On Fri, 2019-10-11 at 14:36 -0400, Steven Rostedt wrote:

On Fri, 11 Oct 2019 11:20:30 -0700
Linus Torvalds [off-list ref] wrote:

quoted

Willing to do that instead?

Honestly, what you described was my preferred solution ;-)

I just didn't want to upset the lockdown crowd if a new tracefs file
was opened without doing this.

Once locked down is set, can it ever be undone without rebooting?

[...]

Earlier versions of the lockdown patch set added a magic SysRq command
to turn it off.  That's not currently present upstream but there may be
plans to add it.

Ben.

-- 
Ben Hutchings
It is easier to change the specification to fit the program
than vice versa.