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=-10.4 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 3B1B0C433E0 for ; Wed, 3 Feb 2021 12:50:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F23A364F6C for ; Wed, 3 Feb 2021 12:50:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230273AbhBCMui (ORCPT ); Wed, 3 Feb 2021 07:50:38 -0500 Received: from pegase1.c-s.fr ([93.17.236.30]:3947 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229567AbhBCMpy (ORCPT ); Wed, 3 Feb 2021 07:45:54 -0500 Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 4DW1bx1lvkz9txxD; Wed, 3 Feb 2021 13:45:01 +0100 (CET) X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id HjMAXj_hX0ua; Wed, 3 Feb 2021 13:45:01 +0100 (CET) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 4DW1bx0MsNz9txxB; Wed, 3 Feb 2021 13:45:01 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 6C76B8B7E6; Wed, 3 Feb 2021 13:45:02 +0100 (CET) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id NgsdGv0kVo9P; Wed, 3 Feb 2021 13:45:02 +0100 (CET) Received: from [172.25.230.103] (po15451.idsi0.si.c-s.fr [172.25.230.103]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 3E2FC8B7E5; Wed, 3 Feb 2021 13:45:02 +0100 (CET) Subject: Re: [PATCH v10 6/6] powerpc: Book3S 64-bit outline-only KASAN support To: Daniel Axtens , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, kasan-dev@googlegroups.com, aneesh.kumar@linux.ibm.com, bsingharora@gmail.com References: <20210203115946.663273-1-dja@axtens.net> <20210203115946.663273-7-dja@axtens.net> From: Christophe Leroy Message-ID: <4b790789-052f-76de-a289-726517026efd@csgroup.eu> Date: Wed, 3 Feb 2021 13:45:00 +0100 User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.7.0 MIME-Version: 1.0 In-Reply-To: <20210203115946.663273-7-dja@axtens.net> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 03/02/2021 à 12:59, Daniel Axtens a écrit : > Implement a limited form of KASAN for Book3S 64-bit machines running under > the Radix MMU, supporting only outline mode. > > diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c > index a66f435dabbf..9a6fd603f0e7 100644 > --- a/arch/powerpc/kernel/process.c > +++ b/arch/powerpc/kernel/process.c > @@ -2157,8 +2157,8 @@ void show_stack(struct task_struct *tsk, unsigned long *stack, > break; > > stack = (unsigned long *) sp; > - newsp = stack[0]; > - ip = stack[STACK_FRAME_LR_SAVE]; > + newsp = READ_ONCE_NOCHECK(stack[0]); > + ip = READ_ONCE_NOCHECK(stack[STACK_FRAME_LR_SAVE]); > if (!firstframe || ip != lr) { > printk("%s["REG"] ["REG"] %pS", > loglvl, sp, ip, (void *)ip); > @@ -2176,17 +2176,19 @@ void show_stack(struct task_struct *tsk, unsigned long *stack, > * See if this is an exception frame. > * We look for the "regshere" marker in the current frame. > */ > - if (validate_sp(sp, tsk, STACK_INT_FRAME_SIZE) > - && stack[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) { > + if (validate_sp(sp, tsk, STACK_INT_FRAME_SIZE) && > + (READ_ONCE_NOCHECK(stack[STACK_FRAME_MARKER]) == > + STACK_FRAME_REGS_MARKER)) { > struct pt_regs *regs = (struct pt_regs *) > (sp + STACK_FRAME_OVERHEAD); > > - lr = regs->link; > + lr = READ_ONCE_NOCHECK(regs->link); > printk("%s--- interrupt: %lx at %pS\n", > - loglvl, regs->trap, (void *)regs->nip); > + loglvl, READ_ONCE_NOCHECK(regs->trap), > + (void *)READ_ONCE_NOCHECK(regs->nip)); > __show_regs(regs); > printk("%s--- interrupt: %lx\n", > - loglvl, regs->trap); > + loglvl, READ_ONCE_NOCHECK(regs->trap)); > > firstframe = 1; > } The above changes look like a bug fix not directly related to KASAN. Should be split out in another patch I think. Christophe