On 03/07/2018 09:37 AM, gregkh@linuxfoundation.org wrote:
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 IDto the 4.9-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: 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 stable@vger.kernel.org know about it.
From f39681ed0f48498b80455095376f11535feea332 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski luto@kernel.org Date: Thu, 29 Jun 2017 08:53:15 -0700 Subject: x86/mm: Give each mm TLB flush generation a unique ID
From: Andy Lutomirski luto@kernel.org
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
Greg, I've only pulled the unique ctx_id part of the original patch and not the tlb_gen changes. The unique ctx_id is a very simple change without needing other related changes that tlb_gen will require.
You may want to update the comment to reflect this.
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 luto@kernel.org Reviewed-by: Nadav Amit nadav.amit@gmail.com Reviewed-by: Thomas Gleixner tglx@linutronix.de Cc: Andrew Morton akpm@linux-foundation.org Cc: Arjan van de Ven arjan@linux.intel.com Cc: Borislav Petkov bp@alien8.de Cc: Dave Hansen dave.hansen@intel.com Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Mel Gorman mgorman@suse.de Cc: Peter Zijlstra peterz@infradead.org Cc: Rik van Riel riel@redhat.com Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/413a91c24dab3ed0caa5f4e4d017d87b0857f920.1498751203... Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Tim Chen tim.c.chen@linux.intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
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 <linux/spinlock.h> #include <linux/mutex.h> +#include <linux/atomic.h> /*
- 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 <asm/tlbflush.h> #include <asm/paravirt.h> #include <asm/mpx.h>
+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