Re: [PATCH 2/3] staging:iio: IIO_EVENT_CODE: Clamp channel numbers

[Jonathan Cameron <jic23@cam.ac.uk>]

On 10/27/11 10:02, Lars-Peter Clausen wrote:
> On 10/27/2011 10:44 AM, Lars-Peter Clausen wrote:
>> Make sure we only use the allotted space for channel numbers in the event mask
>> and do not let them override other fields.
>>
>> Since negative values are valid channel number, cast the channel number to
>> signed when extracting it from an event mask.
>>
>> Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
>> ---
>>  drivers/staging/iio/events.h |    5 +++--
>>  1 files changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/staging/iio/events.h b/drivers/staging/iio/events.h
>> index 7cf9306..fc2b7e5 100644
>> --- a/drivers/staging/iio/events.h
>> +++ b/drivers/staging/iio/events.h
>> @@ -56,7 +56,8 @@ enum iio_event_direction {
>>  		       type, chan, chan1, chan2)			\
>>  	(((u64)type << 56) | ((u64)diff << 55) |			\
>>  	 ((u64)direction << 48) | ((u64)modifier << 40) |		\
>> -	 ((u64)chan_type << 32) | (chan2 << 16) | chan1 | chan)
>> +	 ((u64)chan_type << 32) | (((u16)chan2) << 16) | ((u16)chan1) | \
>> +	 ((u16)chan))
>>  
>>  
>>  #define IIO_EV_DIR_MAX 4
>> @@ -95,7 +96,7 @@ enum iio_event_direction {
>>  
>>  /* Event code number extraction depends on which type of event we have.
>>   * Perhaps review this function in the future*/
>> -#define IIO_EVENT_CODE_EXTRACT_NUM(mask) (mask & 0xFFFF)
>> +#define IIO_EVENT_CODE_EXTRACT_NUM(mask) ((s16)(mask & 0xFFFF))
>>  
> 
> Since we want to use it in userspace this should obviously be __s16, sorry.
> Will fix this before sending the patch on.
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>