Re: [PATCH v2] printk: Add kernel parameter to disable writes to /dev/kmsg

From: Greg Kroah-Hartman
Date: Mon Apr 25 2016 - 15:18:21 EST


On Mon, Apr 25, 2016 at 09:06:51PM +0200, Peter Zijlstra wrote:
> On Mon, Apr 25, 2016 at 02:56:06PM -0400, Steven Rostedt wrote:
> > +static bool __read_mostly devkmsg_disabled;
> > +static int __init disable_devkmsg(char *str)
> > +{
> > + devkmsg_disabled = true;
> > + return 0;
> > +}
> > +__setup("printk.disable_kmsg_write", disable_devkmsg);
>
> Again, please default enable and use an easier name to toggle this.
> Userspace flooding this with junk is really insane.

If you default enable, you break working systems today that want to log
stuff through this interface, sorry.

thanks,

greg k-h