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 X-Spam-Level: X-Spam-Status: No, score=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_NEOMUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id ABCB7C43142 for ; Mon, 25 Jun 2018 12:10:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 63AD72587B for ; Mon, 25 Jun 2018 12:10:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 63AD72587B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933768AbeFYMK1 (ORCPT ); Mon, 25 Jun 2018 08:10:27 -0400 Received: from mx2.suse.de ([195.135.220.15]:42124 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932444AbeFYMFA (ORCPT ); Mon, 25 Jun 2018 08:05:00 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (charybdis-ext-too.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id AC909ABF7; Mon, 25 Jun 2018 12:04:58 +0000 (UTC) Date: Mon, 25 Jun 2018 14:04:54 +0200 From: Petr Mladek To: Andrew Morton Cc: Steven Rostedt , Thierry Escande , David Miller , Rasmus Villemoes , "Tobin C . Harding" , linux-kernel@vger.kernel.org, Andy Shevchenko , Linus Torvalds Subject: Re: [PATCH RESEND] lib/test_printf.c: call wait_for_random_bytes() before plain %p tests Message-ID: <20180625120454.rtf7ram4euvgdc6w@pathway.suse.cz> References: <20180604113708.11554-1-thierry.escande@linaro.org> <20180607122434.i4x7b5ij4p6dpx7w@pathway.suse.cz> <20180622205346.owyjk33wplzh7nhs@home.goodmis.org> <20180625075020.xcb6jqup3dhq2agf@pathway.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180625075020.xcb6jqup3dhq2agf@pathway.suse.cz> User-Agent: NeoMutt/20170421 (1.8.2) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 2018-06-25 09:50:20, Petr Mladek wrote: > On Fri 2018-06-22 23:50:20, Thierry Escande wrote: > > On 22/06/2018 22:53, Steven Rostedt wrote: > > > On Thu, Jun 07, 2018 at 02:24:34PM +0200, Petr Mladek wrote: > > > > On Mon 2018-06-04 13:37:08, Thierry Escande wrote: > > > > > If the test_printf module is loaded before the crng is initialized, the > > > > > plain 'p' tests will fail because the printed address will not be hashed > > > > > and the buffer will contain '(ptrval)' instead. > > > > > This patch adds a call to wait_for_random_bytes() before plain 'p' tests > > > > > to make sure the crng is initialized. > > > > > > > > Hmm, my system did not boot with this patch and > > > > CONFIG_TEST_PRINTF=y > > > > > > And neither does my test box. It killed my tests I was running, as one of the > > > configs I test has this set. > > > > > > It appears that Andrew pulled it in and sent it to Linus, as it is in > > > 4.18-rc1, and I need to now revert this patch to make my tests work. > > > > This patch has been superseded with a v2 and a v3 pushed into Petr > > printk.git tree (https://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk.git/commit/?h=for-4.19&id=ce041c43f22298485122bab15c14d062383fbc67). > > Sorry for the mess... > > Andrew, > > should I send the revert and the better fix to Linus or would you like > to do so? Below is the proposed revert-commit just in case people want to add Reviewed-by tags or so. >From 043f891b70e6197bc181f3b087c2bd04c60fddd2 Mon Sep 17 00:00:00 2001 From: Petr Mladek Date: Mon, 25 Jun 2018 13:28:06 +0200 Subject: [PATCH] Revert "lib/test_printf.c: call wait_for_random_bytes() before plain %p tests" This reverts commit ee410f15b1418f2f4428e79980674c979081bcb7. It might prevent the machine from boot. It would wait for enough randomness at the very beginning of kernel_init(). But there is basically nothing running in parallel that would help to produce any randomness. Reported-by: Steven Rostedt (VMware) Signed-off-by: Petr Mladek --- lib/test_printf.c | 7 ------- 1 file changed, 7 deletions(-) diff --git a/lib/test_printf.c b/lib/test_printf.c index b2aa8f514844..cea592f402ed 100644 --- a/lib/test_printf.c +++ b/lib/test_printf.c @@ -260,13 +260,6 @@ plain(void) { int err; - /* - * Make sure crng is ready. Otherwise we get "(ptrval)" instead - * of a hashed address when printing '%p' in plain_hash() and - * plain_format(). - */ - wait_for_random_bytes(); - err = plain_hash(); if (err) { pr_warn("plain 'p' does not appear to be hashed\n"); -- 2.13.7