diff options
| -rw-r--r-- | mm/mempolicy.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/mm/mempolicy.c b/mm/mempolicy.c index e9fc1c1ae66..c6c61ea6bb8 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -591,16 +591,29 @@ static long do_set_mempolicy(unsigned short mode, unsigned short flags, nodemask_t *nodes) { struct mempolicy *new; + struct mm_struct *mm = current->mm; new = mpol_new(mode, flags, nodes); if (IS_ERR(new)) return PTR_ERR(new); + + /* + * prevent changing our mempolicy while show_numa_maps() + * is using it. + * Note: do_set_mempolicy() can be called at init time + * with no 'mm'. + */ + if (mm) + down_write(&mm->mmap_sem); mpol_put(current->mempolicy); current->mempolicy = new; mpol_set_task_struct_flag(); if (new && new->policy == MPOL_INTERLEAVE && nodes_weight(new->v.nodes)) current->il_next = first_node(new->v.nodes); + if (mm) + up_write(&mm->mmap_sem); + return 0; } |