usb: typec: tcpm: kzalloc + kcalloc to kzalloc_flex

[PATCH] usb: typec: tcpm: kzalloc + kcalloc to kzalloc_flex

Posted by Rosen Penev 1 month ago

Simplifies allocation and allows using __counted_by for extra runtime
analysis.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 drivers/usb/typec/tcpm/tcpm.c | 19 +++++--------------
 1 file changed, 5 insertions(+), 14 deletions(-)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 1d2f3af034c5..272f9187b12d 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -605,9 +605,9 @@ struct altmode_vdm_event {
 	struct kthread_work work;
 	struct tcpm_port *port;
 	u32 header;
-	u32 *data;
 	int cnt;
 	enum tcpm_transmit_type tx_sop_type;
+	u32 data[] __counted_by(cnt);
 };
 
 static const char * const pd_rev[] = {
@@ -1653,7 +1653,6 @@ static void tcpm_queue_vdm_work(struct kthread_work *work)
 	tcpm_queue_vdm(port, event->header, event->data, event->cnt, event->tx_sop_type);
 
 port_unlock:
-	kfree(event->data);
 	kfree(event);
 	mutex_unlock(&port->lock);
 }
@@ -1662,35 +1661,27 @@ static int tcpm_queue_vdm_unlocked(struct tcpm_port *port, const u32 header,
 				   const u32 *data, int cnt, enum tcpm_transmit_type tx_sop_type)
 {
 	struct altmode_vdm_event *event;
-	u32 *data_cpy;
 	int ret = -ENOMEM;
 
-	event = kzalloc_obj(*event);
+	event = kzalloc_flex(*event, data, cnt);
 	if (!event)
 		goto err_event;
 
-	data_cpy = kcalloc(cnt, sizeof(u32), GFP_KERNEL);
-	if (!data_cpy)
-		goto err_data;
-
 	kthread_init_work(&event->work, tcpm_queue_vdm_work);
+	event->cnt = cnt;
 	event->port = port;
 	event->header = header;
-	memcpy(data_cpy, data, sizeof(u32) * cnt);
-	event->data = data_cpy;
-	event->cnt = cnt;
+	memcpy(event->data, data, sizeof(u32) * cnt);
 	event->tx_sop_type = tx_sop_type;
 
 	ret = kthread_queue_work(port->wq, &event->work);
 	if (!ret) {
 		ret = -EBUSY;
-		goto err_queue;
+		goto err_data;
 	}
 
 	return 0;
 
-err_queue:
-	kfree(data_cpy);
 err_data:
 	kfree(event);
 err_event:
-- 
2.53.0

Re: [PATCH] usb: typec: tcpm: kzalloc + kcalloc to kzalloc_flex

Posted by Gustavo A. R. Silva 1 month ago


On 3/6/26 12:16, Rosen Penev wrote:
> Simplifies allocation and allows using __counted_by for extra runtime
> analysis.

Are you finding these with Coccinelle or any other tool?

> 
> Signed-off-by: Rosen Penev <rosenp@gmail.com>

Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Thanks
-Gustavo

> ---
>   drivers/usb/typec/tcpm/tcpm.c | 19 +++++--------------
>   1 file changed, 5 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> index 1d2f3af034c5..272f9187b12d 100644
> --- a/drivers/usb/typec/tcpm/tcpm.c
> +++ b/drivers/usb/typec/tcpm/tcpm.c
> @@ -605,9 +605,9 @@ struct altmode_vdm_event {
>   	struct kthread_work work;
>   	struct tcpm_port *port;
>   	u32 header;
> -	u32 *data;
>   	int cnt;
>   	enum tcpm_transmit_type tx_sop_type;
> +	u32 data[] __counted_by(cnt);
>   };
>   
>   static const char * const pd_rev[] = {
> @@ -1653,7 +1653,6 @@ static void tcpm_queue_vdm_work(struct kthread_work *work)
>   	tcpm_queue_vdm(port, event->header, event->data, event->cnt, event->tx_sop_type);
>   
>   port_unlock:
> -	kfree(event->data);
>   	kfree(event);
>   	mutex_unlock(&port->lock);
>   }
> @@ -1662,35 +1661,27 @@ static int tcpm_queue_vdm_unlocked(struct tcpm_port *port, const u32 header,
>   				   const u32 *data, int cnt, enum tcpm_transmit_type tx_sop_type)
>   {
>   	struct altmode_vdm_event *event;
> -	u32 *data_cpy;
>   	int ret = -ENOMEM;
>   
> -	event = kzalloc_obj(*event);
> +	event = kzalloc_flex(*event, data, cnt);
>   	if (!event)
>   		goto err_event;
>   
> -	data_cpy = kcalloc(cnt, sizeof(u32), GFP_KERNEL);
> -	if (!data_cpy)
> -		goto err_data;
> -
>   	kthread_init_work(&event->work, tcpm_queue_vdm_work);
> +	event->cnt = cnt;
>   	event->port = port;
>   	event->header = header;
> -	memcpy(data_cpy, data, sizeof(u32) * cnt);
> -	event->data = data_cpy;
> -	event->cnt = cnt;
> +	memcpy(event->data, data, sizeof(u32) * cnt);
>   	event->tx_sop_type = tx_sop_type;
>   
>   	ret = kthread_queue_work(port->wq, &event->work);
>   	if (!ret) {
>   		ret = -EBUSY;
> -		goto err_queue;
> +		goto err_data;
>   	}
>   
>   	return 0;
>   
> -err_queue:
> -	kfree(data_cpy);
>   err_data:
>   	kfree(event);
>   err_event:

Re: [PATCH] usb: typec: tcpm: kzalloc + kcalloc to kzalloc_flex

Posted by Rosen Penev 1 month ago

On Fri, Mar 6, 2026 at 10:54 AM Gustavo A. R. Silva
<gustavo@embeddedor.com> wrote:
>
>
>
> On 3/6/26 12:16, Rosen Penev wrote:
> > Simplifies allocation and allows using __counted_by for extra runtime
> > analysis.
>
> Are you finding these with Coccinelle or any other tool?
git grep -B 10 zalloc_objs\( | grep zalloc\(
git grep -B 10 calloc\( | grep zalloc\(

And seeing if it's something that can easily be dealt with. The
__counted_by thing is usually clear in _probe if it's correct.
>
> >
> > Signed-off-by: Rosen Penev <rosenp@gmail.com>
>
> Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
>
> Thanks
> -Gustavo
>
> > ---
> >   drivers/usb/typec/tcpm/tcpm.c | 19 +++++--------------
> >   1 file changed, 5 insertions(+), 14 deletions(-)
> >
> > diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> > index 1d2f3af034c5..272f9187b12d 100644
> > --- a/drivers/usb/typec/tcpm/tcpm.c
> > +++ b/drivers/usb/typec/tcpm/tcpm.c
> > @@ -605,9 +605,9 @@ struct altmode_vdm_event {
> >       struct kthread_work work;
> >       struct tcpm_port *port;
> >       u32 header;
> > -     u32 *data;
> >       int cnt;
> >       enum tcpm_transmit_type tx_sop_type;
> > +     u32 data[] __counted_by(cnt);
> >   };
> >
> >   static const char * const pd_rev[] = {
> > @@ -1653,7 +1653,6 @@ static void tcpm_queue_vdm_work(struct kthread_work *work)
> >       tcpm_queue_vdm(port, event->header, event->data, event->cnt, event->tx_sop_type);
> >
> >   port_unlock:
> > -     kfree(event->data);
> >       kfree(event);
> >       mutex_unlock(&port->lock);
> >   }
> > @@ -1662,35 +1661,27 @@ static int tcpm_queue_vdm_unlocked(struct tcpm_port *port, const u32 header,
> >                                  const u32 *data, int cnt, enum tcpm_transmit_type tx_sop_type)
> >   {
> >       struct altmode_vdm_event *event;
> > -     u32 *data_cpy;
> >       int ret = -ENOMEM;
> >
> > -     event = kzalloc_obj(*event);
> > +     event = kzalloc_flex(*event, data, cnt);
> >       if (!event)
> >               goto err_event;
> >
> > -     data_cpy = kcalloc(cnt, sizeof(u32), GFP_KERNEL);
> > -     if (!data_cpy)
> > -             goto err_data;
> > -
> >       kthread_init_work(&event->work, tcpm_queue_vdm_work);
> > +     event->cnt = cnt;
> >       event->port = port;
> >       event->header = header;
> > -     memcpy(data_cpy, data, sizeof(u32) * cnt);
> > -     event->data = data_cpy;
> > -     event->cnt = cnt;
> > +     memcpy(event->data, data, sizeof(u32) * cnt);
> >       event->tx_sop_type = tx_sop_type;
> >
> >       ret = kthread_queue_work(port->wq, &event->work);
> >       if (!ret) {
> >               ret = -EBUSY;
> > -             goto err_queue;
> > +             goto err_data;
> >       }
> >
> >       return 0;
> >
> > -err_queue:
> > -     kfree(data_cpy);
> >   err_data:
> >       kfree(event);
> >   err_event:
>