linux-kernel - Re: [PATCH v2 2/2] net: dsa: qca: ar9331: export stats64

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: <f80ea68e-9515-0d4e-b2e3-1ae9e8296cd0@pengutronix.de>
Date:   Wed, 2 Dec 2020 13:47:17 +0100
From:   Marc Kleine-Budde <mkl@...gutronix.de>
To:     Oleksij Rempel <o.rempel@...gutronix.de>
Cc:     Andrew Lunn <andrew@...n.ch>,
        Florian Fainelli <f.fainelli@...il.com>,
        linux-mips@...r.kernel.org, Russell King <linux@...linux.org.uk>,
        "David S. Miller" <davem@...emloft.net>,
        Pengutronix Kernel Team <kernel@...gutronix.de>,
        netdev@...r.kernel.org, Jakub Kicinski <kuba@...nel.org>,
        Vladimir Oltean <olteanv@...il.com>,
        Vivien Didelot <vivien.didelot@...il.com>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 2/2] net: dsa: qca: ar9331: export stats64

On 12/2/20 1:43 PM, Oleksij Rempel wrote:
>>> +struct ar9331_sw_priv;
>>> +struct ar9331_sw_port {
>>> +	int idx;
>>> +	struct ar9331_sw_priv *priv;
>>> +	struct delayed_work mib_read;
>>> +	struct ar9331_sw_stats stats;
>>> +	struct mutex lock;		/* stats access */
>>
>> What does the lock protect? It's only used a single time.
> 
> The ar9331_read_stats() function is called from two different contests:
> from worker over ar9331_do_stats_poll() and from user space over
> ar9331_get_stats64().
> 
> The mutex lock should prevent a race in the read modify write operations
> for in the stats->*

Makes sense!

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 |



Download attachment "signature.asc" of type "application/pgp-signature" (489 bytes)