Re: [PATCH] printk: remove unnecessary kmalloc() from syslog during clear

From: Petr Mladek
Date: Tue Jun 26 2018 - 08:43:41 EST


On Mon 2018-06-25 23:44:07, Sergey Senozhatsky wrote:
> On (06/25/18 10:37), Steven Rostedt wrote:
> >
> > Is IMHO rather ugly.
>
> Either way works for me. So I'll leave it to you and Petr to decide :)
>
> > And the original patch has one more advantage. If buf and clear are
> > both NULL/zero, we don't take any locks.
>
> But we never use syslog_print_all(buf = NULL, clear = false). It's either
> NULL/true [move forward clear idx, do not copy to user], or !NULL/use defined
> value [copy to user, move or don't move clear idx forward]

Yup, I suggest the following version as a compromise. It has the code
duplication but I agree that it is negligible. Otherwise, it looks
cleaner.