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 X-Spam-Level: X-Spam-Status: No, score=-4.7 required=3.0 tests=DATE_IN_PAST_96_XX, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C1FC6C2D0E5 for ; Sat, 28 Mar 2020 16:45:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A0A4120748 for ; Sat, 28 Mar 2020 16:45:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727781AbgC1Qnt (ORCPT ); Sat, 28 Mar 2020 12:43:49 -0400 Received: from mx.sdf.org ([205.166.94.20]:50065 "EHLO mx.sdf.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727696AbgC1Qna (ORCPT ); Sat, 28 Mar 2020 12:43:30 -0400 Received: from sdf.org (IDENT:lkml@sdf.lonestar.org [205.166.94.16]) by mx.sdf.org (8.15.2/8.14.5) with ESMTPS id 02SGh7mA016099 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits) verified NO); Sat, 28 Mar 2020 16:43:08 GMT Received: (from lkml@localhost) by sdf.org (8.15.2/8.12.8/Submit) id 02SGh78v026162; Sat, 28 Mar 2020 16:43:07 GMT Message-Id: <202003281643.02SGh78v026162@sdf.org> From: George Spelvin Date: Fri, 29 Nov 2019 17:42:15 -0500 Subject: [RFC PATCH v1 05/50] net/rds/bind.c: Use prandom_u32_max() To: linux-kernel@vger.kernel.org, lkml@sdf.org Cc: Ka-Cheong Poon , Santosh Shilimkar , linux-rdma@vger.kernel.org, rds-devel@oss.oracle.com Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org max_t(u16, prandom_u32(), 2) generates 2 three times as often as any other value. Operating modulo 65534 improves uniformity. Signed-off-by: George Spelvin Cc: Ka-Cheong Poon Cc: Santosh Shilimkar Cc: linux-rdma@vger.kernel.org Cc: rds-devel@oss.oracle.com --- net/rds/bind.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/rds/bind.c b/net/rds/bind.c index 5b5fb4ca8d3e5..8293044767b83 100644 --- a/net/rds/bind.c +++ b/net/rds/bind.c @@ -104,7 +104,7 @@ static int rds_add_bound(struct rds_sock *rs, const struct in6_addr *addr, return -EINVAL; last = rover; } else { - rover = max_t(u16, prandom_u32(), 2); + rover = 2 + prandom_u32_max(65534); last = rover - 1; } -- 2.26.0