From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f72.google.com (mail-wm0-f72.google.com [74.125.82.72]) by kanga.kvack.org (Postfix) with ESMTP id BD4836B007E for ; Sat, 21 May 2016 16:27:59 -0400 (EDT) Received: by mail-wm0-f72.google.com with SMTP id 81so9770743wms.3 for ; Sat, 21 May 2016 13:27:59 -0700 (PDT) Received: from mail-wm0-x242.google.com (mail-wm0-x242.google.com. [2a00:1450:400c:c09::242]) by mx.google.com with ESMTPS id c70si5614414wme.44.2016.05.21.13.27.57 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 21 May 2016 13:27:57 -0700 (PDT) Received: by mail-wm0-x242.google.com with SMTP id n129so5172944wmn.1 for ; Sat, 21 May 2016 13:27:57 -0700 (PDT) Date: Sat, 21 May 2016 22:27:52 +0200 From: Ingo Molnar Subject: Re: [PATCHv9 2/2] selftest/x86: add mremap vdso test Message-ID: <20160521202752.GA31710@gmail.com> References: <1463487232-4377-1-git-send-email-dsafonov@virtuozzo.com> <1463487232-4377-3-git-send-email-dsafonov@virtuozzo.com> <20160520064820.GB29418@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Andy Lutomirski Cc: Dmitry Safonov , "linux-kernel@vger.kernel.org" , Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" , X86 ML , Andrew Morton , "linux-mm@kvack.org" , Dmitry Safonov <0x7f454c46@gmail.com>, Shuah Khan , linux-kselftest@vger.kernel.org * Andy Lutomirski wrote: > On Thu, May 19, 2016 at 11:48 PM, Ingo Molnar wrote: > > > > * Dmitry Safonov wrote: > > > >> Should print on success: > >> [root@localhost ~]# ./test_mremap_vdso_32 > >> AT_SYSINFO_EHDR is 0xf773f000 > >> [NOTE] Moving vDSO: [f773f000, f7740000] -> [a000000, a001000] > >> [OK] > >> Or segfault if landing was bad (before patches): > >> [root@localhost ~]# ./test_mremap_vdso_32 > >> AT_SYSINFO_EHDR is 0xf774f000 > >> [NOTE] Moving vDSO: [f774f000, f7750000] -> [a000000, a001000] > >> Segmentation fault (core dumped) > > > > So I still think that generating potential segfaults is not a proper way to test a > > new feature. How are we supposed to tell the feature still works? I realize that > > glibc is a problem here - but that doesn't really change the QA equation: we are > > adding new kernel code to help essentially a single application out of tens of > > thousands of applications. > > > > At minimum we should have a robust testcase ... > > I think it's robust enough. It will print "[OK]" and exit with 0 on > success and it will crash on failure. The latter should cause make > run_tests to fail reliably. Indeed, you are right - I somehow mis-read it as potentially segfaulting on fixed kernels as well... Will look at applying this after the merge window. Thanks, Ingo -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org