Re: [patch] tracing: off by one in __trace_array_vprintk()

From: Dan Carpenter
Date: Wed Nov 26 2014 - 10:47:05 EST


On Wed, Nov 26, 2014 at 10:22:44AM -0500, Steven Rostedt wrote:
> On Wed, 26 Nov 2014 18:05:41 +0300
> Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote:
>
> > On Wed, Nov 26, 2014 at 09:43:06AM -0500, Steven Rostedt wrote:
> > > I highly doubt it's much of a speed up. And we do that by sacrificing
> > > that one byte of buffer, which would lose the printk if len does equal
> > > TRACE_BUF_SIZE.
> > >
> > > I don't see a bug here. What exactly are you trying to fix?
> >
> > Heh. vsnprintf() is going to put a NUL char at the end of the string
> > even if you don't plan to use it. :P
> >
> > Another option would be to just print truncated output. We could use
> > vscnprintf() and remove the off by one limit check.
>
> Yes, that is a better patch. The previous one wasn't really fixing
> anything. But printing truncated output is better than nothing.
>
> Want to send it officially?
>

Will do.

regards,
dan carpenter

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