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 0AD40C43334 for ; Thu, 23 Jun 2022 18:10:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233990AbiFWSKA (ORCPT ); Thu, 23 Jun 2022 14:10:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46900 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236643AbiFWSIM (ORCPT ); Thu, 23 Jun 2022 14:08:12 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 06613BB019; Thu, 23 Jun 2022 10:19:40 -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 ams.source.kernel.org (Postfix) with ESMTPS id 9E869B824BD; Thu, 23 Jun 2022 17:19:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 004CBC3411B; Thu, 23 Jun 2022 17:19:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1656004776; bh=Trgz+USAQPCv1R/UHnPbOXYDe7Kd+M22X+yARLpqOVw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2GQvIo0CTXPLexM1ZAd/yq5oJiYGCTvAN+SiG+RcNPkJUD/R906m2MqRj1bd8T/qn vZsFL8mgntrbL98EsbW/zwu3jH5Sf+gplfM+QDuGk8/hz8FB6Ywr9AAMsVy0Arct2U ZSo8hT3TRQ0e85E4mNCy0gTPA8uYsQoc+VeTWrqE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Thomas Gleixner , Arnd Bergmann , Richard Weinberger , Anton Ivanov , Johannes Berg , "Jason A. Donenfeld" Subject: [PATCH 4.19 146/234] um: use fallback for random_get_entropy() instead of zero Date: Thu, 23 Jun 2022 18:43:33 +0200 Message-Id: <20220623164347.186686353@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220623164343.042598055@linuxfoundation.org> References: <20220623164343.042598055@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Jason A. Donenfeld" commit 9f13fb0cd11ed2327abff69f6501a2c124c88b5a upstream. In the event that random_get_entropy() can't access a cycle counter or similar, falling back to returning 0 is really not the best we can do. Instead, at least calling random_get_entropy_fallback() would be preferable, because that always needs to return _something_, even falling back to jiffies eventually. It's not as though random_get_entropy_fallback() is super high precision or guaranteed to be entropic, but basically anything that's not zero all the time is better than returning zero all the time. This is accomplished by just including the asm-generic code like on other architectures, which means we can get rid of the empty stub function here. Cc: Thomas Gleixner Cc: Arnd Bergmann Cc: Richard Weinberger Cc: Anton Ivanov Acked-by: Johannes Berg Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman --- arch/um/include/asm/timex.h | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) --- a/arch/um/include/asm/timex.h +++ b/arch/um/include/asm/timex.h @@ -2,13 +2,8 @@ #ifndef __UM_TIMEX_H #define __UM_TIMEX_H -typedef unsigned long cycles_t; - -static inline cycles_t get_cycles (void) -{ - return 0; -} - #define CLOCK_TICK_RATE (HZ) +#include + #endif