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=-17.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL 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 8EECECA9ECF for ; Fri, 1 Nov 2019 22:12:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5BE2A21897 for ; Fri, 1 Nov 2019 22:12:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="q3YTCGLY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727747AbfKAWMI (ORCPT ); Fri, 1 Nov 2019 18:12:08 -0400 Received: from mail-pl1-f202.google.com ([209.85.214.202]:34547 "EHLO mail-pl1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727673AbfKAWMG (ORCPT ); Fri, 1 Nov 2019 18:12:06 -0400 Received: by mail-pl1-f202.google.com with SMTP id u9so1472257plq.1 for ; Fri, 01 Nov 2019 15:12:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=E806Ihq7Qr5kwAxZ8O8jq/5GK0i44oON304BuEfvZ08=; b=q3YTCGLY4SwiQs7Dr523GbwXcyS1rOF4ePlC+I2FlqMLdM1nbvtx89eitGKg3+MPv/ /6kpVC7ib3nqYGqEvd/D7Aja0/Oqw9bqK4yY73IHHngPbb8yNTF80TsjwS3dip4BNdjJ vrTCQU+wyHKRY1+9qAAoEBJOivxjjzkaOrEGQr3vnrSW+SARMhsCk1i/tL9jdyhbVr9G N6J/wBNQprJN4QGbaP/iQ1MEafD71JFawBswZkK6umVAzs2YdsoYpup5A4o/8Tk1dVfR JqWRLp00wfY2sTSArmHg6PdT5yupXzlZUV+YXQhkWVfHN9eXitDPORweXPhbmCnVSWKB z5cQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=E806Ihq7Qr5kwAxZ8O8jq/5GK0i44oON304BuEfvZ08=; b=CJn1m1Jc2+yNpKSwVYoleFM2cnyXzl677bJuAdpciC0ageWccfo1efBrx7bI3CjN4k kCh2ZClv5Q7AhLkuHWGQJb974bGWFDPfprFOx4Mg2sXxXmD1nlyT2ulEv+/biF+pyTl6 85WD3WJ+dkbZyhVZODET2j3SUaVZg87eanmf9kNfFLH5HZbIJquftWvDefIq66GrGpRE ha8INmGbtGLdE3HLYaEV+rZi+9qvCfTkOsKEXfNEHEYgJltzx1M/LIA8VtcYAyWE4inG M8dy07W5Y+P1kmMD6gHJaAjn15Acz1i1VUsqqvyQPXRfLjeUVzWzZe6lcVKq/IxcwV88 4NtQ== X-Gm-Message-State: APjAAAXW2z1mrT4vA2xY8pjNoEYZE23gVhz7cfph4yxIwgyzrF8VQ9WN 07APLN2aTLlgFhlq9+DTq6whey2xontb5aJOtUU= X-Google-Smtp-Source: APXvYqyjCtIlE+FqIkDNQuZrIZu231KKDGdgU5VhgnFa05GlKuF5lFgoXY69KDCGAPVnM5k2sylcp3A3JeY4sKUC4Q0= X-Received: by 2002:a63:7015:: with SMTP id l21mr14741976pgc.200.1572646325115; Fri, 01 Nov 2019 15:12:05 -0700 (PDT) Date: Fri, 1 Nov 2019 15:11:37 -0700 In-Reply-To: <20191101221150.116536-1-samitolvanen@google.com> Message-Id: <20191101221150.116536-5-samitolvanen@google.com> Mime-Version: 1.0 References: <20191018161033.261971-1-samitolvanen@google.com> <20191101221150.116536-1-samitolvanen@google.com> X-Mailer: git-send-email 2.24.0.rc1.363.gb1bccd3e3d-goog Subject: [PATCH v4 04/17] arm64: kernel: avoid x18 __cpu_soft_restart From: Sami Tolvanen To: Will Deacon , Catalin Marinas , Steven Rostedt , Masami Hiramatsu , Ard Biesheuvel Cc: Dave Martin , Kees Cook , Laura Abbott , Mark Rutland , Marc Zyngier , 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, Sami Tolvanen Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 [Sami: updated commit message] Signed-off-by: Sami Tolvanen Reviewed-by: Mark Rutland Reviewed-by: Kees Cook --- 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.rc1.363.gb1bccd3e3d-goog