| From | Sasha Levin <> | Subject | [PATCH AUTOSEL for 4.15 120/189] mm/mempolicy: add nodes_empty check in SYSC_migrate_pages | Date | Mon, 9 Apr 2018 00:18:21 +0000 |
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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@huawei.com 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> --- 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
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