* [PATCH 4.4 037/107] x86/mm: Factor out LDT init from context init
[not found] <20180723122413.003644357@linuxfoundation.org>
@ 2018-07-23 12:41 ` Greg Kroah-Hartman
2018-08-24 23:44 ` Ben Hutchings
2018-07-23 12:41 ` [PATCH 4.4 038/107] x86/mm: Give each mm TLB flush generation a unique ID Greg Kroah-Hartman
1 sibling, 1 reply; 4+ messages in thread
From: Greg Kroah-Hartman @ 2018-07-23 12:41 UTC (permalink / raw)
To: linux-kernel
Cc: Greg Kroah-Hartman, stable, Dave Hansen, Thomas Gleixner,
Andrew Morton, Andy Lutomirski, Borislav Petkov, Brian Gerst,
Dave Hansen, Denys Vlasenko, H. Peter Anvin, Linus Torvalds,
Peter Zijlstra, Rik van Riel, linux-mm, Ingo Molnar,
Srivatsa S. Bhat, Matt Helsley (VMware), Alexey Makhalov, Bo Gan
4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Dave Hansen <dave.hansen@linux.intel.com>
commit 39a0526fb3f7d93433d146304278477eb463f8af upstream
The arch-specific mm_context_t is a great place to put
protection-key allocation state.
But, we need to initialize the allocation state because pkey 0 is
always "allocated". All of the runtime initialization of
mm_context_t is done in *_ldt() manipulation functions. This
renames the existing LDT functions like this:
init_new_context() -> init_new_context_ldt()
destroy_context() -> destroy_context_ldt()
and makes init_new_context() and destroy_context() available for
generic use.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160212210234.DB34FCC5@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Srivatsa S. Bhat <srivatsa@csail.mit.edu>
Reviewed-by: Matt Helsley (VMware) <matt.helsley@gmail.com>
Reviewed-by: Alexey Makhalov <amakhalov@vmware.com>
Reviewed-by: Bo Gan <ganb@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/include/asm/mmu_context.h | 21 ++++++++++++++++-----
arch/x86/kernel/ldt.c | 4 ++--
2 files changed, 18 insertions(+), 7 deletions(-)
--- a/arch/x86/include/asm/mmu_context.h
+++ b/arch/x86/include/asm/mmu_context.h
@@ -52,15 +52,15 @@ struct ldt_struct {
/*
* Used for LDT copy/destruction.
*/
-int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
-void destroy_context(struct mm_struct *mm);
+int init_new_context_ldt(struct task_struct *tsk, struct mm_struct *mm);
+void destroy_context_ldt(struct mm_struct *mm);
#else /* CONFIG_MODIFY_LDT_SYSCALL */
-static inline int init_new_context(struct task_struct *tsk,
- struct mm_struct *mm)
+static inline int init_new_context_ldt(struct task_struct *tsk,
+ struct mm_struct *mm)
{
return 0;
}
-static inline void destroy_context(struct mm_struct *mm) {}
+static inline void destroy_context_ldt(struct mm_struct *mm) {}
#endif
static inline void load_mm_ldt(struct mm_struct *mm)
@@ -102,6 +102,17 @@ static inline void enter_lazy_tlb(struct
this_cpu_write(cpu_tlbstate.state, TLBSTATE_LAZY);
}
+static inline int init_new_context(struct task_struct *tsk,
+ struct mm_struct *mm)
+{
+ init_new_context_ldt(tsk, mm);
+ return 0;
+}
+static inline void destroy_context(struct mm_struct *mm)
+{
+ destroy_context_ldt(mm);
+}
+
extern void switch_mm(struct mm_struct *prev, struct mm_struct *next,
struct task_struct *tsk);
--- a/arch/x86/kernel/ldt.c
+++ b/arch/x86/kernel/ldt.c
@@ -119,7 +119,7 @@ static void free_ldt_struct(struct ldt_s
* we do not have to muck with descriptors here, that is
* done in switch_mm() as needed.
*/
-int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
+int init_new_context_ldt(struct task_struct *tsk, struct mm_struct *mm)
{
struct ldt_struct *new_ldt;
struct mm_struct *old_mm;
@@ -160,7 +160,7 @@ out_unlock:
*
* 64bit: Don't touch the LDT register - we're already in the next thread.
*/
-void destroy_context(struct mm_struct *mm)
+void destroy_context_ldt(struct mm_struct *mm)
{
free_ldt_struct(mm->context.ldt);
mm->context.ldt = NULL;
^ permalink raw reply [flat|nested] 4+ messages in thread* [PATCH 4.4 038/107] x86/mm: Give each mm TLB flush generation a unique ID
[not found] <20180723122413.003644357@linuxfoundation.org>
2018-07-23 12:41 ` [PATCH 4.4 037/107] x86/mm: Factor out LDT init from context init Greg Kroah-Hartman
@ 2018-07-23 12:41 ` Greg Kroah-Hartman
1 sibling, 0 replies; 4+ messages in thread
From: Greg Kroah-Hartman @ 2018-07-23 12:41 UTC (permalink / raw)
To: linux-kernel
Cc: Greg Kroah-Hartman, stable, Andy Lutomirski, Nadav Amit,
Thomas Gleixner, Andrew Morton, Arjan van de Ven, Borislav Petkov,
Dave Hansen, Linus Torvalds, Mel Gorman, Peter Zijlstra,
Rik van Riel, linux-mm, Ingo Molnar, Tim Chen, Srivatsa S. Bhat,
Matt Helsley (VMware), Alexey Makhalov, Bo Gan
4.4-stable review patch. If anyone has any objections, please let me know.
------------------
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
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.git.luto@kernel.org
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>
Signed-off-by: Srivatsa S. Bhat <srivatsa@csail.mit.edu>
Reviewed-by: Matt Helsley (VMware) <matt.helsley@gmail.com>
Reviewed-by: Alexey Makhalov <amakhalov@vmware.com>
Reviewed-by: Bo Gan <ganb@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/include/asm/mmu.h | 15 +++++++++++++--
arch/x86/include/asm/mmu_context.h | 4 ++++
arch/x86/mm/tlb.c | 2 ++
3 files changed, 19 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
@@ -24,6 +30,11 @@ typedef struct {
atomic_t perf_rdpmc_allowed; /* nonzero if rdpmc is allowed */
} 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
@@ -11,6 +11,9 @@
#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)
@@ -105,6 +108,7 @@ 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);
init_new_context_ldt(tsk, mm);
return 0;
}
--- 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;
^ permalink raw reply [flat|nested] 4+ messages in thread