From: Yisheng Xie <xieyishe...@huawei.com>
[ Upstream commit 0486a38bcc4749808edbc848f1bcf232042770fc ]
As in 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.
Link:
http://lkml.kernel.org/r/1510882624-44342-4-git-send-email-xieyishe...@huawei.com
Signed-off-by: Yisheng Xie <xieyishe...@huawei.com>
Acked-by: Vlastimil Babka <vba...@suse.cz>
Cc: Andi Kleen <a...@linux.intel.com>
Cc: Chris Salls <sa...@cs.ucsb.edu>
Cc: Christopher Lameter <c...@linux.com>
Cc: David Rientjes <rient...@google.com>
Cc: Ingo Molnar <mi...@kernel.org>
Cc: Naoya Horiguchi <n-horigu...@ah.jp.nec.com>
Cc: Tan Xiaojun <tanxiao...@huawei.com>
Signed-off-by: Andrew Morton <a...@linux-foundation.org>
Signed-off-by: Linus Torvalds <torva...@linux-foundation.org>
Signed-off-by: Sasha Levin <alexander.le...@microsoft.com>
---
mm/mempolicy.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 80b67805b51d..2d3077ce50cd 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1440,10 +1440,14 @@ SYSCALL_DEFINE4(migrate_pages, pid_t, pid, 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)
--
2.15.1
