From patchwork Fri Oct 2 11:01:02 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 7314771 Return-Path: X-Original-To: patchwork-dri-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 0045D9F32B for ; Fri, 2 Oct 2015 10:58:18 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 1C3C120890 for ; Fri, 2 Oct 2015 10:58:17 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id 9277F20891 for ; Fri, 2 Oct 2015 10:58:15 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 96A336E92E; Fri, 2 Oct 2015 03:58:13 -0700 (PDT) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mail-wi0-f178.google.com (mail-wi0-f178.google.com [209.85.212.178]) by gabe.freedesktop.org (Postfix) with ESMTPS id BF70D6E92D for ; Fri, 2 Oct 2015 03:58:11 -0700 (PDT) Received: by wiclk2 with SMTP id lk2so28456992wic.0 for ; Fri, 02 Oct 2015 03:58:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=8PPKUdhMgDRcYG4qAggN/fCEjtrGwRTUhVaafSMZz10=; b=O2BpmPsKRbTECculLsHA3bwzGLP8hTTxGeDlh9y0dH7+zoUrRvgJgncwGpTRS211YX lh+6byaAhtDv0AAlVnUGtWtVSd8wE1JhTctio7+Tg6PL6gU4HBMcNprD2986auCFlM/c mKl9LT13idh1+rwTJ03aW8g9lq9+lUhMwx90g= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=8PPKUdhMgDRcYG4qAggN/fCEjtrGwRTUhVaafSMZz10=; b=bguwv81eOXMwOowUPt9mi0eXNdTp+h/r8jBAq7Ecs2YQdqIKqV6ggvblixc+8pAwOr vodfpF2xOCrtVMvNlYsPM064P+vbT+mLbVedUL3NdwmAtteAytebgJyRDUD0J7h+pzmV 9+YE8tiNCjcZ0wzK8i3MG7rlwbdkSg9CcxzP14mbDF5n+W9SQedT/UCQfqze6AtPCq63 hGzIvX6UpKRBn6o58Lik7OLUQxuugSMat9g5Jjyk2oxXv5o1cGb5qhj7cmAJTOONMPxY BL+8lY/5dNTXSDJN3VZgh7RKJmGvyH5/FOcJ8kSEYDlRdUqKyhYZMhpq5qUWBEZwmCRE BQYw== X-Gm-Message-State: ALoCoQm5l13o0RzDgQ+iSNV3CmonSetPBRBvlCvDV2PFnswOpZx3i5a6fUtU3D/03FAS8avgUIoj X-Received: by 10.180.74.175 with SMTP id u15mr3405667wiv.66.1443783490390; Fri, 02 Oct 2015 03:58:10 -0700 (PDT) Received: from phenom.ffwll.local (212-51-149-109.fiber7.init7.net. [212.51.149.109]) by smtp.gmail.com with ESMTPSA id mc20sm7797645wic.16.2015.10.02.03.58.09 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 02 Oct 2015 03:58:09 -0700 (PDT) From: Daniel Vetter To: DRI Development Subject: [PATCH] drm/sysfs: Grab lock for edid/modes_show Date: Fri, 2 Oct 2015 13:01:02 +0200 Message-Id: <1443783662-23066-1-git-send-email-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.5.1 In-Reply-To: <1443775171-31600-1-git-send-email-daniel.vetter@ffwll.ch> References: <1443775171-31600-1-git-send-email-daniel.vetter@ffwll.ch> Cc: Daniel Vetter , Intel Graphics Development , Emil Velikov , Julia Lawall X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Spam-Status: No, score=-4.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_MED, T_DKIM_INVALID, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP We chase pointers/lists without taking the locks protecting them, which isn't that good. Fix it. v2: Actually unlock properly, spotted by Julia. v3: Put the label _before_ the mutex_unlock (Emil) Cc: Emil Velikov Cc: Julia Lawall Signed-off-by: Daniel Vetter Reviewed-by: Emil Velikov --- drivers/gpu/drm/drm_sysfs.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/drm_sysfs.c b/drivers/gpu/drm/drm_sysfs.c index 7506de0a75b4..8ceb1cb6166a 100644 --- a/drivers/gpu/drm/drm_sysfs.c +++ b/drivers/gpu/drm/drm_sysfs.c @@ -261,23 +261,29 @@ static ssize_t edid_show(struct file *filp, struct kobject *kobj, struct drm_connector *connector = to_drm_connector(connector_dev); unsigned char *edid; size_t size; + ssize_t ret = 0; + mutex_lock(&connector->dev->mode_config.mutex); if (!connector->edid_blob_ptr) - return 0; + goto unlock; edid = connector->edid_blob_ptr->data; size = connector->edid_blob_ptr->length; if (!edid) - return 0; + goto unlock; if (off >= size) - return 0; + goto unlock; if (off + count > size) count = size - off; memcpy(buf, edid + off, count); - return count; + ret = count; +unlock: + mutex_unlock(&connector->dev->mode_config.mutex); + + return ret; } static ssize_t modes_show(struct device *device, @@ -288,10 +294,12 @@ static ssize_t modes_show(struct device *device, struct drm_display_mode *mode; int written = 0; + mutex_lock(&connector->dev->mode_config.mutex); list_for_each_entry(mode, &connector->modes, head) { written += snprintf(buf + written, PAGE_SIZE - written, "%s\n", mode->name); } + mutex_unlock(&connector->dev->mode_config.mutex); return written; }