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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E7672C433F5 for ; Fri, 29 Apr 2022 09:45:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356809AbiD2Jsy (ORCPT ); Fri, 29 Apr 2022 05:48:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33868 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1356764AbiD2Jsg (ORCPT ); Fri, 29 Apr 2022 05:48:36 -0400 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B7091890AB; Fri, 29 Apr 2022 02:45:18 -0700 (PDT) Received: from dggpemm500023.china.huawei.com (unknown [172.30.72.53]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4KqSCY5cx3zCsSp; Fri, 29 Apr 2022 17:40:41 +0800 (CST) Received: from dggpemm500013.china.huawei.com (7.185.36.172) by dggpemm500023.china.huawei.com (7.185.36.83) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 29 Apr 2022 17:45:16 +0800 Received: from ubuntu1804.huawei.com (10.67.175.36) by dggpemm500013.china.huawei.com (7.185.36.172) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 29 Apr 2022 17:45:16 +0800 From: Chen Zhongjin To: , , CC: , , , , , , , , , , , , , , Subject: [RFC PATCH v4 36/37] arm64: entry: Align stack size for alternative Date: Fri, 29 Apr 2022 17:43:54 +0800 Message-ID: <20220429094355.122389-37-chenzhongjin@huawei.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220429094355.122389-1-chenzhongjin@huawei.com> References: <20220429094355.122389-1-chenzhongjin@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.67.175.36] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To dggpemm500013.china.huawei.com (7.185.36.172) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org In kernel_exit there is a alternative branch for KPTI which causes stack size conflict for two instruction boundaries. To fix that, make both branch move the sp and then revert it in tramp_exit branch. Signed-off-by: Chen Zhongjin --- arch/arm64/kernel/entry.S | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index c7ab5143949f..fa3c5a2cd2c3 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -429,7 +429,11 @@ alternative_if_not ARM64_UNMAP_KERNEL_AT_EL0 ldr lr, [sp, #S_LR] add sp, sp, #PT_REGS_SIZE // restore sp eret -alternative_else_nop_endif +alternative_else + nop + add sp, sp, #PT_REGS_SIZE // restore sp + nop +alternative_endif #ifdef CONFIG_UNMAP_KERNEL_AT_EL0 bne 4f msr far_el1, x29 @@ -726,6 +730,7 @@ alternative_else_nop_endif .endm .macro tramp_exit, regsize = 64 + sub sp, sp, #PT_REGS_SIZE // revert sp tramp_data_read_var x30, this_cpu_vector get_this_cpu_offset x29 ldr x30, [x30, x29] -- 2.17.1