As manpage of migrate_pages, the errno should be set to EINVAL when
none of the node IDs specified by new_nodes are on-line and allowed
by the process's current cpuset context, or none of the specified
nodes contain memory. However, when test by following case:
new_nodes = 0;
old_nodes = 0xf;
ret = migrate_pages(pid, old_nodes, new_nodes, MAX);
The ret will be 0 and no errno is set. As the new_nodes is empty,
we should expect EINVAL as documented.
To fix the case like above, this patch check whether target nodes
AND current task_nodes is empty, and then check whether AND
node_states[N_MEMORY] is empty.
Signed-off-by: Yisheng Xie <xieyisheng1@xxxxxxxxxx>
---
mm/mempolicy.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 65df28d..f604b22 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1433,10 +1433,14 @@ static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode,
goto out_put;
}
- if (!nodes_subset(*new, node_states[N_MEMORY])) {
- err = -EINVAL;
+ task_nodes = cpuset_mems_allowed(current);
+ nodes_and(*new, *new, task_nodes);
+ if (nodes_empty(*new))
+ goto out_put;
+
+ nodes_and(*new, *new, node_states[N_MEMORY]);
+ if (nodes_empty(*new))
goto out_put;
- }
err = security_task_movememory(task);
if (err)
--
1.8.3.1
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