From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964867Ab2HGDxF (ORCPT ); Mon, 6 Aug 2012 23:53:05 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:59635 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757290Ab2HGDiM (ORCPT ); Mon, 6 Aug 2012 23:38:12 -0400 Message-Id: <20120807032757.992864060@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Tue, 07 Aug 2012 04:28:08 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, "H. Peter Anvin" , "Theodore Tso" Subject: [ 13/70] random: Adjust the number of loops when initializing In-Reply-To: <20120807032755.803571133@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:21c:bfff:fe03:f805 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: "H. Peter Anvin" commit 2dac8e54f988ab58525505d7ef982493374433c3 upstream. When we are initializing using arch_get_random_long() we only need to loop enough times to touch all the bytes in the buffer; using poolwords for that does twice the number of operations necessary on a 64-bit machine, since in the random number generator code "word" means 32 bits. Signed-off-by: H. Peter Anvin Cc: "Theodore Ts'o" Link: http://lkml.kernel.org/r/1324589281-31931-1-git-send-email-tytso@mit.edu Signed-off-by: Ben Hutchings --- drivers/char/random.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/char/random.c b/drivers/char/random.c index 3079477..9a2156d 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -975,7 +975,7 @@ static void init_std_data(struct entropy_store *r) now = ktime_get_real(); mix_pool_bytes(r, &now, sizeof(now)); - for (i = r->poolinfo->poolwords; i; i--) { + for (i = r->poolinfo->POOLBYTES; i > 0; i -= sizeof flags) { if (!arch_get_random_long(&flags)) break; mix_pool_bytes(r, &flags, sizeof(flags));