linux-kernel - Re: [PATCH 1/4] printk/NMI: Handle continuous lines and missing newline

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Message-ID: <20161031085147.GN12522@suse.cz>
Date:   Mon, 31 Oct 2016 09:51:47 +0100
From:   David Sterba <dsterba@...e.cz>
To:     Petr Mladek <pmladek@...e.com>
Cc:     Linus Torvalds <torvalds@...ux-foundation.org>,
        Chris Mason <clm@...com>, Josef Bacik <jbacik@...com>,
        Sergey Senozhatsky <sergey.senozhatsky.work@...il.com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Joe Perches <joe@...ches.com>,
        Jaroslav Kysela <perex@...ex.cz>,
        Takashi Iwai <tiwai@...e.com>, linux-kernel@...r.kernel.org,
        Jason Wessel <jason.wessel@...driver.com>
Subject: Re: [PATCH 1/4] printk/NMI: Handle continuous lines and missing
 newline

On Thu, Oct 27, 2016 at 05:52:51PM +0200, Petr Mladek wrote:
> +static int printk_nmi_flush_buffer(unsigned char *start, size_t len)
>  {
> -	const char *buf = s->buffer + start;
> +	unsigned char *c, *end;
> +	bool header;
> +
> +	c = start;
> +	end = start + len;
> +	header = true;
> +
> +	/* Print line by line. */
> +	while (c < end) {
> +		if (*c == '\n') {
> +			printk_nmi_flush_line(start, c - start + 1);
> +			start = ++c;
> +			header = true;
> +			continue;
> +		}
>  
> -	printk_nmi_flush_line(buf, (end - start) + 1);
> +		/* Handle continuous lines or missing new line. */
> +		if ((c + 1 < end) && printk_get_level(c)) {
> +			if (header) {
> +				c += 2;
> +				continue;
> +			}
> +
> +			printk_nmi_flush_line(start, c - start);
> +			start = c++;
> +			header = true;
> +			continue;
> +		}
> +
> +		header = false;
> +		c++;
> +	}
> +
> +	/* Check if there was a partial line. Ignore pure header. */
> +	if (start < end && !header) {
> +		printk_nmi_flush_line(start, end - start);
> +		printk_nmi_flush_line("\n", strlen("\n"));

Not introduced by this patch as it was in the original code and the
compiler is smart enough to replace strlen("\n") with 1, but still it
looks strange.