[PATCH 6/7] uprobes: fold uprobe_reset_state() into uprobe_dup_mmap()

[Oleg Nesterov <oleg@redhat.com>]

Now that we have uprobe_dup_mmap() we can fold uprobe_reset_state()
into the new hook and remove it. mmput()->uprobe_clear_state() can't
be called before dup_mmap().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
 include/linux/uprobes.h |    4 ----
 kernel/events/uprobes.c |   10 ++--------
 kernel/fork.c           |    2 --
 3 files changed, 2 insertions(+), 14 deletions(-)

diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h
index 4a37ab1..30297f9 100644
--- a/include/linux/uprobes.h
+++ b/include/linux/uprobes.h
@@ -118,7 +118,6 @@ extern void uprobe_notify_resume(struct pt_regs *regs);
 extern bool uprobe_deny_signal(void);
 extern bool __weak arch_uprobe_skip_sstep(struct arch_uprobe *aup, struct pt_regs *regs);
 extern void uprobe_clear_state(struct mm_struct *mm);
-extern void uprobe_reset_state(struct mm_struct *mm);
 #else /* !CONFIG_UPROBES */
 struct uprobes_state {
 };
@@ -163,8 +162,5 @@ static inline void uprobe_copy_process(struct task_struct *t)
 static inline void uprobe_clear_state(struct mm_struct *mm)
 {
 }
-static inline void uprobe_reset_state(struct mm_struct *mm)
-{
-}
 #endif /* !CONFIG_UPROBES */
 #endif	/* _LINUX_UPROBES_H */
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 2a42319..81fb2d8 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1150,16 +1150,10 @@ void uprobe_clear_state(struct mm_struct *mm)
 	kfree(area);
 }
 
-/*
- * uprobe_reset_state - Free the area allocated for slots.
- */
-void uprobe_reset_state(struct mm_struct *mm)
-{
-	mm->uprobes_state.xol_area = NULL;
-}
-
 void uprobe_dup_mmap(struct mm_struct *oldmm, struct mm_struct *newmm)
 {
+	newmm->uprobes_state.xol_area = NULL;
+
 	if (test_bit(MMF_HAS_UPROBES, &oldmm->flags))
 		set_bit(MMF_HAS_UPROBES, &newmm->flags);
 }
diff --git a/kernel/fork.c b/kernel/fork.c
index ab970c3..5555f51 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -836,8 +836,6 @@ struct mm_struct *dup_mm(struct task_struct *tsk)
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 	mm->pmd_huge_pte = NULL;
 #endif
-	uprobe_reset_state(mm);
-
 	if (!mm_init(mm, tsk))
 		goto fail_nomem;
 
-- 
1.5.5.1