Messages in this thread | | | From | Andy Shevchenko <> | Date | Sun, 27 Sep 2020 12:00:04 +0300 | Subject | Re: [PATCH v9 07/20] gpiolib: cdev: support GPIO_V2_GET_LINE_IOCTL and GPIO_V2_LINE_GET_VALUES_IOCTL |
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On Sat, Sep 26, 2020 at 12:16 PM Kent Gibson <warthog618@gmail.com> wrote: > On Fri, Sep 25, 2020 at 01:06:02PM +0300, Andy Shevchenko wrote:
...
> Hmmm, there is more to it than I thought - gpiod_request_commit(), > which this code eventually calls, interprets a null label (not an > empty string) as indicating that the user has not set the label, in > which case it will set the desc label to "?". So userspace cannot > force the desc label to be empty. > > We need to keep that label as null in that case to maintain that > behaviour. > > I will add a comment there though. > > Hmmm, having said that, does this form work for you: > > if (ulr.consumer[0] != '\0') { > /* label is only initialized if consumer is set */ > lr->label = kstrndup(ulr.consumer, sizeof(ulr.consumer) - 1, GFP_KERNEL); > ... > > It actually compiles slightly larger, I guess due to the extra parameter > in the kstrndup() call, but may be slightly more readable??
I really don't want to delay this series, choose what you think is better and we may amend it later.
-- With Best Regards, Andy Shevchenko
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