Re: printk: what is going on with additional newlines?

[Steven Rostedt]

On Wed, 30 Aug 2017 10:03:48 +0900
Sergey Senozhatsky <sergey.senozhatsky.work@xxxxxxxxx> wrote:

> Hello,
> 
> On (08/29/17 19:50), Steven Rostedt wrote:
> [..]
> > > A private buffer has none of those issues.  
> > 
> > What about using the seq_buf*() then?
> > 
> > 	struct seq_buf s;
> > 
> > 	buf = kmalloc(mysize);
> > 	seq_buf_init(&s, buf, mysize);
> > 
> > 	seq_printf(&s,"blah blah %d", bah_blah);
> > 	[...]
> > 	seq_printf(&s, "my last print\n");
> > 
> > 	printk("%.*s", s.len, s.buffer);
> > 
> > 	kfree(buf);  
> 
> could do. for a single continuation line printk("%.*s", s.len, s.buffer)
> this will work perfectly fine. for a more general case - backtraces, dumps,
> etc. - this requires some tweaks.

We could simply add a seq_buf_printk() that is implemented in the printk
proper, to parse the seq_buf buffer properly, and add the timestamps and
such.

-- Steve