Re: [PATCH v4 4/6] treewide: use get_random_u32() when possible

[Jason A. Donenfeld]

On Sat, Oct 08, 2022 at 10:18:45PM +0000, David Laight wrote:
> From: Jason A. Donenfeld
> > Sent: 07 October 2022 19:01
> > 
> > The prandom_u32() function has been a deprecated inline wrapper around
> > get_random_u32() for several releases now, and compiles down to the
> > exact same code. Replace the deprecated wrapper with a direct call to
> > the real function. The same also applies to get_random_int(), which is
> > just a wrapper around get_random_u32().
> > 
> ...
> > diff --git a/net/802/garp.c b/net/802/garp.c
> > index f6012f8e59f0..c1bb67e25430 100644
> > --- a/net/802/garp.c
> > +++ b/net/802/garp.c
> > @@ -407,7 +407,7 @@ static void garp_join_timer_arm(struct garp_applicant *app)
> >  {
> >  	unsigned long delay;
> > 
> > -	delay = (u64)msecs_to_jiffies(garp_join_time) * prandom_u32() >> 32;
> > +	delay = (u64)msecs_to_jiffies(garp_join_time) * get_random_u32() >> 32;
> >  	mod_timer(&app->join_timer, jiffies + delay);
> >  }
> > 
> > diff --git a/net/802/mrp.c b/net/802/mrp.c
> > index 35e04cc5390c..3e9fe9f5d9bf 100644
> > --- a/net/802/mrp.c
> > +++ b/net/802/mrp.c
> > @@ -592,7 +592,7 @@ static void mrp_join_timer_arm(struct mrp_applicant *app)
> >  {
> >  	unsigned long delay;
> > 
> > -	delay = (u64)msecs_to_jiffies(mrp_join_time) * prandom_u32() >> 32;
> > +	delay = (u64)msecs_to_jiffies(mrp_join_time) * get_random_u32() >> 32;
> >  	mod_timer(&app->join_timer, jiffies + delay);
> >  }
> > 
> 
> Aren't those:
> 	delay = prandom_u32_max(msecs_to_jiffies(xxx_join_time));

Probably, but too involved and peculiar for this cleanup.

Feel free to send a particular patch to that maintainer.

> 
> 	David
> 
> -
> Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
> Registration No: 1397386 (Wales)