From patchwork Tue Feb 18 22:02:35 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Paul X-Patchwork-Id: 11389841 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 20F1C17F0 for ; Tue, 18 Feb 2020 22:04:00 +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 F3A05207FD for ; Tue, 18 Feb 2020 22:03:59 +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="b6GjIqK+" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F3A05207FD Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=poorly.run Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E2B306EAA8; Tue, 18 Feb 2020 22:03:39 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mail-yw1-xc44.google.com (mail-yw1-xc44.google.com [IPv6:2607:f8b0:4864:20::c44]) by gabe.freedesktop.org (Postfix) with ESMTPS id CE0E86EAA0 for ; Tue, 18 Feb 2020 22:03:38 +0000 (UTC) Received: by mail-yw1-xc44.google.com with SMTP id 192so10181068ywy.0 for ; Tue, 18 Feb 2020 14:03:38 -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=w+pyfuAZAh1veh329AWb5PnerCG5liLmEQyf2lHc9wk=; b=b6GjIqK+0pYuNCj8v1LERZvLllxBF1IyR0j0tjR+d3LlXPeFAnAAbZQPuOBMP3vgb5 FGOYzdQNgGC9xGMhH8dSI92TUW8zYwhh86IaFmDnCtpRZblFjlKN0/A5C/NX1LbLrFnf N2319DmZkzbEi6jO/Kw5Kx4Fluo45rorDBSZM7AJL8D5S0z9ZkMTPs1wgHGumYu0bb3P TdGwWsyfgi9glq7w8tqrby1BmQk2PVZwbm+voVfu71f0MQsluFEsqP8YqtxVYtIkGsqS 5sjafbpeEQHQ5ivOTpE16SnIG+DTnUH2oMDqXV+HqqrpG28zOq5t4UV3TsEpEnZBYT8n D5cw== 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=w+pyfuAZAh1veh329AWb5PnerCG5liLmEQyf2lHc9wk=; b=dxFT7PxNBZGC1EhyZgWAWQXQ6xIqOq9uiLKDqJk1/RMfqpBbcLBXi9QvPN1GVKNkBg riw5PkGvpsBSS9azWof0+rv8gcpK5eUZOV5qef/esPGF0CP1oT8DWrf+MSudwCqlUHUt 2vITirz/dbQE5GT4UrHIUlc+CE7OGK+fskmKUeLtpBuKH+fpDbWEfdhXdlR387X2G7Tz znkV/LXPpH/dQUKG8F3y7ZXZeGWp/Sfl4Zro99YZrzqpXZo/TOkflo7XqzckMvoh+ZIo gUJM6GOwoFC7TclMXKt+AqB4czBoK3QjapmoXdo8CBolBZCHKptnQiYbdd2kfr38sXQS DlRA== X-Gm-Message-State: APjAAAV4euEI1kBJcJlc8dt02fGYSi1Gej7qxt9lAODy6PR/yAi3SoUd CFtjmhers62xO0V7MA4Tj0v66A== X-Google-Smtp-Source: APXvYqxpfdAASF1+BsNwANqir409ZFFa1UOIXtW2WiXcHvw0dGOXhxUCdN7nQ1Ss/UJxBMEpmF3EkQ== X-Received: by 2002:a0d:c245:: with SMTP id e66mr3360131ywd.32.1582063417553; Tue, 18 Feb 2020 14:03:37 -0800 (PST) Received: from localhost ([2620:0:1013:11:1e1:4760:6ce4:fc64]) by smtp.gmail.com with ESMTPSA id s31sm31706ywa.30.2020.02.18.14.03.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 18 Feb 2020 14:03:37 -0800 (PST) From: Sean Paul To: dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org Date: Tue, 18 Feb 2020 17:02:35 -0500 Message-Id: <20200218220242.107265-8-sean@poorly.run> X-Mailer: git-send-email 2.25.0.265.gbab2e86ba0-goog In-Reply-To: <20200218220242.107265-1-sean@poorly.run> References: <20200218220242.107265-1-sean@poorly.run> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH v4 07/14] drm/i915: Protect workers against disappearing connectors X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: daniel.vetter@ffwll.ch, Sean Paul Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" 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. Reviewed-by: Ramalingam C Signed-off-by: Sean Paul Link: https://patchwork.freedesktop.org/patch/msgid/20191212190230.188505-8-sean@poorly.run #v2 Link: https://patchwork.freedesktop.org/patch/msgid/20200117193103.156821-8-sean@poorly.run #v3 Changes in v2: -Added to the set Changes in v3: -Change the WARN_ON condition in intel_hdcp_cleanup to allow for initializing connectors as well Changes in v4: -None --- drivers/gpu/drm/i915/display/intel_hdcp.c | 43 ++++++++++++++++++++--- 1 file changed, 38 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c b/drivers/gpu/drm/i915/display/intel_hdcp.c index c61ade8aa15e6..161f4bcc5bda5 100644 --- a/drivers/gpu/drm/i915/display/intel_hdcp.c +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c @@ -884,8 +884,10 @@ 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 */ @@ -976,6 +978,8 @@ static void intel_hdcp_prop_work(struct work_struct *work) mutex_unlock(&hdcp->mutex); drm_modeset_unlock(&dev_priv->drm.mode_config.connection_mutex); + + drm_connector_put(&connector->base); } bool is_hdcp_supported(struct drm_i915_private *dev_priv, enum port port) @@ -1839,6 +1843,9 @@ 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); @@ -2154,12 +2161,38 @@ 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); + /* + * If the connector is registered, it's possible userspace could kick + * off another HDCP enable, which would re-spawn the workers. + */ + WARN_ON(connector->base.registration_state == DRM_CONNECTOR_REGISTERED); + + /* + * Now that the connector is not registered, 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); + hdcp->shim = NULL; + mutex_unlock(&hdcp->mutex); } void intel_hdcp_atomic_check(struct drm_connector *connector,