[patch 08/17] add hooks to intercept mm creation and destruction

Jeremy Fitzhardinge
2007-04-02T06:02:51Z

[-- Attachment #1: mm-lifetime-hooks.patch --]
[-- Type: text/plain, Size: 14279 bytes --]

Add hooks to allow a paravirt implementation to track the lifetime of
an mm. Paravirtualization requires three hooks, but only two are
needed in common code. They are:

arch_dup_mmap, which is called when a new mmap is created at fork

arch_exit_mmap, which is called when the last process reference to an
mm is dropped, which typically happens on exit and exec.

The third hook is activate_mm, which is called from the arch-specific
activate_mm() macro/function, and so doesn't need stub versions for
other architectures. It's called when an mm is first used.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: linux-arch@vger.kernel.org
Cc: James Bottomley <James.Bottomley@SteelEye.com>
Acked-by: Ingo Molnar <mingo@elte.hu>

---
arch/i386/kernel/paravirt.c | 4 ++++
include/asm-alpha/mmu_context.h | 1 +
include/asm-arm/mmu_context.h | 1 +
include/asm-arm26/mmu_context.h | 2 ++
include/asm-avr32/mmu_context.h | 1 +
include/asm-cris/mmu_context.h | 2 ++
include/asm-frv/mmu_context.h | 1 +
include/asm-generic/mm_hooks.h | 18 ++++++++++++++++++
include/asm-h8300/mmu_context.h | 1 +
include/asm-i386/mmu_context.h | 17 +++++++++++++++--
include/asm-i386/paravirt.h | 23 +++++++++++++++++++++++
include/asm-ia64/mmu_context.h | 1 +
include/asm-m32r/mmu_context.h | 1 +
include/asm-m68k/mmu_context.h | 1 +
include/asm-m68knommu/mmu_context.h | 1 +
include/asm-mips/mmu_context.h | 1 +
include/asm-parisc/mmu_context.h | 1 +
include/asm-powerpc/mmu_context.h | 1 +
include/asm-ppc/mmu_context.h | 1 +
include/asm-s390/mmu_context.h | 2 ++
include/asm-sh/mmu_context.h | 1 +
include/asm-sh64/mmu_context.h | 2 +-
include/asm-sparc/mmu_context.h | 2 ++
include/asm-sparc64/mmu_context.h | 1 +
include/asm-um/mmu_context.h | 2 ++
include/asm-v850/mmu_context.h | 2 ++
include/asm-x86_64/mmu_context.h | 1 +
include/asm-xtensa/mmu_context.h | 1 +
kernel/fork.c | 2 ++
mm/mmap.c | 4 ++++
30 files changed, 96 insertions(+), 3 deletions(-)

===================================================================
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -520,6 +520,10 @@ struct paravirt_ops paravirt_ops = {
.irq_enable_sysexit = native_irq_enable_sysexit,
.iret = native_iret,

+ .dup_mmap = paravirt_nop,
+ .exit_mmap = paravirt_nop,
+ .activate_mm = paravirt_nop,
+
.startup_ipi_hook = paravirt_nop,
};

===================================================================
--- a/include/asm-alpha/mmu_context.h
+++ b/include/asm-alpha/mmu_context.h
@@ -10,6 +10,7 @@
#include <asm/system.h>
#include <asm/machvec.h>
#include <asm/compiler.h>
+#include <asm-generic/mm_hooks.h>

/*
* Force a context reload. This is needed when we change the page
===================================================================
--- a/include/asm-arm/mmu_context.h
+++ b/include/asm-arm/mmu_context.h
@@ -16,6 +16,7 @@
#include <linux/compiler.h>
#include <asm/cacheflush.h>
#include <asm/proc-fns.h>
+#include <asm-generic/mm_hooks.h>

void __check_kvm_seq(struct mm_struct *mm);

===================================================================
--- a/include/asm-arm26/mmu_context.h
+++ b/include/asm-arm26/mmu_context.h
@@ -12,6 +12,8 @@
*/
#ifndef __ASM_ARM_MMU_CONTEXT_H
#define __ASM_ARM_MMU_CONTEXT_H
+
+#include <asm-generic/mm_hooks.h>

#define init_new_context(tsk,mm) 0
#define destroy_context(mm) do { } while(0)
===================================================================
--- a/include/asm-avr32/mmu_context.h
+++ b/include/asm-avr32/mmu_context.h
@@ -15,6 +15,7 @@
#include <asm/tlbflush.h>
#include <asm/pgalloc.h>
#include <asm/sysreg.h>
+#include <asm-generic/mm_hooks.h>

/*
* The MMU "context" consists of two things:
===================================================================
--- a/include/asm-cris/mmu_context.h
+++ b/include/asm-cris/mmu_context.h
@@ -1,5 +1,7 @@
#ifndef __CRIS_MMU_CONTEXT_H
#define __CRIS_MMU_CONTEXT_H
+
+#include <asm-generic/mm_hooks.h>

extern int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
extern void get_mmu_context(struct mm_struct *mm);
===================================================================
--- a/include/asm-frv/mmu_context.h
+++ b/include/asm-frv/mmu_context.h
@@ -15,6 +15,7 @@
#include <asm/setup.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
+#include <asm-generic/mm_hooks.h>

static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
{
===================================================================
--- /dev/null
+++ b/include/asm-generic/mm_hooks.h
@@ -0,0 +1,18 @@
+/*
+ * Define generic no-op hooks for arch_dup_mmap and arch_exit_mmap, to
+ * be included in asm-FOO/mmu_context.h for any arch FOO which doesn't
+ * need to hook these.
+ */
+#ifndef _ASM_GENERIC_MM_HOOKS_H
+#define _ASM_GENERIC_MM_HOOKS_H
+
+static inline void arch_dup_mmap(struct mm_struct *oldmm,
+ struct mm_struct *mm)
+{
+}
+
+static inline void arch_exit_mmap(struct mm_struct *mm)
+{
+}
+
+#endif /* _ASM_GENERIC_MM_HOOKS_H */
===================================================================
--- a/include/asm-h8300/mmu_context.h
+++ b/include/asm-h8300/mmu_context.h
@@ -4,6 +4,7 @@
#include <asm/setup.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
+#include <asm-generic/mm_hooks.h>

static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
{
===================================================================
--- a/include/asm-i386/mmu_context.h
+++ b/include/asm-i386/mmu_context.h
@@ -5,6 +5,16 @@
#include <asm/atomic.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
+#include <asm/paravirt.h>
+#ifndef CONFIG_PARAVIRT
+#include <asm-generic/mm_hooks.h>
+
+static inline void paravirt_activate_mm(struct mm_struct *prev,
+ struct mm_struct *next)
+{
+}
+#endif /* !CONFIG_PARAVIRT */
+

/*
* Used for LDT copy/destruction.
@@ -65,7 +75,10 @@ static inline void switch_mm(struct mm_s
#define deactivate_mm(tsk, mm) \
asm("movl %0,%%gs": :"r" (0));

-#define activate_mm(prev, next) \
- switch_mm((prev),(next),NULL)
+#define activate_mm(prev, next) \
+ do { \
+ paravirt_activate_mm(prev, next); \
+ switch_mm((prev),(next),NULL); \
+ } while(0);

#endif
===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -119,6 +119,12 @@ struct paravirt_ops

void (*io_delay)(void);

+ void (*activate_mm)(struct mm_struct *prev,
+ struct mm_struct *next);
+ void (*dup_mmap)(struct mm_struct *oldmm,
+ struct mm_struct *mm);
+ void (*exit_mmap)(struct mm_struct *mm);
+
#ifdef CONFIG_X86_LOCAL_APIC
void (*apic_write)(unsigned long reg, unsigned long v);
void (*apic_write_atomic)(unsigned long reg, unsigned long v);
@@ -394,6 +400,23 @@ static inline void startup_ipi_hook(int
}
#endif

+static inline void paravirt_activate_mm(struct mm_struct *prev,
+ struct mm_struct *next)
+{
+ paravirt_ops.activate_mm(prev, next);
+}
+
+static inline void arch_dup_mmap(struct mm_struct *oldmm,
+ struct mm_struct *mm)
+{
+ paravirt_ops.dup_mmap(oldmm, mm);
+}
+
+static inline void arch_exit_mmap(struct mm_struct *mm)
+{
+ paravirt_ops.exit_mmap(mm);
+}
+
#define __flush_tlb() paravirt_ops.flush_tlb_user()
#define __flush_tlb_global() paravirt_ops.flush_tlb_kernel()
#define __flush_tlb_single(addr) paravirt_ops.flush_tlb_single(addr)
===================================================================
--- a/include/asm-ia64/mmu_context.h
+++ b/include/asm-ia64/mmu_context.h
@@ -29,6 +29,7 @@
#include <linux/spinlock.h>

#include <asm/processor.h>
+#include <asm-generic/mm_hooks.h>

struct ia64_ctx {
spinlock_t lock;
===================================================================
--- a/include/asm-m32r/mmu_context.h
+++ b/include/asm-m32r/mmu_context.h
@@ -15,6 +15,7 @@
#include <asm/pgalloc.h>
#include <asm/mmu.h>
#include <asm/tlbflush.h>
+#include <asm-generic/mm_hooks.h>

/*
* Cache of MMU context last used.
===================================================================
--- a/include/asm-m68k/mmu_context.h
+++ b/include/asm-m68k/mmu_context.h
@@ -1,6 +1,7 @@
#ifndef __M68K_MMU_CONTEXT_H
#define __M68K_MMU_CONTEXT_H

+#include <asm-generic/mm_hooks.h>

static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
{
===================================================================
--- a/include/asm-m68knommu/mmu_context.h
+++ b/include/asm-m68knommu/mmu_context.h
@@ -4,6 +4,7 @@
#include <asm/setup.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
+#include <asm-generic/mm_hooks.h>

static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
{
===================================================================
--- a/include/asm-mips/mmu_context.h
+++ b/include/asm-mips/mmu_context.h
@@ -20,6 +20,7 @@
#include <asm/mipsmtregs.h>
#include <asm/smtc.h>
#endif /* SMTC */
+#include <asm-generic/mm_hooks.h>

/*
* For the fast tlb miss handlers, we keep a per cpu array of pointers
===================================================================
--- a/include/asm-parisc/mmu_context.h
+++ b/include/asm-parisc/mmu_context.h
@@ -5,6 +5,7 @@
#include <asm/atomic.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
+#include <asm-generic/mm_hooks.h>

static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
{
===================================================================
--- a/include/asm-powerpc/mmu_context.h
+++ b/include/asm-powerpc/mmu_context.h
@@ -10,6 +10,7 @@
#include <linux/mm.h>
#include <asm/mmu.h>
#include <asm/cputable.h>
+#include <asm-generic/mm_hooks.h>

/*
* Copyright (C) 2001 PPC 64 Team, IBM Corp
===================================================================
--- a/include/asm-ppc/mmu_context.h
+++ b/include/asm-ppc/mmu_context.h
@@ -6,6 +6,7 @@
#include <asm/bitops.h>
#include <asm/mmu.h>
#include <asm/cputable.h>
+#include <asm-generic/mm_hooks.h>

/*
* On 32-bit PowerPC 6xx/7xx/7xxx CPUs, we use a set of 16 VSIDs
===================================================================
--- a/include/asm-s390/mmu_context.h
+++ b/include/asm-s390/mmu_context.h
@@ -10,6 +10,8 @@
#define __S390_MMU_CONTEXT_H

#include <asm/pgalloc.h>
+#include <asm-generic/mm_hooks.h>
+
/*
* get a new mmu context.. S390 don't know about contexts.
*/
===================================================================
--- a/include/asm-sh/mmu_context.h
+++ b/include/asm-sh/mmu_context.h
@@ -12,6 +12,7 @@
#include <asm/tlbflush.h>
#include <asm/uaccess.h>
#include <asm/io.h>
+#include <asm-generic/mm_hooks.h>

/*
* The MMU "context" consists of two things:
===================================================================
--- a/include/asm-sh64/mmu_context.h
+++ b/include/asm-sh64/mmu_context.h
@@ -27,7 +27,7 @@ extern unsigned long mmu_context_cache;
extern unsigned long mmu_context_cache;

#include <asm/page.h>
-
+#include <asm-generic/mm_hooks.h>

/* Current mm's pgd */
extern pgd_t *mmu_pdtp_cache;
===================================================================
--- a/include/asm-sparc/mmu_context.h
+++ b/include/asm-sparc/mmu_context.h
@@ -4,6 +4,8 @@
#include <asm/btfixup.h>

#ifndef __ASSEMBLY__
+
+#include <asm-generic/mm_hooks.h>

static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
{
===================================================================
--- a/include/asm-sparc64/mmu_context.h
+++ b/include/asm-sparc64/mmu_context.h
@@ -9,6 +9,7 @@
#include <linux/spinlock.h>
#include <asm/system.h>
#include <asm/spitfire.h>
+#include <asm-generic/mm_hooks.h>

static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
{
===================================================================
--- a/include/asm-um/mmu_context.h
+++ b/include/asm-um/mmu_context.h
@@ -5,6 +5,8 @@

#ifndef __UM_MMU_CONTEXT_H
#define __UM_MMU_CONTEXT_H
+
+#include <asm-generic/mm_hooks.h>

#include "linux/sched.h"
#include "choose-mode.h"
===================================================================
--- a/include/asm-v850/mmu_context.h
+++ b/include/asm-v850/mmu_context.h
@@ -1,5 +1,7 @@
#ifndef __V850_MMU_CONTEXT_H__
#define __V850_MMU_CONTEXT_H__
+
+#include <asm-generic/mm_hooks.h>

#define destroy_context(mm) ((void)0)
#define init_new_context(tsk,mm) 0
===================================================================
--- a/include/asm-x86_64/mmu_context.h
+++ b/include/asm-x86_64/mmu_context.h
@@ -7,6 +7,7 @@
#include <asm/pda.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
+#include <asm-generic/mm_hooks.h>

/*
* possibly do the LDT unload here?
===================================================================
--- a/include/asm-xtensa/mmu_context.h
+++ b/include/asm-xtensa/mmu_context.h
@@ -18,6 +18,7 @@
#include <asm/pgtable.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
+#include <asm-generic/mm_hooks.h>

#define XCHAL_MMU_ASID_BITS 8

===================================================================
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -286,6 +286,8 @@ static inline int dup_mmap(struct mm_str
if (retval)
goto out;
}
+ /* a new mm has just been created */
+ arch_dup_mmap(oldmm, mm);
retval = 0;
out:
up_write(&mm->mmap_sem);
===================================================================
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -29,6 +29,7 @@
#include <asm/uaccess.h>
#include <asm/cacheflush.h>
#include <asm/tlb.h>
+#include <asm/mmu_context.h>

#ifndef arch_mmap_check
#define arch_mmap_check(addr, len, flags) (0)
@@ -1976,6 +1977,9 @@ void exit_mmap(struct mm_struct *mm)
struct vm_area_struct *vma = mm->mmap;
unsigned long nr_accounted = 0;
unsigned long end;
+
+ /* mm's last user has gone, and its about to be pulled down */
+ arch_exit_mmap(mm);

lru_add_drain();
flush_cache_mm(mm);

--