[PATCH v4 4/4] kasan: update documentation for generic kasan

[Walter Wu]

Generic KASAN will support to record the last two call_rcu() call
stacks and print them in KASAN report. So need to update documentation.

Signed-off-by: Walter Wu <walter-zh.wu@xxxxxxxxxxxx>
Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
---
 Documentation/dev-tools/kasan.rst | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/dev-tools/kasan.rst b/Documentation/dev-tools/kasan.rst
index c652d740735d..fede42e6536b 100644
--- a/Documentation/dev-tools/kasan.rst
+++ b/Documentation/dev-tools/kasan.rst
@@ -193,6 +193,9 @@ function calls GCC directly inserts the code to check the shadow memory.
 This option significantly enlarges kernel but it gives x1.1-x2 performance
 boost over outline instrumented kernel.
 
+Generic KASAN prints up to 2 call_rcu() call stacks in reports, the last one
+and the second to last.
+
 Software tag-based KASAN
 ~~~~~~~~~~~~~~~~~~~~~~~~
 
-- 
2.18.0