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 6C57BC4320E for ; Tue, 31 Aug 2021 17:52:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5696B61053 for ; Tue, 31 Aug 2021 17:52:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240726AbhHaRxV (ORCPT ); Tue, 31 Aug 2021 13:53:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56766 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240705AbhHaRxT (ORCPT ); Tue, 31 Aug 2021 13:53:19 -0400 Received: from mail-pj1-x1033.google.com (mail-pj1-x1033.google.com [IPv6:2607:f8b0:4864:20::1033]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 682AAC061575 for ; Tue, 31 Aug 2021 10:52:24 -0700 (PDT) Received: by mail-pj1-x1033.google.com with SMTP id j10-20020a17090a94ca00b00181f17b7ef7so2663656pjw.2 for ; Tue, 31 Aug 2021 10:52:24 -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=j0DpXOqCUH2ZzDK/Oe2NuOnKngrEnBqbd1Y+1vZ30I0=; b=N9ONtQZotBdVgFYr8tLDVhCZpMZnOXYHCBaj9GMDBgs0ARDXdb/QEAe2q592DoUNqY 2xp7cvADLJpeRtLjw00Sa0DQKXGwbSYx3qiQhd59EfiKAq1JldRaqRTyXsjzYAC8fefI xnnLjOFZBEaedepvlX8IbVB7SQ71PXjGBdnIJpNqiKdkjQ6eCy3lsb00Vc5rDGOpc9t0 pOoFWElk7R/2eq9695kiwueWKwdRZNjmBnYiUdEM6Aac5Bk7rjnbNeiwmdyKkLmoCeRu iIuKbwakabWq1IERm5Hjn3SGQtrJvX7pB9N6p2YCS+YF2UE6wzLq3NE9aptBdqJJTwvD 33Qg== 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=j0DpXOqCUH2ZzDK/Oe2NuOnKngrEnBqbd1Y+1vZ30I0=; b=bMuMqkBg7Eu4uuEVUD3S+mTNKlnqJhjyg0KejD4cJe6+hR8p/yHUaBOZt0Ukug+4L7 awHrWLvwzBprkG3jxzx/6IQxidKZV4ysqeMK+AOCnoyA1RTvdhCByDJ869zIIJkk6IXY Azm+ywA6nI0itZvFXYqIo6e+WP2zi949FjtqptJ3z03NIX0YXUSn/ngowj45hyytYg1l LC+aH28jVnWsJkyOAO1DU0NREfgeKEVfNBqZnp72w0l+yaYzd8PBn9VQ4B1CAqKl7G81 8w0j74DJMmHW9A0LMAwOMKo6TCQIKUmBNKSC5JoS+n/Ti//43EAB7jVLtjohGg1P7WB/ ZKDQ== X-Gm-Message-State: AOAM532TP4ULLgXbjY9HOrw51ee5Md8dsLDilHUaFOGt5y6njxOyN/l+ IziGAnl4lvteTUpYq5GZdcQPUi2yfnM= X-Google-Smtp-Source: ABdhPJzshOlya6eaa+3Qzo0Arzj4irzFJlnl4+mU4XY8m1tNjALAbDevtPkf4qNhcI25J46/qLXsJA== X-Received: by 2002:a17:902:ff02:b0:138:b944:e0f0 with SMTP id f2-20020a170902ff0200b00138b944e0f0mr5790640plj.34.1630432343449; Tue, 31 Aug 2021 10:52:23 -0700 (PDT) Received: from localhost ([47.251.3.230]) by smtp.gmail.com with ESMTPSA id 10sm19599323pgd.12.2021.08.31.10.52.22 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 31 Aug 2021 10:52:23 -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 18/24] x86/entry: Add the C version ist_switch_to_kernel_cr3() Date: Wed, 1 Sep 2021 01:50:19 +0800 Message-Id: <20210831175025.27570-19-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 It switches the CR3 to kernel CR3 and returns the original CR3, and the caller should save the return value. It is the C version of SAVE_AND_SWITCH_TO_KERNEL_CR3. Not functional difference intended. Signed-off-by: Lai Jiangshan --- arch/x86/entry/traps.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/arch/x86/entry/traps.c b/arch/x86/entry/traps.c index da55565d43ef..9d6753d0b9fc 100644 --- a/arch/x86/entry/traps.c +++ b/arch/x86/entry/traps.c @@ -785,8 +785,23 @@ static __always_inline void switch_to_kernel_cr3(void) if (static_cpu_has(X86_FEATURE_PTI)) pti_switch_to_kernel_cr3(__native_read_cr3()); } + +static __always_inline unsigned long ist_switch_to_kernel_cr3(void) +{ + unsigned long cr3 = 0; + + if (static_cpu_has(X86_FEATURE_PTI)) { + cr3 = __native_read_cr3(); + + if (cr3 & PTI_USER_PGTABLE_MASK) + pti_switch_to_kernel_cr3(cr3); + } + + return cr3; +} #else static __always_inline void switch_to_kernel_cr3(void) {} +static __always_inline unsigned long ist_switch_to_kernel_cr3(void) { return 0; } #endif /* -- 2.19.1.6.gb485710b