lkml.org 
[lkml]   [2018]   [Jul]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[tip:x86/pti] x86/pgtable/pae: Unshare kernel PMDs when PTI is enabled
Commit-ID:  7ffcf1497c8ab59a705bfafb7401876fd2f6f71e
Gitweb: https://git.kernel.org/tip/7ffcf1497c8ab59a705bfafb7401876fd2f6f71e
Author: Joerg Roedel <jroedel@suse.de>
AuthorDate: Wed, 18 Jul 2018 11:40:53 +0200
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Fri, 20 Jul 2018 01:11:40 +0200

x86/pgtable/pae: Unshare kernel PMDs when PTI is enabled

With PTI the per-process LDT must be mapped into the kernel address-space
for each process, which requires separate kernel PMDs per PGD.

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/1531906876-13451-17-git-send-email-joro@8bytes.org

---
arch/x86/include/asm/pgtable-3level_types.h | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/pgtable-3level_types.h b/arch/x86/include/asm/pgtable-3level_types.h
index 6a59a6d0cc50..78038e057876 100644
--- a/arch/x86/include/asm/pgtable-3level_types.h
+++ b/arch/x86/include/asm/pgtable-3level_types.h
@@ -21,9 +21,10 @@ typedef union {
#endif /* !__ASSEMBLY__ */

#ifdef CONFIG_PARAVIRT
-#define SHARED_KERNEL_PMD (pv_info.shared_kernel_pmd)
+#define SHARED_KERNEL_PMD ((!static_cpu_has(X86_FEATURE_PTI) && \
+ (pv_info.shared_kernel_pmd)))
#else
-#define SHARED_KERNEL_PMD 1
+#define SHARED_KERNEL_PMD (!static_cpu_has(X86_FEATURE_PTI))
#endif

/*
\
 
 \ /
  Last update: 2018-07-20 01:28    [W:0.517 / U:1.224 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site