| Message ID | 20230623075805.1630-1-chanho.min@lge.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] kasan: fix mention for KASAN_HW_TAGS | expand |
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!
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.
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(-)