[PATCH v5 06/17] arm64: stacktrace: Add description of stacktrace/common.h

Kalesh Singh
2022-07-21T05:58:04Z

Add brief description on how to use stacktrace/common.h to implement
a stack unwinder.

Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
---

Changes in v5:
- Add short description of each required function, per Fuad and Marc
- Add Reviewed-by tag from Fuad

arch/arm64/include/asm/stacktrace/common.h | 15 +++++++++++++++
1 file changed, 15 insertions(+)

diff --git a/arch/arm64/include/asm/stacktrace/common.h b/arch/arm64/include/asm/stacktrace/common.h
index 7807752aaab1..be7920ba70b0 100644
--- a/arch/arm64/include/asm/stacktrace/common.h
+++ b/arch/arm64/include/asm/stacktrace/common.h
@@ -2,6 +2,21 @@
/*
* Common arm64 stack unwinder code.
*
+ * To implement a new arm64 stack unwinder:
+ * 1) Include this header
+ *
+ * 2) Provide implementations for the following functions:
+ * on_overflow_stack(): Returns true if SP is on the overflow
+ * stack.
+ * on_accessible_stack(): Returns true is SP is on any accessible
+ * stack.
+ * unwind_next(): Performs validation checks on the frame
+ * pointer, and transitions unwind_state
+ * to the next frame.
+ *
+ * See: arch/arm64/include/asm/stacktrace.h for reference
+ * implementations.
+ *
* Copyright (C) 2012 ARM Ltd.
*/
#ifndef __ASM_STACKTRACE_COMMON_H
--
2.37.0.170.g444d1eabd0-goog