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

[Peter Zijlstra]

On Wed, Aug 05, 2026 at 09:06:29PM -0400, Steven Rostedt wrote:
> 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?

Same as uprobes?