From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754489AbaHEDqM (ORCPT ); Mon, 4 Aug 2014 23:46:12 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:51413 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753513AbaHEDqK (ORCPT ); Mon, 4 Aug 2014 23:46:10 -0400 From: ebiederm@xmission.com (Eric W. Biederman) To: "Kirill A. Shutemov" Cc: Alexander Viro , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, David Howells , Peter Zijlstra , Sasha Levin , Cyrill Gorcunov , Oleg Nesterov , "David S. Miller" , "Kirill A. Shutemov" References: <1407010227-2269-1-git-send-email-kirill@shutemov.name> Date: Mon, 04 Aug 2014 20:42:11 -0700 In-Reply-To: <1407010227-2269-1-git-send-email-kirill@shutemov.name> (Kirill A. Shutemov's message of "Sat, 2 Aug 2014 23:10:27 +0300") Message-ID: <87d2cfzjos.fsf@x220.int.ebiederm.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-AID: U2FsdGVkX18/8kJFM5AUjK5/ENUA/SM3D3UJ2h9XqwA= X-SA-Exim-Connect-IP: 98.234.51.111 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.7 XMSubLong Long Subject * 0.0 T_TM2_M_HEADER_IN_MSG BODY: T_TM2_M_HEADER_IN_MSG * 0.8 BAYES_50 BODY: Bayes spam probability is 40 to 60% * [score: 0.4786] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa01 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject * 0.0 T_TooManySym_02 5+ unique symbols in subject X-Spam-DCC: XMission; sa01 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;"Kirill A. Shutemov" X-Spam-Relay-Country: Subject: Re: [PATCH, RESEND] procfs: silence lockdep warning about read vs. exec seq_file X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Wed, 14 Nov 2012 13:58:17 -0700) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org "Kirill A. Shutemov" writes: > From: "Kirill A. Shutemov" > > Testcase: > > cat /proc/self/maps >/dev/null > chmod +x /proc/self/net/packet > exec /proc/self/net/packet > > It triggers lockdep warning: > I don't know why we allow "chmod +x" on some proc files, notably net-related. > Is it a bug? It looks like we simply did not remove the ability to make those files executable when we realized executable proc files could be a problem. I expect that part of proc could use an audit where someone figures out what makes sense. It does appear that chmod XXX /proc/generic_file is explicitly supported. So we would have to be delicate with any changes in that area to avoid creating userspace regressions. Eric