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@devkernel.io --- 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);