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 4C807CCA485 for ; Wed, 22 Jun 2022 15:54:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1359087AbiFVPyV (ORCPT ); Wed, 22 Jun 2022 11:54:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52694 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1359725AbiFVPxX (ORCPT ); Wed, 22 Jun 2022 11:53:23 -0400 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0F0671095; Wed, 22 Jun 2022 08:52:54 -0700 (PDT) Received: from dggpemm500020.china.huawei.com (unknown [172.30.72.57]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4LSnsX3NGgz1KC7D; Wed, 22 Jun 2022 23:50:40 +0800 (CST) Received: from dggpemm500013.china.huawei.com (7.185.36.172) by dggpemm500020.china.huawei.com (7.185.36.49) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Wed, 22 Jun 2022 23:52:47 +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; Wed, 22 Jun 2022 23:52:47 +0800 From: Chen Zhongjin To: , , , , , CC: , , , , , , , , , , , , , Subject: [PATCH v5 30/33] arm64: entry: Align stack size for alternative Date: Wed, 22 Jun 2022 23:49:17 +0800 Message-ID: <20220622154920.95075-31-chenzhongjin@huawei.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220622154920.95075-1-chenzhongjin@huawei.com> References: <20220622154920.95075-1-chenzhongjin@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.67.175.36] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To dggpemm500013.china.huawei.com (7.185.36.172) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: live-patching@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 d49bfbe81a0d..677e3be471bb 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -430,7 +430,11 @@ 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 @@ -729,6 +733,7 @@ alternative_else_nop_endif .macro tramp_exit, regsize = 64 UNWIND_HINT_EMPTY + 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