[v4] kmsan: Enable on s390

[PATCH v4 15/35] mm: slub: Let KMSAN access metadata

Posted by Ilya Leoshkevich 1 year, 8 months ago

Building the kernel with CONFIG_SLUB_DEBUG and CONFIG_KMSAN causes
KMSAN to complain about touching redzones in kfree().

Fix by extending the existing KASAN-related metadata_access_enable()
and metadata_access_disable() functions to KMSAN.

Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 mm/slub.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/mm/slub.c b/mm/slub.c
index 4dd55cabe701..a290f6c63e7b 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -829,10 +829,12 @@ static int disable_higher_order_debug;
 static inline void metadata_access_enable(void)
 {
 	kasan_disable_current();
+	kmsan_disable_current();
 }
 
 static inline void metadata_access_disable(void)
 {
+	kmsan_enable_current();
 	kasan_enable_current();
 }
 
-- 
2.45.1

Re: [PATCH v4 15/35] mm: slub: Let KMSAN access metadata

Posted by Alexander Potapenko 1 year, 7 months ago

On Thu, Jun 13, 2024 at 5:39 PM Ilya Leoshkevich <iii@linux.ibm.com> wrote:
>
> Building the kernel with CONFIG_SLUB_DEBUG and CONFIG_KMSAN causes
> KMSAN to complain about touching redzones in kfree().
>
> Fix by extending the existing KASAN-related metadata_access_enable()
> and metadata_access_disable() functions to KMSAN.
>
> Acked-by: Vlastimil Babka <vbabka@suse.cz>
> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>