From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762044AbaGRTe4 (ORCPT ); Fri, 18 Jul 2014 15:34:56 -0400 Received: from mail-ig0-f182.google.com ([209.85.213.182]:48758 "EHLO mail-ig0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754906AbaGRTez (ORCPT ); Fri, 18 Jul 2014 15:34:55 -0400 Message-ID: <53C976E1.9040505@linaro.org> Date: Fri, 18 Jul 2014 14:34:57 -0500 From: Alex Elder User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: akpm@linux-foundation.org CC: kay@vrfy.org, pmladek@suse.cz, bp@suse.de, john.stultz@linaro.org, jack@suse.cz, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 3/7] printk: LOG_CONT and LOG_NEWLINE are opposites References: <1405692859-32500-1-git-send-email-elder@linaro.org> <1405692859-32500-4-git-send-email-elder@linaro.org> In-Reply-To: <1405692859-32500-4-git-send-email-elder@linaro.org> X-Enigmail-Version: 1.5.2 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/18/2014 09:14 AM, Alex Elder wrote: > Two log record flags--LOG_CONT and LOG_NEWLINE--are mutually > exclusive. That is, one or the other is always set, but they are > never both set at the same time in a log record flags field. What > follows is a great deal of explanation that aims to prove this > assertion. > > Having that knowledge allows us to simplify a bit of logic, and with > a little more work (in follow-on patches) it allows us to do without > some flag values, considerably simplifying things. And in this patch I inadvertently deleted a hunk. It goes at the end, and I've appended it below. I'm really sorry I screwed these patches up. I got sloppy, and tried to send them out in a hurry this morning. I'm going to post a new version 4 that will correct these things. -Alex > Signed-off-by: Alex Elder > Reviewed-by: Petr Mládek > --- > kernel/printk/printk.c | 18 +++++++++++------- > 1 file changed, 11 insertions(+), 7 deletions(-) > > diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c > index f2a069e..00367b5 100644 > --- a/kernel/printk/printk.c > +++ b/kernel/printk/printk.c > @@ -1006,11 +1006,9 @@ static size_t msg_print_text(const struct printk_log *msg, enum log_flags prev, > prefix = false; > > if (msg->flags & LOG_CONT) { > - if ((prev & LOG_CONT) && !(prev & LOG_NEWLINE)) > + if (prev & LOG_CONT) > prefix = false; > - > - if (!(msg->flags & LOG_NEWLINE)) > - newline = false; > + newline = false; > } > > do { > @@ -1639,10 +1637,16 @@ asmlinkage int vprintk_emit(int facility, int level, > text_len += vscnprintf(text + text_len, > sizeof(textbuf) - text_len, fmt, args); > > - /* mark and strip a trailing newline */ > + /* > + * If there's a trailing newline, flag it and strip it off. > + * Otherwise we assume this is a partial log message, to be > + * continued with the next call. > + */ > if (text_len && text[text_len-1] == '\n') { > text_len--; > - lflags |= LOG_NEWLINE; > + lflags = LOG_NEWLINE; > + } else { > + lflags = LOG_CONT; > } > > /* strip kernel syslog prefix and extract log level or control flags */ > @@ -1672,7 +1676,7 @@ asmlinkage int vprintk_emit(int facility, int level, > level = default_message_loglevel; > > if (dict) > - lflags |= LOG_PREFIX|LOG_NEWLINE; > + lflags = LOG_PREFIX|LOG_NEWLINE; > > if (!(lflags & LOG_NEWLINE)) { > /* > @@ -1700,8 +1700,7 @@ asmlinkage int vprintk_emit(int facility if (cont_add(facility, level, text, text_len)) printed_len += text_len; else - printed_len += log_store(facility, level, - lflags | LOG_CONT, 0, + printed_len += log_store(facility, level, lflags, 0, dict, dictlen, text, text_len); } else { bool stored = false;