# Re: \[RFC PATCH v1 1/1\] tracing/kprobe: Add multi-probe support for 'perf\_kprobe' PMU

- From: Steven Rostedt \<rostedt@goodmis.org\>
- Date: 2023-08-21 14:29:33 
- List: linux-trace-kernel
- Page: https://ratatoskr.run/linux-trace-kernel/2023/08/2310003
- Thread: https://ratatoskr.run/linux-trace-kernel/2023/08/2305677/t.md

```text
On Sun, 20 Aug 2023 03:02:18 -0700
Song Liu [ref] wrote:

> > For the "unique symbol" + offset, you don't need the kallsyms, but need to
> > access the System.map or vmlinux image. In this case, we don't need to expand
> > the CAP_PERFMON capabilities.  
> 
> I agree this is not needed in this case. But I wonder whether it makes sense
> to give CAP_PERFMON access to /proc/kallsyms. Will this change make
> CAP_PERFMON less secure?

I guess the question is, does CAP_PERFMON allow seeing where the kernel
mapped itself via some other means? If not, then no, I would nack this as
being a security hole.

-- Steve
```