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=-2.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FAKE_REPLY_C,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 15217C282DA for ; Wed, 17 Apr 2019 18:15:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CE85920674 for ; Wed, 17 Apr 2019 18:15:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="dNT70rAR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730737AbfDQSPB (ORCPT ); Wed, 17 Apr 2019 14:15:01 -0400 Received: from mail-wm1-f43.google.com ([209.85.128.43]:56299 "EHLO mail-wm1-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725848AbfDQSPB (ORCPT ); Wed, 17 Apr 2019 14:15:01 -0400 Received: by mail-wm1-f43.google.com with SMTP id o25so4482718wmf.5 for ; Wed, 17 Apr 2019 11:15:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:mime-version:content-disposition :user-agent; bh=qknltXgQ5IBlpPlWXUPSOmejXwDtBrUW+UOJB+W3m0o=; b=dNT70rARPL2YKUYplIvRYV7DBpgUPH9AVykEvfqN+Yd/a+10pU1a0aOcpmGJc6G9Bl D4aEPfJUfA77Ny6eM0qhQ/oZvpUaxtGJx5lrkd6KJae2mVQIc1psWNshCZY3lQjoz8Ri fbpLKpKtomzh+yxuxCNK8uiOmMk3YpgGDmjUQHn81BBzlJYg6tiej8aMrhbXUPRCaw4i xkPlV9rqq7ye8LoZpqscDpVGR1YJMt/BLTc7BMou0GHUOlrd/TEDTlgi2I0nofVegO+Y x5qs3TvKcL/QknRXdo9jzXwl9O++AVQT7Tnb8KzjuS/mvXhirsrDXciTp4k7mB8M/9dL y/Bg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:mime-version :content-disposition:user-agent; bh=qknltXgQ5IBlpPlWXUPSOmejXwDtBrUW+UOJB+W3m0o=; b=uC8TDW4rqRtryIF4nQyv8Ief7X3nsL6Ll9UGYV0May5M/GOImLq039C8NibhMxLpJ8 zNJSf4xQY7k1Z4Q8thM5Ajsqm/tUKWwH923REoWVp/LjyiuMC7gieQw9lt1qUI5yeIIN G3K2Qpc0GRkZoNbepWmL1CRFE3uR9uqnfRiBGhdpRD+h+d2k4px80ULpIMw3xiSpzyXX bcgBGiLYWN8bzxJe7tlWrPNvhSGXCSSHRLrCRJHSwEbcFjRWZJTItMNktN0f33DD4FRF RN1UXKQcxce/fYltNlieC9sBiV4+c0mPY6TN8UKIe3vaYQRkyol7UOW0OsBTHug1BkOF 5CyA== X-Gm-Message-State: APjAAAWHdlOTG8BXIi6UDu/uOCTfKq43Yg3M+gspmNyGsX39BEH4UhYF jVrPMkBACHkmtT4mGIVPt4JBGoY= X-Google-Smtp-Source: APXvYqwsTDJMQi3tvMOYxMyoGQiXqG2Tposu/yMqUDpEJ0pONvIb3B49itO1QFWFB5ev5FO8gKh+lw== X-Received: by 2002:a1c:b088:: with SMTP id z130mr696286wme.5.1555524899432; Wed, 17 Apr 2019 11:14:59 -0700 (PDT) Received: from avx2 ([46.53.244.117]) by smtp.gmail.com with ESMTPSA id a6sm46166826wrp.49.2019.04.17.11.14.57 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 17 Apr 2019 11:14:58 -0700 (PDT) Date: Wed, 17 Apr 2019 21:14:55 +0300 From: Alexey Dobriyan To: shajit@codeaurora.org Cc: linux-kernel@vger.kernel.org Subject: Re: fs/proc: Crash observed in next_tgid (fs/proc/base.c) Message-ID: <20190417181455.GA2965@avx2> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Test case: Not some specific test case. Write 2 programs: one forks, clones, and execs randomly (but not going out of control), another does open("/proc"), getdents in a loop. Don't use shell scripts or readdir as they only bring overhead. Run getdents in a loop and several forkers, see what happens.