Messages in this thread Patch in this message | | | From | Yisheng Xie <> | Subject | [PATCH] mm/mempolicy: add node_empty check in SYSC_migrate_pages | Date | Wed, 18 Oct 2017 09:37:40 +0800 |
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As Xiaojun reported the ltp of migrate_pages01 will failed on ARCH arm64 system whoes has 4 nodes[0...3], all have memory and CONFIG_NODES_SHIFT=2:
migrate_pages01 0 TINFO : test_invalid_nodes migrate_pages01 14 TFAIL : migrate_pages_common.c:45: unexpected failure - returned value = 0, expected: -1 migrate_pages01 15 TFAIL : migrate_pages_common.c:55: call succeeded unexpectedly
In this case the test_invalid_nodes of migrate_pages01 will call: SYSC_migrate_pages as:
migrate_pages(0, , {0x0000000000000001}, 64, , {0x0000000000000010}, 64) = 0
For MAX_NUMNODES is 4, so 0x10 nodemask will tread as empty set which makes nodes_subset(*new, node_states[N_MEMORY])
return true, as empty set is subset of any set.
So this is a common issue which also can happens in X86_64 system eg. 8 nodes[0..7], all with memory and CONFIG_NODES_SHIFT=3. Fix it by adding node_empty check in SYSC_migrate_pages.
Reported-by: Tan Xiaojun <tanxiaojun@huawei.com> Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com> --- mm/mempolicy.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/mm/mempolicy.c b/mm/mempolicy.c index a2af6d5..1dfd3cc 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1388,6 +1388,11 @@ static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode, if (err) goto out; + if (nodes_empty(*new)) { + err = -EINVAL; + goto out; + } + /* Find the mm_struct */ rcu_read_lock(); task = pid ? find_task_by_vpid(pid) : current; -- 1.7.12.4
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