From: Sergey Organov > Sent: 23 April 2021 15:40 > > Walter Harms <wharms@xxxxxx> writes: > > > as indepentent observer, > > i would go for Dans solution: > > > > ret = kfifo_to_user(); > > /* if an error occurs just return */ > > if (ret) > > return ret; > > > > /* otherwise return the copied number of bytes */ > > > > return copied; > > > > there is no need for any deeper language knowledge, > > Yep, but this is not idiomatic C, so one looking at this code would > tend to convert it back to ternary, and the actual problem here is that > the type of 'copied' does not match the return type of the function. Actually changing the type of 'ret' to ssize_t is probably the safest change. That works until someone tries to optimise out 'ret' by doing: return kfifo_to_user(...) ?: count; Or rattle through and remove the 'pass by reference' 'count' parameter from kfifo_to_user() in favour of returning the value the callers want. I need to stop looking at this code :-) David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
