This is a note to let you know that I've just added the patch titled

kaiser: delete KAISER_REAL_SWITCH option

to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: kaiser-delete-kaiser_real_switch-option.patch and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From foo@baz Wed Jan 3 18:58:12 CET 2018

From: Hugh Dickins hughd@google.com Date: Sun, 3 Sep 2017 18:30:43 -0700 Subject: kaiser: delete KAISER_REAL_SWITCH option

From: Hugh Dickins hughd@google.com

We fail to see what CONFIG_KAISER_REAL_SWITCH is for: it seems to be left over from early development, and now just obscures tricky parts of the code. Delete it before adding PCIDs, or nokaiser boot option.

(Or if there is some good reason to keep the option, then it needs a help text - and a "depends on KAISER", so that all those without KAISER are not asked the question.)

Signed-off-by: Hugh Dickins hughd@google.com Acked-by: Jiri Kosina jkosina@suse.cz Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/entry/entry_64.S | 4 ---- arch/x86/include/asm/kaiser.h | 4 ---- security/Kconfig | 4 ---- 3 files changed, 12 deletions(-)

--- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -1291,9 +1291,7 @@ ENTRY(nmi) /* %rax is saved above, so OK to clobber here */ movq %cr3, %rax pushq %rax -#ifdef CONFIG_KAISER_REAL_SWITCH andq $(~KAISER_SHADOW_PGD_OFFSET), %rax -#endif movq %rax, %cr3 #endif call do_nmi @@ -1534,9 +1532,7 @@ end_repeat_nmi: /* %rax is saved above, so OK to clobber here */ movq %cr3, %rax pushq %rax -#ifdef CONFIG_KAISER_REAL_SWITCH andq $(~KAISER_SHADOW_PGD_OFFSET), %rax -#endif movq %rax, %cr3 #endif

--- a/arch/x86/include/asm/kaiser.h +++ b/arch/x86/include/asm/kaiser.h @@ -21,17 +21,13 @@

.macro _SWITCH_TO_KERNEL_CR3 reg movq %cr3, \reg -#ifdef CONFIG_KAISER_REAL_SWITCH andq $(~KAISER_SHADOW_PGD_OFFSET), \reg -#endif movq \reg, %cr3 .endm

.macro _SWITCH_TO_USER_CR3 reg movq %cr3, \reg -#ifdef CONFIG_KAISER_REAL_SWITCH orq $(KAISER_SHADOW_PGD_OFFSET), \reg -#endif movq \reg, %cr3 .endm

--- a/security/Kconfig +++ b/security/Kconfig @@ -41,10 +41,6 @@ config KAISER

If you are unsure how to answer this question, answer Y.

-config KAISER_REAL_SWITCH - bool "KAISER: actually switch page tables" - default y - config SECURITYFS bool "Enable the securityfs filesystem" help

Patches currently in stable-queue which might be from hughd@google.com are

queue-4.4/kaiser-vmstat-show-nr_kaisertable-as-nr_overhead.patch queue-4.4/kaiser-add-nokaiser-boot-option-using-alternative.patch queue-4.4/kaiser-fix-unlikely-error-in-alloc_ldt_struct.patch queue-4.4/kaiser-_pgd_alloc-without-__gfp_repeat-to-avoid-stalls.patch queue-4.4/kaiser-kaiser_flush_tlb_on_return_to_user-check-pcid.patch queue-4.4/x86-paravirt-dont-patch-flush_tlb_single.patch queue-4.4/kaiser-merged-update.patch queue-4.4/kaiser-delete-kaiser_real_switch-option.patch queue-4.4/kaiser-kaiser_remove_mapping-move-along-the-pgd.patch queue-4.4/kaiser-fix-perf-crashes.patch queue-4.4/kaiser-drop-is_atomic-arg-to-kaiser_pagetable_walk.patch queue-4.4/kaiser-load_new_mm_cr3-let-switch_user_cr3-flush-user.patch queue-4.4/kaiser-enhanced-by-kernel-and-user-pcids.patch queue-4.4/kaiser-x86_cr3_pcid_noflush-and-x86_cr3_pcid_user.patch queue-4.4/kaiser-use-alternative-instead-of-x86_cr3_pcid_noflush.patch queue-4.4/kaiser-stack-map-page_size-at-thread_size-page_size.patch queue-4.4/kaiser-name-that-0x1000-kaiser_shadow_pgd_offset.patch queue-4.4/kaiser-fix-regs-to-do_nmi-ifndef-config_kaiser.patch queue-4.4/kaiser-do-not-set-_page_nx-on-pgd_none.patch queue-4.4/kaiser-tidied-up-asm-kaiser.h-somewhat.patch queue-4.4/kaiser-cleanups-while-trying-for-gold-link.patch queue-4.4/kaiser-tidied-up-kaiser_add-remove_mapping-slightly.patch queue-4.4/kaiser-fix-build-and-fixme-in-alloc_ldt_struct.patch queue-4.4/kaiser-kernel-address-isolation.patch queue-4.4/kaiser-enomem-if-kaiser_pagetable_walk-null.patch queue-4.4/kaiser-asm-tlbflush.h-handle-nopge-at-lower-level.patch queue-4.4/kaiser-paranoid_entry-pass-cr3-need-to-paranoid_exit.patch queue-4.4/kaiser-kaiser-depends-on-smp.patch queue-4.4/kaiser-pcid-0-for-kernel-and-128-for-user.patch