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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 23519C432BE for ; Tue, 31 Aug 2021 17:51:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0438F61041 for ; Tue, 31 Aug 2021 17:51:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240606AbhHaRwS (ORCPT ); Tue, 31 Aug 2021 13:52:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56420 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240599AbhHaRwN (ORCPT ); Tue, 31 Aug 2021 13:52:13 -0400 Received: from mail-pl1-x62e.google.com (mail-pl1-x62e.google.com [IPv6:2607:f8b0:4864:20::62e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 16166C061760 for ; Tue, 31 Aug 2021 10:51:18 -0700 (PDT) Received: by mail-pl1-x62e.google.com with SMTP id m4so11145775pll.0 for ; Tue, 31 Aug 2021 10:51:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=cKJKix7V4+8OJWG7NYRAywgnyYbhA97Td6yueyJaEo0=; b=sx0/84XcVXA7145IRx0EmPQXqT95ytN4wLAp8nwL8xXi8kYW0NGz2DGMKGH7I6ZCQp IXpwvTSbXh+ZUFmSQkjp//oPngE/Rwh14N9u5NVBC5Un+k1Vj5AqEsjzb2EK5KV3y3bX BfSt8n6m8PPdvqG5ZdavAQ9ro4iJtqtXyyIzDDKBjSMW0u/3sAj0rQT5RubG/OkgE3f0 c/J+yVNdnf7z1eTCjc9Jk2ARe5g+rkQ3oWqLbXvOu9IN8i4MNNSjGQHrIIIvVVurBhSG b0KYHP9Bo4DnXrHdgdDnLbGSBhOdSbSTXmengz9PkEyUvwCx9pJTGtVsWgLds5X1g1Y3 9Hnw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=cKJKix7V4+8OJWG7NYRAywgnyYbhA97Td6yueyJaEo0=; b=VxOqFzWpTgApJC21uO6njAGRVeh+jwEg6jrpohp5Wlwfrrp+lPuxDP5nmwFa+fC+eC V8SlOYbeq4AVXB/0U8crQUD0SKg8rtACuKZD1a6zqJBpg9MX2fH67uHnKlPHgievV+3r wo3IbjVNVf3ZQLch/Jp3beoFzSAASKYurR1AZPiOUDd/74te3CyTEe/fmyuTT9Jn7avB 4Olzpxk8drTfxp81y1zqGX2HcYE8Ww1Z7gTpWHwFEcdrPEA5SnbXsV3iHN1fGHEwapGw EtOczrxh/p5xYy0rjJbEnqKLuAMkgwG4mY3+pOHAGyh7P1S5LtQMY9VFiR3jNBrRH82O 8Y9w== X-Gm-Message-State: AOAM531U5LsYiSDMxkAWHp9r+63AzHQ2/e12FFM+zVj2pJcLWdzRXeW0 XIWG1UWtGeZOwY4dbQhO5kLtaLlUyOE= X-Google-Smtp-Source: ABdhPJxFRIVycVYQI6vcXMeAwzkKTHZ57mLC+Kt2c3mIuRxxIY0MQbs2aRwZyYKKHmUcUqdfBmn5fA== X-Received: by 2002:a17:90a:af92:: with SMTP id w18mr6624650pjq.98.1630432277471; Tue, 31 Aug 2021 10:51:17 -0700 (PDT) Received: from localhost ([47.251.3.230]) by smtp.gmail.com with ESMTPSA id u21sm21989951pgk.57.2021.08.31.10.51.16 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 31 Aug 2021 10:51:17 -0700 (PDT) From: Lai Jiangshan To: linux-kernel@vger.kernel.org Cc: Lai Jiangshan , Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" Subject: [PATCH 08/24] x86/traps: Add C verion of SWITCH_TO_KERNEL_CR3 as switch_to_kernel_cr3() Date: Wed, 1 Sep 2021 01:50:09 +0800 Message-Id: <20210831175025.27570-9-jiangshanlai@gmail.com> X-Mailer: git-send-email 2.19.1.6.gb485710b In-Reply-To: <20210831175025.27570-1-jiangshanlai@gmail.com> References: <20210831175025.27570-1-jiangshanlai@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Lai Jiangshan The C version switch_to_kernel_cr3() implements SWITCH_TO_KERNEL_CR3(). No functional difference intended. Signed-off-by: Lai Jiangshan --- arch/x86/entry/traps.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/arch/x86/entry/traps.c b/arch/x86/entry/traps.c index ef07ae5fb3a0..9b7d0f15402e 100644 --- a/arch/x86/entry/traps.c +++ b/arch/x86/entry/traps.c @@ -765,6 +765,30 @@ struct bad_iret_stack *fixup_bad_iret(struct bad_iret_stack *s) BUG_ON(!user_mode(&new_stack->regs)); return new_stack; } + +#ifdef CONFIG_PAGE_TABLE_ISOLATION +static __always_inline void pti_switch_to_kernel_cr3(unsigned long user_cr3) +{ + /* + * Clear PCID and "PAGE_TABLE_ISOLATION bit", point CR3 + * at kernel pagetables: + */ + unsigned long cr3 = user_cr3 & ~PTI_USER_PGTABLE_AND_PCID_MASK; + + if (static_cpu_has(X86_FEATURE_PCID)) + cr3 |= X86_CR3_PCID_NOFLUSH; + + native_write_cr3(cr3); +} + +static __always_inline void switch_to_kernel_cr3(void) +{ + if (static_cpu_has(X86_FEATURE_PTI)) + pti_switch_to_kernel_cr3(__native_read_cr3()); +} +#else +static __always_inline void switch_to_kernel_cr3(void) {} +#endif #endif static bool is_sysenter_singlestep(struct pt_regs *regs) -- 2.19.1.6.gb485710b