From: Yisheng Xie <xieyisheng1@xxxxxxxxxx> Subject: mm/mempolicy: add nodes_empty check in SYSC_migrate_pages 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@xxxxxxxxxx Signed-off-by: Yisheng Xie <xieyisheng1@xxxxxxxxxx> Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx> Cc: Chris Salls <salls@xxxxxxxxxxx> Cc: Christopher Lameter <cl@xxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx> Cc: Tan Xiaojun <tanxiaojun@xxxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/mempolicy.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff -puN mm/mempolicy.c~mm-mempolicy-add-nodes_empty-check-in-sysc_migrate_pages mm/mempolicy.c --- a/mm/mempolicy.c~mm-mempolicy-add-nodes_empty-check-in-sysc_migrate_pages +++ a/mm/mempolicy.c @@ -1433,10 +1433,14 @@ 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) _ -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
