On Thu, Oct 6, 2022 at 6:47 AM Jason Gunthorpe <jgg@xxxxxxxx> wrote: > > On Wed, Oct 05, 2022 at 11:48:42PM +0200, Jason A. Donenfeld wrote: > > > index 14392c942f49..499a425a3379 100644 > > --- a/drivers/infiniband/hw/cxgb4/cm.c > > +++ b/drivers/infiniband/hw/cxgb4/cm.c > > @@ -734,7 +734,7 @@ static int send_connect(struct c4iw_ep *ep) > > &ep->com.remote_addr; > > int ret; > > enum chip_type adapter_type = ep->com.dev->rdev.lldi.adapter_type; > > - u32 isn = (prandom_u32() & ~7UL) - 1; > > + u32 isn = (get_random_u32() & ~7UL) - 1; > > Maybe this wants to be written as > > (prandom_max(U32_MAX >> 7) << 7) | 7 > > ? Holy smokes. Yea I guess maybe? It doesn't exactly gain anything or make the code clearer though, and is a little bit more magical than I'd like on a first pass. > > > diff --git a/drivers/infiniband/ulp/ipoib/ipoib_cm.c b/drivers/infiniband/ulp/ipoib/ipoib_cm.c > > index fd9d7f2c4d64..a605cf66b83e 100644 > > --- a/drivers/infiniband/ulp/ipoib/ipoib_cm.c > > +++ b/drivers/infiniband/ulp/ipoib/ipoib_cm.c > > @@ -465,7 +465,7 @@ static int ipoib_cm_req_handler(struct ib_cm_id *cm_id, > > goto err_qp; > > } > > > > - psn = prandom_u32() & 0xffffff; > > + psn = get_random_u32() & 0xffffff; > > prandom_max(0xffffff + 1) That'd work, but again it's not more clear. Authors here are going for a 24-bit number, and masking seems like a clear way to express that. Jason
