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 X-Spam-Level: X-Spam-Status: No, score=-12.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5E8A6C4363D for ; Thu, 24 Sep 2020 14:21:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EA68A221EB for ; Thu, 24 Sep 2020 14:21:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="cUBotEzS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728233AbgIXOVE (ORCPT ); Thu, 24 Sep 2020 10:21:04 -0400 Received: from smtp-fw-2101.amazon.com ([72.21.196.25]:60403 "EHLO smtp-fw-2101.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727974AbgIXOVC (ORCPT ); Thu, 24 Sep 2020 10:21:02 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1600957262; x=1632493262; h=to:cc:from:subject:message-id:date:mime-version: content-transfer-encoding; bh=AXfCp1SiddQmAtKsdozKcAnnSiVqTWsFP9hnxw69msY=; b=cUBotEzSki0Jc+pjtFKv78oMhAVaizhY732drj82syQAQ0TJPVYMSzKU Maj8lbLxRhqjDLzAecX6hOuEgtb2a5Pw84g78d5xnv5ee5dlP5pSRlav6 myDnOj57T3Lzdgyy3N6FWgLceCQAzWKmhjdLnL8J3lOHnug59z9ic9hRF U=; X-IronPort-AV: E=Sophos;i="5.77,298,1596499200"; d="scan'208";a="55840363" Received: from iad12-co-svc-p1-lb1-vlan2.amazon.com (HELO email-inbound-relay-2b-81e76b79.us-west-2.amazon.com) ([10.43.8.2]) by smtp-border-fw-out-2101.iad2.amazon.com with ESMTP; 24 Sep 2020 14:21:01 +0000 Received: from EX13MTAUWC002.ant.amazon.com (pdx4-ws-svc-p6-lb7-vlan3.pdx.amazon.com [10.170.41.166]) by email-inbound-relay-2b-81e76b79.us-west-2.amazon.com (Postfix) with ESMTPS id B2731A081C; Thu, 24 Sep 2020 14:20:59 +0000 (UTC) Received: from EX13D12UWC002.ant.amazon.com (10.43.162.253) by EX13MTAUWC002.ant.amazon.com (10.43.162.240) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Thu, 24 Sep 2020 14:20:59 +0000 Received: from [192.168.7.67] (10.43.162.133) by EX13D12UWC002.ant.amazon.com (10.43.162.253) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Thu, 24 Sep 2020 14:20:58 +0000 To: Jan Kiszka , Kieran Bingham CC: From: George Prekas Subject: [PATCH v2] scripts/gdb: fix list_for_each Message-ID: <4ae23bb1-c333-f669-da2d-fa35c4f49018@amazon.com> Date: Thu, 24 Sep 2020 09:20:56 -0500 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Originating-IP: [10.43.162.133] X-ClientProxiedBy: EX13D47UWA001.ant.amazon.com (10.43.163.6) To EX13D12UWC002.ant.amazon.com (10.43.162.253) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If the list is uninitialized (next pointer is NULL), list_for_each gets stuck in an infinite loop. Print a message and treat list as empty. Signed-off-by: George Prekas ---  scripts/gdb/linux/lists.py | 5 +++++  1 file changed, 5 insertions(+) diff --git a/scripts/gdb/linux/lists.py b/scripts/gdb/linux/lists.py index c487ddf09d38..bae4d70b7eae 100644 --- a/scripts/gdb/linux/lists.py +++ b/scripts/gdb/linux/lists.py @@ -27,6 +27,11 @@ def list_for_each(head):          raise TypeError("Must be struct list_head not {}"                             .format(head.type)) +    if head['next'] == 0: +        gdb.write("list_for_each: Uninitialized list '{}' treated as empty\n" +                     .format(head.address)) +        return +      node = head['next'].dereference()      while node.address != head.address:          yield node.address -- 2.16.6