From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752591AbZEJMkP (ORCPT ); Sun, 10 May 2009 08:40:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752225AbZEJMj7 (ORCPT ); Sun, 10 May 2009 08:39:59 -0400 Received: from mail-gx0-f166.google.com ([209.85.217.166]:38596 "EHLO mail-gx0-f166.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752169AbZEJMj7 (ORCPT ); Sun, 10 May 2009 08:39:59 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; b=rLdmMRtZsSXkKx61EtS3cXnGAumumfHYSaBOce940Lixh8Gu20H/gorV5Imq1Dx4bX TNpvju1Y9yJRpZHQ+k6XWB5icjkrfqIoBv+Ecg+WNfP063N62IIrPKUiQgir3jzgxgix x+8oYg47lbL+ev6IKIOlCqz6ZKhY5a622nsl4= MIME-Version: 1.0 In-Reply-To: <1241957948.9562.2.camel@laptop> References: <20090508081608.GA25117@localhost> <2f11576a0905100159m32c36a9ep9fb7cc5604c60b2@mail.gmail.com> <20090510092053.GA7651@localhost> <2f11576a0905100229m2c5e6a67md555191dc8c374ae@mail.gmail.com> <20090510100335.GC7651@localhost> <2f11576a0905100315j2c810e96mc29b84647dc565c2@mail.gmail.com> <20090510112149.GA8633@localhost> <2f11576a0905100439u38c8bccak355ec23953950d6@mail.gmail.com> <20090510114454.GA8891@localhost> <1241957948.9562.2.camel@laptop> Date: Sun, 10 May 2009 21:39:58 +0900 X-Google-Sender-Auth: 86c00fecb75a3977 Message-ID: <2f11576a0905100539l1512170oc64f7aee2864e8d5@mail.gmail.com> Subject: Re: [PATCH -mm] vmscan: make mapped executable pages the first class citizen From: KOSAKI Motohiro To: Peter Zijlstra Cc: Wu Fengguang , Alan Cox , Andrew Morton , "hannes@cmpxchg.org" , "riel@redhat.com" , "linux-kernel@vger.kernel.org" , "tytso@mit.edu" , "linux-mm@kvack.org" , "elladan@eskimo.com" , "npiggin@suse.de" , "cl@linux-foundation.org" , "minchan.kim@gmail.com" Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >> > They always use mmap(PROT_READ | PROT_WRITE | PROT_EXEC) for anycase. >> > Please google it. you can find various example. >> >> How widely is PROT_EXEC abused? Would you share some of your google results? > > That's a security bug right there and should be fixed regardless of our > heuristics. Yes, should be. but it's not security issue. it doesn't make any security hole. Plus, this claim doesn't help to solve end-user problems. I think the basic concept of the patch is right. - executable mapping is important for good latency - executable file is relatively small The last problem is, The patch assume executable mappings is rare, but it isn't guranteed. How do we separate truth executable mapping and mis-used PROT_EXEC usage? From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id 699D76B009F for ; Sun, 10 May 2009 08:39:22 -0400 (EDT) Received: by yw-out-1718.google.com with SMTP id 5so1208020ywm.26 for ; Sun, 10 May 2009 05:39:58 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1241957948.9562.2.camel@laptop> References: <20090508081608.GA25117@localhost> <2f11576a0905100159m32c36a9ep9fb7cc5604c60b2@mail.gmail.com> <20090510092053.GA7651@localhost> <2f11576a0905100229m2c5e6a67md555191dc8c374ae@mail.gmail.com> <20090510100335.GC7651@localhost> <2f11576a0905100315j2c810e96mc29b84647dc565c2@mail.gmail.com> <20090510112149.GA8633@localhost> <2f11576a0905100439u38c8bccak355ec23953950d6@mail.gmail.com> <20090510114454.GA8891@localhost> <1241957948.9562.2.camel@laptop> Date: Sun, 10 May 2009 21:39:58 +0900 Message-ID: <2f11576a0905100539l1512170oc64f7aee2864e8d5@mail.gmail.com> Subject: Re: [PATCH -mm] vmscan: make mapped executable pages the first class citizen From: KOSAKI Motohiro Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Peter Zijlstra Cc: Wu Fengguang , Alan Cox , Andrew Morton , "hannes@cmpxchg.org" , "riel@redhat.com" , "linux-kernel@vger.kernel.org" , "tytso@mit.edu" , "linux-mm@kvack.org" , "elladan@eskimo.com" , "npiggin@suse.de" , "cl@linux-foundation.org" , "minchan.kim@gmail.com" List-ID: >> > They always use mmap(PROT_READ | PROT_WRITE | PROT_EXEC) for anycase. >> > Please google it. you can find various example. >> >> How widely is PROT_EXEC abused? Would you share some of your google results? > > That's a security bug right there and should be fixed regardless of our > heuristics. Yes, should be. but it's not security issue. it doesn't make any security hole. Plus, this claim doesn't help to solve end-user problems. I think the basic concept of the patch is right. - executable mapping is important for good latency - executable file is relatively small The last problem is, The patch assume executable mappings is rare, but it isn't guranteed. How do we separate truth executable mapping and mis-used PROT_EXEC usage? -- 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