4.9-stable review patch. If anyone has any objections, please let me know.
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From: Yisheng Xie xieyisheng1@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-xieyisheng1@huawe... Signed-off-by: Yisheng Xie xieyisheng1@huawei.com Acked-by: Vlastimil Babka vbabka@suse.cz Cc: Andi Kleen ak@linux.intel.com Cc: Chris Salls salls@cs.ucsb.edu Cc: Christopher Lameter cl@linux.com Cc: David Rientjes rientjes@google.com Cc: Ingo Molnar mingo@kernel.org Cc: Naoya Horiguchi n-horiguchi@ah.jp.nec.com Cc: Tan Xiaojun tanxiaojun@huawei.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- mm/mempolicy.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
--- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1442,10 +1442,14 @@ SYSCALL_DEFINE4(migrate_pages, pid_t, pi 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)