Re: [PATCH v4 3/3] tracefs: make root directory world-traversable

[Steven Rostedt]

On Fri, 15 May 2026 15:40:07 -0400
Anubhav Shelat <ashelat@xxxxxxxxxx> wrote:

> Change the default tracefs mount mode from 0700 to 0755. This allows
> unprivileged users to access the eventfs directories underneath which
> already use 0755.
> 
> Tracing data files use mode 0440 and 0640 so they are not exposed by
> this change. Only the format and id files, which have been marked as
> work-readable, become accessible.
> 
> Directory listings of kprobes and uprobes, which contain functions or
> binaries, become visible to unprivileged users but do not contain kernel
> addresses. Admins using probes can restore the previous behavior with
> chmod or mount -o mode=700.
> 

I've been thinking about this and I believe a better approach is to
make a eventfs that is mounted at:

 /sys/kernel/events

and be the same directory structure as /sys/kernel/tracing/events but
only contain read only files like "id" and "format". This directory
would be mounted as 555 and readable by all.

-- Steve