This adds the flag parameter to the __ksm_exit() call. This allows to
distinguish if this call is for an prctl or madvise invocation.
Signed-off-by: Stefan Roesch <shr@xxxxxxxxxxxx>
---
include/linux/ksm.h | 8 +++++---
mm/ksm.c | 8 ++++++--
2 files changed, 11 insertions(+), 5 deletions(-)
diff --git a/include/linux/ksm.h b/include/linux/ksm.h
index 50e6b56092f3..d38a05a36298 100644
--- a/include/linux/ksm.h
+++ b/include/linux/ksm.h
@@ -18,8 +18,8 @@
#ifdef CONFIG_KSM
int ksm_madvise(struct vm_area_struct *vma, unsigned long start,
unsigned long end, int advice, unsigned long *vm_flags);
-void __ksm_exit(struct mm_struct *mm);
int __ksm_enter(struct mm_struct *mm, int flag);
+void __ksm_exit(struct mm_struct *mm, int flag);
static inline int ksm_fork(struct mm_struct *mm, struct mm_struct *oldmm)
{
@@ -32,8 +32,10 @@ static inline int ksm_fork(struct mm_struct *mm, struct mm_struct *oldmm)
static inline void ksm_exit(struct mm_struct *mm)
{
- if (test_bit(MMF_VM_MERGEABLE, &mm->flags))
- __ksm_exit(mm);
+ if (test_bit(MMF_VM_MERGE_ANY, &mm->flags))
+ __ksm_exit(mm, MMF_VM_MERGE_ANY);
+ else if (test_bit(MMF_VM_MERGEABLE, &mm->flags))
+ __ksm_exit(mm, MMF_VM_MERGEABLE);
}
/*
diff --git a/mm/ksm.c b/mm/ksm.c
index afc0980592af..3597ae52fe7b 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -2665,12 +2665,16 @@ int __ksm_enter(struct mm_struct *mm, int flag)
return 0;
}
-void __ksm_exit(struct mm_struct *mm)
+void __ksm_exit(struct mm_struct *mm, int flag)
{
struct ksm_mm_slot *mm_slot;
struct mm_slot *slot;
int easy_to_free = 0;
+ if (!(current->flags & PF_EXITING) && flag == MMF_VM_MERGE_ANY &&
+ test_bit(MMF_VM_MERGE_ANY, &mm->flags))
+ clear_bit(MMF_VM_MERGE_ANY, &mm->flags);
+
/*
* This process is exiting: if it's straightforward (as is the
* case when ksmd was never running), free mm_slot immediately.
@@ -2697,7 +2701,7 @@ void __ksm_exit(struct mm_struct *mm)
if (easy_to_free) {
mm_slot_free(mm_slot_cache, mm_slot);
- clear_bit(MMF_VM_MERGEABLE, &mm->flags);
+ clear_bit(flag, &mm->flags);
mmdrop(mm);
} else if (mm_slot) {
mmap_write_lock(mm);
--
2.30.2
