From f34570e1f6c56f5557b9a3acd73fce47f5727479 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Mon, 22 May 2017 15:30:01 -0700 Subject: [PATCH 03/14] x86/mm: Reimplement flush_tlb_page() using flush_tlb_mm_range() 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 Acked-by: Kees Cook Cc: Andrew Morton Cc: Borislav Petkov Cc: Dave Hansen Cc: Linus Torvalds Cc: Mel Gorman Cc: Michal Hocko Cc: Nadav Amit Cc: Nadav Amit Cc: Peter Zijlstra Cc: Rik van Riel Cc: Thomas Gleixner Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/3cc3847cf888d8907577569b8bac3f01992ef8f9.1495492063.git.luto@kernel.org Signed-off-by: Ingo Molnar Cc: Hugh Dickins Signed-off-by: Greg Kroah-Hartman --- arch/x86/include/asm/tlbflush.h | 6 +++++- arch/x86/mm/tlb.c | 27 --------------------------- 2 files changed, 5 insertions(+), 28 deletions(-) diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h index db8952a..eb5b512 100644 --- a/arch/x86/include/asm/tlbflush.h +++ b/arch/x86/include/asm/tlbflush.h @@ -353,11 +353,15 @@ static inline void flush_tlb_kernel_range(unsigned long start, flush_tlb_mm_range(vma->vm_mm, start, end, vma->vm_flags) extern void flush_tlb_all(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); +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, unsigned long start, unsigned long end); diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index 2f9d41f..6884228 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -387,33 +387,6 @@ void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start, 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, 0UL); - - preempt_enable(); -} - static void do_flush_tlb_all(void *info) { count_vm_tlb_event(NR_TLB_REMOTE_FLUSH_RECEIVED); -- 2.7.4