1 files changed, 80 insertions, 0 deletions
diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c
new file mode 100644
index 000000000000..66419e908e21
--- /dev/null
+++ b/mm/kasan/hw_tags.c
@@ -0,0 +1,80 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * This file contains core hardware tag-based KASAN code.
+ *
+ * Copyright (c) 2020 Google, Inc.
+ * Author: Andrey Konovalov <andreyknvl@google.com>
+ */
+
+#define pr_fmt(fmt) "kasan: " fmt
+
+#include <linux/kasan.h>
+#include <linux/kernel.h>
+#include <linux/memory.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/types.h>
+
+#include "kasan.h"
+
+/* kasan_init_hw_tags_cpu() is called for each CPU. */
+void kasan_init_hw_tags_cpu(void)
+{
+	hw_init_tags(KASAN_TAG_MAX);
+	hw_enable_tagging();
+}
+
+/* kasan_init_hw_tags() is called once on boot CPU. */
+void __init kasan_init_hw_tags(void)
+{
+	pr_info("KernelAddressSanitizer initialized\n");
+}
+
+void *kasan_reset_tag(const void *addr)
+{
+	return reset_tag(addr);
+}
+
+void poison_range(const void *address, size_t size, u8 value)
+{
+	hw_set_mem_tag_range(reset_tag(address),
+			round_up(size, KASAN_GRANULE_SIZE), value);
+}
+
+void unpoison_range(const void *address, size_t size)
+{
+	hw_set_mem_tag_range(reset_tag(address),
+			round_up(size, KASAN_GRANULE_SIZE), get_tag(address));
+}
+
+u8 random_tag(void)
+{
+	return hw_get_random_tag();
+}
+
+bool check_invalid_free(void *addr)
+{
+	u8 ptr_tag = get_tag(addr);
+	u8 mem_tag = hw_get_mem_tag(addr);
+
+	return (mem_tag == KASAN_TAG_INVALID) ||
+		(ptr_tag != KASAN_TAG_KERNEL && ptr_tag != mem_tag);
+}
+
+void kasan_set_free_info(struct kmem_cache *cache,
+				void *object, u8 tag)
+{
+	struct kasan_alloc_meta *alloc_meta;
+
+	alloc_meta = get_alloc_info(cache, object);
+	kasan_set_track(&alloc_meta->free_track[0], GFP_NOWAIT);
+}
+
+struct kasan_track *kasan_get_free_track(struct kmem_cache *cache,
+				void *object, u8 tag)
+{
+	struct kasan_alloc_meta *alloc_meta;
+
+	alloc_meta = get_alloc_info(cache, object);
+	return &alloc_meta->free_track[0];
+}