Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 667CCC4332F for ; Mon, 20 Dec 2021 09:11:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230438AbhLTJLV (ORCPT ); Mon, 20 Dec 2021 04:11:21 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:43832 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229474AbhLTJLU (ORCPT ); Mon, 20 Dec 2021 04:11:20 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id A3C7BB80E2F; Mon, 20 Dec 2021 09:11:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 78C06C36AF1; Mon, 20 Dec 2021 09:11:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1639991477; bh=nEOzzl3wgkRPT0ygPKzT3y34sfnV1NTZVShiBXQle80=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=S+pQs5PylnYAzTQdboNEcFEcb/0jEv235YQ31EGzXeMNcNWFYDzI2wRBRs75VPCZo A6o71kUHuefFXz25TPekWC/tqGShH7/xuyF2uQNXW7aoNHBBi4OjIfgWj5nrvpv9wE fTk9wXuIR2O5A1JgAo1v4ectbqb9S3o8AkF8SjZfqjIJmcCFPexSnyuvnFZ+aaXfsQ VYHbHoSqvDIVC2KRrygV2Gxe0WKtX3SJn7BEv+uULTy6pa33iGoYu5CW0f11JRgCDI sNZ2pODyIgIxISqGX9atx2cRHiRqV8gVCiyVP0CM+nIdkCFsnU37aWYtREBkmMGthR 7QlP2UUR7W5+w== Received: by mail-ua1-f53.google.com with SMTP id p37so16464475uae.8; Mon, 20 Dec 2021 01:11:17 -0800 (PST) X-Gm-Message-State: AOAM533KCzZ969lQtWNl0dOydZQUsidLKZMI11ebZ5TQ/eb5wiiK+j4u wRcIpb66uBoFaoPB75BKt/Y90vdBhH9aAukrYpw= X-Google-Smtp-Source: ABdhPJwE5vVG3rt8d+HcTmKlAQnW1OXabBV+eLKlgaa5VIIm58YsDnEYQVdu+coTipMz0kob8hRz5mDIgjhyqqjdiuc= X-Received: by 2002:ab0:3055:: with SMTP id x21mr4783242ual.97.1639991476313; Mon, 20 Dec 2021 01:11:16 -0800 (PST) MIME-Version: 1.0 References: <20211206104657.433304-1-alexandre.ghiti@canonical.com> <20211206104657.433304-13-alexandre.ghiti@canonical.com> In-Reply-To: <20211206104657.433304-13-alexandre.ghiti@canonical.com> From: Guo Ren Date: Mon, 20 Dec 2021 17:11:05 +0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v3 12/13] riscv: Initialize thread pointer before calling C functions To: Alexandre Ghiti Cc: Jonathan Corbet , Paul Walmsley , Palmer Dabbelt , Albert Ou , Zong Li , Anup Patel , Atish Patra , Christoph Hellwig , Andrey Ryabinin , Alexander Potapenko , Andrey Konovalov , Dmitry Vyukov , Ard Biesheuvel , Arnd Bergmann , Kees Cook , Guo Ren , Heinrich Schuchardt , Mayuresh Chitale , panqinglin2020@iscas.ac.cn, Linux Doc Mailing List , linux-riscv , Linux Kernel Mailing List , kasan-dev@googlegroups.com, linux-efi@vger.kernel.org, linux-arch Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 7, 2021 at 11:55 AM Alexandre Ghiti wrote: > > Because of the stack canary feature that reads from the current task > structure the stack canary value, the thread pointer register "tp" must > be set before calling any C function from head.S: by chance, setup_vm Shall we disable -fstack-protector for setup_vm() with __attribute__? Actually, we've already init tp later. > and all the functions that it calls does not seem to be part of the > functions where the canary check is done, but in the following commits, > some functions will. > > Fixes: f2c9699f65557a31 ("riscv: Add STACKPROTECTOR supported") > Signed-off-by: Alexandre Ghiti > --- > arch/riscv/kernel/head.S | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S > index c3c0ed559770..86f7ee3d210d 100644 > --- a/arch/riscv/kernel/head.S > +++ b/arch/riscv/kernel/head.S > @@ -302,6 +302,7 @@ clear_bss_done: > REG_S a0, (a2) > > /* Initialize page tables and relocate to virtual addresses */ > + la tp, init_task > la sp, init_thread_union + THREAD_SIZE > XIP_FIXUP_OFFSET sp > #ifdef CONFIG_BUILTIN_DTB > -- > 2.32.0 > -- Best Regards Guo Ren ML: https://lore.kernel.org/linux-csky/