kasan: Cleanup the __HAVE_ARCH_SHADOW_MAP usage

As Linus suggested, __HAVE_ARCH_XYZ is "stupid" and "having historical
uses of it doesn't make it good". So migrate __HAVE_ARCH_SHADOW_MAP to
separate macros named after the respective functions.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: WANG Xuerui <git@xen0n.name>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

arch/loongarch/include/asm/kasan.h

@@ -10,8 +10,6 @@
 #include <asm/io.h>
 #include <asm/pgtable.h>
 
-#define __HAVE_ARCH_SHADOW_MAP
-
 #define KASAN_SHADOW_SCALE_SHIFT 3
 #define KASAN_SHADOW_OFFSET	_AC(CONFIG_KASAN_SHADOW_OFFSET, UL)
 
@@ -68,6 +66,7 @@ static __always_inline bool kasan_arch_is_ready(void)
 	return !kasan_early_stage;
 }
 
+#define kasan_mem_to_shadow kasan_mem_to_shadow
 static inline void *kasan_mem_to_shadow(const void *addr)
 {
 	if (!kasan_arch_is_ready()) {
@@ -97,6 +96,7 @@ static inline void *kasan_mem_to_shadow(const void *addr)
 	}
 }
 
+#define kasan_shadow_to_mem kasan_shadow_to_mem
 static inline const void *kasan_shadow_to_mem(const void *shadow_addr)
 {
 	unsigned long addr = (unsigned long)shadow_addr;
@@ -119,6 +119,12 @@ static inline const void *kasan_shadow_to_mem(const void *shadow_addr)
 	}
 }
 
+#define addr_has_metadata addr_has_metadata
+static __always_inline bool addr_has_metadata(const void *addr)
+{
+	return (kasan_mem_to_shadow((void *)addr) != NULL);
+}
+
 void kasan_init(void);
 asmlinkage void kasan_early_init(void);
 

include/linux/kasan.h

@@ -54,7 +54,7 @@ extern p4d_t kasan_early_shadow_p4d[MAX_PTRS_PER_P4D];
 int kasan_populate_early_shadow(const void *shadow_start,
 				const void *shadow_end);
 
-#ifndef __HAVE_ARCH_SHADOW_MAP
+#ifndef kasan_mem_to_shadow
 static inline void *kasan_mem_to_shadow(const void *addr)
 {
 	return (void *)((unsigned long)addr >> KASAN_SHADOW_SCALE_SHIFT)

mm/kasan/kasan.h

@@ -291,7 +291,7 @@ struct kasan_stack_ring {
 
 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
 
-#ifndef __HAVE_ARCH_SHADOW_MAP
+#ifndef kasan_shadow_to_mem
 static inline const void *kasan_shadow_to_mem(const void *shadow_addr)
 {
 	return (void *)(((unsigned long)shadow_addr - KASAN_SHADOW_OFFSET)
@@ -299,15 +299,13 @@ static inline const void *kasan_shadow_to_mem(const void *shadow_addr)
 }
 #endif
 
+#ifndef addr_has_metadata
 static __always_inline bool addr_has_metadata(const void *addr)
 {
-#ifdef __HAVE_ARCH_SHADOW_MAP
-	return (kasan_mem_to_shadow((void *)addr) != NULL);
-#else
 	return (kasan_reset_tag(addr) >=
 		kasan_shadow_to_mem((void *)KASAN_SHADOW_START));
-#endif
 }
+#endif
 
 /**
  * kasan_check_range - Check memory region, and report if invalid access.