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 96C57C433F5 for ; Fri, 27 May 2022 11:49:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343945AbiE0LtP (ORCPT ); Fri, 27 May 2022 07:49:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57132 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352095AbiE0LpW (ORCPT ); Fri, 27 May 2022 07:45:22 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D3CCF140868; Fri, 27 May 2022 04:41:57 -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 4E0DD61D46; Fri, 27 May 2022 11:41:57 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5CEC0C385A9; Fri, 27 May 2022 11:41:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1653651716; bh=YVFCm9IvwmgkDNWZPZYSkH8bYCAZpNilJPeiWNu6Xuk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tJa0bnddslGgrff/oR3XdFvx18vcwFhEHGEjrGcL3j9vikd7djdrXtCHhoLu4R+YO vFvET2O+j0tldo+yu1VsqZRnRAcIFPKBdP1P9zyXXOba1aR8Bsph8rJKtV+9RaMSns ZSd3m50ompDFxeVjMAAPlwSztBrR9rbVKwwHO5q4= 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 5.17 075/111] m68k: use fallback for random_get_entropy() instead of zero Date: Fri, 27 May 2022 10:49:47 +0200 Message-Id: <20220527084830.091696429@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220527084819.133490171@linuxfoundation.org> References: <20220527084819.133490171@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