linux-kernel - Re: [PATCH v3 5/6] can: c_can: prepare to up the message objects number

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: <1154674280.137227.1614682252245@mail1.libero.it>
Date:   Tue, 2 Mar 2021 11:50:52 +0100 (CET)
From:   Dario Binacchi <dariobin@...ero.it>
To:     Marc Kleine-Budde <mkl@...gutronix.de>
Cc:     linux-kernel@...r.kernel.org,
        Federico Vaga <federico.vaga@...il.com>,
        Alexander Stein <alexander.stein@...tec-electronic.com>,
        "David S. Miller" <davem@...emloft.net>,
        Jakub Kicinski <kuba@...nel.org>,
        Oliver Hartkopp <socketcan@...tkopp.net>,
        Vincent Mailhol <mailhol.vincent@...adoo.fr>,
        Wolfgang Grandegger <wg@...ndegger.com>,
        YueHaibing <yuehaibing@...wei.com>,
        Zhang Qilong <zhangqilong3@...wei.com>,
        linux-can@...r.kernel.org, netdev@...r.kernel.org
Subject: Re: [PATCH v3 5/6] can: c_can: prepare to up the message objects
 number

Hi Marc,

> Il 01/03/2021 20:45 Marc Kleine-Budde <mkl@...gutronix.de> ha scritto:
> 
>  
> On 01.03.2021 18:21:42, Dario Binacchi wrote:
> > > > @@ -730,7 +728,7 @@ static void c_can_do_tx(struct net_device *dev)
> > > >  	while ((idx = ffs(pend))) {
> > > >  		idx--;
> > > >  		pend &= ~(1 << idx);
> > > > -		obj = idx + C_CAN_MSG_OBJ_TX_FIRST;
> > > > +		obj = idx + priv->msg_obj_tx_first;
> > > >  		c_can_inval_tx_object(dev, IF_TX, obj);
> > > >  		can_get_echo_skb(dev, idx, NULL);
> > > >  		bytes += priv->dlc[idx];
> > > > @@ -740,7 +738,7 @@ static void c_can_do_tx(struct net_device *dev)
> > > >  	/* Clear the bits in the tx_active mask */
> > > >  	atomic_sub(clr, &priv->tx_active);
> > > >  
> > > > -	if (clr & (1 << (C_CAN_MSG_OBJ_TX_NUM - 1)))
> > > > +	if (clr & (1 << (priv->msg_obj_tx_num - 1)))
> > > 
> > > Do we need 1UL here, too?
> > 
> > Do you agree if I use the BIT macro ?
> 
> No, please use GENMASK(priv->msg_obj_tx_num, 0) here.
> 

In case of 64 message objects, msg_obj_tx_num = 32, and 1 << (priv->msg_obj_tx_num - 1) = 0x80000000. 
GENMASK(priv->msg_obj_tx_num, 0) = 0. 
BIT(priv->msg_obj_tx_num - 1) = 0x80000000.

Thanks and regards,
Dario

> regrads,
> Marc
> 
> -- 
> Pengutronix e.K.                 | Marc Kleine-Budde           |
> Embedded Linux                   | https://www.pengutronix.de  |
> Vertretung West/Dortmund         | Phone: +49-231-2826-924     |
> Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-5555 |