kasan: rename SHADOW layout macros to META

This is a preparatory commit for the upcoming addition of a new hardware
tag-based (MTE-based) KASAN mode.

Hardware tag-based KASAN won't be using shadow memory, but will reuse
these macros.  Rename "SHADOW" to implementation-neutral "META".

No functional changes.

Link: https://lkml.kernel.org/r/f96244ec59dc17db35173ec352c5592b14aefaf8.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Signed-off-by: Vincenzo Frascino <[email protected]>
Reviewed-by: Marco Elver <[email protected]>
Reviewed-by: Alexander Potapenko <[email protected]>
Tested-by: Vincenzo Frascino <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Branislav Rankov <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Evgenii Stepanov <[email protected]>
Cc: Kevin Brodsky <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

mm/kasan/report.c

@@ -33,11 +33,11 @@
 #include "kasan.h"
 #include "../slab.h"
 
-/* Shadow layout customization. */
-#define SHADOW_BYTES_PER_BLOCK 1
-#define SHADOW_BLOCKS_PER_ROW 16
-#define SHADOW_BYTES_PER_ROW (SHADOW_BLOCKS_PER_ROW * SHADOW_BYTES_PER_BLOCK)
-#define SHADOW_ROWS_AROUND_ADDR 2
+/* Metadata layout customization. */
+#define META_BYTES_PER_BLOCK 1
+#define META_BLOCKS_PER_ROW 16
+#define META_BYTES_PER_ROW (META_BLOCKS_PER_ROW * META_BYTES_PER_BLOCK)
+#define META_ROWS_AROUND_ADDR 2
 
 static unsigned long kasan_flags;
 
@@ -240,7 +240,7 @@ static void print_address_description(void *addr, u8 tag)
 
 static bool row_is_guilty(const void *row, const void *guilty)
 {
-	return (row <= guilty) && (guilty < row + SHADOW_BYTES_PER_ROW);
+	return (row <= guilty) && (guilty < row + META_BYTES_PER_ROW);
 }
 
 static int shadow_pointer_offset(const void *row, const void *shadow)
@@ -249,7 +249,7 @@ static int shadow_pointer_offset(const void *row, const void *shadow)
 	 *    3 + (BITS_PER_LONG/8)*2 chars.
 	 */
 	return 3 + (BITS_PER_LONG/8)*2 + (shadow - row)*2 +
-		(shadow - row) / SHADOW_BYTES_PER_BLOCK + 1;
+		(shadow - row) / META_BYTES_PER_BLOCK + 1;
 }
 
 static void print_memory_metadata(const void *addr)
@@ -259,15 +259,15 @@ static void print_memory_metadata(const void *addr)
 	const void *shadow_row;
 
 	shadow_row = (void *)round_down((unsigned long)shadow,
-					SHADOW_BYTES_PER_ROW)
-		- SHADOW_ROWS_AROUND_ADDR * SHADOW_BYTES_PER_ROW;
+					META_BYTES_PER_ROW)
+		- META_ROWS_AROUND_ADDR * META_BYTES_PER_ROW;
 
 	pr_err("Memory state around the buggy address:\n");
 
-	for (i = -SHADOW_ROWS_AROUND_ADDR; i <= SHADOW_ROWS_AROUND_ADDR; i++) {
+	for (i = -META_ROWS_AROUND_ADDR; i <= META_ROWS_AROUND_ADDR; i++) {
 		const void *kaddr = kasan_shadow_to_mem(shadow_row);
 		char buffer[4 + (BITS_PER_LONG/8)*2];
-		char shadow_buf[SHADOW_BYTES_PER_ROW];
+		char shadow_buf[META_BYTES_PER_ROW];
 
 		snprintf(buffer, sizeof(buffer),
 			(i == 0) ? ">%px: " : " %px: ", kaddr);
@@ -276,17 +276,17 @@ static void print_memory_metadata(const void *addr)
 		 * function, because generic functions may try to
 		 * access kasan mapping for the passed address.
 		 */
-		memcpy(shadow_buf, shadow_row, SHADOW_BYTES_PER_ROW);
+		memcpy(shadow_buf, shadow_row, META_BYTES_PER_ROW);
 		print_hex_dump(KERN_ERR, buffer,
-			DUMP_PREFIX_NONE, SHADOW_BYTES_PER_ROW, 1,
-			shadow_buf, SHADOW_BYTES_PER_ROW, 0);
+			DUMP_PREFIX_NONE, META_BYTES_PER_ROW, 1,
+			shadow_buf, META_BYTES_PER_ROW, 0);
 
 		if (row_is_guilty(shadow_row, shadow))
 			pr_err("%*c\n",
 				shadow_pointer_offset(shadow_row, shadow),
 				'^');
 
-		shadow_row += SHADOW_BYTES_PER_ROW;
+		shadow_row += META_BYTES_PER_ROW;
 	}
 }