From: Marcelo Ricardo Leitner > Sent: 13 May 2020 19:03 > > On Wed, May 13, 2020 at 08:26:47AM +0200, Christoph Hellwig wrote: > > Add a helper to directly get the SCTP_PRIMARY_ADDR sockopt from kernel > > space without going through a fake uaccess. > > Same comment as on the other dlm/sctp patch. Wouldn't it be best to write sctp_[gs]etsockotp() that use a kernel buffer and then implement the user-space calls using a wrapper that does the copies to an on-stack (or malloced if big) buffer. That will also simplify the code be removing all the copies and -EFAULT returns. Only the size checks will be needed and the code can assume the buffer is at least the size of the on-stack buffer. Our SCTP code uses SO_REUSADDR, SCTP_EVENTS, SCTP_NODELAY, SCTP_STATUS, SCTP_INITMSG, IPV6_ONLY, SCTP_SOCKOPT_BINDX_ADD and SO_LINGER. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)