kasan: split out generic_report.c from report.c

Move generic KASAN specific error reporting routines to generic_report.c
without any functional changes, leaving common error reporting code in
report.c to be later reused by tag-based KASAN.

Link: http://lkml.kernel.org/r/ba48c32f8e5aefedee78998ccff0413bee9e0f5b.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/kasan/kasan.h

@@ -109,11 +109,18 @@ static inline const void *kasan_shadow_to_mem(const void *shadow_addr)
 		<< KASAN_SHADOW_SCALE_SHIFT);
 }
 
+static inline bool addr_has_shadow(const void *addr)
+{
+	return (addr >= kasan_shadow_to_mem((void *)KASAN_SHADOW_START));
+}
+
 void kasan_poison_shadow(const void *address, size_t size, u8 value);
 
 void check_memory_region(unsigned long addr, size_t size, bool write,
 				unsigned long ret_ip);
 
+const char *get_bug_type(struct kasan_access_info *info);
+
 void kasan_report(unsigned long addr, size_t size,
 		bool is_write, unsigned long ip);
 void kasan_report_invalid_free(void *object, unsigned long ip);