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 D5F87C43334 for ; Thu, 23 Jun 2022 17:04:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231869AbiFWRER (ORCPT ); Thu, 23 Jun 2022 13:04:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48846 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233510AbiFWRCt (ORCPT ); Thu, 23 Jun 2022 13:02:49 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 13AA0506F6; Thu, 23 Jun 2022 09:54:36 -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 9398161F8D; Thu, 23 Jun 2022 16:54:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4B9DCC3411B; Thu, 23 Jun 2022 16:54:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1656003266; bh=8DhdpDlWsHvSEYXlcJF7C+zOOW9FKPxj970R1hxlBfM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jlts1jHHxZI7k4EU5s4Q/XxZwDl381J2Qrxu0VWM4l64LzfVsWF2FWnk+ano0A9pI uhjxRwu2b2wwSBaWoSSmzdNKRTd3ltd0KhXiNSyA4/qcHQwwweYXoysl7DuCCp+Mt8 +zIvN9mb3+cczTjWmU+l+QVoAB2QZtcGoYWTPxuc= 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 4.9 184/264] m68k: use fallback for random_get_entropy() instead of zero Date: Thu, 23 Jun 2022 18:42:57 +0200 Message-Id: <20220623164349.275016342@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220623164344.053938039@linuxfoundation.org> References: <20220623164344.053938039@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 @@ -34,7 +34,7 @@ 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