Re: [PATCH -v4 2/2] printk: Add kernel parameter to control writes to /dev/kmsg

From: Dave Young
Date: Mon Jul 18 2016 - 01:20:45 EST


On 07/18/16 at 06:44am, Borislav Petkov wrote:
> On Mon, Jul 18, 2016 at 10:18:09AM +0800, Dave Young wrote:
> > I would say avoiding ratelimit during boot make no much sense. Userspace can not
> > write to /dev/kmsg when system_state == SYSTEM_BOOTING because init process
> > has not run yet.
>
> You're right - kernel_init() sets SYSTEM_RUNNING before running the init
> process. I probably should kill all that logic in the second patch.
>
> > I means to set printk.devkmsg=off by default, userspace can set it to
> > on by sysctl.
>
> That can't happen: DEVKMSG_LOG_MASK_LOCK.

Sorry, seems I do not get your point, suppose using the bis defined in your
patch, shouldn't below work?

#define DEVKMSG_LOG_MASK_DEFAULT 2

Thanks
Dave