This is a note to let you know that I've just added the patch titled
x86/mm: Reimplement flush_tlb_page() using flush_tlb_mm_range()
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-mm-reimplement-flush_tlb_page-using-flush_tlb_mm_range.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From ca6c99c0794875c6d1db6e22f246699691ab7e6b Mon Sep 17 00:00:00 2001
From: Andy Lutomirski <luto@xxxxxxxxxx>
Date: Mon, 22 May 2017 15:30:01 -0700
Subject: x86/mm: Reimplement flush_tlb_page() using flush_tlb_mm_range()
From: Andy Lutomirski <luto@xxxxxxxxxx>
commit ca6c99c0794875c6d1db6e22f246699691ab7e6b upstream.
flush_tlb_page() was very similar to flush_tlb_mm_range() except that
it had a couple of issues:
- It was missing an smp_mb() in the case where
current->active_mm != mm. (This is a longstanding bug reported by Nadav Amit)
- It was missing tracepoints and vm counter updates.
The only reason that I can see for keeping it at as a separate
function is that it could avoid a few branches that
flush_tlb_mm_range() needs to decide to flush just one page. This
hardly seems worthwhile. If we decide we want to get rid of those
branches again, a better way would be to introduce an
__flush_tlb_mm_range() helper and make both flush_tlb_page() and
flush_tlb_mm_range() use it.
Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
Acked-by: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Borislav Petkov <bpetkov@xxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Nadav Amit <nadav.amit@xxxxxxxxx>
Cc: Nadav Amit <namit@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
Link: http://lkml.kernel.org/r/3cc3847cf888d8907577569b8bac3f01992ef8f9.1495492063.git.luto@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Eduardo Valentin <eduval@xxxxxxxxxx>
Signed-off-by: Eduardo Valentin <edubezval@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/include/asm/tlbflush.h | 5 ++++-
arch/x86/mm/tlb.c | 27 ---------------------------
2 files changed, 4 insertions(+), 28 deletions(-)
--- a/arch/x86/include/asm/tlbflush.h
+++ b/arch/x86/include/asm/tlbflush.h
@@ -304,12 +304,15 @@ static inline void flush_tlb_kernel_rang
extern void flush_tlb_all(void);
extern void flush_tlb_current_task(void);
-extern void flush_tlb_page(struct vm_area_struct *, unsigned long);
extern void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
unsigned long end, unsigned long vmflag);
extern void flush_tlb_kernel_range(unsigned long start, unsigned long end);
#define flush_tlb() flush_tlb_current_task()
+static inline void flush_tlb_page(struct vm_area_struct *vma, unsigned long a)
+{
+ flush_tlb_mm_range(vma->vm_mm, a, a + PAGE_SIZE, VM_NONE);
+}
void native_flush_tlb_others(const struct cpumask *cpumask,
struct mm_struct *mm,
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -369,33 +369,6 @@ out:
preempt_enable();
}
-void flush_tlb_page(struct vm_area_struct *vma, unsigned long start)
-{
- struct mm_struct *mm = vma->vm_mm;
-
- preempt_disable();
-
- if (current->active_mm == mm) {
- if (current->mm) {
- /*
- * Implicit full barrier (INVLPG) that synchronizes
- * with switch_mm.
- */
- __flush_tlb_one(start);
- } else {
- leave_mm(smp_processor_id());
-
- /* Synchronize with switch_mm. */
- smp_mb();
- }
- }
-
- if (cpumask_any_but(mm_cpumask(mm), smp_processor_id()) < nr_cpu_ids)
- flush_tlb_others(mm_cpumask(mm), mm, start, start + PAGE_SIZE);
-
- preempt_enable();
-}
-
static void do_flush_tlb_all(void *info)
{
count_vm_tlb_event(NR_TLB_REMOTE_FLUSH_RECEIVED);
Patches currently in stable-queue which might be from luto@xxxxxxxxxx are
queue-4.9/x86-mm-refactor-flush_tlb_mm_range-to-merge-local-and-remote-cases.patch
queue-4.9/x86-mm-pass-flush_tlb_info-to-flush_tlb_others-etc.patch
queue-4.9/x86-mm-rework-lazy-tlb-to-track-the-actual-loaded-mm.patch
queue-4.9/x86-mm-kvm-teach-kvm-s-vmx-code-that-cr3-isn-t-a-constant.patch
queue-4.9/x86-mm-use-new-merged-flush-logic-in-arch_tlbbatch_flush.patch
queue-4.9/x86-kvm-vmx-simplify-segment_base.patch
queue-4.9/x86-entry-unwind-create-stack-frames-for-saved-interrupt-registers.patch
queue-4.9/x86-mm-reduce-indentation-in-flush_tlb_func.patch
queue-4.9/x86-mm-remove-the-up-asm-tlbflush.h-code-always-use-the-formerly-smp-code.patch
queue-4.9/x86-mm-reimplement-flush_tlb_page-using-flush_tlb_mm_range.patch
queue-4.9/mm-x86-mm-make-the-batched-unmap-tlb-flush-api-more-generic.patch
queue-4.9/x86-kvm-vmx-defer-tr-reload-after-vm-exit.patch
queue-4.9/x86-mm-change-the-leave_mm-condition-for-local-tlb-flushes.patch
queue-4.9/x86-mm-be-more-consistent-wrt-page_shift-vs-page_size-in-tlb-flush-code.patch