Re: [PATCH] input: psmouse: Add unlock mutex before to exit psmouse_attr_set_protocol
From: Dmitry Torokhov
Date: Tue Oct 01 2024 - 09:09:53 EST
Hi Alessandro,
On Tue, Oct 01, 2024 at 01:08:38PM +0200, Alessandro Zanni wrote:
> In error handling code for "no such device" or memory already used,
> release the mutex before to return.
>
> Found with Coccinelle static analisys tool,
> script: https://coccinelle.gitlabpages.inria.fr/website/rules/mut.cocci
>
> Signed-off-by: Alessandro Zanni <alessandro.zanni87@xxxxxxxxx>
> ---
> drivers/input/mouse/psmouse-base.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/input/mouse/psmouse-base.c b/drivers/input/mouse/psmouse-base.c
> index 5a4defe9cf32..cb3a125d8d7c 100644
> --- a/drivers/input/mouse/psmouse-base.c
> +++ b/drivers/input/mouse/psmouse-base.c
> @@ -1930,11 +1930,13 @@ static ssize_t psmouse_attr_set_protocol(struct psmouse *psmouse, void *data, co
>
> if (serio->drv != &psmouse_drv) {
> input_free_device(new_dev);
> + mutex_unlock(&psmouse_mutex);
I am sorry, bit this makes absolutely no sense. This mutex is taken
(and then released) in psmouse_attr_set_helper() wrapper.
psmouse_attr_set_protocol() momentarily drops and then reacquires it,
but it should not release it either failure or success parts.
Thanks.
--
Dmitry