[PATCH] kasan, doc: note kasan.fault=panic_on_write behaviour for async modes

From: Marco Elver
Date: Tue Jun 20 2023 - 13:17:57 EST


Note the behaviour of kasan.fault=panic_on_write for async modes, since
all asynchronous faults will result in panic (even if they are reads).

Fixes: 452c03fdbed0 ("kasan: add support for kasan.fault=panic_on_write")
Signed-off-by: Marco Elver <elver@xxxxxxxxxx>
---
Documentation/dev-tools/kasan.rst | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Documentation/dev-tools/kasan.rst b/Documentation/dev-tools/kasan.rst
index 7f37a46af574..f4acf9c2e90f 100644
--- a/Documentation/dev-tools/kasan.rst
+++ b/Documentation/dev-tools/kasan.rst
@@ -110,7 +110,9 @@ parameter can be used to control panic and reporting behaviour:
- ``kasan.fault=report``, ``=panic``, or ``=panic_on_write`` controls whether
to only print a KASAN report, panic the kernel, or panic the kernel on
invalid writes only (default: ``report``). The panic happens even if
- ``kasan_multi_shot`` is enabled.
+ ``kasan_multi_shot`` is enabled. Note that when using asynchronous mode of
+ Hardware Tag-Based KASAN, ``kasan.fault=panic_on_write`` always panics on
+ asynchronously checked accesses (including reads).

Software and Hardware Tag-Based KASAN modes (see the section about various
modes below) support altering stack trace collection behavior:
--
2.41.0.185.g7c58973941-goog