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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 7ED2DC43219 for ; Fri, 3 May 2019 11:20:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 574F9206C3 for ; Fri, 3 May 2019 11:20:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727445AbfECLUk convert rfc822-to-8bit (ORCPT ); Fri, 3 May 2019 07:20:40 -0400 Received: from eu-smtp-delivery-151.mimecast.com ([146.101.78.151]:22483 "EHLO eu-smtp-delivery-151.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726377AbfECLUj (ORCPT ); Fri, 3 May 2019 07:20:39 -0400 Received: from AcuMS.aculab.com (156.67.243.126 [156.67.243.126]) (Using TLS) by relay.mimecast.com with ESMTP id uk-mta-147-uNDlfnUDNzGCnnkqEq6Diw-1; Fri, 03 May 2019 12:20:33 +0100 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b:0:43c:695e:880f:8750) by AcuMS.aculab.com (fd9f:af1c:a25b:0:43c:695e:880f:8750) with Microsoft SMTP Server (TLS) id 15.0.1347.2; Fri, 3 May 2019 12:20:32 +0100 Received: from AcuMS.Aculab.com ([fe80::43c:695e:880f:8750]) by AcuMS.aculab.com ([fe80::43c:695e:880f:8750%12]) with mapi id 15.00.1347.000; Fri, 3 May 2019 12:20:32 +0100 From: David Laight To: 'Joel Savitz' , "linux-kernel@vger.kernel.org" CC: Thomas Gleixner , Ingo Molnar , Masami Hiramatsu , Waiman Long , Mauro Carvalho Chehab , Kristina Martsenko , Andrew Morton , Cyrill Gorcunov , Kees Cook , "Gustavo A. R. Silva" , YueHaibing , Micah Morton , Yang Shi , Jann Horn , Alexey Dobriyan , Rafael Aquini , Michael Kerrisk Subject: RE: [PATCH 2/2] prctl.2: Document the new PR_GET_TASK_SIZE option Thread-Topic: [PATCH 2/2] prctl.2: Document the new PR_GET_TASK_SIZE option Thread-Index: AQHVARtLvJKGJytP2U6L8JAWp4DVLqZZQYQA Date: Fri, 3 May 2019 11:20:32 +0000 Message-ID: References: <1556824391-24060-1-git-send-email-jsavitz@redhat.com> <1556824391-24060-3-git-send-email-jsavitz@redhat.com> In-Reply-To: <1556824391-24060-3-git-send-email-jsavitz@redhat.com> Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 X-MC-Unique: uNDlfnUDNzGCnnkqEq6Diw-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Joel Savitz > Sent: 02 May 2019 20:13 > Add a short explanation of the new PR_GET_TASK_SIZE option for the benefit > of future generations. > > Signed-off-by: Joel Savitz > --- > man2/prctl.2 | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/man2/prctl.2 b/man2/prctl.2 > index 06d8e13c7..35a6a3919 100644 > --- a/man2/prctl.2 > +++ b/man2/prctl.2 > @@ -49,6 +49,7 @@ > .\" 2013-01-10 Kees Cook, document PR_SET_PTRACER > .\" 2012-02-04 Michael Kerrisk, document PR_{SET,GET}_CHILD_SUBREAPER > .\" 2014-11-10 Dave Hansen, document PR_MPX_{EN,DIS}ABLE_MANAGEMENT > +.\" 2019-05-02 Joel Savitz, document PR_GET_TASK_SIZE > .\" > .\" > .TH PRCTL 2 2019-03-06 "Linux" "Linux Programmer's Manual" > @@ -1375,6 +1376,14 @@ system call on Tru64). > for information on versions and architectures) > Return unaligned access control bits, in the location pointed to by > .IR "(unsigned int\ *) arg2" . > +.TP > +.B PR_GET_TASK_SIZE > +Copy the value of TASK_SIZE to the userspace address in > +.IR "arg2" . > +Return > +.B EFAULT > +if this operation fails. > + Shouldn't this say what the value is? ISTR a recent patch to change the was the 'used to be constant' TASK_SIZE is defined. I think it might be 'The highest userspace virtual address the current process can use.' But I might be wrong. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)