On 12/26/23 14:04, Tom Zanussi wrote:
> Hi Randy,
>
> On Tue, 2023-12-26 at 13:09 -0800, Randy Dunlap wrote:
>> Hi--
>>
>> On 12/26/23 12:53, Tom Zanussi wrote:
>>> In some configurations e.g. systems with CXL, a numa node can have
>>> 0
>>> cpus and cpumask_nth() will return a cpu value that doesn't exist,
>>> which will result in an attempt to add an entry to the wq table at
>>> a
>>> bad index.
>>>
>>> To fix this, when iterating the cpus for a node, skip any node that
>>> doesn't have cpus.
>>>
>>> Also, as a precaution, add a warning and bail if cpumask_nth()
>>> returns
>>> a nonexistent cpu.
>>>
>>> Reported-by: Zhang, Rex <rex.zhang@xxxxxxxxx>
>>> Signed-off-by: Tom Zanussi <tom.zanussi@xxxxxxxxxxxxxxx>
>>> ---
>>> drivers/crypto/intel/iaa/iaa_crypto_main.c | 14 +++++++++++---
>>> 1 file changed, 11 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/crypto/intel/iaa/iaa_crypto_main.c
>>> b/drivers/crypto/intel/iaa/iaa_crypto_main.c
>>> index 5093361b0107..782157a74043 100644
>>> --- a/drivers/crypto/intel/iaa/iaa_crypto_main.c
>>> +++ b/drivers/crypto/intel/iaa/iaa_crypto_main.c
>>> @@ -1017,12 +1017,17 @@ static void rebalance_wq_table(void)
>>> return;
>>> }
>>>
>>> - for_each_online_node(node) {
>>> + for_each_node_with_cpus(node) {
>>> node_cpus = cpumask_of_node(node);
>>>
>>> for (cpu = 0; cpu < nr_cpus_per_node; cpu++) {
>>> int node_cpu = cpumask_nth(cpu, node_cpus);
>>>
>>> + if (WARN_ON(node_cpu >= nr_cpu_ids)) {
>>> + pr_debug("node_cpu %d doesn't
>>> exist!\n", node_cpu);
>>> + return;
>>> + }
>>> +
>>> if ((cpu % cpus_per_iaa) == 0)
>>> iaa++;
>>>
>>> @@ -2095,10 +2100,13 @@ static struct idxd_device_driver
>>> iaa_crypto_driver = {
>>> static int __init iaa_crypto_init_module(void)
>>> {
>>> int ret = 0;
>>> + int node;
>>>
>>> nr_cpus = num_online_cpus();
>>> - nr_nodes = num_online_nodes();
>>> - nr_cpus_per_node = nr_cpus / nr_nodes;
>>> + for_each_node_with_cpus(node)
>>> + nr_nodes++;
>>> + if (nr_nodes)
>>> + nr_cpus_per_node = nr_cpus / nr_nodes;
>>
>> If nr_nodes == 0, nr_cpus_per_node is not initialized here.
>> Is it initialized somewhere else, or just not used if nr_nodes is 0?
>>
>
> nr_cpus_per_node is initialized to 0 elsewhere (as a static global).
>
> It seems to me nr_nodes should always be at least 1. From my testing
> with !CONFIG_NUMA, nr_nodes is set to 1 in that case; not sure how you
> can get actually get nr_nodes == 0 if you have any cpus working. The
> check is there to avoid dividing by 0 but maybe the right thing to is
> BUG_ON(!nr_nodes) and return an error, and remove that check...
I think it's OK as is then.
and I hope that we never see the WARN_ON() up above. :)
>>>
>>> if (crypto_has_comp("deflate-generic", 0, 0))
>>> deflate_generic_tfm = crypto_alloc_comp("deflate-
>>> generic", 0, 0);
>>
>
Thanks.
--
#Randy
