Re: [PATCH] arm64: hw_breakpoint: Save privilege of access control via ptrace

Oleg Nesterov
2024-06-20T09:09:52Z

On 06/20, Tiezhu Yang wrote:
>
> On 06/19/2024 11:15 PM, Oleg Nesterov wrote:
> >>--- a/include/uapi/linux/perf_event.h
> >>+++ b/include/uapi/linux/perf_event.h
> >>@@ -467,6 +467,7 @@ struct perf_event_attr {
> >> __u32 wakeup_watermark; /* bytes before wakeup */
> >> };
> >>
> >>+ __u8 bp_priv;
> >> __u32 bp_type;
> >
> >Is it safe to add the new member in the middle of uapi struct?
> >This will break userspace...
>
> Let me put the new member "bp_priv" at the end of uapi struct
> perf_event_attr in the next version if you are OK with it.

And add PERF_ATTR_SIZE_VER9 ?

Well, you can safely ignore me, you should ask the maintainers ;)

But to me the very idea of arm64-specific and "kernel only" member in
perf_event_attr looks a bit strange.

Oleg.