From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-f69.google.com (mail-ed1-f69.google.com [209.85.208.69]) by kanga.kvack.org (Postfix) with ESMTP id E11536B029A for ; Wed, 18 Jul 2018 05:41:37 -0400 (EDT) Received: by mail-ed1-f69.google.com with SMTP id p5-v6so1699139edh.16 for ; Wed, 18 Jul 2018 02:41:37 -0700 (PDT) Received: from theia.8bytes.org (8bytes.org. [81.169.241.247]) by mx.google.com with ESMTPS id o15-v6si1909040edr.34.2018.07.18.02.41.36 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 18 Jul 2018 02:41:36 -0700 (PDT) From: Joerg Roedel Subject: [PATCH 30/39] x86/mm/pti: Clone entry-text again in pti_finalize() Date: Wed, 18 Jul 2018 11:41:07 +0200 Message-Id: <1531906876-13451-31-git-send-email-joro@8bytes.org> In-Reply-To: <1531906876-13451-1-git-send-email-joro@8bytes.org> References: <1531906876-13451-1-git-send-email-joro@8bytes.org> Sender: owner-linux-mm@kvack.org List-ID: 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 From: Joerg Roedel The mapping for entry-text might have changed in the kernel after it was cloned to the user page-table. Clone again to update the user page-table to bring the mapping in sync with the kernel again. Signed-off-by: Joerg Roedel --- arch/x86/mm/pti.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c index 1825f30..b879ccd 100644 --- a/arch/x86/mm/pti.c +++ b/arch/x86/mm/pti.c @@ -404,7 +404,7 @@ static void __init pti_setup_espfix64(void) /* * Clone the populated PMDs of the entry and irqentry text and force it RO. */ -static void __init pti_clone_entry_text(void) +static void pti_clone_entry_text(void) { pti_clone_pmds((unsigned long) __entry_text_start, (unsigned long) __irqentry_text_end, @@ -528,13 +528,18 @@ void __init pti_init(void) } /* - * Finalize the kernel mappings in the userspace page-table. + * Finalize the kernel mappings in the userspace page-table. Some of the + * mappings for the kernel image might have changed since pti_init() + * cloned them. This is because parts of the kernel image have been + * mapped RO and/or NX. These changes need to be cloned again to the + * userspace page-table. */ void pti_finalize(void) { /* - * Do this after all of the manipulation of the - * kernel text page tables are complete. + * We need to clone everything (again) that maps parts of the + * kernel image. */ + pti_clone_entry_text(); pti_clone_kernel_text(); } -- 2.7.4