Merge "mm, oom_reaper: fix memory corruption" (76afd35f) · Commits · e / devices / android_kernel_fairphone_FP3

include/linux/oom.h

+9 −0

Original line number	Diff line number	Diff line
		@@ -63,6 +63,15 @@ static inline bool tsk_is_oom_victim(struct task_struct * tsk)
		return tsk->signal->oom_mm;
		}

		/*
		* Use this helper if tsk->mm != mm and the victim mm needs a special
		* handling. This is guaranteed to stay true after once set.
		*/
		static inline bool mm_is_oom_victim(struct mm_struct *mm)
		{
		return test_bit(MMF_OOM_VICTIM, &mm->flags);
		}

		extern unsigned long oom_badness(struct task_struct *p,
		struct mem_cgroup memcg, const nodemask_t nodemask,
		unsigned long totalpages);

+1 −0

Original line number	Diff line number	Diff line
		@@ -636,6 +636,7 @@ static inline int get_dumpable(struct mm_struct *mm)
		#define MMF_OOM_SKIP 21 /* mm is of no interest for the OOM killer */
		#define MMF_UNSTABLE 22 /* mm is unstable for copy_from_user */
		#define MMF_HUGE_ZERO_PAGE 23 /* mm has ever used the global huge zero page */
		#define MMF_OOM_VICTIM 25 /* mm is the oom victim */

		#define MMF_INIT_MASK (MMF_DUMPABLE_MASK \| MMF_DUMP_FILTER_MASK)

+5 −5

Original line number	Diff line number	Diff line
		@@ -2984,20 +2984,20 @@ void exit_mmap(struct mm_struct *mm)
		/* Use -1 here to ensure all VMAs in the mm are unmapped */
		unmap_vmas(&tlb, vma, 0, -1);

		set_bit(MMF_OOM_SKIP, &mm->flags);
		if (unlikely(tsk_is_oom_victim(current))) {
		if (unlikely(mm_is_oom_victim(mm))) {
		/*
		* Wait for oom_reap_task() to stop working on this
		* mm. Because MMF_OOM_SKIP is already set before
		* calling down_read(), oom_reap_task() will not run
		* on this "mm" post up_write().
		*
		* tsk_is_oom_victim() cannot be set from under us
		* either because current->mm is already set to NULL
		* mm_is_oom_victim() cannot be set from under us
		* either because victim->mm is already set to NULL
		* under task_lock before calling mmput and oom_mm is
		* set not NULL by the OOM killer only if current->mm
		* set not NULL by the OOM killer only if victim->mm
		* is found not NULL while holding the task_lock.
		*/
		set_bit(MMF_OOM_SKIP, &mm->flags);
		down_write(&mm->mmap_sem);
		up_write(&mm->mmap_sem);
		}

+3 −1

Original line number	Diff line number	Diff line
		@@ -677,8 +677,10 @@ static void mark_oom_victim(struct task_struct *tsk)
		return;

		/* oom_mm is bound to the signal struct life time. */
		if (!cmpxchg(&tsk->signal->oom_mm, NULL, mm))
		if (!cmpxchg(&tsk->signal->oom_mm, NULL, mm)) {
		atomic_inc(&tsk->signal->oom_mm->mm_count);
		set_bit(MMF_OOM_VICTIM, &mm->flags);
		}

		/*
		* Make sure that the task is woken up from uninterruptible sleep