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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 88D36CA9EC9 for ; Fri, 1 Nov 2019 03:47:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5BBD22067D for ; Fri, 1 Nov 2019 03:47:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="OUr7ArDi" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729757AbfKADrH (ORCPT ); Thu, 31 Oct 2019 23:47:07 -0400 Received: from mail-pl1-f195.google.com ([209.85.214.195]:33309 "EHLO mail-pl1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726600AbfKADrG (ORCPT ); Thu, 31 Oct 2019 23:47:06 -0400 Received: by mail-pl1-f195.google.com with SMTP id y8so3760783plk.0 for ; Thu, 31 Oct 2019 20:47:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=u5Q9VGAIWgqBExeYcYbdu3s9udgqDxFzlJQ7eRueT/Q=; b=OUr7ArDiqHbONLazU8MgPIGz23M1A8vMM7F8b9Md5DVHQ+EZhCFgoZlMZ+G5HTnpZ+ wE2eqONi9hN3i5Bcrge6nsj37dKyheWOwYi04/RxLQQQWFlzKYDXXwSGgtrWINXpoHTa pu2AouoST0OW8JKhXcovsqIH4Xg7eOJ6N8a30= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=u5Q9VGAIWgqBExeYcYbdu3s9udgqDxFzlJQ7eRueT/Q=; b=tPCXj4hLeOmSHlRxVsmVz7I3rB9MWEJFgT4yYR91Wp9t2ZZ0X9XCSy2dwQsLK4iqg0 3Wu4mK8AlhBGrCspWGEhpJnLiSION6LDloQgbOl2bw/cfi2HbgAkbOeWCL84qQCT66Zc jnJYo29nrZ6yDhhljer3Yq8Jqbe1tJxwQwABANvXpR+LWFx6k+q/HL9ygyb4mXnwhmUU c8jc7Z1vRFGGoSUehI646zDS6EM3AW6q62Ymuejgab58GMeYxk0jnFHX/7EchRU1Y7Hf c2Lka+Jy4nfo0yf7pSSFO9WeEzv58N82AsOBfj051PFWQdD00klLrWuFfDc+4Mt6GykR kwNg== X-Gm-Message-State: APjAAAUtNxHaluHmLd3BycPyqejOzwScXAPXTXlUHWssLa9SGdeSYScn JOMGTKUJB2lWmCStsMlpy4l5EQ== X-Google-Smtp-Source: APXvYqzxXwp35RHwMjtICT5o/o5TX+pRdcY4/XDk99r6vm9qvXrxFtMjtkTLjrDyCFVkkuXacPUM+g== X-Received: by 2002:a17:902:9042:: with SMTP id w2mr10476445plz.323.1572580026099; Thu, 31 Oct 2019 20:47:06 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id z2sm5943741pgo.13.2019.10.31.20.47.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 31 Oct 2019 20:47:05 -0700 (PDT) Date: Thu, 31 Oct 2019 20:47:04 -0700 From: Kees Cook To: samitolvanen@google.com Cc: Will Deacon , Catalin Marinas , Steven Rostedt , Masami Hiramatsu , Ard Biesheuvel , Dave Martin , Laura Abbott , Mark Rutland , Nick Desaulniers , Jann Horn , Miguel Ojeda , Masahiro Yamada , clang-built-linux@googlegroups.com, kernel-hardening@lists.openwall.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 04/17] arm64: kernel: avoid x18 __cpu_soft_restart Message-ID: <201910312046.53A31D394@keescook> References: <20191018161033.261971-1-samitolvanen@google.com> <20191031164637.48901-1-samitolvanen@google.com> <20191031164637.48901-5-samitolvanen@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191031164637.48901-5-samitolvanen@google.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 31, 2019 at 09:46:24AM -0700, samitolvanen@google.com wrote: > From: Ard Biesheuvel > > The code in __cpu_soft_restart() uses x18 as an arbitrary temp register, > which will shortly be disallowed. So use x8 instead. > > Link: https://patchwork.kernel.org/patch/9836877/ > Signed-off-by: Ard Biesheuvel This one is easy to validate! ;) Reviewed-by: Kees Cook -Kees > Signed-off-by: Sami Tolvanen > Reviewed-by: Mark Rutland > --- > arch/arm64/kernel/cpu-reset.S | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/kernel/cpu-reset.S b/arch/arm64/kernel/cpu-reset.S > index 6ea337d464c4..32c7bf858dd9 100644 > --- a/arch/arm64/kernel/cpu-reset.S > +++ b/arch/arm64/kernel/cpu-reset.S > @@ -42,11 +42,11 @@ ENTRY(__cpu_soft_restart) > mov x0, #HVC_SOFT_RESTART > hvc #0 // no return > > -1: mov x18, x1 // entry > +1: mov x8, x1 // entry > mov x0, x2 // arg0 > mov x1, x3 // arg1 > mov x2, x4 // arg2 > - br x18 > + br x8 > ENDPROC(__cpu_soft_restart) > > .popsection > -- > 2.24.0.rc0.303.g954a862665-goog > -- Kees Cook 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 ACD21CA9EC9 for ; Fri, 1 Nov 2019 03:47:11 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 84EBE208CB for ; Fri, 1 Nov 2019 03:47:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="BzfNgmp4"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="OUr7ArDi" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 84EBE208CB Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chromium.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=khq9rCbwV0kGpVCcebu2Buzu+Z4pgm3vt4pQmRb5GQU=; b=BzfNgmp4HLL4RF Ns+4HEkgh1wgFv/MgjqAilVK8tz/mIwPPwbG2MnQLHAOaWeTFkONvBr4DxTSKy5Rz4hAwVFUBi4AJ SjtASEVoIgN2Dt1zgHBnuMM7scCF9D5Of+WikT1EBMcnDlPwopYHiH0YcmoJw/MpGXGXpEy+tZn8y xxpxs/389EfhFQNYRjZX+zjFyxVtMWM6o4fEkjz1EWhF/7hvia90BY0waVYqpgCofibn1f3MTd3hQ uIrPzee7yjVv0AbWn78uG7/MSjKnOAEutEFWJtCOQLKnvwe0Ud+MTznvlDVw7/zWo7ZPk3ywgy2hG cmSHtesE3VRdKk9oMKog==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iQNu3-0004wo-13; Fri, 01 Nov 2019 03:47:11 +0000 Received: from mail-pl1-x643.google.com ([2607:f8b0:4864:20::643]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1iQNtz-0004wA-9Q for linux-arm-kernel@lists.infradead.org; Fri, 01 Nov 2019 03:47:08 +0000 Received: by mail-pl1-x643.google.com with SMTP id x6so3742169pln.2 for ; Thu, 31 Oct 2019 20:47:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=u5Q9VGAIWgqBExeYcYbdu3s9udgqDxFzlJQ7eRueT/Q=; b=OUr7ArDiqHbONLazU8MgPIGz23M1A8vMM7F8b9Md5DVHQ+EZhCFgoZlMZ+G5HTnpZ+ wE2eqONi9hN3i5Bcrge6nsj37dKyheWOwYi04/RxLQQQWFlzKYDXXwSGgtrWINXpoHTa pu2AouoST0OW8JKhXcovsqIH4Xg7eOJ6N8a30= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=u5Q9VGAIWgqBExeYcYbdu3s9udgqDxFzlJQ7eRueT/Q=; b=e7VkWpRZBa3LFlweBJGdenbIH2pM0NzzYsSIcBNZyq1ZTDxvx0mM040V9oLme1//7f PbT+IBGJ0DB94V2FnvAbI6+NCf5vS+/0VV73S+P99uXhInzBnhqQsRUwF9cvGsN8tBve 2zZ1o1xk7o2AuR+mpD2yz1JD6UE3TCf8/OVrx6sWBOzQzvNdfisH4coE1gr467IuAauL ju6okPl/o2O/JPrOdPpeTR5RXi49j2+1+g/VboqVLZTPQJVMBCzCcRTQSMQoyS0Klxlq q9O9Mr2xvrM0H9gbHCKSC2hHdUhOGbxQZwry35RmzQSS4eqtdVcboT6vb6uJPu4tdqtS x+Cw== X-Gm-Message-State: APjAAAUEDAXejY+9aL8hI0Ru3XmZn2cnZFCopf5rd/0nyYkcmLSyIKUd HGFwjhO88BFljDuq2os6/5jHXQ== X-Google-Smtp-Source: APXvYqzxXwp35RHwMjtICT5o/o5TX+pRdcY4/XDk99r6vm9qvXrxFtMjtkTLjrDyCFVkkuXacPUM+g== X-Received: by 2002:a17:902:9042:: with SMTP id w2mr10476445plz.323.1572580026099; Thu, 31 Oct 2019 20:47:06 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id z2sm5943741pgo.13.2019.10.31.20.47.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 31 Oct 2019 20:47:05 -0700 (PDT) Date: Thu, 31 Oct 2019 20:47:04 -0700 From: Kees Cook To: samitolvanen@google.com Subject: Re: [PATCH v3 04/17] arm64: kernel: avoid x18 __cpu_soft_restart Message-ID: <201910312046.53A31D394@keescook> References: <20191018161033.261971-1-samitolvanen@google.com> <20191031164637.48901-1-samitolvanen@google.com> <20191031164637.48901-5-samitolvanen@google.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20191031164637.48901-5-samitolvanen@google.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191031_204707_327065_A7612A1C X-CRM114-Status: GOOD ( 15.49 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , clang-built-linux@googlegroups.com, Ard Biesheuvel , Masahiro Yamada , Catalin Marinas , Jann Horn , Nick Desaulniers , linux-kernel@vger.kernel.org, Steven Rostedt , Miguel Ojeda , Masami Hiramatsu , kernel-hardening@lists.openwall.com, Laura Abbott , Will Deacon , Dave Martin , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Oct 31, 2019 at 09:46:24AM -0700, samitolvanen@google.com wrote: > From: Ard Biesheuvel > > The code in __cpu_soft_restart() uses x18 as an arbitrary temp register, > which will shortly be disallowed. So use x8 instead. > > Link: https://patchwork.kernel.org/patch/9836877/ > Signed-off-by: Ard Biesheuvel This one is easy to validate! ;) Reviewed-by: Kees Cook -Kees > Signed-off-by: Sami Tolvanen > Reviewed-by: Mark Rutland > --- > arch/arm64/kernel/cpu-reset.S | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/kernel/cpu-reset.S b/arch/arm64/kernel/cpu-reset.S > index 6ea337d464c4..32c7bf858dd9 100644 > --- a/arch/arm64/kernel/cpu-reset.S > +++ b/arch/arm64/kernel/cpu-reset.S > @@ -42,11 +42,11 @@ ENTRY(__cpu_soft_restart) > mov x0, #HVC_SOFT_RESTART > hvc #0 // no return > > -1: mov x18, x1 // entry > +1: mov x8, x1 // entry > mov x0, x2 // arg0 > mov x1, x3 // arg1 > mov x2, x4 // arg2 > - br x18 > + br x8 > ENDPROC(__cpu_soft_restart) > > .popsection > -- > 2.24.0.rc0.303.g954a862665-goog > -- Kees Cook _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel