[lkml]   [2017]   [Mar]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[PATCH 4.10 160/167] powerpc/xmon: Fix data-breakpoint
4.10-stable review patch.  If anyone has any objections, please let me know.


From: Ravi Bangoria <>

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 <>
Signed-off-by: Michael Ellerman <>
Signed-off-by: Greg Kroah-Hartman <>

arch/powerpc/kernel/hw_breakpoint.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

--- a/arch/powerpc/kernel/hw_breakpoint.c
+++ b/arch/powerpc/kernel/hw_breakpoint.c
@@ -228,8 +228,10 @@ int hw_breakpoint_handler(struct die_arg

bp = __this_cpu_read(bp_per_reg);
- if (!bp)
+ if (!bp) {
goto out;
+ }
info = counter_arch_bp(bp);


 \ /
  Last update: 2017-03-10 10:44    [W:0.563 / U:24.012 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site