Re: [PATCH 1/3] tee: qcomtee: call: Fix confusing cleanup.h syntax

[Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>]

On 12/12/2025 01:55, Sumit Garg wrote:
> On Mon, Dec 08, 2025 at 03:08:45AM +0100, Krzysztof Kozlowski wrote:
>> Initializing automatic __free variables to NULL without need (e.g.
>> branches with different allocations), followed by actual allocation is
>> in contrary to explicit coding rules guiding cleanup.h:
>>
>> "Given that the "__free(...) = NULL" pattern for variables defined at
>> the top of the function poses this potential interdependency problem the
>> recommendation is to always define and assign variables in one statement
>> and not group variable definitions at the top of the function when
>> __free() is used."
>>
>> Code does not have a bug, but is less readable and uses discouraged
>> coding practice, so fix that by moving declaration to the place of
>> assignment.
> 
> Okay I see but..
> 
>>
>> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
>> ---
>>  drivers/tee/qcomtee/call.c | 17 ++++++++---------
>>  1 file changed, 8 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/tee/qcomtee/call.c b/drivers/tee/qcomtee/call.c
>> index 65f9140d4e1f..8f8830f0df26 100644
>> --- a/drivers/tee/qcomtee/call.c
>> +++ b/drivers/tee/qcomtee/call.c
>> @@ -395,9 +395,7 @@ static int qcomtee_object_invoke(struct tee_context *ctx,
>>  				 struct tee_ioctl_object_invoke_arg *arg,
>>  				 struct tee_param *params)
>>  {
>> -	struct qcomtee_object_invoke_ctx *oic __free(kfree) = NULL;
>>  	struct qcomtee_context_data *ctxdata = ctx->data;
>> -	struct qcomtee_arg *u __free(kfree) = NULL;
>>  	struct qcomtee_object *object;
>>  	int i, ret, result;
>>  
>> @@ -412,12 +410,14 @@ static int qcomtee_object_invoke(struct tee_context *ctx,
>>  	}
>>  
>>  	/* Otherwise, invoke a QTEE object: */
>> -	oic = qcomtee_object_invoke_ctx_alloc(ctx);
>> +	struct qcomtee_object_invoke_ctx *oic __free(kfree) =
>> +		qcomtee_object_invoke_ctx_alloc(ctx);
>>  	if (!oic)
>>  		return -ENOMEM;
>>  
>>  	/* +1 for ending QCOMTEE_ARG_TYPE_INV. */
>> -	u = kcalloc(arg->num_params + 1, sizeof(*u), GFP_KERNEL);
>> +	struct qcomtee_arg *u __free(kfree) = kcalloc(arg->num_params + 1, sizeof(*u),
>> +						      GFP_KERNEL);
> 
> ..this makes the code less readable with variable declarations floating

Which is intentional.

> within the function. I would rather favor to not use the cleanup.h construct
> but use explicit kfree() invocations instead like it's done in all other
> allocations in the TEE subsystem.

Sure, fair. I just don't get why introducing cleanup.h without actually
accepting its explicitly documented style...


Best regards,
Krzysztof