Date: Thu, 6 Nov 2014 14:24:02 -0500
From: Steven Rostedt <rostedt@goodmis.org>
To: Petr Mladek <pmladek@suse.cz>
Cc: linux-kernel@vger.kernel.org, Ingo Molnar <mingo@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Jiri Kosina <jkosina@suse.cz>, "H. Peter Anvin" <hpa@zytor.com>,
        Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [RFC][PATCH 07/12 v3] tracing: Have seq_buf use full buffer
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On Thu, 6 Nov 2014 16:31:07 +0100
Petr Mladek <pmladek@suse.cz> wrote:

 
> I like the idea of having the exception only in the bitmap code and filling
> the whole buffer in other cases.
> 
> I am now in doubts about the overflow state. A solution would
> be to add an "overflow" flag to struct seq_bug. I agree that it
> is ugly but it looks more secure then "len = size + 1".
> 
> Well, I do not have that strong opinion about it. What do you think?

Ideally, I want struct seq_buf defined only within seq_buf.c, and all
users must access the buffer via function methods.

We would need to remove all the inline calls, which will have a small
affect on performance. But most seq_buf code is for output of text,
where this overhead would be a nit to the total cost of operations.

That would get rid of all users that think it's safe to access
s->buffer + s->len.

-- Steve
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