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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 726B7C43381 for ; Wed, 27 Feb 2019 17:08:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4CD7D20842 for ; Wed, 27 Feb 2019 17:08:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730684AbfB0RIf (ORCPT ); Wed, 27 Feb 2019 12:08:35 -0500 Received: from foss.arm.com ([217.140.101.70]:36860 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730633AbfB0RIc (ORCPT ); Wed, 27 Feb 2019 12:08:32 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 43FFEA78; Wed, 27 Feb 2019 09:08:32 -0800 (PST) Received: from e112269-lin.arm.com (e112269-lin.cambridge.arm.com [10.1.196.69]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 089B63F738; Wed, 27 Feb 2019 09:08:28 -0800 (PST) From: Steven Price To: linux-mm@kvack.org Cc: Steven Price , Andy Lutomirski , Ard Biesheuvel , Arnd Bergmann , Borislav Petkov , Catalin Marinas , Dave Hansen , Ingo Molnar , James Morse , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Peter Zijlstra , Thomas Gleixner , Will Deacon , x86@kernel.org, "H. Peter Anvin" , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Mark Rutland , "Liang, Kan" Subject: [PATCH v3 33/34] x86/mm: Convert ptdump_walk_pgd_level_core() to take an mm_struct Date: Wed, 27 Feb 2019 17:06:07 +0000 Message-Id: <20190227170608.27963-34-steven.price@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190227170608.27963-1-steven.price@arm.com> References: <20190227170608.27963-1-steven.price@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org An mm_struct is needed to enable x86 to use of the generic walk_page_range() function. In the case of walking the user page tables (when CONFIG_PAGE_TABLE_ISOLATION is enabled), it is necessary to create a fake_mm structure because there isn't an mm_struct with a pointer to the pgd of the user page tables. This fake_mm structure is initialised with the minimum necessary for the generic page walk code. Signed-off-by: Steven Price --- arch/x86/mm/dump_pagetables.c | 36 ++++++++++++++++++++--------------- 1 file changed, 21 insertions(+), 15 deletions(-) diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c index fb4b9212cae5..40a8b0da2170 100644 --- a/arch/x86/mm/dump_pagetables.c +++ b/arch/x86/mm/dump_pagetables.c @@ -111,8 +111,6 @@ static struct addr_marker address_markers[] = { [END_OF_SPACE_NR] = { -1, NULL } }; -#define INIT_PGD ((pgd_t *) &init_top_pgt) - #else /* CONFIG_X86_64 */ enum address_markers_idx { @@ -147,8 +145,6 @@ static struct addr_marker address_markers[] = { [END_OF_SPACE_NR] = { -1, NULL } }; -#define INIT_PGD (swapper_pg_dir) - #endif /* !CONFIG_X86_64 */ /* Multipliers for offsets within the PTEs */ @@ -520,10 +516,10 @@ static inline bool is_hypervisor_range(int idx) #endif } -static void ptdump_walk_pgd_level_core(struct seq_file *m, pgd_t *pgd, +static void ptdump_walk_pgd_level_core(struct seq_file *m, struct mm_struct *mm, bool checkwx, bool dmesg) { - pgd_t *start = pgd; + pgd_t *start = mm->pgd; pgprotval_t prot, eff; int i; struct pg_state st = {}; @@ -570,39 +566,49 @@ static void ptdump_walk_pgd_level_core(struct seq_file *m, pgd_t *pgd, void ptdump_walk_pgd_level(struct seq_file *m, struct mm_struct *mm) { - ptdump_walk_pgd_level_core(m, mm->pgd, false, true); + ptdump_walk_pgd_level_core(m, mm, false, true); } +#ifdef CONFIG_PAGE_TABLE_ISOLATION +static void ptdump_walk_pgd_level_user_core(struct seq_file *m, + struct mm_struct *mm, + bool checkwx, bool dmesg) +{ + struct mm_struct fake_mm = { + .pgd = kernel_to_user_pgdp(mm->pgd) + }; + init_rwsem(&fake_mm.mmap_sem); + ptdump_walk_pgd_level_core(m, &fake_mm, checkwx, dmesg); +} +#endif + void ptdump_walk_pgd_level_debugfs(struct seq_file *m, struct mm_struct *mm, bool user) { - pgd_t *pgd = mm->pgd; #ifdef CONFIG_PAGE_TABLE_ISOLATION if (user && static_cpu_has(X86_FEATURE_PTI)) - pgd = kernel_to_user_pgdp(pgd); + ptdump_walk_pgd_level_user_core(m, mm, false, false); + else #endif - ptdump_walk_pgd_level_core(m, pgd, false, false); + ptdump_walk_pgd_level_core(m, mm, false, false); } EXPORT_SYMBOL_GPL(ptdump_walk_pgd_level_debugfs); void ptdump_walk_user_pgd_level_checkwx(void) { #ifdef CONFIG_PAGE_TABLE_ISOLATION - pgd_t *pgd = INIT_PGD; - if (!(__supported_pte_mask & _PAGE_NX) || !static_cpu_has(X86_FEATURE_PTI)) return; pr_info("x86/mm: Checking user space page tables\n"); - pgd = kernel_to_user_pgdp(pgd); - ptdump_walk_pgd_level_core(NULL, pgd, true, false); + ptdump_walk_pgd_level_user_core(NULL, &init_mm, true, false); #endif } void ptdump_walk_pgd_level_checkwx(void) { - ptdump_walk_pgd_level_core(NULL, INIT_PGD, true, false); + ptdump_walk_pgd_level_core(NULL, &init_mm, true, false); } static int __init pt_dump_init(void) -- 2.20.1