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Diffstat (limited to 'mm/mempolicy.c')
-rw-r--r--mm/mempolicy.c82
1 files changed, 69 insertions, 13 deletions
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 5bc0a96beb51..f969da5dd8a2 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1275,33 +1275,42 @@ SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode,
const unsigned long __user *, new_nodes)
{
const struct cred *cred = current_cred(), *tcred;
- struct mm_struct *mm;
+ struct mm_struct *mm = NULL;
struct task_struct *task;
- nodemask_t old;
- nodemask_t new;
nodemask_t task_nodes;
int err;
+ nodemask_t *old;
+ nodemask_t *new;
+ NODEMASK_SCRATCH(scratch);
+
+ if (!scratch)
+ return -ENOMEM;
+
+ old = &scratch->mask1;
+ new = &scratch->mask2;
- err = get_nodes(&old, old_nodes, maxnode);
+ err = get_nodes(old, old_nodes, maxnode);
if (err)
- return err;
+ goto out;
- err = get_nodes(&new, new_nodes, maxnode);
+ err = get_nodes(new, new_nodes, maxnode);
if (err)
- return err;
+ goto out;
/* Find the mm_struct */
read_lock(&tasklist_lock);
task = pid ? find_task_by_vpid(pid) : current;
if (!task) {
read_unlock(&tasklist_lock);
- return -ESRCH;
+ err = -ESRCH;
+ goto out;
}
mm = get_task_mm(task);
read_unlock(&tasklist_lock);
+ err = -EINVAL;
if (!mm)
- return -EINVAL;
+ goto out;
/*
* Check if this process has the right to modify the specified
@@ -1322,12 +1331,12 @@ SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode,
task_nodes = cpuset_mems_allowed(task);
/* Is the user allowed to access the target nodes? */
- if (!nodes_subset(new, task_nodes) && !capable(CAP_SYS_NICE)) {
+ if (!nodes_subset(*new, task_nodes) && !capable(CAP_SYS_NICE)) {
err = -EPERM;
goto out;
}
- if (!nodes_subset(new, node_states[N_HIGH_MEMORY])) {
+ if (!nodes_subset(*new, node_states[N_HIGH_MEMORY])) {
err = -EINVAL;
goto out;
}
@@ -1336,10 +1345,13 @@ SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode,
if (err)
goto out;
- err = do_migrate_pages(mm, &old, &new,
+ err = do_migrate_pages(mm, old, new,
capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE);
out:
- mmput(mm);
+ if (mm)
+ mmput(mm);
+ NODEMASK_SCRATCH_FREE(scratch);
+
return err;
}
@@ -1712,6 +1724,50 @@ bool init_nodemask_of_mempolicy(nodemask_t *mask)
}
#endif
+/*
+ * mempolicy_nodemask_intersects
+ *
+ * If tsk's mempolicy is "default" [NULL], return 'true' to indicate default
+ * policy. Otherwise, check for intersection between mask and the policy
+ * nodemask for 'bind' or 'interleave' policy. For 'perferred' or 'local'
+ * policy, always return true since it may allocate elsewhere on fallback.
+ *
+ * Takes task_lock(tsk) to prevent freeing of its mempolicy.
+ */
+bool mempolicy_nodemask_intersects(struct task_struct *tsk,
+ const nodemask_t *mask)
+{
+ struct mempolicy *mempolicy;
+ bool ret = true;
+
+ if (!mask)
+ return ret;
+ task_lock(tsk);
+ mempolicy = tsk->mempolicy;
+ if (!mempolicy)
+ goto out;
+
+ switch (mempolicy->mode) {
+ case MPOL_PREFERRED:
+ /*
+ * MPOL_PREFERRED and MPOL_F_LOCAL are only preferred nodes to
+ * allocate from, they may fallback to other nodes when oom.
+ * Thus, it's possible for tsk to have allocated memory from
+ * nodes in mask.
+ */
+ break;
+ case MPOL_BIND:
+ case MPOL_INTERLEAVE:
+ ret = nodes_intersects(mempolicy->v.nodes, *mask);
+ break;
+ default:
+ BUG();
+ }
+out:
+ task_unlock(tsk);
+ return ret;
+}
+
/* Allocate a page in interleaved policy.
Own path because it needs to do special accounting. */
static struct page *alloc_page_interleave(gfp_t gfp, unsigned order,