hw-breakpoints: sample HW breakpoint over kernel data address

This patch introduces a sample kernel module to demonstrate the use of Hardware
Breakpoint feature. It places a breakpoint over the kernel variable 'pid_max'
to monitor all write operations and emits a function-backtrace when done.

Signed-off-by: K.Prasad <prasad@linux.vnet.ibm.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
diff --git a/samples/Kconfig b/samples/Kconfig
index b75d28c..8458516 100644
--- a/samples/Kconfig
+++ b/samples/Kconfig
@@ -45,5 +45,11 @@
 	default m
 	depends on SAMPLE_KPROBES && KRETPROBES
 
+config SAMPLE_HW_BREAKPOINT
+	tristate "Build kernel hardware breakpoint examples -- loadable module only"
+	depends on HAVE_HW_BREAKPOINT && m
+	help
+	  This builds kernel hardware breakpoint example modules.
+
 endif # SAMPLES