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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 07C90C433FE for ; Tue, 26 Oct 2021 14:29:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E60E5610F8 for ; Tue, 26 Oct 2021 14:29:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236559AbhJZObY (ORCPT ); Tue, 26 Oct 2021 10:31:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55172 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236604AbhJZObJ (ORCPT ); Tue, 26 Oct 2021 10:31:09 -0400 Received: from mail-pj1-x1034.google.com (mail-pj1-x1034.google.com [IPv6:2607:f8b0:4864:20::1034]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 84088C061224 for ; Tue, 26 Oct 2021 07:28:44 -0700 (PDT) Received: by mail-pj1-x1034.google.com with SMTP id lx5-20020a17090b4b0500b001a262880e99so1836067pjb.5 for ; Tue, 26 Oct 2021 07:28:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=3kMfdZR7u3SGVAlrTiFoKn2/xZAEuhY7vC7t+axQgCY=; b=mYh6Ur38+KcKTY2kh7RNV36y3KogCi1bV69Xn81by9+Iq3gBGmCXhD6ntYXvbBlhgj xYi4BWYsLQ4+H+BokkYXmCnQ/27r4sY8t5us41Q4+6Js7r634FDRFIlfJ1RsYb7EvtFC x47whYvUHvp0m34sZ3/p5JVlgUwmPeBaTPgKxPpHBPt9JgbJxVxHaBoY7DG7z1iDcNYx VzbniPUPM5nGDpaQ0NyT3RqwtHansbkm6kBeqJxAGm4+Q54/jS4DfFqVf6J3CbkrLF1Y X4p61scn770LXiP+53lY1XFF3OrqANJLmTHzSYXl9efkAAMjKOheu9L+qnJHOxgvdNht hLww== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=3kMfdZR7u3SGVAlrTiFoKn2/xZAEuhY7vC7t+axQgCY=; b=0vWhezpk40xcWf/n6uxpQuEsKoEI2aDB3UR/etOitfFq5RBd3OrdqqU+SbvcFkSrDm rxKQrKgTSheEXvRWzgbphdw6FzCaf4y4Dk4/1/zft5z+/waOv5lBLr85qize3I98UQro s0pLrJ48w7qqYtrUOdtrIFNl6OVwFID3FoQNSWQCNw1b+tH/7BxKXKpPYxVjhYaYjNdg oGDRSsuKnT07aVXohcqvLZM8Pu2+0iXn13u70Zh/opMzOl2Tj2bYsVnbPJHhFFLzExPC zZ3znn4YzMh/2UxD8LhPgr72UIzDRV5g+aokuCCkY+a3xR+R371K9fqSNEMCHtSIr+7f 41YA== X-Gm-Message-State: AOAM531GVns7CFHcGUpgWGJ99GHK3Eu7zmPS8yzFeS+c4jZicYMPzv8D Y1XFVt7H+MrUSr+Uz3K44oR5k+tSHBc= X-Google-Smtp-Source: ABdhPJymq1mRT2yJPvB4IR2vllLVnLcE8bIOQlOyMSlQ1/99sd3gnVzgiuU9GxDXAxo6fBDFPX8BnA== X-Received: by 2002:a17:90b:4b06:: with SMTP id lx6mr42923042pjb.220.1635258523985; Tue, 26 Oct 2021 07:28:43 -0700 (PDT) Received: from localhost ([47.88.5.130]) by smtp.gmail.com with ESMTPSA id a25sm3608351pfl.115.2021.10.26.07.28.43 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 26 Oct 2021 07:28:43 -0700 (PDT) From: Lai Jiangshan To: linux-kernel@vger.kernel.org Cc: x86@kernel.org, Lai Jiangshan , Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" Subject: [PATCH V4 15/50] x86/entry: Add C verion of SWITCH_TO_KERNEL_CR3 as switch_to_kernel_cr3() Date: Tue, 26 Oct 2021 22:27:47 +0800 Message-Id: <20211026142824.18362-5-jiangshanlai@gmail.com> X-Mailer: git-send-email 2.19.1.6.gb485710b In-Reply-To: <20211026141420.17138-1-jiangshanlai@gmail.com> References: <20211026141420.17138-1-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/entry64.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/arch/x86/entry/entry64.c b/arch/x86/entry/entry64.c index 9813a30dbadb..9a5c535b1ddf 100644 --- a/arch/x86/entry/entry64.c +++ b/arch/x86/entry/entry64.c @@ -14,3 +14,27 @@ #include extern unsigned char asm_load_gs_index_gs_change[]; + +#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 -- 2.19.1.6.gb485710b