2 files changed, 7 insertions, 5 deletions

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 79827ce03e3..14df8806ff2 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -1158,6 +1158,7 @@ static int show_numa_map(struct seq_file *m, void *v, int is_pid)
         struct vm_area_struct *vma = v;
         struct numa_maps *md = &numa_priv->md;
         struct file *file = vma->vm_file;
+        struct task_struct *task = proc_priv->task;
         struct mm_struct *mm = vma->vm_mm;
         struct mm_walk walk = {};
         struct mempolicy *pol;
@@ -1177,9 +1178,11 @@ static int show_numa_map(struct seq_file *m, void *v, int is_pid)
         walk.private = md;
         walk.mm = mm;
 
-        pol = get_vma_policy(proc_priv->task, vma, vma->vm_start);
+        task_lock(task);
+        pol = get_vma_policy(task, vma, vma->vm_start);
         mpol_to_str(buffer, sizeof(buffer), pol, 0);
         mpol_cond_put(pol);
+        task_unlock(task);
 
         seq_printf(m, "%08lx %s", vma->vm_start, buffer);
 
@@ -1189,7 +1192,7 @@ static int show_numa_map(struct seq_file *m, void *v, int is_pid)
         } else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
                 seq_printf(m, " heap");
         } else {
-                pid_t tid = vm_is_stack(proc_priv->task, vma, is_pid);
+                pid_t tid = vm_is_stack(task, vma, is_pid);
                 if (tid != 0) {
                         /*
                          * Thread stack in /proc/PID/task/TID/maps or
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 0b78fb9ea65..d04a8a54c29 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1536,9 +1536,8 @@ asmlinkage long compat_sys_mbind(compat_ulong_t start, compat_ulong_t len,
  *
  * Returns effective policy for a VMA at specified address.
  * Falls back to @task or system default policy, as necessary.
- * Current or other task's task mempolicy and non-shared vma policies
- * are protected by the task's mmap_sem, which must be held for read by
- * the caller.
+ * Current or other task's task mempolicy and non-shared vma policies must be
+ * protected by task_lock(task) by the caller.
  * Shared policies [those marked as MPOL_F_SHARED] require an extra reference
  * count--added by the get_policy() vm_op, as appropriate--to protect against
  * freeing by another task.  It is the caller's responsibility to free the