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

Petr Mladek
2014-11-06T15:13:24Z

On Wed 2014-11-05 15:21:30, Steven Rostedt wrote:
> On Wed, 5 Nov 2014 17:31:50 +0100
> Petr Mladek <pmladek@suse.cz> wrote:
>
>
> > > /**
> > > * seq_buf_print_seq - move the contents of seq_buf into a seq_file
> > > @@ -55,7 +55,7 @@ int seq_buf_vprintf(struct seq_buf *s, const char *fmt, va_list args)
> > >
> > > if (s->len < s->size) {
> > > len = vsnprintf(s->buffer + s->len, s->size - s->len, fmt, args);
> > > - if (s->len + len < s->size) {
> > > + if (s->len + len <= s->size) {
> >
> > This is always true because we limit vsnprintf() to write (s->size -
> > s->len) bytes. Similar problem is also in the other parts of this
> > patch.
>
> No, len is the length of bytes that should have been written, not the
> amount that has been written.

That is cool! I did not know that there was also this variant of the
printf() functions. I am still learning.

Best Regards,
Petr