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 4CBD7C433EF for ; Thu, 23 Jun 2022 17:39:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234160AbiFWRjv (ORCPT ); Thu, 23 Jun 2022 13:39:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44036 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234431AbiFWRg5 (ORCPT ); Thu, 23 Jun 2022 13:36:57 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D35648EFB5; Thu, 23 Jun 2022 10:06:45 -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 D578461D11; Thu, 23 Jun 2022 17:06:35 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8EC42C3411B; Thu, 23 Jun 2022 17:06:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1656003995; bh=YVFCm9IvwmgkDNWZPZYSkH8bYCAZpNilJPeiWNu6Xuk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZAzSDnj7NraUbBkV8RGakD81NC1ZiuLSJ2GuZy8uVTwWY2WWj2ztzW0xSpxeJXLJA Hwr+5yTFXGIjDx8jDns6GyOgcML5MJqRykFqgxx5tx0cn+GaMXWxHbO9wp89vPKXpT 1ylEArhTtIU3ayqWvU6auHWfqet0BF6gLOTjuHlE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Thomas Gleixner , Arnd Bergmann , Geert Uytterhoeven , "Jason A. Donenfeld" Subject: [PATCH 4.14 154/237] m68k: use fallback for random_get_entropy() instead of zero Date: Thu, 23 Jun 2022 18:43:08 +0200 Message-Id: <20220623164347.586457056@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220623164343.132308638@linuxfoundation.org> References: <20220623164343.132308638@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 0f392c95391f2d708b12971a07edaa7973f9eece 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. Cc: Thomas Gleixner Cc: Arnd Bergmann Acked-by: Geert Uytterhoeven Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman --- arch/m68k/include/asm/timex.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/m68k/include/asm/timex.h +++ b/arch/m68k/include/asm/timex.h @@ -35,7 +35,7 @@ static inline unsigned long random_get_e { if (mach_random_get_entropy) return mach_random_get_entropy(); - return 0; + return random_get_entropy_fallback(); } #define random_get_entropy random_get_entropy