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=-7.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, 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 3A5E5C46466 for ; Tue, 6 Oct 2020 16:46:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E3520206DD for ; Tue, 6 Oct 2020 16:46:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602002816; bh=6N+wobMAF8IDk/3qDidkLTePM+37ZvHyxc4HmXmoJ1c=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=x2ydeMFj98Lyb7xC4aZOHxVHEeL7MIMopYS+q6HW+1K21P6azHe6WmSYENroxQHx+ 1qY4lm7DL9CMnHRcjgzD1XCl2pnZT5L69S+cCvazlk4UAnLp3oBCR5YATz6Li+AWc6 ILXTuj2Dl4YDP/Q/LBHW7/S8qtA2vjI1gGv7L1as= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726128AbgJFQqz (ORCPT ); Tue, 6 Oct 2020 12:46:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:60226 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725769AbgJFQqz (ORCPT ); Tue, 6 Oct 2020 12:46:55 -0400 Received: from mail-lf1-f49.google.com (mail-lf1-f49.google.com [209.85.167.49]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 42E4E207EA; Tue, 6 Oct 2020 16:46:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602002814; bh=6N+wobMAF8IDk/3qDidkLTePM+37ZvHyxc4HmXmoJ1c=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=BF9Y+dblnnqOoSkiL8Cu4L+HICS17ElwDmAcgBEhWIW0dK9tYf7dz5YiIFggv2lR4 R4wad3CFaPcdR0am35OTcuG7bD1vJOrcwe6UAF3WYDnrwhsy9aiA1tpcbgfA+yaxIc qEsTKDBh+N3Os2f049MjERzQ03NlRgf/RBsOK5nY= Received: by mail-lf1-f49.google.com with SMTP id y11so15803890lfl.5; Tue, 06 Oct 2020 09:46:54 -0700 (PDT) X-Gm-Message-State: AOAM531MSPkdIT025t2CfGjU9lWE7Rj7MD5NanQgv9bfiFd7bzsSJHEB z8nu4jBQmz2m/nw5QGtYjKXHVDYzA23TTYv3ono= X-Google-Smtp-Source: ABdhPJwtmt0yVvix028cPsVw2WUiutEQ6nut7CVVXsWMH1AsUC4wFfHGzamo+vtertKc8n/lduNuaP6Rc5riToZ+vuI= X-Received: by 2002:a19:7508:: with SMTP id y8mr771313lfe.540.1602002812413; Tue, 06 Oct 2020 09:46:52 -0700 (PDT) MIME-Version: 1.0 References: <1593266228-61125-1-git-send-email-guoren@kernel.org> <1593266228-61125-2-git-send-email-guoren@kernel.org> <20200911204512.GA2705@aurel32.net> <20200914103836.GB2705@aurel32.net> <87lfgzeidk.fsf@igel.home> In-Reply-To: From: Guo Ren Date: Wed, 7 Oct 2020 00:46:40 +0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH V2 1/3] riscv: Fixup static_obj() fail To: Atish Patra Cc: Andreas Schwab , Tycho Andersen , Albert Ou , Nick Hu , Anup Patel , Palmer Dabbelt , Linux Kernel Mailing List , linux-csky@vger.kernel.org, Guo Ren , Zong Li , Paul Walmsley , Greentime Hu , Thomas Gleixner , linux-riscv Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 6, 2020 at 3:14 AM Atish Patra wrote: > > On Thu, Sep 24, 2020 at 9:19 AM Guo Ren wrote: > > > > How about this, revert the commit and don't free INIT_DATA_SECTION. I > > think the solution is safe enough, but wast a little memory. > > > > diff --git a/arch/riscv/kernel/vmlinux.lds.S b/arch/riscv/kernel/vmlinux.lds.S > > index f3586e3..34d00d9 100644 > > --- a/arch/riscv/kernel/vmlinux.lds.S > > +++ b/arch/riscv/kernel/vmlinux.lds.S > > @@ -22,13 +22,11 @@ SECTIONS > > /* Beginning of code and text segment */ > > . = LOAD_OFFSET; > > _start = .; > > - _stext = .; > > HEAD_TEXT_SECTION > > . = ALIGN(PAGE_SIZE); > > > > __init_begin = .; > > INIT_TEXT_SECTION(PAGE_SIZE) > > - INIT_DATA_SECTION(16) > > . = ALIGN(8); > > __soc_early_init_table : { > > __soc_early_init_table_start = .; > > @@ -55,6 +53,7 @@ SECTIONS > > . = ALIGN(SECTION_ALIGN); > > .text : { > > _text = .; > > + _stext = .; > > TEXT_TEXT > > SCHED_TEXT > > CPUIDLE_TEXT > > @@ -67,6 +66,8 @@ SECTIONS > > _etext = .; > > } > > > > + INIT_DATA_SECTION(16) > > + > > I think you need to move EXIT_DATA as well. Currently, we have init > data & text in one section. It's not related to this issue. There is two check code problem: 1. static int static_obj(const void *obj) { unsigned long start = (unsigned long) &_stext, end = (unsigned long) &_end, addr = (unsigned long) obj; /* * static variable? */ if ((addr >= start) && (addr < end)) return 1; 2. /* Is this address range in the kernel text area? */ static inline void check_kernel_text_object(const unsigned long ptr, unsigned long n, bool to_user) { unsigned long textlow = (unsigned long)_stext; unsigned long texthigh = (unsigned long)_etext; unsigned long textlow_linear, texthigh_linear; if (overlaps(ptr, n, textlow, texthigh)) usercopy_abort("kernel text", NULL, to_user, ptr - textlow, n); The patch of commit: a0fa4027dc911 (riscv: Fixup static_obj() fail) broke 2th. > In general it is better idea to separate those similar to ARM64. > Additionally, ARM64 applies different mapping for init data & text > as the init data section is marked as non-executable[1] Yes, it's safer to protect init text & init data, but it's should be another patch. > > However, we don't modify any permission for any init sections. Should > we do that as well ? Agree, we should do that. > > [1] https://patchwork.kernel.org/patch/9572869/ > > > /* Start of data section */ > > _sdata = .; > > RO_DATA(SECTION_ALIGN) > > > > On Thu, Sep 24, 2020 at 3:36 PM Andreas Schwab wrote: > > > > > > On Sep 14 2020, Aurelien Jarno wrote: > > > > > > > How should we proceed to get that fixed in time for 5.9? For the older > > > > branches where it has been backported (so far 5.7 and 5.8), should we > > > > just get that commit reverted instead? > > > > > > Can this please be resolved ASAP? > > > > > > Andreas. > > > > > > -- > > > Andreas Schwab, schwab@linux-m68k.org > > > GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1 > > > "And now for something completely different." > > > > > > > > -- > > Best Regards > > Guo Ren > > > > ML: https://lore.kernel.org/linux-csky/ > > > > _______________________________________________ > > linux-riscv mailing list > > linux-riscv@lists.infradead.org > > http://lists.infradead.org/mailman/listinfo/linux-riscv > > > > -- > Regards, > Atish -- Best Regards Guo Ren ML: https://lore.kernel.org/linux-csky/