lib/Kconfig.kasan | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
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@gmail.com>
Signed-off-by: Chanho Min <chanho.min@lge.com>
---
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
On Fri, Jun 23, 2023 at 9:58 AM Chanho Min <chanho.min@lge.com> wrote: > > 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@gmail.com> > Signed-off-by: Chanho Min <chanho.min@lge.com> > --- > 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 > Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Thank you!
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