Re: [PATCH v12 05/11] x86: hw_breakpoint: Add a kconfig to clarify when a breakpoint fires

[Masami Hiramatsu (Google) <mhiramat@kernel.org>]

On Mon, 17 Aug 2026 20:10:58 +0800
Jinchao Wang <wangjinchao600@gmail.com> wrote:

> On 8/7/2026 11:34 PM, Masami Hiramatsu (Google) wrote:
> > From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> > 
> > Add CONFIG_HAVE_POST_BREAKPOINT_HOOK which indicates the hw_breakpoint
> > on that architecture fires after the target memory has been modified.
> > This is currently x86 only behavior.
> > 
> > Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> > ---
> >  Changes in v11:
> >   - Move select to alphabetically sorted place.
> > ---
> >  arch/Kconfig         |   10 ++++++++++
> >  arch/x86/Kconfig     |    1 +
> >  kernel/trace/Kconfig |    1 +
> >  3 files changed, 12 insertions(+)
> > 
> > diff --git a/arch/Kconfig b/arch/Kconfig
> > index bea383408e32..a096952987a8 100644
> > --- a/arch/Kconfig
> > +++ b/arch/Kconfig
> > @@ -457,6 +457,16 @@ config HAVE_MIXED_BREAKPOINTS_REGS
> >  	  Select this option if your arch implements breakpoints under the
> >  	  latter fashion.
> >  
> > +config HAVE_POST_BREAKPOINT_HOOK
> > +	bool
> > +	depends on HAVE_HW_BREAKPOINT
> > +	help
> > +	  Depending on the arch implementation of hardware breakpoints,
> > +	  some of them provide breakpoint hook after the target memory
> > +	  is modified.
> > +	  Select this option if your arch implements breakpoints overflow
> > +	  handler hooks after the target memory is modified.
> > +
> >  config HAVE_MODIFY_LOCAL_HW_BREAKPOINT_ADDR
> >  	bool
> >  	depends on HAVE_HW_BREAKPOINT
> > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> > index 33908103d9a0..533010ab29a9 100644
> > --- a/arch/x86/Kconfig
> > +++ b/arch/x86/Kconfig
> > @@ -287,6 +287,7 @@ config X86
> >  	select MMU_GATHER_RCU_TABLE_FREE
> >  	select MMU_GATHER_MERGE_VMAS
> >  	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
> > +	select HAVE_POST_BREAKPOINT_HOOK
> >  	select HAVE_REGS_AND_STACK_ACCESS_API
> >  	select HAVE_RELIABLE_STACKTRACE		if UNWINDER_ORC || STACK_VALIDATION
> >  	select HAVE_FUNCTION_ARG_ACCESS_API
> > diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
> > index b58c2565024f..d9b6fa5c35d9 100644
> > --- a/kernel/trace/Kconfig
> > +++ b/kernel/trace/Kconfig
> > @@ -866,6 +866,7 @@ config WPROBE_EVENTS
> >  	bool "Enable wprobe-based dynamic events"
> >  	depends on TRACING
> >  	depends on HAVE_HW_BREAKPOINT
> > +	depends on HAVE_POST_BREAKPOINT_HOOK
> >  	select PROBE_EVENTS
> >  	select DYNAMIC_EVENTS
> >  	help
> > 
> Reviewed-by: Jinchao Wang <wangjinchao600@gmail.com>

Thank you for your review!

I'll update this series.

Thanks,

-- 
Masami Hiramatsu (Google) <mhiramat@kernel.org>