netdev - Re: [PATCH iwl-next] ice: remove null checks before devm

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Message-ID: <08806483-959b-925d-2099-561d0f0278f8@intel.com>
Date: Wed, 31 May 2023 00:06:15 +0200
From: Przemek Kitszel <przemyslaw.kitszel@...el.com>
To: Simon Horman <simon.horman@...igine.com>
CC: <intel-wired-lan-bounces@...osl.org>, Jesse Brandeburg
	<jesse.brandeburg@...el.com>, Tony Nguyen <anthony.l.nguyen@...el.com>,
	Anirudh Venkataramanan <anirudh.venkataramanan@...el.com>, Victor Raj
	<victor.raj@...el.com>, Michal Swiatkowski
	<michal.swiatkowski@...ux.intel.com>, Jacob Keller
	<jacob.e.keller@...el.com>, Martyna Szapar-Mudlaw
	<martyna.szapar-mudlaw@...ux.intel.com>, Michal Wilczynski
	<michal.wilczynski@...el.com>, <netdev@...r.kernel.org>
Subject: Re: [PATCH iwl-next] ice: remove null checks before devm_kfree()
 calls

On 5/30/23 20:10, Simon Horman wrote:
> On Tue, May 30, 2023 at 01:25:49PM +0200, Przemek Kitszel wrote:
>> We all know they are redundant.
>>
>> Reviewed-by: Michal Swiatkowski <michal.swiatkowski@...ux.intel.com>
>> Reviewed-by: Michal Wilczynski <michal.wilczynski@...el.com>
>> Signed-off-by: Przemek Kitszel <przemyslaw.kitszel@...el.com>
> 
> ...
> 
>> diff --git a/drivers/net/ethernet/intel/ice/ice_flow.c b/drivers/net/ethernet/intel/ice/ice_flow.c
>> index ef103e47a8dc..85cca572c22a 100644
>> --- a/drivers/net/ethernet/intel/ice/ice_flow.c
>> +++ b/drivers/net/ethernet/intel/ice/ice_flow.c
>> @@ -1303,23 +1303,6 @@ ice_flow_find_prof_id(struct ice_hw *hw, enum ice_block blk, u64 prof_id)
>>   	return NULL;
>>   }
>>   
>> -/**
>> - * ice_dealloc_flow_entry - Deallocate flow entry memory
>> - * @hw: pointer to the HW struct
>> - * @entry: flow entry to be removed
>> - */
>> -static void
>> -ice_dealloc_flow_entry(struct ice_hw *hw, struct ice_flow_entry *entry)
>> -{
>> -	if (!entry)
>> -		return;
>> -
>> -	if (entry->entry)
>> -		devm_kfree(ice_hw_to_dev(hw), entry->entry);
>> -
>> -	devm_kfree(ice_hw_to_dev(hw), entry);
>> -}
>> -
>>   /**
>>    * ice_flow_rem_entry_sync - Remove a flow entry
>>    * @hw: pointer to the HW struct
>> @@ -1335,7 +1318,8 @@ ice_flow_rem_entry_sync(struct ice_hw *hw, enum ice_block __always_unused blk,

More context would include following:

         if (!entry)
                 return -EINVAL;


>>   
>>   	list_del(&entry->l_entry);
>>   
>> -	ice_dealloc_flow_entry(hw, entry);
>> +	devm_kfree(ice_hw_to_dev(hw), entry->entry);
> 
> Hi Przemek,
> 
> Previously entry was not dereferenced if it was NULL.
> Now it is. Can that occur?

The check is right above the default 3-line context provided by git, see 
above.

> 
>> +	devm_kfree(ice_hw_to_dev(hw), entry);
>>   
>>   	return 0;
>>   }
> 
> ...