linux-kernel - Re: [PATCH 2/4] printk/kdb: Handle more message headers

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Date:   Thu, 27 Oct 2016 09:57:45 -0700
From:   Joe Perches <joe@...ches.com>
To:     Petr Mladek <pmladek@...e.com>,
        Linus Torvalds <torvalds@...ux-foundation.org>
Cc:     Andrew Morton <akpm@...ux-foundation.org>,
        Sergey Senozhatsky <sergey.senozhatsky.work@...il.com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Jason Wessel <jason.wessel@...driver.com>,
        Jaroslav Kysela <perex@...ex.cz>,
        Takashi Iwai <tiwai@...e.com>, Chris Mason <clm@...com>,
        Josef Bacik <jbacik@...com>, David Sterba <dsterba@...e.com>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/4] printk/kdb: Handle more message headers

On Thu, 2016-10-27 at 17:52 +0200, Petr Mladek wrote:
> The commit 4bcc595ccd80decb4245096e ("printk: reinstate KERN_CONT for
> printing continuation lines") allows to define more message headers
> for a single message. The motivation is that continuous lines might
> get mixed. Therefore it make sense to define the right log level
> for every piece of a cont line.
> 
> This patch introduces printk_skip_headers() that will skip all
> headers and uses it in the kdb code instead of printk_skip_level().
> 
> This approach helps to fix other printk_skip_level() users
> independently.
> 
> Signed-off-by: Petr Mladek <pmladek@...e.com>
> ---
>  include/linux/printk.h    | 8 ++++++++
>  kernel/debug/kdb/kdb_io.c | 2 +-
>  2 files changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/include/linux/printk.h b/include/linux/printk.h
[]
> @@ -31,6 +31,14 @@ static inline const char *printk_skip_level(const char *buffer)
>  	return buffer;
>  }
>  
> +static inline const char *printk_skip_headers(const char *buffer)
> +{
> +	while (printk_get_level(buffer))
> +		buffer += 2;

At some point a level might be more than 1 char and
it would be good to keep that check in just one place
so using printk_skip_level would be more consistent.