From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B228AC43217 for ; Sun, 9 Oct 2022 00:26:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229750AbiJIA0a (ORCPT ); Sat, 8 Oct 2022 20:26:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59700 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229563AbiJIA0Z (ORCPT ); Sat, 8 Oct 2022 20:26:25 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2F5D22E9FB; Sat, 8 Oct 2022 17:26:24 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id BA4A960B29; Sun, 9 Oct 2022 00:26:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8A7A8C43142; Sun, 9 Oct 2022 00:26:21 +0000 (UTC) Authentication-Results: smtp.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="PX4nnIOK" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1665275176; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=7zZXtzJcFLYkSrXJJYKIVFffp4v7t60F00p3NU1sSks=; b=PX4nnIOKh3FHa9d1G132kBTXFxz7qYQBOTukTgSGG6fc4aKl+1ua8ttlw/vsoBqgsW+CHC NTGzZbQmolIFuqf8+kDGOqJtdV61Oxsts7vNgF2zGCk6Fi2PVF9YyHTL3BJyD+I6xXQNse S5HVOwfe+G2V37JJFP20h8mZS0WLTwM= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id 9a9a9268 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Sun, 9 Oct 2022 00:26:15 +0000 (UTC) Received: by mail-ua1-f42.google.com with SMTP id i20so2853853ual.4; Sat, 08 Oct 2022 17:26:12 -0700 (PDT) X-Gm-Message-State: ACrzQf3Wjg3OFrVFWd3xt6aGIRFkt/c9uMxhTuPtcyIAkwN2yc3FLGiN 2KRFuspzQ4ilrmTnT6wNLAZnPPKKcFMMdZKoRuc= X-Google-Smtp-Source: AMsMyM7Ghd+rNLLkdUe772S1SZ8rADl1G6UAF0aO2TFON1i86eRArx6SOwts50zdZDWmmLpyXWt8nLKkLulPCRn4G5w= X-Received: by 2002:ab0:70b9:0:b0:3d7:84d8:35ae with SMTP id q25-20020ab070b9000000b003d784d835aemr6771029ual.24.1665275171232; Sat, 08 Oct 2022 17:26:11 -0700 (PDT) MIME-Version: 1.0 References: <20221007180107.216067-1-Jason@zx2c4.com> <20221007180107.216067-5-Jason@zx2c4.com> In-Reply-To: From: "Jason A. Donenfeld" Date: Sat, 8 Oct 2022 18:26:00 -0600 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v4 4/6] treewide: use get_random_u32() when possible To: David Laight Cc: "linux-kernel@vger.kernel.org" , "patches@lists.linux.dev" , Andreas Noever , Andrew Morton , Andy Shevchenko , Borislav Petkov , Catalin Marinas , =?UTF-8?Q?Christoph_B=C3=B6hmwalder?= , Christoph Hellwig , Christophe Leroy , Daniel Borkmann , Dave Airlie , Dave Hansen , "David S . Miller" , Eric Dumazet , Florian Westphal , Greg Kroah-Hartman , "H . Peter Anvin" , Heiko Carstens , Helge Deller , Herbert Xu , Huacai Chen , Hugh Dickins , Jakub Kicinski , "James E . J . Bottomley" , Jan Kara , Jason Gunthorpe , Jens Axboe , Johannes Berg , Jonathan Corbet , Jozsef Kadlecsik , KP Singh , Kees Cook , Marco Elver , Mauro Carvalho Chehab , Michael Ellerman , Pablo Neira Ayuso , Paolo Abeni , Peter Zijlstra , Richard Weinberger , Russell King , "Theodore Ts'o" , Thomas Bogendoerfer , Thomas Gleixner , Thomas Graf , Ulf Hansson , Vignesh Raghavendra , WANG Xuerui , Will Deacon , Yury Norov , "dri-devel@lists.freedesktop.org" , "kasan-dev@googlegroups.com" , "kernel-janitors@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-block@vger.kernel.org" , "linux-crypto@vger.kernel.org" , "linux-doc@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "linux-media@vger.kernel.org" , "linux-mips@vger.kernel.org" , "linux-mm@kvack.org" , "linux-mmc@vger.kernel.org" , "linux-mtd@lists.infradead.org" , "linux-nvme@lists.infradead.org" , "linux-parisc@vger.kernel.org" , "linux-rdma@vger.kernel.org" , "linux-s390@vger.kernel.org" , "linux-um@lists.infradead.org" , "linux-usb@vger.kernel.org" , "linux-wireless@vger.kernel.org" , "linuxppc-dev@lists.ozlabs.org" , "loongarch@lists.linux.dev" , "netdev@vger.kernel.org" , "sparclinux@vger.kernel.org" , "x86@kernel.org" , =?UTF-8?B?VG9rZSBIw7hpbGFuZC1Kw7hyZ2Vuc2Vu?= , Chuck Lever , Jan Kara , Mika Westerberg Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Oct 8, 2022 at 4:37 PM Jason A. Donenfeld wrote: > > 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. I guess the cocci patch looks like this, so maybe I'll put that in 1/7 if I respin this. @@ expression E; identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; typedef u64; @@ - ((u64)(E) * get_random_u32() >> 32) + prandom_u32_max(E)