From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:44806 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932905AbeCGRhL (ORCPT ); Wed, 7 Mar 2018 12:37:11 -0500 Subject: Patch "x86/mm: Give each mm TLB flush generation a unique ID" has been added to the 4.9-stable tree To: luto@kernel.org, akpm@linux-foundation.org, arjan@linux.intel.com, bp@alien8.de, dave.hansen@intel.com, gregkh@linuxfoundation.org, mgorman@suse.de, mingo@kernel.org, nadav.amit@gmail.com, peterz@infradead.org, riel@redhat.com, tglx@linutronix.de, tim.c.chen@linux.intel.com, torvalds@linux-foundation.org Cc: , From: Date: Wed, 07 Mar 2018 09:37:02 -0800 Message-ID: <152044422213249@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled x86/mm: Give each mm TLB flush generation a unique ID 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-give-each-mm-tlb-flush-generation-a-unique-id.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 know about it. >>From f39681ed0f48498b80455095376f11535feea332 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Thu, 29 Jun 2017 08:53:15 -0700 Subject: x86/mm: Give each mm TLB flush generation a unique ID From: Andy Lutomirski commit f39681ed0f48498b80455095376f11535feea332 upstream. This adds two new variables to mmu_context_t: ctx_id and tlb_gen. ctx_id uniquely identifies the mm_struct and will never be reused. For a given mm_struct (and hence ctx_id), tlb_gen is a monotonic count of the number of times that a TLB flush has been requested. The pair (ctx_id, tlb_gen) can be used as an identifier for TLB flush actions and will be used in subsequent patches to reliably determine whether all needed TLB flushes have occurred on a given CPU. This patch is split out for ease of review. By itself, it has no real effect other than creating and updating the new variables. Signed-off-by: Andy Lutomirski Reviewed-by: Nadav Amit Reviewed-by: Thomas Gleixner Cc: Andrew Morton Cc: Arjan van de Ven Cc: Borislav Petkov Cc: Dave Hansen Cc: Linus Torvalds Cc: Mel Gorman Cc: Peter Zijlstra Cc: Rik van Riel Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/413a91c24dab3ed0caa5f4e4d017d87b0857f920.1498751203.git.luto@kernel.org Signed-off-by: Ingo Molnar Signed-off-by: Tim Chen Signed-off-by: Greg Kroah-Hartman --- arch/x86/include/asm/mmu.h | 15 +++++++++++++-- arch/x86/include/asm/mmu_context.h | 5 +++++ arch/x86/mm/tlb.c | 2 ++ 3 files changed, 20 insertions(+), 2 deletions(-) --- a/arch/x86/include/asm/mmu.h +++ b/arch/x86/include/asm/mmu.h @@ -3,12 +3,18 @@ #include #include +#include /* - * The x86 doesn't have a mmu context, but - * we put the segment information here. + * x86 has arch-specific MMU state beyond what lives in mm_struct. */ typedef struct { + /* + * ctx_id uniquely identifies this mm_struct. A ctx_id will never + * be reused, and zero is not a valid ctx_id. + */ + u64 ctx_id; + #ifdef CONFIG_MODIFY_LDT_SYSCALL struct ldt_struct *ldt; #endif @@ -33,6 +39,11 @@ typedef struct { #endif } mm_context_t; +#define INIT_MM_CONTEXT(mm) \ + .context = { \ + .ctx_id = 1, \ + } + void leave_mm(int cpu); #endif /* _ASM_X86_MMU_H */ --- a/arch/x86/include/asm/mmu_context.h +++ b/arch/x86/include/asm/mmu_context.h @@ -12,6 +12,9 @@ #include #include #include + +extern atomic64_t last_mm_ctx_id; + #ifndef CONFIG_PARAVIRT static inline void paravirt_activate_mm(struct mm_struct *prev, struct mm_struct *next) @@ -106,6 +109,8 @@ static inline void enter_lazy_tlb(struct static inline int init_new_context(struct task_struct *tsk, struct mm_struct *mm) { + mm->context.ctx_id = atomic64_inc_return(&last_mm_ctx_id); + #ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS if (cpu_feature_enabled(X86_FEATURE_OSPKE)) { /* pkey 0 is the default and always allocated */ --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -29,6 +29,8 @@ * Implement flush IPI by CALL_FUNCTION_VECTOR, Alex Shi */ +atomic64_t last_mm_ctx_id = ATOMIC64_INIT(1); + struct flush_tlb_info { struct mm_struct *flush_mm; unsigned long flush_start; Patches currently in stable-queue which might be from luto@kernel.org are queue-4.9/nospec-allow-index-argument-to-have-const-qualified-type.patch queue-4.9/x86-speculation-use-indirect-branch-prediction-barrier-in-context-switch.patch queue-4.9/x86-mm-give-each-mm-tlb-flush-generation-a-unique-id.patch