Re: [PATCH] mac802154: Rename kfree_rcu() to kvfree_rcu_mightsleep()

[Joel Fernandes]

> On Mar 16, 2023, at 12:36 PM, Stefan Schmidt <stefan@xxxxxxxxxxxxxxxxxx> wrote:
> 
> Hello Joel.
> 
>> On 10.03.23 02:31, Joel Fernandes (Google) wrote:
>> The k[v]free_rcu() macro's single-argument form is deprecated.
>> Therefore switch to the new k[v]free_rcu_mightsleep() variant. The goal
>> is to avoid accidental use of the single-argument forms, which can
>> introduce functionality bugs in atomic contexts and latency bugs in
>> non-atomic contexts.
>> The callers are holding a mutex so the context allows blocking. Hence
>> using the API with a single argument will be fine, but use its new name.
>> There is no functionality change with this patch.
>> Fixes: 57588c71177f ("mac802154: Handle passive scanning")
>> Signed-off-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
>> ---
>> Please Ack the patch but we can carry it through the RCU tree as well if
>> needed, as it is not a bug per-se and we are not dropping the old API before
>> the next release.
> 
> The "but we can carry it" part throws me off here. Not sure if you want this through the RCU tree (I suppose). In that case see my ack below.
> 
> If you want me to take it through my wpan tree instead let me know.

We will take this with your Ack below, thank you!

 - Joel


>>  net/mac802154/scan.c | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>> diff --git a/net/mac802154/scan.c b/net/mac802154/scan.c
>> index 9b0933a185eb..5c191bedd72c 100644
>> --- a/net/mac802154/scan.c
>> +++ b/net/mac802154/scan.c
>> @@ -52,7 +52,7 @@ static int mac802154_scan_cleanup_locked(struct ieee802154_local *local,
>>      request = rcu_replace_pointer(local->scan_req, NULL, 1);
>>      if (!request)
>>          return 0;
>> -    kfree_rcu(request);
>> +    kvfree_rcu_mightsleep(request);
>>        /* Advertize first, while we know the devices cannot be removed */
>>      if (aborted)
>> @@ -403,7 +403,7 @@ int mac802154_stop_beacons_locked(struct ieee802154_local *local,
>>      request = rcu_replace_pointer(local->beacon_req, NULL, 1);
>>      if (!request)
>>          return 0;
>> -    kfree_rcu(request);
>> +    kvfree_rcu_mightsleep(request);
>>        nl802154_beaconing_done(wpan_dev);
>>  
> 
> 
> Acked-by: Stefan Schmidt <stefan@xxxxxxxxxxxxxxxxxx>
> 
> regards
> Stefan Schmidt