linux-kernel - Re: [PATCH net-next v17 13/14] net: ethtool: Add support for tsconfig command to get/set hwtstamp config

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20240926104712.6a55d263@kmaincent-XPS-13-7390>
Date: Thu, 26 Sep 2024 10:47:12 +0200
From: Kory Maincent <kory.maincent@...tlin.com>
To: Jakub Kicinski <kuba@...nel.org>
Cc: Florian Fainelli <florian.fainelli@...adcom.com>, Broadcom internal
 kernel review list <bcm-kernel-feedback-list@...adcom.com>, Andrew Lunn
 <andrew@...n.ch>, Heiner Kallweit <hkallweit1@...il.com>, Russell King
 <linux@...linux.org.uk>, "David S. Miller" <davem@...emloft.net>, Eric
 Dumazet <edumazet@...gle.com>, Paolo Abeni <pabeni@...hat.com>, Richard
 Cochran <richardcochran@...il.com>, Radu Pirea
 <radu-nicolae.pirea@....nxp.com>, Jay Vosburgh <j.vosburgh@...il.com>, Andy
 Gospodarek <andy@...yhouse.net>, Nicolas Ferre
 <nicolas.ferre@...rochip.com>, Claudiu Beznea <claudiu.beznea@...on.dev>,
 Willem de Bruijn <willemdebruijn.kernel@...il.com>, Jonathan Corbet
 <corbet@....net>, Horatiu Vultur <horatiu.vultur@...rochip.com>,
 UNGLinuxDriver@...rochip.com, Simon Horman <horms@...nel.org>, Vladimir
 Oltean <vladimir.oltean@....com>, donald.hunter@...il.com,
 danieller@...dia.com, ecree.xilinx@...il.com, Thomas Petazzoni
 <thomas.petazzoni@...tlin.com>, linux-kernel@...r.kernel.org,
 netdev@...r.kernel.org, linux-doc@...r.kernel.org, Maxime Chevallier
 <maxime.chevallier@...tlin.com>, Rahul Rameshbabu <rrameshbabu@...dia.com>,
 Willem de Bruijn <willemb@...gle.com>, Shannon Nelson
 <shannon.nelson@....com>, Alexandra Winter <wintera@...ux.ibm.com>
Subject: Re: [PATCH net-next v17 13/14] net: ethtool: Add support for
 tsconfig command to get/set hwtstamp config

Hello Jakub, 

On Mon, 15 Jul 2024 07:59:26 -0700
Jakub Kicinski <kuba@...nel.org> wrote:

Thanks for the review and sorry for the late reply.

> On Tue, 09 Jul 2024 15:53:45 +0200 Kory Maincent wrote:
> > +	/* Get the hwtstamp config from netlink */
> > +	if (tb[ETHTOOL_A_TSCONFIG_TX_TYPES]) {
> > +		ret = ethnl_parse_bitset(&req_tx_type, &mask,
> > +					 __HWTSTAMP_TX_CNT,
> > +					 tb[ETHTOOL_A_TSCONFIG_TX_TYPES],
> > +					 ts_tx_type_names, info->extack);
> > +		if (ret < 0)
> > +			goto err_clock_put;
> > +
> > +		/* Select only one tx type at a time */
> > +		if (ffs(req_tx_type) != fls(req_tx_type)) {
> > +			ret = -EINVAL;
> > +			goto err_clock_put;
> > +		}
> > +
> > +		hwtst_config.tx_type = ffs(req_tx_type) - 1;
> > +	}
> > +	if (tb[ETHTOOL_A_TSCONFIG_RX_FILTERS]) {
> > +		ret = ethnl_parse_bitset(&req_rx_filter, &mask,
> > +					 __HWTSTAMP_FILTER_CNT,
> > +					 tb[ETHTOOL_A_TSCONFIG_RX_FILTERS],
> > +					 ts_rx_filter_names, info->extack);
> > +		if (ret < 0)
> > +			goto err_clock_put;
> > +
> > +		/* Select only one rx filter at a time */
> > +		if (ffs(req_rx_filter) != fls(req_rx_filter)) {
> > +			ret = -EINVAL;
> > +			goto err_clock_put;
> > +		}
> > +
> > +		hwtst_config.rx_filter = ffs(req_rx_filter) - 1;
> > +	}
> > +	if (tb[ETHTOOL_A_TSCONFIG_HWTSTAMP_FLAGS]) {
> > +		ret = nla_get_u32(tb[ETHTOOL_A_TSCONFIG_HWTSTAMP_FLAGS]);
> > +		if (ret < 0)
> > +			goto err_clock_put;
> > +		hwtst_config.flags = ret;
> > +	}  
> 
> We should be tracking mod on these, too. Separately from the provider
> mod bit, let's not call the driver and send notification if nothing
> changed.

Ok

> > +	ret = net_hwtstamp_validate(&hwtst_config);
> > +	if (ret)
> > +		goto err_clock_put;
> > +
> > +	/* Disable current time stamping if we try to enable another one */
> > +	if (mod && (hwtst_config.tx_type || hwtst_config.rx_filter)) {
> > +		struct kernel_hwtstamp_config zero_config = {0};
> > +
> > +		ret = dev_set_hwtstamp_phylib(dev, &zero_config,
> > info->extack);
> > +		if (ret < 0)
> > +			goto err_clock_put;
> > +	}
> > +
> > +	/* Changed the selected hwtstamp source if needed */
> > +	if (mod) {
> > +		struct hwtstamp_provider *__hwtstamp;
> > +
> > +		__hwtstamp = rcu_replace_pointer_rtnl(dev->hwtstamp,
> > hwtstamp);
> > +		if (__hwtstamp)
> > +			call_rcu(&__hwtstamp->rcu_head,
> > +				 remove_hwtstamp_provider);
> > +	}
> > +
> > +	ret = dev_set_hwtstamp_phylib(dev, &hwtst_config, info->extack);
> > +	if (ret < 0)
> > +		return ret;  
> 
> We can't unwind to old state here?

Yes indeed we could unwind old state here. I will update it in next version.

> Driver can change hwtst_config right? "upgrade" the rx_filter 
> to a broader one, IIRC. Shouldn't we reply to the set command with 
> the resulting configuration, in case it changed? Basically provide 
> the same info as the notification would.

Yes, the driver does that.
Indeed that's a good idea to report the resulting configuration.
I will take a look at how I can do that.

Regards,
-- 
Köry Maincent, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com