Messages in this thread | | | Date | Mon, 28 Jan 2013 11:57:39 +0100 | From | Florian Vaussard <> | Subject | Re: [PATCH v2 1/3] pwm: Add pwm_cansleep() as exported API to users |
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Le 28/01/2013 10:57, Thierry Reding a écrit : > On Mon, Jan 28, 2013 at 10:36:07AM +0100, Florian Vaussard wrote: >> Hello, >> >> Le 28/01/2013 09:45, Peter Ujfalusi a écrit : >>> hi Thierry, >>> >>> On 01/26/2013 06:40 AM, Thierry Reding wrote: > [...] >>>>> +{ >>>>> + return pwm->chip->can_sleep; >>>>> +} >>>>> +EXPORT_SYMBOL_GPL(pwm_cansleep); >>>> >>>> Would it make sense to check for NULL pointers here? I guess that >>>> passing NULL into the function could be considered a programming error >>>> and an oops would be okay, but in that case there's no point in making >>>> the function return an int. Also see my next comment. >>> >>> While it is unlikely to happen it is better to be safe, something like this >>> will do: >>> >>> return pwm ? pwm->chip->can_sleep : 0; >>> >> >> Ok. And what about: >> >> BUG_ON(pwm == NULL); >> return pwm->chip->can_sleep; > > I don't think we need that. In case pwm == NULL, dereferencing it will > oops anyway. So either we make it safe and return an error code, or we > let it oops without explicit BUG_ON(). >
Calling this function with a NULL pointer is a programming error, so there is no error codes for such errors. I propose to return bool, and let it oops if such case happens.
Regards,
Florian -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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