[PATCH 2/4] printk: store instead of processing cont parts

[Joe Perches]

On Mon, 2020-07-20 at 11:30 -0700, Linus Torvalds wrote:
> On Sun, Jul 19, 2020 at 6:51 PM Sergey Senozhatsky
> <sergey.senozhatsky at gmail.com> wrote:
> > Do I get it right, what you are saying is - when we process a PR_CONT
> > message the cont buffer should already contain previous non-LOG_NEWLINE
> > and non-PR_CONT message, otherwise it's a bug?
> 
> No.
> 
> I'm saying that the code that does PR_CONT should have done *some*
> printing before, otherwise it's at the very least questionable.
> 
> IOW, you can't just randomly start printing with PR_CONT, without
> having established _some_ context for it.

I believe there are at least a few cases that
_only_ use pr_cont to emit
complete lines.

For example: SEQ_printf in kernel/sched/debug.c