From patchwork Wed Jul 11 11:29:43 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joerg Roedel X-Patchwork-Id: 10519535 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 256BA603D7 for ; Wed, 11 Jul 2018 11:32:45 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2949628592 for ; Wed, 11 Jul 2018 11:32:45 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1D17C285A5; Wed, 11 Jul 2018 11:32:45 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=unavailable version=3.3.1 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B244928592 for ; Wed, 11 Jul 2018 11:32:44 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8BF5A6B0298; Wed, 11 Jul 2018 07:30:25 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 895AF6B0299; Wed, 11 Jul 2018 07:30:25 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7ABCF6B029A; Wed, 11 Jul 2018 07:30:25 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from mail-ed1-f72.google.com (mail-ed1-f72.google.com [209.85.208.72]) by kanga.kvack.org (Postfix) with ESMTP id 1B1F46B0299 for ; Wed, 11 Jul 2018 07:30:25 -0400 (EDT) Received: by mail-ed1-f72.google.com with SMTP id v26-v6so3469931eds.9 for ; Wed, 11 Jul 2018 04:30:25 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:dkim-signature:from:to:cc:subject:date :message-id:in-reply-to:references; bh=a7TvZetQgpGsRi0tRe2KY1CoKeC2YyRA8rSQNNSNVK8=; b=QBmGoDUwH9/r64mvl4O8YJAHYRQZNIZM6yxbHDJCIQ667Of75wlAyyS07Rf8b27qNL 3o/fwNKMyt9iVCvQTF+JCfgnal4n7w4k4Ij55NygdGo3M3lKqoBBmI1trLoP1VTA9e1D k49ECIHfMcsrqSv331n6HmCQhgSBFq6qNtEbMCwo42GHZ/o4ZkmgT4+pmO5YYbJKxHTt HyaOYu7EWODVWwfa4jxOsCIGvQNMJAzMr335xhj6d4Y9DK2k6Ji1irth8CU/AHfD38kv od1u1lx33F/2ZAVWrk1NqQwrnyfd6r9dbpobjQkS1mayMlzk8xBwd/O24jtzCxLgHRSB Yc0g== X-Gm-Message-State: APt69E1TDEWXCkut5WljQzEmS+wXGsBMBjx0oKmZOblhs+8W1wjMQCoc eJAOuDRcGpHLR3a6s+2YiFlrr01QK+Wnrz8D4UYTo6xvMC2GcoPwBH9MX7l+3fRS2icV/ni+zhI ATJI0YCNeg85SHqXiMxfPxNVxLCtpvL+TeYyWsWRrBLR953eLV1I5AMf8mRTCTF9kDQ== X-Received: by 2002:a50:9ece:: with SMTP id a72-v6mr23189767edf.92.1531308624675; Wed, 11 Jul 2018 04:30:24 -0700 (PDT) X-Google-Smtp-Source: AAOMgpfvkeQhICFsRC9OtnMefb2gtD9BjPUcBX3Z+V+YqeHVhPGYsG30HWNqTtyEXtxblZGL5cB3 X-Received: by 2002:a50:9ece:: with SMTP id a72-v6mr23189727edf.92.1531308624043; Wed, 11 Jul 2018 04:30:24 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1531308624; cv=none; d=google.com; s=arc-20160816; b=TYseniNjXWmmSBLdicoX1QlCqbltcOUXdzQXOAE0asorrI2A2PQzuQ86TWwKvZqeAb DF4RgpFVYkk0qwJt+SrTUVFVNlWpZ3iWffpHzLahmYXE6muVv75EVXZXmvh/3t/eBhMF dyM8K2jsJGvmelUS5Z5yLYckS0z+E5AduxcdCIm+5DQEyfL383IdLbc2Ork6+aTxKw2I mo+JAJuJ1dlr+ruRKx4MNC8++147zCmefJG4fTI3DguFLUy1lf9s3kxiui24E/g6WYW1 KfssxyDeq9Yzxtjfc7PJ1knmXSerMNCwtPmue+oEqJmQNcGxS+v3s4MYkm72nvoBjlLe BtiA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature:arc-authentication-results; bh=a7TvZetQgpGsRi0tRe2KY1CoKeC2YyRA8rSQNNSNVK8=; b=n1uZZTLcRCJLp1JN14Bptr/IAPwevCOQ9+GfhokUb0dmsWUG3z4LVuWAjMbeKG/cSy 1cl5WzZJY0B1tgR57WKrGVTimmuahLb9wsezKCyZfT3znv/Um84wL+GpZn7xV6f8Vp9s cxwN6gKIsFgzaiDzYQ1X0wR/zGj8iOaeFwQCYmaVZmYnKbyvr+dhfpJG25g46ZbEKfp+ hteMyYPG67ErYsLUzVp8XLAkt4U96ofAbdwN4Q93QQzeSVAbJ/8U2nDz3x177oRoe1S7 Dsx98ClI9SjDvEmRuYNjtRPQV9dc/V4kGK5Ptj10ddHvm80/xjPbWwIV9Y+abVZqanmz begQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass (test mode) header.i=@8bytes.org header.s=mail-1 header.b=iIo7R2LF; spf=pass (google.com: domain of joro@8bytes.org designates 81.169.241.247 as permitted sender) smtp.mailfrom=joro@8bytes.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=8bytes.org Received: from theia.8bytes.org (8bytes.org. [81.169.241.247]) by mx.google.com with ESMTPS id s33-v6si11529346edb.123.2018.07.11.04.30.23 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 11 Jul 2018 04:30:24 -0700 (PDT) Received-SPF: pass (google.com: domain of joro@8bytes.org designates 81.169.241.247 as permitted sender) client-ip=81.169.241.247; Authentication-Results: mx.google.com; dkim=pass (test mode) header.i=@8bytes.org header.s=mail-1 header.b=iIo7R2LF; spf=pass (google.com: domain of joro@8bytes.org designates 81.169.241.247 as permitted sender) smtp.mailfrom=joro@8bytes.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=8bytes.org Received: by theia.8bytes.org (Postfix, from userid 1000) id B329030A3; Wed, 11 Jul 2018 13:30:07 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=8bytes.org; s=mail-1; t=1531308608; bh=dnHDZhM/YiYbEYMQFwJk/GwQKVbFCx4cKYQ5WVAFrZ0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iIo7R2LFbfVuDZd9v7qik9fUvmfvCcw7ICofwMT9sW/g2K1Wx691q1ZEwWwGNXByK jRZO175RHvEWRZIymg9mbDqLS0V73vd17UmFtWtwuvJPz3l+OunJg9rFuMuQi3jAY3 guGnFGhikK4XoPv9Z/UJRW1EWnqI1CWYW2OiKBShPBgbJ6TawRrL2vMob3+qDUsFPl 8cZHb3lq4HW3joV76WM3S+0f2V+dXp3T1VdMMx8uJRKRYY88WT1lZYpYNJlQXt0K+9 vEytgDietDDFTlI6DZKi3rmXf3AZ3YibTTdpkToyMUnd+FswCct27PkXil8nCP1vRz xHNJQqJCRn9jw== From: Joerg Roedel To: Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" Cc: x86@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Linus Torvalds , Andy Lutomirski , Dave Hansen , Josh Poimboeuf , Juergen Gross , Peter Zijlstra , Borislav Petkov , Jiri Kosina , Boris Ostrovsky , Brian Gerst , David Laight , Denys Vlasenko , Eduardo Valentin , Greg KH , Will Deacon , aliguori@amazon.com, daniel.gruss@iaik.tugraz.at, hughd@google.com, keescook@google.com, Andrea Arcangeli , Waiman Long , Pavel Machek , "David H . Gutteridge" , jroedel@suse.de, joro@8bytes.org Subject: [PATCH 36/39] x86/ldt: Enable LDT user-mapping for PAE Date: Wed, 11 Jul 2018 13:29:43 +0200 Message-Id: <1531308586-29340-37-git-send-email-joro@8bytes.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1531308586-29340-1-git-send-email-joro@8bytes.org> References: <1531308586-29340-1-git-send-email-joro@8bytes.org> X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: X-Virus-Scanned: ClamAV using ClamSMTP From: Joerg Roedel This adds the needed special case for PAE to get the LDT mapped into the user page-table when PTI is enabled. The big difference to the other paging modes is that we don't have a full top-level PGD entry available for the LDT, but only PMD entry. Signed-off-by: Joerg Roedel --- arch/x86/include/asm/mmu_context.h | 5 ---- arch/x86/kernel/ldt.c | 53 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 53 insertions(+), 5 deletions(-) diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h index bbc796e..eeeb928 100644 --- a/arch/x86/include/asm/mmu_context.h +++ b/arch/x86/include/asm/mmu_context.h @@ -71,12 +71,7 @@ struct ldt_struct { static inline void *ldt_slot_va(int slot) { -#ifdef CONFIG_X86_64 return (void *)(LDT_BASE_ADDR + LDT_SLOT_STRIDE * slot); -#else - BUG(); - return (void *)fix_to_virt(FIX_HOLE); -#endif } /* diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c index 69af9a0..733e6ac 100644 --- a/arch/x86/kernel/ldt.c +++ b/arch/x86/kernel/ldt.c @@ -126,6 +126,57 @@ static void do_sanity_check(struct mm_struct *mm, } } +#ifdef CONFIG_X86_PAE + +static pmd_t *pgd_to_pmd_walk(pgd_t *pgd, unsigned long va) +{ + p4d_t *p4d; + pud_t *pud; + + if (pgd->pgd == 0) + return NULL; + + p4d = p4d_offset(pgd, va); + if (p4d_none(*p4d)) + return NULL; + + pud = pud_offset(p4d, va); + if (pud_none(*pud)) + return NULL; + + return pmd_offset(pud, va); +} + +static void map_ldt_struct_to_user(struct mm_struct *mm) +{ + pgd_t *k_pgd = pgd_offset(mm, LDT_BASE_ADDR); + pgd_t *u_pgd = kernel_to_user_pgdp(k_pgd); + pmd_t *k_pmd, *u_pmd; + + k_pmd = pgd_to_pmd_walk(k_pgd, LDT_BASE_ADDR); + u_pmd = pgd_to_pmd_walk(u_pgd, LDT_BASE_ADDR); + + if (static_cpu_has(X86_FEATURE_PTI) && !mm->context.ldt) + set_pmd(u_pmd, *k_pmd); +} + +static void sanity_check_ldt_mapping(struct mm_struct *mm) +{ + pgd_t *k_pgd = pgd_offset(mm, LDT_BASE_ADDR); + pgd_t *u_pgd = kernel_to_user_pgdp(k_pgd); + bool had_kernel, had_user; + pmd_t *k_pmd, *u_pmd; + + k_pmd = pgd_to_pmd_walk(k_pgd, LDT_BASE_ADDR); + u_pmd = pgd_to_pmd_walk(u_pgd, LDT_BASE_ADDR); + had_kernel = (k_pmd->pmd != 0); + had_user = (u_pmd->pmd != 0); + + do_sanity_check(mm, had_kernel, had_user); +} + +#else /* !CONFIG_X86_PAE */ + static void map_ldt_struct_to_user(struct mm_struct *mm) { pgd_t *pgd = pgd_offset(mm, LDT_BASE_ADDR); @@ -143,6 +194,8 @@ static void sanity_check_ldt_mapping(struct mm_struct *mm) do_sanity_check(mm, had_kernel, had_user); } +#endif /* CONFIG_X86_PAE */ + /* * If PTI is enabled, this maps the LDT into the kernelmode and * usermode tables for the given mm.