From mboxrd@z Thu Jan  1 00:00:00 1970
From: Dan Carpenter <dan.carpenter@oracle.com>
Subject: Re: [PATCH v7 4/4] gpiolib: Implement fast processing path in
 get/set array
Date: Thu, 20 Sep 2018 21:05:29 +0300
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Cc: Andrew Lunn <andrew@lunn.ch>, Ulf Hansson <ulf.hansson@linaro.org>,
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 Krzysztof Kozlowski <krzk@kernel.org>, Kishon Vijay Abraham I <kishon@ti.com>,
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To: Janusz Krzysztofik <jmkrzyszt@gmail.com>
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On Thu, Sep 20, 2018 at 05:48:22PM +0200, Janusz Krzysztofik wrote:
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index a53d17745d21..5bc3447949c9 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -2880,7 +2880,7 @@ int gpiod_get_array_value_complex(bool raw, bool can_sleep,
>  			__set_bit(hwgpio, mask);
>  
>  			if (array_info)
> -				find_next_zero_bit(array_info->get_mask,
> +				i = find_next_zero_bit(array_info->get_mask,
>  						   array_size, i);

We could mark find_next_zero_bit() and friends as a __must_check
functions so we avoid this bug in the future.  I have a more complicated
idea how to detect these bugs in a generic way using Smatch but it will
take longer to implement.

regards,
dan carpenter