[PATCH v2] kasan: fix mention for KASAN_HW_TAGS

From: Chanho Min
Date: Fri Jun 23 2023 - 03:58:13 EST


This patch fixes description of the KASAN_HW_TAGS's memory consumption.
KASAN_HW_TAGS are dependent on the HW implementation and are not reserved
from system memory like shadow memory.

Suggested-by: Andrey Konovalov <andreyknvl@xxxxxxxxx>
Signed-off-by: Chanho Min <chanho.min@xxxxxxx>
---
lib/Kconfig.kasan | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan
index fdca89c05745..f8f9e12510b7 100644
--- a/lib/Kconfig.kasan
+++ b/lib/Kconfig.kasan
@@ -124,7 +124,8 @@ config KASAN_HW_TAGS
Supported only on arm64 CPUs starting from ARMv8.5 and relies on
Memory Tagging Extension and Top Byte Ignore.

- Consumes about 1/32nd of available memory.
+ Does not consume memory by itself but relies on the 1/32nd of
+ available memory being reserved by the firmware when MTE is enabled.

May potentially introduce problems related to pointer casting and
comparison, as it embeds a tag into the top byte of each pointer.
--
2.17.1