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=-17.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 BB289C4167B for ; Thu, 10 Dec 2020 12:13:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7521223D20 for ; Thu, 10 Dec 2020 12:13:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726078AbgLJMNH (ORCPT ); Thu, 10 Dec 2020 07:13:07 -0500 Received: from mail.kernel.org ([198.145.29.99]:57116 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387506AbgLJMMi (ORCPT ); Thu, 10 Dec 2020 07:12:38 -0500 From: Will Deacon Authentication-Results: mail.kernel.org; dkim=permerror (bad message/signature format) To: linux-kernel@vger.kernel.org Cc: kernel-team@android.com, Will Deacon , Yu Zhao , Minchan Kim , Peter Zijlstra , Thomas Gleixner , Linus Torvalds , Vlastimil Babka , Mohamed Alzayat , "Aneesh Kumar K.V" , linux-mm@kvack.org Subject: [PATCH v2 6/6] x86/ldt: Use tlb_gather_mmu_fullmm() when freeing LDT page-tables Date: Thu, 10 Dec 2020 12:11:10 +0000 Message-Id: <20201210121110.10094-7-will@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20201210121110.10094-1-will@kernel.org> References: <20201210121110.10094-1-will@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org free_ldt_pgtables() uses the MMU gather API for batching TLB flushes over the call to free_pgd_range(). However, tlb_gather_mmu() expects to operate on user addresses and so passing LDT_{BASE,END}_ADDR will confuse the range setting logic in __tlb_adjust_range(), causing the gather to identify a range starting at TASK_SIZE. Such a large range will be converted into a 'fullmm' flush by the low-level invalidation code, so change the caller to invoke tlb_gather_mmu_fullmm() directly. Cc: Thomas Gleixner Signed-off-by: Will Deacon --- arch/x86/kernel/ldt.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c index 7ad9834e0d95..aa15132228da 100644 --- a/arch/x86/kernel/ldt.c +++ b/arch/x86/kernel/ldt.c @@ -398,7 +398,13 @@ static void free_ldt_pgtables(struct mm_struct *mm) if (!boot_cpu_has(X86_FEATURE_PTI)) return; - tlb_gather_mmu(&tlb, mm); + /* + * Although free_pgd_range() is intended for freeing user + * page-tables, it also works out for kernel mappings on x86. + * We use tlb_gather_mmu_fullmm() to avoid confusing the + * range-tracking logic in __tlb_adjust_range(). + */ + tlb_gather_mmu_fullmm(&tlb, mm); free_pgd_range(&tlb, start, end, start, end); tlb_finish_mmu(&tlb); #endif -- 2.29.2.576.ga3fc446d84-goog