Re: [PATCH] procfs: fix the output format in /proc/PID/wchan

From: Yafang Shao
Date: Thu Nov 22 2018 - 08:30:32 EST


On Thu, Nov 22, 2018 at 7:40 PM Alexey Dobriyan <adobriyan@xxxxxxxxx> wrote:
>
> On Wed, Nov 21, 2018 at 07:28:44PM -0800, Andrew Morton wrote:
> > On Mon, 19 Nov 2018 19:17:52 +0800 Yafang Shao <laoar.shao@xxxxxxxxx> wrote:
> >
> > > Just add the missing newline.
> > >
> > > ...
> > >
> > > --- a/fs/proc/base.c
> > > +++ b/fs/proc/base.c
> > > @@ -370,11 +370,12 @@ static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
> > > wchan = get_wchan(task);
> > > if (wchan && !lookup_symbol_name(wchan, symname)) {
> > > seq_puts(m, symname);
> > > + seq_putc(m, '\n');
> > > return 0;
> > > }
> > >
> > > print0:
> > > - seq_putc(m, '0');
> > > + seq_puts(m, "0\n");
> > > return 0;
> > > }
> > > #endif /* CONFIG_KALLSYMS */
> >
> > What is presently wrong with the wchan output? The changelog
> > should explain such things, please.
>
> It is just newline to make "cat /proc/*/wchan" output look cool.
> But newline can break something.

Could you pls. show some examples for what the newline may break ?

Thanks
Yafang