Commit ba0364e2 authored Jul 18, 2018 by Joerg Roedel Committed by Thomas Gleixner Jul 20, 2018

x86/mm/pti: Clone entry-text again in pti_finalize()



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 <jroedel@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Pavel Machek <pavel@ucw.cz>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: linux-mm@kvack.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Waiman Long <llong@redhat.com>
Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca>
Cc: joro@8bytes.org
Link: https://lkml.kernel.org/r/1531906876-13451-31-git-send-email-joro@8bytes.org

parent b976690f

arch/x86/mm/pti.c

+9 −4

Original line number	Diff line number	Diff line
		@@ -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();
		}