[PATCH AUTOSEL for 4.15 120/189] mm/mempolicy: add nodes_empty check in SYSC_migrate_pages

[Sasha Levin]

From: Yisheng Xie 

[ 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 
Acked-by: Vlastimil Babka 
Cc: Andi Kleen 
Cc: Chris Salls 
Cc: Christopher Lameter 
Cc: David Rientjes 
Cc: Ingo Molnar 
Cc: Naoya Horiguchi 
Cc: Tan Xiaojun 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin 
---
 mm/mempolicy.c | 10 +++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index c9b807eca74c..277b6454954e 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1435,10 +1435,14 @@ 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

[PATCH AUTOSEL for 4.15 120/189] mm/mempolicy: add nodes_empty check in SYSC_migrate_pages

[Sasha Levin]

From: Yisheng Xie 

[ 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 
Acked-by: Vlastimil Babka 
Cc: Andi Kleen 
Cc: Chris Salls 
Cc: Christopher Lameter 
Cc: David Rientjes 
Cc: Ingo Molnar 
Cc: Naoya Horiguchi 
Cc: Tan Xiaojun 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin 
---
 mm/mempolicy.c | 10 +++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index c9b807eca74c..277b6454954e 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1435,10 +1435,14 @@ 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