powerpc/xmon: Fix data-breakpoint

commit c21a493a2b44650707d06741601894329486f2ad upstream.

Currently 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.

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Willy Tarreau <w@1wt.eu>

This commit is contained in:

Ravi Bangoria

2016-11-22 14:55:59 +05:30

committed by

Willy Tarreau

parent 4289b9c0f9

commit 96a14fea86

1 changed files with 3 additions and 1 deletions

									
										arch/powerpc/kernel/hw_breakpoint.c
									
		+3
		-1
	
												View File
												
				@@ -228,8 +228,10 @@ int __kprobes hw_breakpoint_handler(struct die_args *args)

					rcu_read_lock();

					bp = __get_cpu_var(bp_per_reg);

					if (!bp)

					if (!bp) {

						rc = NOTIFY_DONE;

						goto out;

					}

					info = counter_arch_bp(bp);

					/*