lkml.org 
[lkml]   [2019]   [Mar]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH v2 3/6] leds: netdev trigger: move newline handling back to device_name_store
    On Thu 2019-03-14 15:06:16, Rasmus Villemoes wrote:
    > Currently, setting device_name to a 15-character name requires
    > avoiding a trailing newline (e.g. by using 'echo -n' or 'printf'),
    > which is inconsistent and potentially surprising. Instead of
    > potentially including a newline in the copy and then overwriting it,
    > move the newline detection logic to the sysfs handler itself, and
    > handle it by passing a smaller buffer size to
    > netdev_trig_set_device().
    >
    > This also makes netdev_trig_set_device() a better fit for a future
    > user, which will not need the newline truncation logic.
    >
    > We still have to tell userspace we consumed all the bytes it gave us,
    > so we have to stash the original value of size.
    >
    > Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>

    Acked-by: Pavel Machek <pavel@ucw.cz>

    > ---
    > drivers/leds/trigger/ledtrig-netdev.c | 8 +++++---
    > 1 file changed, 5 insertions(+), 3 deletions(-)
    >
    > diff --git a/drivers/leds/trigger/ledtrig-netdev.c b/drivers/leds/trigger/ledtrig-netdev.c
    > index 21605033e322..c35439291424 100644
    > --- a/drivers/leds/trigger/ledtrig-netdev.c
    > +++ b/drivers/leds/trigger/ledtrig-netdev.c
    > @@ -114,8 +114,6 @@ static void netdev_trig_set_device(struct led_netdev_data *trigger_data,
    >
    > memcpy(trigger_data->device_name, buf, size);
    > trigger_data->device_name[size] = 0;
    > - if (size > 0 && trigger_data->device_name[size - 1] == '\n')
    > - trigger_data->device_name[size - 1] = 0;
    >
    > if (trigger_data->device_name[0] != 0)
    > trigger_data->net_dev =
    > @@ -134,7 +132,11 @@ static ssize_t device_name_store(struct device *dev,
    > size_t size)
    > {
    > struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
    > + size_t orig_size = size;
    >
    > + /* Ignore trailing newline */
    > + if (size > 0 && buf[size - 1] == '\n')
    > + size--;
    > if (size >= IFNAMSIZ)
    > return -EINVAL;
    >
    > @@ -147,7 +149,7 @@ static ssize_t device_name_store(struct device *dev,
    > set_baseline_state(trigger_data);
    > spin_unlock_bh(&trigger_data->lock);
    >
    > - return size;
    > + return orig_size;
    > }
    >
    > static DEVICE_ATTR_RW(device_name);

    --
    (english) http://www.livejournal.com/~pavelmachek
    (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
    [unhandled content-type:application/pgp-signature]
    \
     
     \ /
      Last update: 2019-03-18 12:26    [W:4.296 / U:0.144 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site