Re: [PATCH] powerpc/xmon: Fix data-breakpoint
From: Michael Ellerman
Date: Tue Nov 22 2016 - 06:35:25 EST
Ravi Bangoria <ravi.bangoria@xxxxxxxxxxxxxxxxxx> writes:
> Xmon data-breakpoint feature is broken.
> Whenever there is a watchpoint match occurs, hw_breakpoint_handler will
> be called by do_break via notifier chains mechanism. If watchpoint is
> registered by xmon, hw_breakpoint_handler won't find any associated
> perf_event and returns immediately with NOTIFY_STOP. Similarly, do_break
> also returns without notifying to xmon.
> Solve this by returning NOTIFY_DONE when hw_breakpoint_handler does not
> find any perf_event associated with matched watchpoint.
.. rather than NOTIFY_STOP, which tells the core code to continue
calling the other breakpoint handlers including the xmon one.
Also any idea when we broke this?