Re: [PATCH v11 04/11] tracing: wprobe: Add watchpoint probe event based on hardware breakpoint

[Steven Rostedt]

On Wed, 5 Aug 2026 21:39:09 +0200
Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:

> > > This seems limited to kernel addresses only? Should not also userspace
> > > addresses be supported?  
> > 
> > Hmm, how would that work? The address is global for all tasks, so if you
> > add a user space address, what task would that be for? The one writing the
> > probe?  
> 
> Schedule the watchpoint along with the task of course. Given there is
> breakpoint/perf integration this should be trivial.

I meant, what task is it attached to? Usually the way a probe works is to
create the probe and then enable it.

 # cd /sys/kernel/tracing
 # echo 'w:my_jiffies w@jiffies:8 value=+0($addr)' >> dynamic_events
 # echo 1 > events/wprobes/my_jiffies/enable

If the address is in user space, which task would that address be for?

What would the API look like? Should we add a pid to that for a specific task?

Maybe use zero for current task?

-- Steve