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authorDave Hansen <dave.hansen@linux.intel.com>2017-12-04 17:08:03 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-01-02 22:31:02 +0300
commit3dfd9fd8d897214b1a880c7fd8ed36b88faa1c02 (patch)
tree31ae7b6fb3f67e317185a74cbb4f7c1a78ac885b /security
parent33d9d7836f0fa02777667d72bc815c12fbe61cac (diff)
downloadlinux-3dfd9fd8d897214b1a880c7fd8ed36b88faa1c02.tar.xz
x86/mm/pti: Add Kconfig
commit 385ce0ea4c078517fa51c261882c4e72fba53005 upstream. Finally allow CONFIG_PAGE_TABLE_ISOLATION to be enabled. PARAVIRT generally requires that the kernel not manage its own page tables. It also means that the hypervisor and kernel must agree wholeheartedly about what format the page tables are in and what they contain. PAGE_TABLE_ISOLATION, unfortunately, changes the rules and they can not be used together. I've seen conflicting feedback from maintainers lately about whether they want the Kconfig magic to go first or last in a patch series. It's going last here because the partially-applied series leads to kernels that can not boot in a bunch of cases. I did a run through the entire series with CONFIG_PAGE_TABLE_ISOLATION=y to look for build errors, though. [ tglx: Removed SMP and !PARAVIRT dependencies as they not longer exist ] Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> 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: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.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: linux-mm@kvack.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'security')
-rw-r--r--security/Kconfig11
1 files changed, 11 insertions, 0 deletions
diff --git a/security/Kconfig b/security/Kconfig
index e8e449444e65..6614b9312b45 100644
--- a/security/Kconfig
+++ b/security/Kconfig
@@ -54,6 +54,17 @@ config SECURITY_NETWORK
implement socket and networking access controls.
If you are unsure how to answer this question, answer N.
+config PAGE_TABLE_ISOLATION
+ bool "Remove the kernel mapping in user mode"
+ depends on X86_64 && !UML
+ default y
+ help
+ This feature reduces the number of hardware side channels by
+ ensuring that the majority of kernel addresses are not mapped
+ into userspace.
+
+ See Documentation/x86/pagetable-isolation.txt for more details.
+
config SECURITY_INFINIBAND
bool "Infiniband Security Hooks"
depends on SECURITY && INFINIBAND