The patch titled
Subject: kasan, doc: note kasan.fault=panic_on_write behaviour for async modes
has been added to the -mm mm-unstable branch. Its filename is
kasan-doc-note-kasanfault=panic_on_write-behaviour-for-async-modes.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/kasan-doc-note-kasanfault=panic_on_write-behaviour-for-async-modes.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Marco Elver <elver@xxxxxxxxxx>
Subject: kasan, doc: note kasan.fault=panic_on_write behaviour for async modes
Date: Tue, 20 Jun 2023 19:17:35 +0200
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).
Link: https://lkml.kernel.org/r/ZJHfL6vavKUZ3Yd8@xxxxxxxxxxxxxxxx
Fixes: 452c03fdbed0 ("kasan: add support for kasan.fault=panic_on_write")
Signed-off-by: Marco Elver <elver@xxxxxxxxxx>
Reviewed-by: Andrey Konovalov <andreyknvl@xxxxxxxxx>
Cc: Aleksandr Nogikh <nogikh@xxxxxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Taras Madan <tarasmadan@xxxxxxxxxx>
Cc: Vincenzo Frascino <vincenzo.frascino@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/dev-tools/kasan.rst | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/Documentation/dev-tools/kasan.rst~kasan-doc-note-kasanfault=panic_on_write-behaviour-for-async-modes
+++ a/Documentation/dev-tools/kasan.rst
@@ -110,7 +110,9 @@ parameter can be used to control panic a
- ``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:
_
Patches currently in -mm which might be from elver@xxxxxxxxxx are
kasan-doc-note-kasanfault=panic_on_write-behaviour-for-async-modes.patch
