1 files changed, 20 insertions, 0 deletions

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 02a63ac04178..7411bfb0b7cc 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -202,6 +202,26 @@ static int proc_root_link(struct inode *inode, struct dentry **dentry, struct vf
          (task->state == TASK_STOPPED || task->state == TASK_TRACED) && \
          security_ptrace(current,task) == 0))
 
+struct mm_struct *mm_for_maps(struct task_struct *task)
+{
+        struct mm_struct *mm = get_task_mm(task);
+        if (!mm)
+                return NULL;
+        down_read(&mm->mmap_sem);
+        task_lock(task);
+        if (task->mm != mm)
+                goto out;
+        if (task->mm != current->mm && __ptrace_may_attach(task) < 0)
+                goto out;
+        task_unlock(task);
+        return mm;
+out:
+        task_unlock(task);
+        up_read(&mm->mmap_sem);
+        mmput(mm);
+        return NULL;
+}
+
 static int proc_pid_cmdline(struct task_struct *task, char * buffer)
 {
         int res = 0;