Messages in this thread | | | Date | Mon, 25 Apr 2016 20:50:15 +0200 | From | Peter Zijlstra <> | Subject | Re: printk: Add kernel parameter to disable writes to /dev/kmsg |
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On Mon, Apr 25, 2016 at 01:06:29PM -0400, Steven Rostedt wrote: > Over the weekend my server was acting funny. The display wasn't working > well, and I assumed that a driver was going bad. I went to look at the > kernel dmesg, but the buffer only had the following over and over: > > [226062.401405] systemd-logind[3511]: Removed session 4168. > [226063.381051] systemd-logind[3511]: Removed session 4169.
> The kernel buffer was completely overridden by useless spewing from
Yes it does this. I usually fix this with: apt-get install sysvinit
> diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c > index bfbf284e4218..b704b48415a0 100644 > --- a/kernel/printk/printk.c > +++ b/kernel/printk/printk.c > @@ -85,6 +85,15 @@ static struct lockdep_map console_lock_dep_map = { > }; > #endif > > +static bool devkmsg_disabled; > +static int __init disable_devkmsg(char *str) > +{ > + devkmsg_disabled = true; > + return 0; > +} > +__setup("disable_devkmsg_write", disable_devkmsg); > +
Can't we default enable this? Or at the very least make this easier to type? I'll never remember how exactly this thing will be called.
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