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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 73800C43381 for ; Fri, 26 Feb 2021 01:22:38 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D6FD164F37 for ; Fri, 26 Feb 2021 01:22:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D6FD164F37 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 616438D0007; Thu, 25 Feb 2021 20:22:37 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 5C7416B0112; Thu, 25 Feb 2021 20:22:37 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4DB568D0007; Thu, 25 Feb 2021 20:22:37 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0217.hostedemail.com [216.40.44.217]) by kanga.kvack.org (Postfix) with ESMTP id 2FC6B6B0111 for ; Thu, 25 Feb 2021 20:22:37 -0500 (EST) Received: from smtpin17.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 039DF18477196 for ; Fri, 26 Feb 2021 01:22:37 +0000 (UTC) X-FDA: 77858669154.17.C4377AD Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf05.hostedemail.com (Postfix) with ESMTP id 9FEF6E0011C0 for ; Fri, 26 Feb 2021 01:22:35 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 40F4864F31; Fri, 26 Feb 2021 01:22:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1614302555; bh=xz9opxgThwFT45Sk7LQLdNJWyrpuVqtOy/u3NZiOnhQ=; h=Date:From:To:Subject:In-Reply-To:From; b=kjgOkjhMJcKenyPdnRaWGIZKN75a57+6AcAche4rH98rE0bbDCfN90IiXPGn2aUAz UnJFxnd5CA4gIj0QYdZajyO7T0AhVu7GLbr+caLTT4Bd4lg22zqm0BLdyMRQgPdZo9 uE5paqwa2jy1miqy9iCIsyZwvgaYJszjcuT5DFB4= Date: Thu, 25 Feb 2021 17:22:34 -0800 From: Andrew Morton To: akpm@linux-foundation.org, jan.kiszka@siemens.com, kbingham@kernel.org, linux-mm@kvack.org, mm-commits@vger.kernel.org, prekageo@amazon.com, torvalds@linux-foundation.org Subject: [patch 114/118] scripts/gdb: fix list_for_each Message-ID: <20210226012234.Xo_rgwHyK%akpm@linux-foundation.org> In-Reply-To: <20210225171452.713967e96554bb6a53e44a19@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 9FEF6E0011C0 X-Stat-Signature: wixzb4jdsm48t4g65spyfs8ste8jxw1q Received-SPF: none (linux-foundation.org>: No applicable sender policy available) receiver=imf05; identity=mailfrom; envelope-from=""; helo=mail.kernel.org; client-ip=198.145.29.99 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1614302555-452819 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: George Prekas Subject: scripts/gdb: fix list_for_each 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. Link: https://lkml.kernel.org/r/4ae23bb1-c333-f669-da2d-fa35c4f49018@amazon.com Signed-off-by: George Prekas Reviewed-by: Jan Kiszka Cc: Kieran Bingham Signed-off-by: Andrew Morton --- scripts/gdb/linux/lists.py | 5 +++++ 1 file changed, 5 insertions(+) --- a/scripts/gdb/linux/lists.py~scripts-gdb-fix-list_for_each +++ a/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 _