[PATCH v8 11/27] sched/ksw: add per-task context

Jinchao Wang
2025-11-10T16:37:31Z

Introduce struct ksw_ctx to enable lockless per-task state
tracking. This is required because KStackWatch operates in NMI context
(via kprobe handler) where traditional locking is unsafe.

Signed-off-by: Jinchao Wang <wangjinchao600@gmail.com>
---
include/linux/kstackwatch_types.h | 14 ++++++++++++++
include/linux/sched.h | 5 +++++
2 files changed, 19 insertions(+)
create mode 100644 include/linux/kstackwatch_types.h

diff --git a/include/linux/kstackwatch_types.h b/include/linux/kstackwatch_types.h
new file mode 100644
index 000000000000..8c4e9b0f0c6a
--- /dev/null
+++ b/include/linux/kstackwatch_types.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_KSTACKWATCH_TYPES_H
+#define _LINUX_KSTACKWATCH_TYPES_H
+#include <linux/types.h>
+
+struct ksw_watchpoint;
+struct ksw_ctx {
+ struct ksw_watchpoint *wp;
+ ulong sp;
+ u16 depth;
+ u16 generation;
+};
+
+#endif /* _LINUX_KSTACKWATCH_TYPES_H */
diff --git a/include/linux/sched.h b/include/linux/sched.h
index b469878de25c..db49325428b3 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -22,6 +22,7 @@
#include <linux/sem_types.h>
#include <linux/shm.h>
#include <linux/kmsan_types.h>
+#include <linux/kstackwatch_types.h>
#include <linux/mutex_types.h>
#include <linux/plist_types.h>
#include <linux/hrtimer_types.h>
@@ -1487,6 +1488,10 @@ struct task_struct {
struct kmsan_ctx kmsan_ctx;
#endif

+#if IS_ENABLED(CONFIG_KSTACKWATCH)
+ struct ksw_ctx ksw_ctx;
+#endif
+
#if IS_ENABLED(CONFIG_KUNIT)
struct kunit *kunit_test;
#endif
--
2.43.0