linux-kernel - Re: [PATCH] usb: cdnsp: remove not used variables

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <Yd1KBiRB/ByZ2Kx1@kroah.com>
Date:   Tue, 11 Jan 2022 10:12:38 +0100
From:   Greg KH <gregkh@...uxfoundation.org>
To:     Pawel Laszczak <pawell@...ence.com>
Cc:     peter.chen@...nel.org, linux-usb@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] usb: cdnsp: remove not used variables

On Tue, Jan 11, 2022 at 09:59:34AM +0100, Pawel Laszczak wrote:
> From: Pawel Laszczak <pawell@...ence.com>
> 
> Patch removes not used variables:
>  - ret from cdnsp_decode_trb function
>  - temp_64 from cdnsp_run function
> 
> Reported-by: kernel test robot <lkp@...el.com>
> Signed-off-by: Pawel Laszczak <pawell@...ence.com>
> ---
>  drivers/usb/cdns3/cdnsp-debug.h  | 287 +++++++++++++++----------------
>  drivers/usb/cdns3/cdnsp-gadget.c |   3 -
>  2 files changed, 138 insertions(+), 152 deletions(-)
> 
> diff --git a/drivers/usb/cdns3/cdnsp-debug.h b/drivers/usb/cdns3/cdnsp-debug.h
> index a8776df2d4e0..29f3cf7ddbaa 100644
> --- a/drivers/usb/cdns3/cdnsp-debug.h
> +++ b/drivers/usb/cdns3/cdnsp-debug.h
> @@ -182,206 +182,195 @@ static inline const char *cdnsp_decode_trb(char *str, size_t size, u32 field0,
>  	int ep_id = TRB_TO_EP_INDEX(field3) - 1;
>  	int type = TRB_FIELD_TO_TYPE(field3);
>  	unsigned int ep_num;
> -	int ret = 0;

Please fix this function to properly handle the ret value, as I think it
should be checked, right?

> --- a/drivers/usb/cdns3/cdnsp-gadget.c
> +++ b/drivers/usb/cdns3/cdnsp-gadget.c
> @@ -1243,12 +1243,9 @@ static int cdnsp_run(struct cdnsp_device *pdev,
>  		     enum usb_device_speed speed)
>  {
>  	u32 fs_speed = 0;
> -	u64 temp_64;
>  	u32 temp;
>  	int ret;
>  
> -	temp_64 = cdnsp_read_64(&pdev->ir_set->erst_dequeue);
> -	temp_64 &= ~ERST_PTR_MASK;
>  	temp = readl(&pdev->ir_set->irq_control);
>  	temp &= ~IMOD_INTERVAL_MASK;
>  	temp |= ((IMOD_DEFAULT_INTERVAL / 250) & IMOD_INTERVAL_MASK);
> -- 
> 2.25.1
> 

A separate patch for this.

Also, are you SURE this is ok to do?  Did you check it on the hardware
that a read is not needed here for it to work properly?

This type of "warning" is horrible for dealing with hardware devices,
always treat it as incorrect unless you can prove otherwise.

thanks,

greg k-h