From patchwork Mon Jul 22 15:42:07 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Price X-Patchwork-Id: 11052873 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4156B1398 for ; Mon, 22 Jul 2019 15:50:46 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2D64C27FB3 for ; Mon, 22 Jul 2019 15:50:46 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2123028438; Mon, 22 Jul 2019 15:50:46 +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=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id B87B427FB3 for ; Mon, 22 Jul 2019 15:50:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=uJDzszkWe4kwzjuLHUHZKwIaUPGXpI7O2UdFdMZKA5E=; b=o+/M3qn9sDoXBS 4om4OY7qybzWqrT80GEl6R/aZnDP8CZoanUpEzT/Md2iCuGMJAFLZOns0J1LegIdepBS8S0Fqxcn5 QO5L65ATc/k/+c0G9W/3vCaPa63Hozgx/jDR5FumFAVMVZ3xS8xW+tlUUz/+IJUy2iTntvCMtEWIu d6gnaj+bI7sJKzUrAJhQA6YK/ThN5F8obYvUyjO3uue/37ieTBdBOpb1r7VMjIlrukrVfoFsTbHsy oa3CbIhL0OWwUGi1r4kssOQFwcdfCrOo07SX1uKAg7oUSekMspMbW4W4oG4b2A5navgzzObFaPbjA 1bSn+mxwatJ8i1gPyuuA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hpaaK-0000vd-TM; Mon, 22 Jul 2019 15:50:45 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hpaT6-0002H3-DG for linux-arm-kernel@lists.infradead.org; Mon, 22 Jul 2019 15:43:18 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 16C1515A2; Mon, 22 Jul 2019 08:43:16 -0700 (PDT) Received: from e112269-lin.arm.com (e112269-lin.cambridge.arm.com [10.1.196.133]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8186F3F694; Mon, 22 Jul 2019 08:43:13 -0700 (PDT) From: Steven Price To: linux-mm@kvack.org Subject: [PATCH v9 18/21] x86: mm: Convert ptdump_walk_pgd_level_core() to take an mm_struct Date: Mon, 22 Jul 2019 16:42:07 +0100 Message-Id: <20190722154210.42799-19-steven.price@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190722154210.42799-1-steven.price@arm.com> References: <20190722154210.42799-1-steven.price@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190722_084316_716536_2D0C718B X-CRM114-Status: GOOD ( 15.26 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , x86@kernel.org, Arnd Bergmann , Ard Biesheuvel , Peter Zijlstra , Catalin Marinas , Dave Hansen , linux-kernel@vger.kernel.org, Steven Price , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Ingo Molnar , Borislav Petkov , Andy Lutomirski , "H. Peter Anvin" , James Morse , Thomas Gleixner , Will Deacon , Andrew Morton , linux-arm-kernel@lists.infradead.org, "Liang, Kan" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP 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 bcaf27b637e0..546e28a7785c 100644 --- a/arch/x86/mm/dump_pagetables.c +++ b/arch/x86/mm/dump_pagetables.c @@ -107,8 +107,6 @@ 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 { @@ -143,8 +141,6 @@ 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 */ @@ -516,10 +512,10 @@ 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 = {}; @@ -566,39 +562,49 @@ 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 && boot_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) || !boot_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)