From patchwork Fri Oct 2 08:39:31 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 7314071 Return-Path: X-Original-To: patchwork-intel-gfx@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id BFCFABF90C for ; Fri, 2 Oct 2015 08:36:47 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id E46C92084D for ; Fri, 2 Oct 2015 08:36:45 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id 1E92E20890 for ; Fri, 2 Oct 2015 08:36:45 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 02836721C5; Fri, 2 Oct 2015 01:36:44 -0700 (PDT) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mail-wi0-f179.google.com (mail-wi0-f179.google.com [209.85.212.179]) by gabe.freedesktop.org (Postfix) with ESMTPS id 7D5D1721C5 for ; Fri, 2 Oct 2015 01:36:42 -0700 (PDT) Received: by wicge5 with SMTP id ge5so22747314wic.0 for ; Fri, 02 Oct 2015 01:36:40 -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=d4As+ILXH75+XamYGsvxl2C0wg4y/ptPpqycABBNOBc=; b=F6mGzbIsTTnMazPMP0Z2+N1PXPZwKoqPoNxWKpJLkl2xiTcnl+T3kHBCYBvHT+LpbD 1tV19rXF+xrd6AOZB0I/+ANo750Oo68rMsvE64twwmhru9668VfC6DgC2lophy5TPfr5 OMhTXdbm1wkUWR3L7/Ub4DMQDLjGeC6NL+MD4= 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=d4As+ILXH75+XamYGsvxl2C0wg4y/ptPpqycABBNOBc=; b=TpQQu15gvcZ+51JcfEwqOeAI9K5vRt+z2QDWyX0RLMxMni8OZ01PMpWDoA6Mb5jdyj r4UOGwABK+Xdyp5mTscu3zsBtAWLAv0fVE8n1smK7UK9NSdCYeyfK2ffj+G6rQp50Dk8 HtzvBYqk31LWV6EwKFVHkqkwxNIJpjhmceJ5VvRyCu9ArNvt07QDMsyEfwfv0EcjonTE pqkdEZ+5RAI3Ens0qSM42+aET4Dn6nkdrs3cJwvLWWcgErqGVXHX3jxxv5+9jZibZqFV +lBCk4NTlMvaMSgIkeXhFO2Z9ptCNZqNWYZTTtrG11K6hSHCxG+NnsE4LB5/B0l6tQgI 2A3A== X-Gm-Message-State: ALoCoQk/mgGKrbZe3cdEc6xm039cbIZAhOwkwVe2FR5x/pysjnmohGQ/qx/6Gp3C/0uzx10PUDyq X-Received: by 10.180.105.138 with SMTP id gm10mr2760577wib.37.1443775000833; Fri, 02 Oct 2015 01:36:40 -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 lh11sm7201524wic.18.2015.10.02.01.36.39 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 02 Oct 2015 01:36:39 -0700 (PDT) From: Daniel Vetter To: DRI Development Date: Fri, 2 Oct 2015 10:39:31 +0200 Message-Id: <1443775171-31600-1-git-send-email-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.5.1 In-Reply-To: <1443513993-5228-2-git-send-email-daniel.vetter@ffwll.ch> References: <1443513993-5228-2-git-send-email-daniel.vetter@ffwll.ch> Cc: Daniel Vetter , Intel Graphics Development , Julia Lawall Subject: [Intel-gfx] [PATCH] drm/sysfs: Grab lock for edid/modes_show X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" 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. Cc: Julia Lawall Signed-off-by: Daniel Vetter --- 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..9bffa63fe849 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; + mutex_unlock(&connector->dev->mode_config.mutex); +unlock: + + 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; }