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=-3.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 A33AAC433DF for ; Fri, 29 May 2020 00:04:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7C7CF2075F for ; Fri, 29 May 2020 00:04:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=ellerman.id.au header.i=@ellerman.id.au header.b="o1PcgC9S" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437970AbgE2AEr (ORCPT ); Thu, 28 May 2020 20:04:47 -0400 Received: from ozlabs.org ([203.11.71.1]:55491 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2437912AbgE2AEo (ORCPT ); Thu, 28 May 2020 20:04:44 -0400 Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 49Y4Z15pqnz9sSr; Fri, 29 May 2020 10:04:41 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ellerman.id.au; s=201909; t=1590710682; bh=1k66Zb1qj7uZTPSgBhIL++YFWp+iDlmiX28l8erpYqg=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=o1PcgC9S+oeama+IYyXAsikM6eJBkAXJmRybBTKTG3nSLKRN/+hbWjBYIkEGNOD3w tEHBgjs7AGq/z4oYtKerEUcCSRiMBzSmG4qjrOCA2nF+dJvQiTEw2KuxCYF5XU9DCr N+XSySMPJqa76fXQHmt2yDDly3t+AdPhuTsUJTNS49HueAQoCWdsPHKpdsfe5tweBU x7x+Yfzwv41BQJORdPCye2b0AifE/ScvPRRUiWwWgWy58CaJCnx2EvfEhMWEp1kpfJ D9lfo8oDfXHVRE8MlYZaKv42OkimVKzpeGxJbXVOr+VB9CdFzP5EGWfAqsH7fKsBZq 4EA2vxLFfmfcw== From: Michael Ellerman To: Daniel Borkmann , 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 Subject: Re: [PATCH] powerpc/bpf: Enable bpf_probe_read{, str}() on powerpc again In-Reply-To: References: <20200527122844.19524-1-pmladek@suse.com> <87ftbkkh00.fsf@mpe.ellerman.id.au> <20200528091351.GE3529@linux-b0ei> <87d06ojlib.fsf@mpe.ellerman.id.au> Date: Fri, 29 May 2020 10:05:05 +1000 Message-ID: <87y2pbip1q.fsf@mpe.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Daniel Borkmann writes: > 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. cheers