From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <benh@au1.ibm.com>
Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com
 [148.163.156.1])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (No client certificate requested)
 by lists.ozlabs.org (Postfix) with ESMTPS id 3zb1cH2FJpzF0vC
 for <linuxppc-dev@lists.ozlabs.org>; Tue,  6 Feb 2018 08:55:43 +1100 (AEDT)
Received: from pps.filterd (m0098410.ppops.net [127.0.0.1])
 by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id
 w15LsiQ9100360
 for <linuxppc-dev@lists.ozlabs.org>; Mon, 5 Feb 2018 16:55:40 -0500
Received: from e06smtp14.uk.ibm.com (e06smtp14.uk.ibm.com [195.75.94.110])
 by mx0a-001b2d01.pphosted.com with ESMTP id 2fxv2hg70q-1
 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT)
 for <linuxppc-dev@lists.ozlabs.org>; Mon, 05 Feb 2018 16:55:40 -0500
Received: from localhost
 by e06smtp14.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only!
 Violators will be prosecuted
 for <linuxppc-dev@lists.ozlabs.org> from <benh@au1.ibm.com>;
 Mon, 5 Feb 2018 21:55:37 -0000
Subject: Re: Kernel 4.15 lost set_robust_list support on POWER 9
From: Benjamin Herrenschmidt <benh@au1.ibm.com>
Reply-To: benh@au1.ibm.com
To: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com>,
 linuxppc-dev@lists.ozlabs.org, npiggin@gmail.com, mpe@ellerman.id.au
Cc: Florian Weimer <fweimer@redhat.com>, Jiri Slaby <jslaby@suse.cz>,
 "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Date: Tue, 06 Feb 2018 08:55:31 +1100
In-Reply-To: <d5f533cf-bd97-794a-38e8-6b6d8c005023@linux.vnet.ibm.com>
References: <3ef0c599-0285-e77a-c002-e21152823fb8@redhat.com>
 <d5f533cf-bd97-794a-38e8-6b6d8c005023@linux.vnet.ibm.com>
Content-Type: text/plain; charset="UTF-8"
Mime-Version: 1.0
Message-Id: <1517867731.2312.146.camel@au1.ibm.com>
List-Id: Linux on PowerPC Developers Mail List <linuxppc-dev.lists.ozlabs.org>
List-Unsubscribe: <https://lists.ozlabs.org/options/linuxppc-dev>,
 <mailto:linuxppc-dev-request@lists.ozlabs.org?subject=unsubscribe>
List-Archive: <http://lists.ozlabs.org/pipermail/linuxppc-dev/>
List-Post: <mailto:linuxppc-dev@lists.ozlabs.org>
List-Help: <mailto:linuxppc-dev-request@lists.ozlabs.org?subject=help>
List-Subscribe: <https://lists.ozlabs.org/listinfo/linuxppc-dev>,
 <mailto:linuxppc-dev-request@lists.ozlabs.org?subject=subscribe>

On Mon, 2018-02-05 at 19:14 -0200, Mauricio Faria de Oliveira wrote:
> Nick, Michael,

+Aneesh.

> On 02/05/2018 10:48 AM, Florian Weimer wrote:
> > 7041  set_robust_list(0x7fff93dc3980, 24) = -1 ENOSYS (Function not 
> > implemented)
> 
> The regression was introduced by commit 371b8044 ("powerpc/64s: 
> Initialize ISAv3 MMU registers before setting partition table").
> 
> The problem is Radix MMU specific (does not occur with 'disable_radix'),
> and does not occur with that code reverted (ie do not set PIDR to zero).
> 
> Do you see any reasons why?
> (wondering if at all related to access_ok() in include/asm/uaccess.h)
> 
> with:
> 
>      # strace -e set_robust_list -f ./test
>      set_robust_list(0x7fffa4b03910, 24)     = -1 ENOSYS (Function not 
> implemented)
>      +++ exited with 1 +++
> 
>      # uname -r
>      4.15.0
> 
> without:
> 
>      # strace -e set_robust_list -f ./test
>      set_robust_list(0x7fff889c3910, 24)     = 0
>      +++ exited with 0 +++
> 
>      # uname -r
>      4.15.0.nopidr