This is a note to let you know that I've just added the patch titled
kaiser: fix regs to do_nmi() ifndef CONFIG_KAISER
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
The filename of the patch is:
kaiser-fix-regs-to-do_nmi-ifndef-config_kaiser.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(a)vger.kernel.org> know about it.
>From foo@baz Wed Jan 3 18:58:12 CET 2018
From: Hugh Dickins <hughd(a)google.com>
Date: Thu, 21 Sep 2017 20:39:56 -0700
Subject: kaiser: fix regs to do_nmi() ifndef CONFIG_KAISER
From: Hugh Dickins <hughd(a)google.com>
pjt has observed that nmi's second (nmi_from_kernel) call to do_nmi()
adjusted the %rdi regs arg, rightly when CONFIG_KAISER, but wrongly
when not CONFIG_KAISER.
Although the minimal change is to add an #ifdef CONFIG_KAISER around
the addq line, that looks cluttered, and I prefer how the first call
to do_nmi() handled it: prepare args in %rdi and %rsi before getting
into the CONFIG_KAISER block, since it does not touch them at all.
And while we're here, place the "#ifdef CONFIG_KAISER" that follows
each, to enclose the "Unconditionally restore CR3" comment: matching
how the "Unconditionally use kernel CR3" comment above is enclosed.
Signed-off-by: Hugh Dickins <hughd(a)google.com>
Acked-by: Jiri Kosina <jkosina(a)suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
arch/x86/entry/entry_64.S | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1297,12 +1297,13 @@ ENTRY(nmi)
movq %rax, %cr3
#endif
call do_nmi
+
+#ifdef CONFIG_KAISER
/*
* Unconditionally restore CR3. I know we return to
* kernel code that needs user CR3, but do we ever return
* to "user mode" where we need the kernel CR3?
*/
-#ifdef CONFIG_KAISER
popq %rax
mov %rax, %cr3
#endif
@@ -1526,6 +1527,8 @@ end_repeat_nmi:
SWAPGS
xorl %ebx, %ebx
1:
+ movq %rsp, %rdi
+ movq $-1, %rsi
#ifdef CONFIG_KAISER
/* Unconditionally use kernel CR3 for do_nmi() */
/* %rax is saved above, so OK to clobber here */
@@ -1538,16 +1541,14 @@ end_repeat_nmi:
#endif
/* paranoidentry do_nmi, 0; without TRACE_IRQS_OFF */
- movq %rsp, %rdi
- addq $8, %rdi /* point %rdi at ptregs, fixed up for CR3 */
- movq $-1, %rsi
call do_nmi
+
+#ifdef CONFIG_KAISER
/*
* Unconditionally restore CR3. We might be returning to
* kernel code that needs user CR3, like just just before
* a sysret.
*/
-#ifdef CONFIG_KAISER
popq %rax
mov %rax, %cr3
#endif
Patches currently in stable-queue which might be from hughd(a)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
This is a note to let you know that I've just added the patch titled
kaiser: fix unlikely error in alloc_ldt_struct()
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
The filename of the patch is:
kaiser-fix-unlikely-error-in-alloc_ldt_struct.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(a)vger.kernel.org> know about it.
>From foo@baz Wed Jan 3 18:58:12 CET 2018
From: Hugh Dickins <hughd(a)google.com>
Date: Mon, 4 Dec 2017 20:13:35 -0800
Subject: kaiser: fix unlikely error in alloc_ldt_struct()
From: Hugh Dickins <hughd(a)google.com>
An error from kaiser_add_mapping() here is not at all likely, but
Eric Biggers rightly points out that __free_ldt_struct() relies on
new_ldt->size being initialized: move that up.
Signed-off-by: Hugh Dickins <hughd(a)google.com>
Acked-by: Jiri Kosina <jkosina(a)suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
arch/x86/kernel/ldt.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/x86/kernel/ldt.c
+++ b/arch/x86/kernel/ldt.c
@@ -79,11 +79,11 @@ static struct ldt_struct *alloc_ldt_stru
ret = kaiser_add_mapping((unsigned long)new_ldt->entries, alloc_size,
__PAGE_KERNEL);
+ new_ldt->size = size;
if (ret) {
__free_ldt_struct(new_ldt);
return NULL;
}
- new_ldt->size = size;
return new_ldt;
}
Patches currently in stable-queue which might be from hughd(a)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
This is a note to let you know that I've just added the patch titled
kaiser: fix build and FIXME in alloc_ldt_struct()
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
The filename of the patch is:
kaiser-fix-build-and-fixme-in-alloc_ldt_struct.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(a)vger.kernel.org> know about it.
>From foo@baz Wed Jan 3 18:58:12 CET 2018
From: Hugh Dickins <hughd(a)google.com>
Date: Sun, 3 Sep 2017 17:09:44 -0700
Subject: kaiser: fix build and FIXME in alloc_ldt_struct()
From: Hugh Dickins <hughd(a)google.com>
Include linux/kaiser.h instead of asm/kaiser.h to build ldt.c without
CONFIG_KAISER. kaiser_add_mapping() does already return an error code,
so fix the FIXME.
Signed-off-by: Hugh Dickins <hughd(a)google.com>
Acked-by: Jiri Kosina <jkosina(a)suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
arch/x86/kernel/ldt.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)
--- a/arch/x86/kernel/ldt.c
+++ b/arch/x86/kernel/ldt.c
@@ -16,9 +16,9 @@
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/uaccess.h>
+#include <linux/kaiser.h>
#include <asm/ldt.h>
-#include <asm/kaiser.h>
#include <asm/desc.h>
#include <asm/mmu_context.h>
#include <asm/syscalls.h>
@@ -49,7 +49,7 @@ static struct ldt_struct *alloc_ldt_stru
{
struct ldt_struct *new_ldt;
int alloc_size;
- int ret = 0;
+ int ret;
if (size > LDT_ENTRIES)
return NULL;
@@ -77,10 +77,8 @@ static struct ldt_struct *alloc_ldt_stru
return NULL;
}
- // FIXME: make kaiser_add_mapping() return an error code
- // when it fails
- kaiser_add_mapping((unsigned long)new_ldt->entries, alloc_size,
- __PAGE_KERNEL);
+ ret = kaiser_add_mapping((unsigned long)new_ldt->entries, alloc_size,
+ __PAGE_KERNEL);
if (ret) {
__free_ldt_struct(new_ldt);
return NULL;
Patches currently in stable-queue which might be from hughd(a)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
This is a note to let you know that I've just added the patch titled
kaiser: ENOMEM if kaiser_pagetable_walk() NULL
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
The filename of the patch is:
kaiser-enomem-if-kaiser_pagetable_walk-null.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(a)vger.kernel.org> know about it.
>From foo@baz Wed Jan 3 18:58:12 CET 2018
From: Hugh Dickins <hughd(a)google.com>
Date: Sun, 3 Sep 2017 18:48:02 -0700
Subject: kaiser: ENOMEM if kaiser_pagetable_walk() NULL
From: Hugh Dickins <hughd(a)google.com>
kaiser_add_user_map() took no notice when kaiser_pagetable_walk() failed.
And avoid its might_sleep() when atomic (though atomic at present unused).
Signed-off-by: Hugh Dickins <hughd(a)google.com>
Acked-by: Jiri Kosina <jkosina(a)suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
arch/x86/mm/kaiser.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
--- a/arch/x86/mm/kaiser.c
+++ b/arch/x86/mm/kaiser.c
@@ -99,11 +99,11 @@ static pte_t *kaiser_pagetable_walk(unsi
pgd_t *pgd = native_get_shadow_pgd(pgd_offset_k(address));
gfp_t gfp = (GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO);
- might_sleep();
if (is_atomic) {
gfp &= ~GFP_KERNEL;
gfp |= __GFP_HIGH | __GFP_ATOMIC;
- }
+ } else
+ might_sleep();
if (pgd_none(*pgd)) {
WARN_ONCE(1, "All shadow pgds should have been populated");
@@ -160,13 +160,17 @@ int kaiser_add_user_map(const void *__st
unsigned long end_addr = PAGE_ALIGN(start_addr + size);
unsigned long target_address;
- for (;address < end_addr; address += PAGE_SIZE) {
+ for (; address < end_addr; address += PAGE_SIZE) {
target_address = get_pa_from_mapping(address);
if (target_address == -1) {
ret = -EIO;
break;
}
pte = kaiser_pagetable_walk(address, false);
+ if (!pte) {
+ ret = -ENOMEM;
+ break;
+ }
if (pte_none(*pte)) {
set_pte(pte, __pte(flags | target_address));
} else {
Patches currently in stable-queue which might be from hughd(a)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
This is a note to let you know that I've just added the patch titled
kaiser: drop is_atomic arg to kaiser_pagetable_walk()
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
The filename of the patch is:
kaiser-drop-is_atomic-arg-to-kaiser_pagetable_walk.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(a)vger.kernel.org> know about it.
>From foo@baz Wed Jan 3 18:58:12 CET 2018
From: Hugh Dickins <hughd(a)google.com>
Date: Sun, 29 Oct 2017 11:36:19 -0700
Subject: kaiser: drop is_atomic arg to kaiser_pagetable_walk()
From: Hugh Dickins <hughd(a)google.com>
I have not observed a might_sleep() warning from setup_fixmap_gdt()'s
use of kaiser_add_mapping() in our tree (why not?), but like upstream
we have not provided a way for that to pass is_atomic true down to
kaiser_pagetable_walk(), and at startup it's far from a likely source
of trouble: so just delete the walk's is_atomic arg and might_sleep().
Signed-off-by: Hugh Dickins <hughd(a)google.com>
Acked-by: Jiri Kosina <jkosina(a)suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
arch/x86/mm/kaiser.c | 10 ++--------
1 file changed, 2 insertions(+), 8 deletions(-)
--- a/arch/x86/mm/kaiser.c
+++ b/arch/x86/mm/kaiser.c
@@ -108,19 +108,13 @@ static inline unsigned long get_pa_from_
*
* Returns a pointer to a PTE on success, or NULL on failure.
*/
-static pte_t *kaiser_pagetable_walk(unsigned long address, bool is_atomic)
+static pte_t *kaiser_pagetable_walk(unsigned long address)
{
pmd_t *pmd;
pud_t *pud;
pgd_t *pgd = native_get_shadow_pgd(pgd_offset_k(address));
gfp_t gfp = (GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO);
- if (is_atomic) {
- gfp &= ~GFP_KERNEL;
- gfp |= __GFP_HIGH | __GFP_ATOMIC;
- } else
- might_sleep();
-
if (pgd_none(*pgd)) {
WARN_ONCE(1, "All shadow pgds should have been populated");
return NULL;
@@ -195,7 +189,7 @@ static int kaiser_add_user_map(const voi
ret = -EIO;
break;
}
- pte = kaiser_pagetable_walk(address, false);
+ pte = kaiser_pagetable_walk(address);
if (!pte) {
ret = -ENOMEM;
break;
Patches currently in stable-queue which might be from hughd(a)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
This is a note to let you know that I've just added the patch titled
kaiser: do not set _PAGE_NX on pgd_none
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
The filename of the patch is:
kaiser-do-not-set-_page_nx-on-pgd_none.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(a)vger.kernel.org> know about it.
>From foo@baz Wed Jan 3 18:58:12 CET 2018
From: Hugh Dickins <hughd(a)google.com>
Date: Tue, 5 Sep 2017 12:05:01 -0700
Subject: kaiser: do not set _PAGE_NX on pgd_none
From: Hugh Dickins <hughd(a)google.com>
native_pgd_clear() uses native_set_pgd(), so native_set_pgd() must
avoid setting the _PAGE_NX bit on an otherwise pgd_none() entry:
usually that just generated a warning on exit, but sometimes
more mysterious and damaging failures (our production machines
could not complete booting).
The original fix to this just avoided adding _PAGE_NX to
an empty entry; but eventually more problems surfaced with kexec,
and EFI mapping expected to be a problem too. So now instead
change native_set_pgd() to update shadow only if _PAGE_USER:
A few places (kernel/machine_kexec_64.c, platform/efi/efi_64.c for sure)
use set_pgd() to set up a temporary internal virtual address space, with
physical pages remapped at what Kaiser regards as userspace addresses:
Kaiser then assumes a shadow pgd follows, which it will try to corrupt.
This appears to be responsible for the recent kexec and kdump failures;
though it's unclear how those did not manifest as a problem before.
Ah, the shadow pgd will only be assumed to "follow" if the requested
pgd is on an even-numbered page: so I suppose it was going wrong 50%
of the time all along.
What we need is a flag to set_pgd(), to tell it we're dealing with
userspace. Er, isn't that what the pgd's _PAGE_USER bit is saying?
Add a test for that. But we cannot do the same for pgd_clear()
(which may be called to clear corrupted entries - set aside the
question of "corrupt in which pgd?" until later), so there just
rely on pgd_clear() not being called in the problematic cases -
with a WARN_ON_ONCE() which should fire half the time if it is.
But this is getting too big for an inline function: move it into
arch/x86/mm/kaiser.c (which then demands a boot/compressed mod);
and de-void and de-space native_get_shadow/normal_pgd() while here.
Signed-off-by: Hugh Dickins <hughd(a)google.com>
Acked-by: Jiri Kosina <jkosina(a)suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
arch/x86/boot/compressed/misc.h | 1
arch/x86/include/asm/pgtable_64.h | 51 +++++++++-----------------------------
arch/x86/mm/kaiser.c | 42 +++++++++++++++++++++++++++++++
3 files changed, 56 insertions(+), 38 deletions(-)
--- a/arch/x86/boot/compressed/misc.h
+++ b/arch/x86/boot/compressed/misc.h
@@ -9,6 +9,7 @@
*/
#undef CONFIG_PARAVIRT
#undef CONFIG_PARAVIRT_SPINLOCKS
+#undef CONFIG_KAISER
#undef CONFIG_KASAN
#include <linux/linkage.h>
--- a/arch/x86/include/asm/pgtable_64.h
+++ b/arch/x86/include/asm/pgtable_64.h
@@ -107,61 +107,36 @@ static inline void native_pud_clear(pud_
}
#ifdef CONFIG_KAISER
-static inline pgd_t * native_get_shadow_pgd(pgd_t *pgdp)
+extern pgd_t kaiser_set_shadow_pgd(pgd_t *pgdp, pgd_t pgd);
+
+static inline pgd_t *native_get_shadow_pgd(pgd_t *pgdp)
{
- return (pgd_t *)(void*)((unsigned long)(void*)pgdp | (unsigned long)PAGE_SIZE);
+ return (pgd_t *)((unsigned long)pgdp | (unsigned long)PAGE_SIZE);
}
-static inline pgd_t * native_get_normal_pgd(pgd_t *pgdp)
+static inline pgd_t *native_get_normal_pgd(pgd_t *pgdp)
{
- return (pgd_t *)(void*)((unsigned long)(void*)pgdp & ~(unsigned long)PAGE_SIZE);
+ return (pgd_t *)((unsigned long)pgdp & ~(unsigned long)PAGE_SIZE);
}
#else
-static inline pgd_t * native_get_shadow_pgd(pgd_t *pgdp)
+static inline pgd_t kaiser_set_shadow_pgd(pgd_t *pgdp, pgd_t pgd)
+{
+ return pgd;
+}
+static inline pgd_t *native_get_shadow_pgd(pgd_t *pgdp)
{
BUILD_BUG_ON(1);
return NULL;
}
-static inline pgd_t * native_get_normal_pgd(pgd_t *pgdp)
+static inline pgd_t *native_get_normal_pgd(pgd_t *pgdp)
{
return pgdp;
}
#endif /* CONFIG_KAISER */
-/*
- * Page table pages are page-aligned. The lower half of the top
- * level is used for userspace and the top half for the kernel.
- * This returns true for user pages that need to get copied into
- * both the user and kernel copies of the page tables, and false
- * for kernel pages that should only be in the kernel copy.
- */
-static inline bool is_userspace_pgd(void *__ptr)
-{
- unsigned long ptr = (unsigned long)__ptr;
-
- return ((ptr % PAGE_SIZE) < (PAGE_SIZE / 2));
-}
-
static inline void native_set_pgd(pgd_t *pgdp, pgd_t pgd)
{
-#ifdef CONFIG_KAISER
- pteval_t extra_kern_pgd_flags = 0;
- /* Do we need to also populate the shadow pgd? */
- if (is_userspace_pgd(pgdp)) {
- native_get_shadow_pgd(pgdp)->pgd = pgd.pgd;
- /*
- * Even if the entry is *mapping* userspace, ensure
- * that userspace can not use it. This way, if we
- * get out to userspace running on the kernel CR3,
- * userspace will crash instead of running.
- */
- extra_kern_pgd_flags = _PAGE_NX;
- }
- pgdp->pgd = pgd.pgd;
- pgdp->pgd |= extra_kern_pgd_flags;
-#else /* CONFIG_KAISER */
- *pgdp = pgd;
-#endif
+ *pgdp = kaiser_set_shadow_pgd(pgdp, pgd);
}
static inline void native_pgd_clear(pgd_t *pgd)
--- a/arch/x86/mm/kaiser.c
+++ b/arch/x86/mm/kaiser.c
@@ -303,4 +303,46 @@ void kaiser_remove_mapping(unsigned long
unmap_pud_range_nofree(pgd, addr, end);
}
}
+
+/*
+ * Page table pages are page-aligned. The lower half of the top
+ * level is used for userspace and the top half for the kernel.
+ * This returns true for user pages that need to get copied into
+ * both the user and kernel copies of the page tables, and false
+ * for kernel pages that should only be in the kernel copy.
+ */
+static inline bool is_userspace_pgd(pgd_t *pgdp)
+{
+ return ((unsigned long)pgdp % PAGE_SIZE) < (PAGE_SIZE / 2);
+}
+
+pgd_t kaiser_set_shadow_pgd(pgd_t *pgdp, pgd_t pgd)
+{
+ /*
+ * Do we need to also populate the shadow pgd? Check _PAGE_USER to
+ * skip cases like kexec and EFI which make temporary low mappings.
+ */
+ if (pgd.pgd & _PAGE_USER) {
+ if (is_userspace_pgd(pgdp)) {
+ native_get_shadow_pgd(pgdp)->pgd = pgd.pgd;
+ /*
+ * Even if the entry is *mapping* userspace, ensure
+ * that userspace can not use it. This way, if we
+ * get out to userspace running on the kernel CR3,
+ * userspace will crash instead of running.
+ */
+ pgd.pgd |= _PAGE_NX;
+ }
+ } else if (!pgd.pgd) {
+ /*
+ * pgd_clear() cannot check _PAGE_USER, and is even used to
+ * clear corrupted pgd entries: so just rely on cases like
+ * kexec and EFI never to be using pgd_clear().
+ */
+ if (!WARN_ON_ONCE((unsigned long)pgdp & PAGE_SIZE) &&
+ is_userspace_pgd(pgdp))
+ native_get_shadow_pgd(pgdp)->pgd = pgd.pgd;
+ }
+ return pgd;
+}
#endif /* CONFIG_KAISER */
Patches currently in stable-queue which might be from hughd(a)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
This is a note to let you know that I've just added the patch titled
kaiser: disabled on Xen PV
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
The filename of the patch is:
kaiser-disabled-on-xen-pv.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(a)vger.kernel.org> know about it.
>From foo@baz Wed Jan 3 18:58:12 CET 2018
From: Jiri Kosina <jkosina(a)suse.cz>
Date: Tue, 2 Jan 2018 14:19:49 +0100
Subject: kaiser: disabled on Xen PV
From: Jiri Kosina <jkosina(a)suse.cz>
Kaiser cannot be used on paravirtualized MMUs (namely reading and writing CR3).
This does not work with KAISER as the CR3 switch from and to user space PGD
would require to map the whole XEN_PV machinery into both.
More importantly, enabling KAISER on Xen PV doesn't make too much sense, as PV
guests use distinct %cr3 values for kernel and user already.
Signed-off-by: Jiri Kosina <jkosina(a)suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
arch/x86/mm/kaiser.c | 5 +++++
1 file changed, 5 insertions(+)
--- a/arch/x86/mm/kaiser.c
+++ b/arch/x86/mm/kaiser.c
@@ -264,6 +264,9 @@ void __init kaiser_check_boottime_disabl
char arg[5];
int ret;
+ if (boot_cpu_has(X86_FEATURE_XENPV))
+ goto silent_disable;
+
ret = cmdline_find_option(boot_command_line, "pti", arg, sizeof(arg));
if (ret > 0) {
if (!strncmp(arg, "on", 2))
@@ -291,6 +294,8 @@ enable:
disable:
pr_info("Kernel/User page tables isolation: disabled\n");
+
+silent_disable:
kaiser_enabled = 0;
setup_clear_cpu_cap(X86_FEATURE_KAISER);
}
Patches currently in stable-queue which might be from jkosina(a)suse.cz 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/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-disabled-on-xen-pv.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
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;a=sum…
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(a)vger.kernel.org> know about it.
>From foo@baz Wed Jan 3 18:58:12 CET 2018
From: Hugh Dickins <hughd(a)google.com>
Date: Sun, 3 Sep 2017 18:30:43 -0700
Subject: kaiser: delete KAISER_REAL_SWITCH option
From: Hugh Dickins <hughd(a)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(a)google.com>
Acked-by: Jiri Kosina <jkosina(a)suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)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(a)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