAW1cz7dSaGmgCWbz+A+JZNBEPfFw=; b=dEA4zMNnIdCOQm/3smOJFgbJYds9Pme/1ju+ffKdcuzVwbH5iyXXsGdASFzhpFobN6 0PKA3OGm4qQvRfx37HFZDv8IFNpFBpAp1EZv4A2BFelv/F2Q2V28ce40GN5k0U5vPh+q y+6WZE/iMpd6dCrByXCwHSjNJTSlpmPKdp/HMG5XL58plpzZ+wxptglap5q7i1rch3eX o6uABe9MGTLjdVyGNIOhH8hwPj1f0kvPCll2zf6lbZwWBAjaUYPMbTs78pCK3XWNeVmc 70ppLsIGrRyclT+j9b8oerRxTG1sX9JHYrFHM9ZwR3MdK1G2NyhZp+tzEnDp39CEjW8F /9+A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=ZvNOwIquqfbZ0FAAW1cz7dSaGmgCWbz+A+JZNBEPfFw=; b=BZTLk0UuJUodtHm+DPTRjC0REO7baHqjVu8OUhoZ2eDn/aMEklZ2dLiu47OALIqqvt X1LgltbIy1i5mnEOm9FEHHpaxAWKAH9Vsq1+kWJN8hoCLyRMLpBl9PnSg//2hmEyyO1A K9S2A40lCOBfab7azAS+7Pr0kqxj1kczf/JTdmf+NdodQPKPKPrIrIkyGeAGOZ/A/E6t 6VyiveANGwVNL7RSDZJG4QLoYu/1n0NOl2RVKCtKDIaY1oWKKwg+zyyhUwkAjEy/HBKa K4+YKeC41betttRa10nW0xaHbiu+tX5FfTeDbCFsrTKs608+Msez/yMyxTln3joyW4aa v4Gg== X-Gm-Message-State: APjAAAWfqwZsCc06gWSc8HN8YVyOg0q4oSuIQzBtHexnUFMeedVjcgPT f+j4BjEaabxXlvjiCoGvj1oDGvrHeJ4urw== X-Google-Smtp-Source: APXvYqzkDw2iZkzhPBPwvabFRqvsTLh92aBkO6Oc/SrmkPPiWIfhCvtzXoP4yEuMfsW9OJOCAt6eXQ== X-Received: by 2002:a25:cf55:: with SMTP id f82mr5744881ybg.253.1576177363389; Thu, 12 Dec 2019 11:02:43 -0800 (PST) Received: from localhost ([2620:0:1013:11:1e1:4760:6ce4:fc64]) by smtp.gmail.com with ESMTPSA id b135sm2734323ywb.50.2019.12.12.11.02.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 12 Dec 2019 11:02:42 -0800 (PST) From: Sean Paul To: dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org Subject: [PATCH v2 07/12] drm/i915: Protect workers against disappearing connectors Date: Thu, 12 Dec 2019 14:02:25 -0500 Message-Id: <20191212190230.188505-8-sean@poorly.run> X-Mailer: git-send-email 2.24.1.735.g03f4e72817-goog In-Reply-To: <20191212190230.188505-1-sean@poorly.run> References: <20191212190230.188505-1-sean@poorly.run> MIME-Version: 1.0 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: daniel.vetter@ffwll.ch, rodrigo.vivi@intel.com, Sean Paul Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Sean Paul This patch adds some protection against connectors being destroyed before the HDCP workers are finished. For check_work, we do a synchronous cancel after the connector is unregistered which will ensure that it is finished before destruction. In the case of prop_work, we can't do a synchronous wait since it needs to take connection_mutex which could cause deadlock. Instead, we'll take a reference on the connector when scheduling prop_work and give it up once we're done. Signed-off-by: Sean Paul Changes in v2: - Added to the set Reviewed-by: Ramalingam C --- drivers/gpu/drm/i915/display/intel_hdcp.c | 38 ++++++++++++++++++++--- 1 file changed, 33 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c b/drivers/gpu/drm/i915/display/intel_hdcp.c index 798e7e1a19fc..c79dca2c74d1 100644 --- a/drivers/gpu/drm/i915/display/intel_hdcp.c +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c @@ -863,8 +863,10 @@ static void intel_hdcp_update_value(struct intel_connector *connector, return; hdcp->value = value; - if (update_property) + if (update_property) { + drm_connector_get(&connector->base); schedule_work(&hdcp->prop_work); + } } /* Implements Part 3 of the HDCP authorization procedure */ @@ -954,6 +956,8 @@ static void intel_hdcp_prop_work(struct work_struct *work) mutex_unlock(&hdcp->mutex); drm_modeset_unlock(&dev->mode_config.connection_mutex); + + drm_connector_put(&connector->base); } bool is_hdcp_supported(struct drm_i915_private *dev_priv, enum port port) @@ -1802,6 +1806,9 @@ static void intel_hdcp_check_work(struct work_struct *work) check_work); struct intel_connector *connector = intel_hdcp_to_connector(hdcp); + if (drm_connector_is_unregistered(&connector->base)) + return; + if (!intel_hdcp2_check_link(connector)) schedule_delayed_work(&hdcp->check_work, DRM_HDCP2_CHECK_PERIOD_MS); @@ -2076,12 +2083,33 @@ void intel_hdcp_component_fini(struct drm_i915_private *dev_priv) void intel_hdcp_cleanup(struct intel_connector *connector) { - if (!connector->hdcp.shim) + struct intel_hdcp *hdcp = &connector->hdcp; + + if (!hdcp->shim) return; - mutex_lock(&connector->hdcp.mutex); - kfree(connector->hdcp.port_data.streams); - mutex_unlock(&connector->hdcp.mutex); + WARN_ON(!drm_connector_is_unregistered(&connector->base)); + + /* + * Now that the connector is unregistered, check_work won't be run, but + * cancel any outstanding instances of it + */ + cancel_delayed_work_sync(&hdcp->check_work); + + /* + * We don't cancel prop_work in the same way as check_work since it + * requires connection_mutex which could be held while calling this + * function. Instead, we rely on the connector references grabbed before + * scheduling prop_work to ensure the connector is alive when prop_work + * is run. So if we're in the destroy path (which is where this + * function should be called), we're "guaranteed" that prop_work is not + * active (tl;dr This Should Never Happen). + */ + WARN_ON(work_pending(&hdcp->prop_work)); + + mutex_lock(&hdcp->mutex); + kfree(hdcp->port_data.streams); + mutex_unlock(&hdcp->mutex); } void intel_hdcp_atomic_check(struct drm_connector *connector,