Re: [PATCH] HID: hidraw: enforce minors_lock locking via lockdep

[Benjamin Tissoires]

On Thu, Nov 8, 2018 at 10:38 PM Jiri Kosina <jikos@xxxxxxxxxx> wrote:
>
> From: Jiri Kosina <jkosina@xxxxxxx>
>
> lockdep is much more powerful enforcing the locking rules than code comments,
> so let's switch to it.
>
> Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
> ---

Looks good to me.

Reviewed-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>

Cheers,
Benjamin

>  drivers/hid/hidraw.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c
> index 4a44e48e08b2..cf2af069204f 100644
> --- a/drivers/hid/hidraw.c
> +++ b/drivers/hid/hidraw.c
> @@ -107,8 +107,6 @@ static ssize_t hidraw_read(struct file *file, char __user *buffer, size_t count,
>
>  /*
>   * The first byte of the report buffer is expected to be a report number.
> - *
> - * This function is to be called with the minors_lock mutex held.
>   */
>  static ssize_t hidraw_send_report(struct file *file, const char __user *buffer, size_t count, unsigned char report_type)
>  {
> @@ -117,6 +115,8 @@ static ssize_t hidraw_send_report(struct file *file, const char __user *buffer,
>         __u8 *buf;
>         int ret = 0;
>
> +       lockdep_assert_held(&minors_lock);
> +
>         if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
>                 ret = -ENODEV;
>                 goto out;
> @@ -192,6 +192,8 @@ static ssize_t hidraw_get_report(struct file *file, char __user *buffer, size_t
>         int ret = 0, len;
>         unsigned char report_number;
>
> +       lockdep_assert_held(&minors_lock);
> +
>         if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
>                 ret = -ENODEV;
>                 goto out;
> --
> Jiri Kosina
> SUSE Labs
>