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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 96EF1C433E0 for ; Thu, 28 May 2020 15:06:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 82BE420814 for ; Thu, 28 May 2020 15:06:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404056AbgE1PG7 (ORCPT ); Thu, 28 May 2020 11:06:59 -0400 Received: from www62.your-server.de ([213.133.104.62]:39948 "EHLO www62.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2403787AbgE1PG6 (ORCPT ); Thu, 28 May 2020 11:06:58 -0400 Received: from sslproxy03.your-server.de ([88.198.220.132]) by www62.your-server.de with esmtpsa (TLSv1.2:DHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89_1) (envelope-from ) id 1jeK75-0001th-BD; Thu, 28 May 2020 17:06:31 +0200 Received: from [178.196.57.75] (helo=pc-9.home) by sslproxy03.your-server.de with esmtpsa (TLSv1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jeK74-000Ei1-Ul; Thu, 28 May 2020 17:06:30 +0200 Subject: Re: [PATCH] powerpc/bpf: Enable bpf_probe_read{, str}() on powerpc again To: Michael Ellerman , Petr Mladek Cc: Miroslav Benes , Benjamin Herrenschmidt , Paul Mackerras , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Alexei Starovoitov , Masami Hiramatsu , Brendan Gregg , Christoph Hellwig , bpf@vger.kernel.org References: <20200527122844.19524-1-pmladek@suse.com> <87ftbkkh00.fsf@mpe.ellerman.id.au> <20200528091351.GE3529@linux-b0ei> <87d06ojlib.fsf@mpe.ellerman.id.au> From: Daniel Borkmann Message-ID: Date: Thu, 28 May 2020 17:06:30 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: <87d06ojlib.fsf@mpe.ellerman.id.au> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Authenticated-Sender: daniel@iogearbox.net X-Virus-Scanned: Clear (ClamAV 0.102.2/25826/Thu May 28 14:33:30 2020) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/28/20 2:23 PM, Michael Ellerman wrote: > Petr Mladek writes: >> On Thu 2020-05-28 11:03:43, Michael Ellerman wrote: >>> Petr Mladek writes: >>>> The commit 0ebeea8ca8a4d1d453a ("bpf: Restrict bpf_probe_read{, str}() only >>>> to archs where they work") caused that bpf_probe_read{, str}() functions >>>> were not longer available on architectures where the same logical address >>>> might have different content in kernel and user memory mapping. These >>>> architectures should use probe_read_{user,kernel}_str helpers. >>>> >>>> For backward compatibility, the problematic functions are still available >>>> on architectures where the user and kernel address spaces are not >>>> overlapping. This is defined CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE. >>>> >>>> At the moment, these backward compatible functions are enabled only >>>> on x86_64, arm, and arm64. Let's do it also on powerpc that has >>>> the non overlapping address space as well. >>>> >>>> Signed-off-by: Petr Mladek >>> >>> This seems like it should have a Fixes: tag and go into v5.7? >> >> Good point: >> >> Fixes: commit 0ebeea8ca8a4d1d4 ("bpf: Restrict bpf_probe_read{, str}() only to archs where they work") >> >> And yes, it should ideally go into v5.7 either directly or via stable. >> >> Should I resend the patch with Fixes and >> Cc: stable@vger.kernel.org #v45.7 lines, please? > > If it goes into v5.7 then it doesn't need a Cc: stable, and I guess a > Fixes: tag is nice to have but not so important as it already mentions > the commit that caused the problem. So a resend probably isn't > necessary. > > Acked-by: Michael Ellerman > > Daniel can you pick this up, or should I? Yeah I'll take it into bpf tree for v5.7. Thanks everyone, Daniel