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-rw-r--r--kernel/events/uprobes.c22
-rw-r--r--kernel/fork.c1
2 files changed, 22 insertions, 1 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 3e2996b809be..33870b17e1dd 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -647,6 +647,7 @@ static int
install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm,
struct vm_area_struct *vma, unsigned long vaddr)
{
+ bool first_uprobe;
int ret;
/*
@@ -678,7 +679,17 @@ install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm,
uprobe->flags |= UPROBE_COPY_INSN;
}
+ /*
+ * set MMF_HAS_UPROBES in advance for uprobe_pre_sstep_notifier(),
+ * the task can hit this breakpoint right after __replace_page().
+ */
+ first_uprobe = !test_bit(MMF_HAS_UPROBES, &mm->flags);
+ if (first_uprobe)
+ set_bit(MMF_HAS_UPROBES, &mm->flags);
+
ret = set_swbp(&uprobe->arch, mm, vaddr);
+ if (ret && first_uprobe)
+ clear_bit(MMF_HAS_UPROBES, &mm->flags);
return ret;
}
@@ -1032,6 +1043,9 @@ void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned lon
if (!atomic_read(&vma->vm_mm->mm_users)) /* called by mmput() ? */
return;
+ if (!test_bit(MMF_HAS_UPROBES, &vma->vm_mm->flags))
+ return;
+
/* TODO: unmapping uprobe(s) will need more work */
}
@@ -1142,6 +1156,12 @@ 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)
+{
+ if (test_bit(MMF_HAS_UPROBES, &oldmm->flags))
+ set_bit(MMF_HAS_UPROBES, &newmm->flags);
+}
+
/*
* - search for a free slot.
*/
@@ -1507,7 +1527,7 @@ int uprobe_pre_sstep_notifier(struct pt_regs *regs)
{
struct uprobe_task *utask;
- if (!current->mm)
+ if (!current->mm || !test_bit(MMF_HAS_UPROBES, &current->mm->flags))
return 0;
utask = current->utask;
diff --git a/kernel/fork.c b/kernel/fork.c
index 912b6f6fe5b8..cbb5f9fcd3e8 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -353,6 +353,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
down_write(&oldmm->mmap_sem);
flush_cache_dup_mm(oldmm);
+ uprobe_dup_mmap(oldmm, mm);
/*
* Not linked in yet - no deadlock potential:
*/