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 B3395C43334 for ; Mon, 20 Jun 2022 14:01:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347176AbiFTOBY (ORCPT ); Mon, 20 Jun 2022 10:01:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44198 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352723AbiFTN46 (ORCPT ); Mon, 20 Jun 2022 09:56:58 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E4178BA2; Mon, 20 Jun 2022 06:22:51 -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 5E33560A52; Mon, 20 Jun 2022 13:17:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 512ADC3411C; Mon, 20 Jun 2022 13:17:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1655731067; bh=Trgz+USAQPCv1R/UHnPbOXYDe7Kd+M22X+yARLpqOVw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=k5f3/tndnQQVAUvF8lFhypQNUIs+Zp4Pht4aZkvGW1PNUM7VbcpJ8/sXLv3nPYKwf YatSGQb2Td7YU+x6kURwa5vPtjDjtpCMIanEuSe+wW5PD3OpItU02Vy9bBAldOCox7 vWs4p8fs8trIZSrl9XT1uyIfRQrwDV4k701h7C+g= 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 5.4 142/240] um: use fallback for random_get_entropy() instead of zero Date: Mon, 20 Jun 2022 14:50:43 +0200 Message-Id: <20220620124743.124037992@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220620124737.799371052@linuxfoundation.org> References: <20220620124737.799371052@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: stable@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