KASAN_VMALLOC_KEEP_TAG
if (WARN_ON_ONCE(flags & KASAN_VMALLOC_KEEP_TAG))
__kasan_unpoison_vmalloc(addr, size, flags | KASAN_VMALLOC_KEEP_TAG);
KASAN_VMALLOC_KEEP_TAG);
tag = (flags & KASAN_VMALLOC_KEEP_TAG) ? get_tag(start) : kasan_random_tag();
if (unlikely(!(flags & KASAN_VMALLOC_KEEP_TAG)))