Linux-Doc Archive mirror
 help / color / mirror / Atom feed
From: Simon Horman <horms@kernel.org>
To: Kory Maincent <kory.maincent@bootlin.com>
Cc: Florian Fainelli <florian.fainelli@broadcom.com>,
	Broadcom internal kernel review list
	<bcm-kernel-feedback-list@broadcom.com>,
	Andrew Lunn <andrew@lunn.ch>,
	Heiner Kallweit <hkallweit1@gmail.com>,
	Russell King <linux@armlinux.org.uk>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Richard Cochran <richardcochran@gmail.com>,
	Radu Pirea <radu-nicolae.pirea@oss.nxp.com>,
	Jay Vosburgh <j.vosburgh@gmail.com>,
	Andy Gospodarek <andy@greyhouse.net>,
	Nicolas Ferre <nicolas.ferre@microchip.com>,
	Claudiu Beznea <claudiu.beznea@tuxon.dev>,
	Willem de Bruijn <willemdebruijn.kernel@gmail.com>,
	Jonathan Corbet <corbet@lwn.net>,
	Horatiu Vultur <horatiu.vultur@microchip.com>,
	UNGLinuxDriver@microchip.com,
	Vladimir Oltean <vladimir.oltean@nxp.com>,
	Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-doc@vger.kernel.org,
	Maxime Chevallier <maxime.chevallier@bootlin.com>,
	Rahul Rameshbabu <rrameshbabu@nvidia.com>
Subject: Re: [PATCH net-next v12 12/13] net: ethtool: tsinfo: Add support for hwtstamp provider and get/set hwtstamp config
Date: Sat, 4 May 2024 11:33:05 +0100	[thread overview]
Message-ID: <20240504103305.GD3167983@kernel.org> (raw)
In-Reply-To: <20240430-feature_ptp_netnext-v12-12-2c5f24b6a914@bootlin.com>

On Tue, Apr 30, 2024 at 05:49:55PM +0200, Kory Maincent wrote:
> Enhance 'get' command to retrieve tsinfo of hwtstamp providers within a
> network topology and read current hwtstamp configuration.
> 
> Introduce support for ETHTOOL_MSG_TSINFO_SET ethtool netlink socket to
> configure hwtstamp of a PHC provider. Note that simultaneous hwtstamp
> isn't supported; configuring a new one disables the previous setting.
> 
> Also, add support for a specific dump command to retrieve all hwtstamp
> providers within the network topology, with added functionality for
> filtered dump to target a single interface.
> 
> Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>

...

> diff --git a/net/core/dev_ioctl.c b/net/core/dev_ioctl.c
> index acb0cadb7512..ec6dd81a5add 100644
> --- a/net/core/dev_ioctl.c
> +++ b/net/core/dev_ioctl.c
> @@ -270,10 +270,13 @@ static int dev_eth_ioctl(struct net_device *dev,
>  int dev_get_hwtstamp_phylib(struct net_device *dev,
>  			    struct kernel_hwtstamp_config *cfg)
>  {
> -	if (dev->hwtstamp) {
> -		struct ptp_clock *ptp = dev->hwtstamp->ptp;
> +	struct hwtstamp_provider *hwtstamp;
>  
> -		cfg->qualifier = dev->hwtstamp->qualifier;
> +	hwtstamp = rtnl_dereference(dev->hwtstamp);
> +	if (hwtstamp) {
> +		struct ptp_clock *ptp = hwtstamp->ptp;
> +
> +		cfg->qualifier = hwtstamp->qualifier;
>  		if (ptp_clock_from_phylib(ptp))
>  			return phy_hwtstamp_get(ptp_clock_phydev(ptp), cfg);
>  
> @@ -340,13 +343,15 @@ int dev_set_hwtstamp_phylib(struct net_device *dev,
>  {
>  	const struct net_device_ops *ops = dev->netdev_ops;
>  	struct kernel_hwtstamp_config old_cfg = {};
> +	struct hwtstamp_provider *hwtstamp;
>  	struct phy_device *phydev;
>  	bool changed = false;
>  	bool phy_ts;
>  	int err;
>  
> -	if (dev->hwtstamp) {
> -		struct ptp_clock *ptp = dev->hwtstamp->ptp;
> +	hwtstamp = rtnl_dereference(dev->hwtstamp);
> +	if (hwtstamp) {
> +		struct ptp_clock *ptp = hwtstamp->ptp;
>  
>  		if (ptp_clock_from_phylib(ptp)) {
>  			phy_ts = true;

Hi Kory,

A few lines beyond this hunk, within the "if (hwtstamp)" block,
is the following:

		cfg->qualifier = dev->hwtstamp->qualifier;

Now that dev->hwtstamp is managed using RCU, I don't think it is correct
to dereference it directly like this. Rather, the hwtstamp local variable,
which has rcu_dereference'd this pointer should be used:

		 cfg->qualifier = hwtstamp->qualifier;

Flagged by Sparse.

...

> diff --git a/net/ethtool/tsinfo.c b/net/ethtool/tsinfo.c

...

> +static int ethnl_tsinfo_dump_one_dev(struct sk_buff *skb, struct net_device *dev,
> +				     struct netlink_callback *cb)
> +{
> +	struct ethnl_tsinfo_dump_ctx *ctx = (void *)cb->ctx;
> +	struct ptp_clock *ptp;
> +	int ret;
> +
> +	netdev_for_each_ptp_clock_start(dev, ctx->pos_phcindex, ptp,
> +					ctx->pos_phcindex) {
> +		ret = ethnl_tsinfo_dump_one_ptp(skb, dev, cb, ptp);
> +		if (ret < 0 && ret != -EOPNOTSUPP)
> +			break;
> +		ctx->pos_phcqualifier = HWTSTAMP_PROVIDER_QUALIFIER_PRECISE;
> +	}
> +
> +	return ret;

Perhaps it is not possible, but if the loop iterates zero times then
ret will be used uninitialised here.

Flagged by Smatch.

> +}

...

  reply	other threads:[~2024-05-04 10:34 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-30 15:49 [PATCH net-next v12 00/13] net: Make timestamping selectable Kory Maincent
2024-04-30 15:49 ` [PATCH net-next v12 01/13] net_tstamp: Add TIMESTAMPING SOFTWARE and HARDWARE mask Kory Maincent
2024-04-30 15:49 ` [PATCH net-next v12 02/13] net: Move dev_set_hwtstamp_phylib to net/core/dev.h Kory Maincent
2024-04-30 15:49 ` [PATCH net-next v12 03/13] net: Make dev_get_hwtstamp_phylib accessible Kory Maincent
2024-04-30 15:49 ` [PATCH net-next v12 04/13] net: Make net_hwtstamp_validate accessible Kory Maincent
2024-04-30 15:49 ` [PATCH net-next v12 05/13] net: Change the API of PHY default timestamp to MAC Kory Maincent
2024-04-30 15:49 ` [PATCH net-next v12 06/13] net: net_tstamp: Add unspec field to hwtstamp_source enumeration Kory Maincent
2024-04-30 15:49 ` [PATCH net-next v12 07/13] net: Add struct kernel_ethtool_ts_info Kory Maincent
2024-04-30 15:49 ` [PATCH net-next v12 08/13] ptp: Add phc source and helpers to register specific PTP clock or get information Kory Maincent
2024-04-30 15:49 ` [PATCH net-next v12 09/13] net: Add the possibility to support a selected hwtstamp in netdevice Kory Maincent
2024-05-02  2:10   ` Jakub Kicinski
2024-04-30 15:49 ` [PATCH net-next v12 10/13] net: netdevsim: ptp_mock: Convert to netdev_ptp_clock_register Kory Maincent
2024-04-30 15:49 ` [PATCH net-next v12 11/13] net: macb: " Kory Maincent
2024-04-30 15:49 ` [PATCH net-next v12 12/13] net: ethtool: tsinfo: Add support for hwtstamp provider and get/set hwtstamp config Kory Maincent
2024-05-04 10:33   ` Simon Horman [this message]
2024-05-17 15:12     ` Kory Maincent
2024-04-30 15:49 ` [PATCH net-next v12 13/13] netlink: specs: tsinfo: Enhance netlink attributes and add a set command Kory Maincent
2024-05-02  2:14   ` Jakub Kicinski
2024-05-17 15:58     ` Kory Maincent
2024-05-02  2:09 ` [PATCH net-next v12 00/13] net: Make timestamping selectable Jakub Kicinski
2024-05-17 15:13   ` Kory Maincent

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20240504103305.GD3167983@kernel.org \
    --to=horms@kernel.org \
    --cc=UNGLinuxDriver@microchip.com \
    --cc=andrew@lunn.ch \
    --cc=andy@greyhouse.net \
    --cc=bcm-kernel-feedback-list@broadcom.com \
    --cc=claudiu.beznea@tuxon.dev \
    --cc=corbet@lwn.net \
    --cc=davem@davemloft.net \
    --cc=edumazet@google.com \
    --cc=florian.fainelli@broadcom.com \
    --cc=hkallweit1@gmail.com \
    --cc=horatiu.vultur@microchip.com \
    --cc=j.vosburgh@gmail.com \
    --cc=kory.maincent@bootlin.com \
    --cc=kuba@kernel.org \
    --cc=linux-doc@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux@armlinux.org.uk \
    --cc=maxime.chevallier@bootlin.com \
    --cc=netdev@vger.kernel.org \
    --cc=nicolas.ferre@microchip.com \
    --cc=pabeni@redhat.com \
    --cc=radu-nicolae.pirea@oss.nxp.com \
    --cc=richardcochran@gmail.com \
    --cc=rrameshbabu@nvidia.com \
    --cc=thomas.petazzoni@bootlin.com \
    --cc=vladimir.oltean@nxp.com \
    --cc=willemdebruijn.kernel@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).