Add Kconfig and Makefile infrastructure for KStackWatch, a real-time tool
for debugging kernel stack corruption.
The implementation is located under `mm/kstackwatch/`.
Signed-off-by: Jinchao Wang <wangjinchao...@gmail.com>
---
mm/Kconfig.debug | 10 ++++++++++
mm/Makefile | 1 +
mm/kstackwatch/Makefile | 2 ++
mm/kstackwatch/kernel.c | 24 ++++++++++++++++++++++++
mm/kstackwatch/kstackwatch.h | 5 +++++
mm/kstackwatch/stack.c | 1 +
mm/kstackwatch/watch.c | 1 +
7 files changed, 44 insertions(+)
create mode 100644 mm/kstackwatch/Makefile
create mode 100644 mm/kstackwatch/kernel.c
create mode 100644 mm/kstackwatch/kstackwatch.h
create mode 100644 mm/kstackwatch/stack.c
create mode 100644 mm/kstackwatch/watch.c
diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug
index 32b65073d0cc..c2cc8c7b595f 100644
--- a/mm/Kconfig.debug
+++ b/mm/Kconfig.debug
@@ -309,3 +309,13 @@ config PER_VMA_LOCK_STATS
overhead in the page fault path.
If in doubt, say N.
+
+config KSTACK_WATCH
+ tristate "Kernel Stack Watch"
+ depends on STACKPROTECTOR && HAVE_HW_BREAKPOINT && KPROBES && FPROBE
+ help
+ A lightweight real-time debugging tool to detect stack corruption.
+ It can watch either the canary or local variable and tracks
+ the recursive depth of the monitored function.
+
+ If unsure, say N.
diff --git a/mm/Makefile b/mm/Makefile
index ef54aa615d9d..665c9f2bf987 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-$(CONFIG_KSTACK_WATCH) += kstackwatch/
obj-$(CONFIG_FAILSLAB) += failslab.o
obj-$(CONFIG_FAIL_PAGE_ALLOC) += fail_page_alloc.o
obj-$(CONFIG_MEMTEST) += memtest.o
diff --git a/mm/kstackwatch/Makefile b/mm/kstackwatch/Makefile
new file mode 100644
index 000000000000..84a46cb9a766
--- /dev/null
+++ b/mm/kstackwatch/Makefile
@@ -0,0 +1,2 @@
+obj-$(CONFIG_KSTACK_WATCH) += 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..93379a0a0f7e
--- /dev/null
+++ b/mm/kstackwatch/kernel.c
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/module.h>
+
+MODULE_AUTHOR("Jinchao Wang");
+MODULE_DESCRIPTION("Kernel Stack Watch");
+MODULE_LICENSE("GPL");
+
+static int __init kstackwatch_init(void)
+{
+ pr_info("KSW: module loaded\n");
+ pr_info("KSW: usage:\n");
+ pr_info("KSW: echo 'function+ip_offset[+depth]
[local_var_offset:local_var_len]' > /proc/kstackwatch\n");
+
+ return 0;
+}
+
+static void __exit kstackwatch_exit(void)
+{
+ pr_info("KSW: Module unloaded\n");
+}
+
+module_init(kstackwatch_init);
+module_exit(kstackwatch_exit);
diff --git a/mm/kstackwatch/kstackwatch.h b/mm/kstackwatch/kstackwatch.h
new file mode 100644
index 000000000000..0273ef478a26
--- /dev/null
+++ b/mm/kstackwatch/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/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
