[PATCH v8 04/27] mm/ksw: add build system support

[Jinchao Wang <wangjinchao600@gmail.com>]

Add Kconfig and Makefile infrastructure.

The implementation is located under `mm/kstackwatch/`.

Signed-off-by: Jinchao Wang <wangjinchao600@gmail.com>
---
 include/linux/kstackwatch.h |  5 +++++
 mm/Kconfig                  |  1 +
 mm/Makefile                 |  1 +
 mm/kstackwatch/Kconfig      | 14 ++++++++++++++
 mm/kstackwatch/Makefile     |  2 ++
 mm/kstackwatch/kernel.c     | 23 +++++++++++++++++++++++
 mm/kstackwatch/stack.c      |  1 +
 mm/kstackwatch/watch.c      |  1 +
 8 files changed, 48 insertions(+)
 create mode 100644 include/linux/kstackwatch.h
 create mode 100644 mm/kstackwatch/Kconfig
 create mode 100644 mm/kstackwatch/Makefile
 create mode 100644 mm/kstackwatch/kernel.c
 create mode 100644 mm/kstackwatch/stack.c
 create mode 100644 mm/kstackwatch/watch.c

diff --git a/include/linux/kstackwatch.h b/include/linux/kstackwatch.h
new file mode 100644
index 000000000000..0273ef478a26
--- /dev/null
+++ b/include/linux/kstackwatch.h
@@ -0,0 +1,5 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _KSTACKWATCH_H
+#define _KSTACKWATCH_H
+
+#endif /* _KSTACKWATCH_H */
diff --git a/mm/Kconfig b/mm/Kconfig
index 0e26f4fc8717..61d4e6edadf2 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -1373,5 +1373,6 @@ config FIND_NORMAL_PAGE
 	def_bool n
 
 source "mm/damon/Kconfig"
+source "mm/kstackwatch/Kconfig"
 
 endmenu
diff --git a/mm/Makefile b/mm/Makefile
index 21abb3353550..efc101816f00 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -92,6 +92,7 @@ obj-$(CONFIG_PAGE_POISONING) += page_poison.o
 obj-$(CONFIG_KASAN)	+= kasan/
 obj-$(CONFIG_KFENCE) += kfence/
 obj-$(CONFIG_KMSAN)	+= kmsan/
+obj-$(CONFIG_KSTACKWATCH)	+= kstackwatch/
 obj-$(CONFIG_FAILSLAB) += failslab.o
 obj-$(CONFIG_FAIL_PAGE_ALLOC) += fail_page_alloc.o
 obj-$(CONFIG_MEMTEST)		+= memtest.o
diff --git a/mm/kstackwatch/Kconfig b/mm/kstackwatch/Kconfig
new file mode 100644
index 000000000000..496caf264f35
--- /dev/null
+++ b/mm/kstackwatch/Kconfig
@@ -0,0 +1,14 @@
+config KSTACKWATCH
+	bool "Kernel Stack Watch"
+	depends on HAVE_HW_BREAKPOINT && KPROBES && FPROBE && STACKTRACE
+	help
+	  A lightweight real-time debugging tool to detect stack corruption
+	  and abnormal stack usage patterns in the kernel. It monitors stack
+	  boundaries and detects overwrites in real time using hardware
+	  breakpoints and probe-based instrumentation.
+
+	  This feature is intended for kernel developers or advanced users
+	  diagnosing rare stack overflow or memory corruption bugs. It may
+	  introduce minor overhead during runtime monitoring.
+
+	  If unsure, say N.
diff --git a/mm/kstackwatch/Makefile b/mm/kstackwatch/Makefile
new file mode 100644
index 000000000000..c99c621eac02
--- /dev/null
+++ b/mm/kstackwatch/Makefile
@@ -0,0 +1,2 @@
+obj-$(CONFIG_KSTACKWATCH)	+= kstackwatch.o
+kstackwatch-y := kernel.o stack.o watch.o
diff --git a/mm/kstackwatch/kernel.c b/mm/kstackwatch/kernel.c
new file mode 100644
index 000000000000..78f1d019225f
--- /dev/null
+++ b/mm/kstackwatch/kernel.c
@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+
+static int __init kstackwatch_init(void)
+{
+	pr_info("module loaded\n");
+	return 0;
+}
+
+static void __exit kstackwatch_exit(void)
+{
+	pr_info("module unloaded\n");
+}
+
+module_init(kstackwatch_init);
+module_exit(kstackwatch_exit);
+
+MODULE_AUTHOR("Jinchao Wang");
+MODULE_DESCRIPTION("Kernel Stack Watch");
+MODULE_LICENSE("GPL");
+
diff --git a/mm/kstackwatch/stack.c b/mm/kstackwatch/stack.c
new file mode 100644
index 000000000000..cec594032515
--- /dev/null
+++ b/mm/kstackwatch/stack.c
@@ -0,0 +1 @@
+// SPDX-License-Identifier: GPL-2.0
diff --git a/mm/kstackwatch/watch.c b/mm/kstackwatch/watch.c
new file mode 100644
index 000000000000..cec594032515
--- /dev/null
+++ b/mm/kstackwatch/watch.c
@@ -0,0 +1 @@
+// SPDX-License-Identifier: GPL-2.0
-- 
2.43.0