From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <jgg@ziepe.ca>
Received: from mail-qt1-f177.google.com (mail-qt1-f177.google.com
	[209.85.160.177])
	by mail19.linbit.com (LINBIT Mail Daemon) with ESMTP id 65F074203D5
	for <drbd-dev@lists.linbit.com>; Thu,  6 Oct 2022 15:15:38 +0200 (CEST)
Received: by mail-qt1-f177.google.com with SMTP id fb18so900392qtb.12
	for <drbd-dev@lists.linbit.com>; Thu, 06 Oct 2022 06:15:37 -0700 (PDT)
Date: Thu, 6 Oct 2022 10:15:35 -0300
From: Jason Gunthorpe <jgg@ziepe.ca>
To: "Jason A. Donenfeld" <Jason@zx2c4.com>
Message-ID: <Yz7U99PPl8uHCLFY@ziepe.ca>
References: <20221005214844.2699-1-Jason@zx2c4.com>
	<20221005214844.2699-4-Jason@zx2c4.com> <Yz7OdfKZeGkpZSKb@ziepe.ca>
	<CAHmME9r_vNRFFjUvqx8QkBddg_kQU=FMgpk9TqOVZdvX6zXHNg@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <CAHmME9r_vNRFFjUvqx8QkBddg_kQU=FMgpk9TqOVZdvX6zXHNg@mail.gmail.com>
Cc: linux-fbdev@vger.kernel.org, linux-doc@vger.kernel.org,
	linux-wireless@vger.kernel.org, dri-devel@lists.freedesktop.org,
	linux-mm@kvack.org, linux-sctp@vger.kernel.org,
	target-devel@vger.kernel.org, linux-mtd@lists.infradead.org,
	linux-stm32@st-md-mailman.stormreply.com,
	drbd-dev@lists.linbit.com, dev@openvswitch.org,
	rds-devel@oss.oracle.com, linux-scsi@vger.kernel.org,
	dccp@vger.kernel.org, linux-rdma@vger.kernel.org,
	kasan-dev@googlegroups.com, lvs-devel@vger.kernel.org,
	coreteam@netfilter.org, tipc-discussion@lists.sourceforge.net,
	linux-ext4@vger.kernel.org, linux-media@vger.kernel.org,
	linux-actions@lists.infradead.org, linux-nfs@vger.kernel.org,
	linux-block@vger.kernel.org, dmaengine@vger.kernel.org,
	linux-nvme@lists.infradead.org, SHA-cyfmac-dev-list@infineon.com,
	linux-hams@vger.kernel.org, ceph-devel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, cake@lists.bufferbloat.net,
	brcm80211-dev-list.pdl@broadcom.com, linux-raid@vger.kernel.org,
	netdev@vger.kernel.org, linux-usb@vger.kernel.org,
	linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-f2fs-devel@lists.sourceforge.net,
	linux-xfs@vger.kernel.org, netfilter-devel@vger.kernel.org,
	linux-crypto@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linuxppc-dev@lists.ozlabs.org
Subject: Re: [Drbd-dev] [PATCH v1 3/5] treewide: use get_random_u32() when
	possible
List-Id: "*Coordination* of development, patches,
	contributions -- *Questions* \(even to developers\) go to drbd-user,
	please." <drbd-dev.lists.linbit.com>
List-Unsubscribe: <https://lists.linbit.com/mailman/options/drbd-dev>,
	<mailto:drbd-dev-request@lists.linbit.com?subject=unsubscribe>
List-Archive: <http://lists.linbit.com/pipermail/drbd-dev>
List-Post: <mailto:drbd-dev@lists.linbit.com>
List-Help: <mailto:drbd-dev-request@lists.linbit.com?subject=help>
List-Subscribe: <https://lists.linbit.com/mailman/listinfo/drbd-dev>,
	<mailto:drbd-dev-request@lists.linbit.com?subject=subscribe>

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