[PATCH mm v4 15/39] kasan: clean up metadata byte definitions

andrey.konovalov at linux.dev andrey.konovalov at linux.dev
Mon Dec 20 13:59:30 PST 2021


From: Andrey Konovalov <andreyknvl at google.com>

Most of the metadata byte values are only used for Generic KASAN.

Remove KASAN_KMALLOC_FREETRACK definition for !CONFIG_KASAN_GENERIC
case, and put it along with other metadata values for the Generic
mode under a corresponding ifdef.

Signed-off-by: Andrey Konovalov <andreyknvl at google.com>
Reviewed-by: Alexander Potapenko <glider at google.com>
---
 mm/kasan/kasan.h | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index c17fa8d26ffe..952cd6f9ca46 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -71,15 +71,16 @@ static inline bool kasan_sync_fault_possible(void)
 #define KASAN_PAGE_REDZONE      0xFE  /* redzone for kmalloc_large allocations */
 #define KASAN_KMALLOC_REDZONE   0xFC  /* redzone inside slub object */
 #define KASAN_KMALLOC_FREE      0xFB  /* object was freed (kmem_cache_free/kfree) */
-#define KASAN_KMALLOC_FREETRACK 0xFA  /* object was freed and has free track set */
 #else
 #define KASAN_FREE_PAGE         KASAN_TAG_INVALID
 #define KASAN_PAGE_REDZONE      KASAN_TAG_INVALID
 #define KASAN_KMALLOC_REDZONE   KASAN_TAG_INVALID
 #define KASAN_KMALLOC_FREE      KASAN_TAG_INVALID
-#define KASAN_KMALLOC_FREETRACK KASAN_TAG_INVALID
 #endif
 
+#ifdef CONFIG_KASAN_GENERIC
+
+#define KASAN_KMALLOC_FREETRACK 0xFA  /* object was freed and has free track set */
 #define KASAN_GLOBAL_REDZONE    0xF9  /* redzone for global variable */
 #define KASAN_VMALLOC_INVALID   0xF8  /* unallocated space in vmapped page */
 
@@ -110,6 +111,8 @@ static inline bool kasan_sync_fault_possible(void)
 #define KASAN_ABI_VERSION 1
 #endif
 
+#endif /* CONFIG_KASAN_GENERIC */
+
 /* Metadata layout customization. */
 #define META_BYTES_PER_BLOCK 1
 #define META_BLOCKS_PER_ROW 16
-- 
2.25.1




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