linux-kernel - Re: [PATCH v1 3/5] treewide: use get_random

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Date:   Thu, 6 Oct 2022 10:15:35 -0300
From:   Jason Gunthorpe <jgg@...pe.ca>
To:     "Jason A. Donenfeld" <Jason@...c4.com>
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Subject: Re: [PATCH v1 3/5] treewide: use get_random_u32() when possible

On Thu, Oct 06, 2022 at 07:05:48AM -0600, Jason A. Donenfeld wrote:

> > > 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.

vs just asking directly for a 24 bit number?

Jason