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

[Sumit Garg <sumit.garg@kernel.org>]

On Fri, Dec 12, 2025 at 02:07:40AM +0100, Krzysztof Kozlowski wrote:
> 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...
> 

TBH, it is likely overlooked during review of the QTEE driver. Having a
builtin warning for the undesired syntax would help the reviewers here.

-Sumit