As manpage of migrate_pages, the errno should be set to EINVAL when none
of the specified nodes contain memory. However, when new_nodes is null,
i.e. the specified nodes also do not have memory, as the 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.
This patch is to add nodes_empty check to fix above case.
Signed-off-by: Yisheng Xie <xieyisheng1@xxxxxxxxxx>
---
mm/mempolicy.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 8798ecb..58352cc 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1402,6 +1402,11 @@ static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode,
if (err)
goto out;
+ if (nodes_empty(*new)) {
+ err = -EINVAL;
+ goto out;
+ }
+
/* Find the mm_struct */
rcu_read_lock();
task = pid ? find_task_by_vpid(pid) : current;
--
1.7.12.4
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