| 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
| ||
|
Message-ID: <20210301103024.GA31897@duo.ucw.cz>
Date: Mon, 1 Mar 2021 11:30:24 +0100
From: Pavel Machek <pavel@....cz>
To: Marek Behún <kabel@...nel.org>
Cc: netdev@...r.kernel.org, linux-leds@...r.kernel.org,
Dan Murphy <dmurphy@...com>,
Russell King <linux@...linux.org.uk>,
Andrew Lunn <andrew@...n.ch>,
Matthias Schiffer <matthias.schiffer@...tq-group.com>,
"David S. Miller" <davem@...emloft.net>,
Jacek Anaszewski <jacek.anaszewski@...il.com>,
Ben Whitten <ben.whitten@...il.com>
Subject: Re: [PATCH RFC leds + net-next 2/7] leds: trigger: netdev: simplify
the driver by using bit field members
On Fri 2020-10-30 12:44:30, Marek Behún wrote:
> Use bit fields members in struct led_netdev_data instead of one mode
> member and set_bit/clear_bit/test_bit functions. These functions are
> suitable for longer or variable length bit arrays.
They also provide atomicity guarantees. If you can explain why this is
safe, we can do this, but it needs _way_ better changelog.
Pavel
> Signed-off-by: Marek Behún <kabel@...nel.org>
> ---
> drivers/leds/trigger/ledtrig-netdev.c | 69 ++++++++++++---------------
> 1 file changed, 30 insertions(+), 39 deletions(-)
>
> diff --git a/drivers/leds/trigger/ledtrig-netdev.c b/drivers/leds/trigger/ledtrig-netdev.c
> index 4f6b73e3b491..8f013b6df4fa 100644
> --- a/drivers/leds/trigger/ledtrig-netdev.c
> +++ b/drivers/leds/trigger/ledtrig-netdev.c
> @@ -49,11 +49,11 @@ struct led_netdev_data {
> atomic_t interval;
> unsigned int last_activity;
>
> - unsigned long mode;
> -#define NETDEV_LED_LINK 0
> -#define NETDEV_LED_TX 1
> -#define NETDEV_LED_RX 2
> -#define NETDEV_LED_MODE_LINKUP 3
> + unsigned link:1;
> + unsigned tx:1;
> + unsigned rx:1;
> +
> + unsigned linkup:1;
> };
>
> enum netdev_led_attr {
> @@ -73,10 +73,10 @@ static void set_baseline_state(struct led_netdev_data *trigger_data)
> if (!led_cdev->blink_brightness)
> led_cdev->blink_brightness = led_cdev->max_brightness;
>
> - if (!test_bit(NETDEV_LED_MODE_LINKUP, &trigger_data->mode))
> + if (!trigger_data->linkup)
> led_set_brightness(led_cdev, LED_OFF);
> else {
> - if (test_bit(NETDEV_LED_LINK, &trigger_data->mode))
> + if (trigger_data->link)
> led_set_brightness(led_cdev,
> led_cdev->blink_brightness);
> else
> @@ -85,8 +85,7 @@ static void set_baseline_state(struct led_netdev_data *trigger_data)
> /* If we are looking for RX/TX start periodically
> * checking stats
> */
> - if (test_bit(NETDEV_LED_TX, &trigger_data->mode) ||
> - test_bit(NETDEV_LED_RX, &trigger_data->mode))
> + if (trigger_data->tx || trigger_data->rx)
> schedule_delayed_work(&trigger_data->work, 0);
> }
> }
> @@ -131,10 +130,10 @@ static ssize_t device_name_store(struct device *dev,
> trigger_data->net_dev =
> dev_get_by_name(&init_net, trigger_data->device_name);
>
> - clear_bit(NETDEV_LED_MODE_LINKUP, &trigger_data->mode);
> + trigger_data->linkup = 0;
> if (trigger_data->net_dev != NULL)
> if (netif_carrier_ok(trigger_data->net_dev))
> - set_bit(NETDEV_LED_MODE_LINKUP, &trigger_data->mode);
> + trigger_data->linkup = 1;
>
> trigger_data->last_activity = 0;
>
> @@ -150,23 +149,24 @@ static ssize_t netdev_led_attr_show(struct device *dev, char *buf,
> enum netdev_led_attr attr)
> {
> struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
> - int bit;
> + int val;
>
> switch (attr) {
> case NETDEV_ATTR_LINK:
> - bit = NETDEV_LED_LINK;
> + val = trigger_data->link;
> break;
> case NETDEV_ATTR_TX:
> - bit = NETDEV_LED_TX;
> + val = trigger_data->tx;
> break;
> case NETDEV_ATTR_RX:
> - bit = NETDEV_LED_RX;
> + val = trigger_data->rx;
> break;
> default:
> - return -EINVAL;
> + /* unreachable */
> + break;
> }
>
> - return sprintf(buf, "%u\n", test_bit(bit, &trigger_data->mode));
> + return sprintf(buf, "%u\n", val);
> }
>
> static ssize_t netdev_led_attr_store(struct device *dev, const char *buf,
> @@ -175,33 +175,28 @@ static ssize_t netdev_led_attr_store(struct device *dev, const char *buf,
> struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
> unsigned long state;
> int ret;
> - int bit;
>
> ret = kstrtoul(buf, 0, &state);
> if (ret)
> return ret;
>
> + cancel_delayed_work_sync(&trigger_data->work);
> +
> switch (attr) {
> case NETDEV_ATTR_LINK:
> - bit = NETDEV_LED_LINK;
> + trigger_data->link = state;
> break;
> case NETDEV_ATTR_TX:
> - bit = NETDEV_LED_TX;
> + trigger_data->tx = state;
> break;
> case NETDEV_ATTR_RX:
> - bit = NETDEV_LED_RX;
> + trigger_data->rx = state;
> break;
> default:
> - return -EINVAL;
> + /* unreachable */
> + break;
> }
>
> - cancel_delayed_work_sync(&trigger_data->work);
> -
> - if (state)
> - set_bit(bit, &trigger_data->mode);
> - else
> - clear_bit(bit, &trigger_data->mode);
> -
> set_baseline_state(trigger_data);
>
> return size;
> @@ -315,7 +310,7 @@ static int netdev_trig_notify(struct notifier_block *nb,
>
> spin_lock_bh(&trigger_data->lock);
>
> - clear_bit(NETDEV_LED_MODE_LINKUP, &trigger_data->mode);
> + trigger_data->linkup = 0;
> switch (evt) {
> case NETDEV_CHANGENAME:
> case NETDEV_REGISTER:
> @@ -331,7 +326,7 @@ static int netdev_trig_notify(struct notifier_block *nb,
> case NETDEV_UP:
> case NETDEV_CHANGE:
> if (netif_carrier_ok(dev))
> - set_bit(NETDEV_LED_MODE_LINKUP, &trigger_data->mode);
> + trigger_data->linkup = 1;
> break;
> }
>
> @@ -360,21 +355,17 @@ static void netdev_trig_work(struct work_struct *work)
> }
>
> /* If we are not looking for RX/TX then return */
> - if (!test_bit(NETDEV_LED_TX, &trigger_data->mode) &&
> - !test_bit(NETDEV_LED_RX, &trigger_data->mode))
> + if (!trigger_data->tx && !trigger_data->rx)
> return;
>
> dev_stats = dev_get_stats(trigger_data->net_dev, &temp);
> - new_activity =
> - (test_bit(NETDEV_LED_TX, &trigger_data->mode) ?
> - dev_stats->tx_packets : 0) +
> - (test_bit(NETDEV_LED_RX, &trigger_data->mode) ?
> - dev_stats->rx_packets : 0);
> + new_activity = (trigger_data->tx ? dev_stats->tx_packets : 0) +
> + (trigger_data->rx ? dev_stats->rx_packets : 0);
>
> if (trigger_data->last_activity != new_activity) {
> led_stop_software_blink(trigger_data->led_cdev);
>
> - invert = test_bit(NETDEV_LED_LINK, &trigger_data->mode);
> + invert = trigger_data->link;
> interval = jiffies_to_msecs(
> atomic_read(&trigger_data->interval));
> /* base state is ON (link present) */
> --
> 2.26.2
--
http://www.livejournal.com/~pavelmachek
Download attachment "signature.asc" of type "application/pgp-signature" (196 bytes)
Powered by blists - more mailing lists