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 1E99DC433F5 for ; Fri, 27 May 2022 08:54:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344053AbiE0Ix7 (ORCPT ); Fri, 27 May 2022 04:53:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58738 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350065AbiE0IxK (ORCPT ); Fri, 27 May 2022 04:53:10 -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 0FA1F5C74A; Fri, 27 May 2022 01:52:37 -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 15E5561D3D; Fri, 27 May 2022 08:52:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B69D4C34100; Fri, 27 May 2022 08:52:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1653641556; bh=Trgz+USAQPCv1R/UHnPbOXYDe7Kd+M22X+yARLpqOVw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=w7tDwd2tUwyQZQnW2Rml27p+hsB8vwgs5eIDJXTDb03trH6zO4NTq9IyAvAhGuRES AtvnqjuR4LbaJN38J3nJQk9UYhj8YWrIfTmGJUG/aS6ZZcG22YG5JpgsjJI/bN+Z5O Z99qC9SbGGxAejAZxeSTeNw31LUOY48OSciehhzc= 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 5.18 17/47] um: use fallback for random_get_entropy() instead of zero Date: Fri, 27 May 2022 10:49:57 +0200 Message-Id: <20220527084804.121132542@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220527084801.223648383@linuxfoundation.org> References: <20220527084801.223648383@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