[RFC PATCH 1/2] kasan: hw_tags: Use KASAN_PAGE_REDZONE for vmalloc redzoning

[Dev Jain]

In preparation for adding "tag only on alloc" boot time option, use
KASAN_PAGE_REDZONE instead of KASAN_TAG_INVALID for poisoning the tail end
of the vmalloc allocation.

Although both values are the same for hw tags, KASAN_SLAB_REDZONE is used
for poisoning the tail end of a kmalloc object allocation, so maintain
the pattern.

Signed-off-by: Dev Jain <dev.jain at arm.com>
---
 mm/kasan/hw_tags.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c
index cbef5e450954e..c1a2b48808ed7 100644
--- a/mm/kasan/hw_tags.c
+++ b/mm/kasan/hw_tags.c
@@ -375,7 +375,7 @@ void *__kasan_unpoison_vmalloc(const void *start, unsigned long size,
 	redzone_start = round_up((unsigned long)start + size,
 				 KASAN_GRANULE_SIZE);
 	redzone_size = round_up(redzone_start, PAGE_SIZE) - redzone_start;
-	kasan_poison((void *)redzone_start, redzone_size, KASAN_TAG_INVALID,
+	kasan_poison((void *)redzone_start, redzone_size, KASAN_PAGE_REDZONE,
 		     flags & KASAN_VMALLOC_INIT);
 
 	/*
-- 
2.43.0