Re: [RFC][PATCH 07/12 v3] tracing: Have seq_buf use full buffer

Steven Rostedt
2014-11-06T19:24:28Z

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