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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,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 24891C433E0 for ; Thu, 25 Mar 2021 10:29:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E447E61A2D for ; Thu, 25 Mar 2021 10:29:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230105AbhCYK3G (ORCPT ); Thu, 25 Mar 2021 06:29:06 -0400 Received: from elvis.franken.de ([193.175.24.41]:58945 "EHLO elvis.franken.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229716AbhCYK2s (ORCPT ); Thu, 25 Mar 2021 06:28:48 -0400 Received: from uucp (helo=alpha) by elvis.franken.de with local-bsmtp (Exim 3.36 #1) id 1lPNEM-0007Ug-00; Thu, 25 Mar 2021 11:28:46 +0100 Received: by alpha.franken.de (Postfix, from userid 1000) id CCBECC1C81; Thu, 25 Mar 2021 11:17:12 +0100 (CET) Date: Thu, 25 Mar 2021 11:17:12 +0100 From: Thomas Bogendoerfer To: Tiezhu Yang Cc: "Maciej W. Rozycki" , linux-mips@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, Xuefeng Li , Christoph Hellwig Subject: Re: [PATCH v2] MIPS/bpf: Enable bpf_probe_read{, str}() on MIPS again Message-ID: <20210325101712.GA6893@alpha.franken.de> References: <1616034557-5844-1-git-send-email-yangtiezhu@loongson.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 22, 2021 at 03:12:59PM +0800, Tiezhu Yang wrote: > On 03/22/2021 12:46 PM, Maciej W. Rozycki wrote: > > On Thu, 18 Mar 2021, Tiezhu Yang wrote: > > > > > diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig > > > index 160b3a8..4b94ec7 100644 > > > --- a/arch/mips/Kconfig > > > +++ b/arch/mips/Kconfig > > > @@ -6,6 +6,7 @@ config MIPS > > > select ARCH_BINFMT_ELF_STATE if MIPS_FP_SUPPORT > > > select ARCH_HAS_FORTIFY_SOURCE > > > select ARCH_HAS_KCOV > > > + select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE > > Hmm, documentation on ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE seems rather > > scarce, but based on my guess shouldn't this be "if !EVA"? > > > > Maciej > > I do not quite know what the effect if MIPS EVA (Enhanced Virtual > Addressing) > is set, I saw that ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE should be > restricted > to archs with non-overlapping address ranges. > > I wonder whether MIPS EVA will generate overlapping address ranges? they can overlap in EVA mode. > If yes, it is better to make ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE depend > on !EVA on MIPS. Could please add the change ? Thomas. -- Crap can work. Given enough thrust pigs will fly, but it's not necessarily a good idea. [ RFC1925, 2.3 ]