From 249207e4f46d4a491228e8655a3433946c54ba2a Mon Sep 17 00:00:00 2001 From: Ravi Bangoria Date: Tue, 22 Nov 2016 14:55:59 +0530 Subject: [PATCH] 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 Signed-off-by: Michael Ellerman [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings --- arch/powerpc/kernel/hw_breakpoint.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c index 2bc0584be81c..844c0e66dd30 100644 --- a/arch/powerpc/kernel/hw_breakpoint.c +++ b/arch/powerpc/kernel/hw_breakpoint.c @@ -226,8 +226,10 @@ 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); /* -- 2.39.2