From: Tim Chen <tim.c.chen@linux.intel.com>
To: stable@vger.kernel.org, Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>,
Andy Lutomirski <luto@kernel.org>,
Nadav Amit <nadav.amit@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
Andrew Morton <akpm@linux-foundation.org>,
Arjan van de Ven <arjan@linux.intel.com>,
Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@intel.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Mel Gorman <mgorman@suse.de>,
Peter Zijlstra <peterz@infradead.org>,
Rik van Riel <riel@redhat.com>, Ingo Molnar <mingo@kernel.org>,
David Woodhouse <dwmw@amazon.co.uk>,
ak@linux.intel.com, karahmed@amazon.de, pbonzini@redhat.com,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: [PATCH 1/2] x86/mm: Give each mm a unique ID
Date: Fri, 2 Mar 2018 13:32:09 -0800 [thread overview]
Message-ID: <3351ba53a3b570ba08f2a0f5a59d01b7d80a8955.1520026221.git.tim.c.chen@linux.intel.com> (raw)
In-Reply-To: <cover.1520026221.git.tim.c.chen@linux.intel.com>
In-Reply-To: <cover.1520026221.git.tim.c.chen@linux.intel.com>
From: Andy Lutomirski <luto@kernel.org>
commit: f39681ed0f48498b80455095376f11535feea332
This adds a new variable to mmu_context_t: ctx_id.
ctx_id uniquely identifies the mm_struct and will never be reused.
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.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
---
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(-)
diff --git a/arch/x86/include/asm/mmu.h b/arch/x86/include/asm/mmu.h
index 8b272a0..e2e0934 100644
--- 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 */
diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h
index d23e355..5a295bb 100644
--- 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 mm_struct *mm, struct task_struct *tsk)
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 */
diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
index 578973a..fa74bf5 100644
--- 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;
--
2.9.4
next prev parent reply other threads:[~2018-03-02 21:32 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-02 21:32 [PATCH 0/2] Backport IBPB on context switch to non-dumpable process Tim Chen
2018-03-02 21:32 ` Tim Chen [this message]
2018-03-07 17:30 ` [PATCH 1/2] x86/mm: Give each mm a unique ID Greg Kroah-Hartman
2018-03-08 18:23 ` Tim Chen
2018-03-10 1:04 ` Tim Chen
2018-03-10 1:14 ` Greg Kroah-Hartman
2018-03-02 21:32 ` [PATCH 2/2] x86/speculation: Use Indirect Branch Prediction Barrier in context switch Tim Chen
2018-03-03 8:54 ` [PATCH 0/2] Backport IBPB on context switch to non-dumpable process Greg Kroah-Hartman
2018-03-03 11:37 ` Woodhouse, David
2018-03-07 17:32 ` Greg Kroah-Hartman
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