Re: [PATCH 1/7 v2] tracefs: Revert ccbd54ff54e8 ("tracefs: Restrict tracefs when the kernel is locked down")

From: Steven Rostedt
Date: Sat Oct 12 2019 - 20:35:07 EST

On Sat, 12 Oct 2019 15:56:15 -0700
Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:

> On Fri, Oct 11, 2019 at 5:59 PM Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
> >
> >
> > I bisected this down to the addition of the proxy_ops into tracefs for
> > lockdown. It appears that the allocation of the proxy_ops and then freeing
> > it in the destroy_inode callback, is causing havoc with the memory system.
> > Reading the documentation about destroy_inode and talking with Linus about
> > this, this is buggy and wrong.
> Can you still add the explanation about the inode memory leak to this message?
> Right now it just says "it's buggy and wrong". True. But doesn't
> explain _why_ it is buggy and wrong.

Sure. The patches just finished my testing (along with other fixes that
I need to send you). I have to make a few other updates in the change
log though, so I'll be rebasing them (but not touching the code), to
clean up the change logs.

-- Steve