[PATCH v9 02/10] x86: hw_breakpoint: Add a kconfig to clarify when a breakpoint fires

[Masami Hiramatsu (Google)]

From: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>

Add CONFIG_HAVE_POST_BREAKPOINT_HOOK which indicates the hw_breakpoint
on that architecture fires after the target memory has been modified.
This is currently x86 only behavior.

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
---
 arch/Kconfig         |   10 ++++++++++
 arch/x86/Kconfig     |    1 +
 kernel/trace/Kconfig |    1 +
 3 files changed, 12 insertions(+)

diff --git a/arch/Kconfig b/arch/Kconfig
index fa7507ac8e13..959aee9568ff 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -457,6 +457,16 @@ config HAVE_MIXED_BREAKPOINTS_REGS
 	  Select this option if your arch implements breakpoints under the
 	  latter fashion.
 
+config HAVE_POST_BREAKPOINT_HOOK
+	bool
+	depends on HAVE_HW_BREAKPOINT
+	help
+	  Depending on the arch implementation of hardware breakpoints,
+	  some of them provide breakpoint hook after the target memory
+	  is modified.
+	  Select this option if your arch implements breakpoints overflow
+	  handler hooks after the target memory is modified.
+
 config HAVE_USER_RETURN_NOTIFIER
 	bool
 
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index bdad90f210e4..6b7e14ef8cfb 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -246,6 +246,7 @@ config X86
 	select HAVE_FUNCTION_TRACER
 	select HAVE_GCC_PLUGINS
 	select HAVE_HW_BREAKPOINT
+	select HAVE_POST_BREAKPOINT_HOOK
 	select HAVE_IOREMAP_PROT
 	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
 	select HAVE_IRQ_TIME_ACCOUNTING
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index b58c2565024f..d9b6fa5c35d9 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -866,6 +866,7 @@ config WPROBE_EVENTS
 	bool "Enable wprobe-based dynamic events"
 	depends on TRACING
 	depends on HAVE_HW_BREAKPOINT
+	depends on HAVE_POST_BREAKPOINT_HOOK
 	select PROBE_EVENTS
 	select DYNAMIC_EVENTS
 	help