kasan: integrate the common part of two KASAN tag-based modes

[linux-2.6-microblaze.git] / mm / kasan / tags.c

diff --git a/mm/kasan/tags.c b/mm/kasan/tags.c
new file mode 100644 (file)
index 0000000..8f48b95
--- /dev/null
+++ b/mm/kasan/tags.c
@@ -0,0 +1,59 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * This file contains common tag-based KASAN code.
+ *
+ * Copyright (c) 2018 Google, Inc.
+ * Copyright (c) 2020 Google, Inc.
+ */
+
+#include <linux/init.h>
+#include <linux/kasan.h>
+#include <linux/kernel.h>
+#include <linux/memory.h>
+#include <linux/mm.h>
+#include <linux/static_key.h>
+#include <linux/string.h>
+#include <linux/types.h>
+
+#include "kasan.h"
+
+void kasan_set_free_info(struct kmem_cache *cache,
+                               void *object, u8 tag)
+{
+       struct kasan_alloc_meta *alloc_meta;
+       u8 idx = 0;
+
+       alloc_meta = kasan_get_alloc_meta(cache, object);
+       if (!alloc_meta)
+               return;
+
+#ifdef CONFIG_KASAN_TAGS_IDENTIFY
+       idx = alloc_meta->free_track_idx;
+       alloc_meta->free_pointer_tag[idx] = tag;
+       alloc_meta->free_track_idx = (idx + 1) % KASAN_NR_FREE_STACKS;
+#endif
+
+       kasan_set_track(&alloc_meta->free_track[idx], GFP_NOWAIT);
+}
+
+struct kasan_track *kasan_get_free_track(struct kmem_cache *cache,
+                               void *object, u8 tag)
+{
+       struct kasan_alloc_meta *alloc_meta;
+       int i = 0;
+
+       alloc_meta = kasan_get_alloc_meta(cache, object);
+       if (!alloc_meta)
+               return NULL;
+
+#ifdef CONFIG_KASAN_TAGS_IDENTIFY
+       for (i = 0; i < KASAN_NR_FREE_STACKS; i++) {
+               if (alloc_meta->free_pointer_tag[i] == tag)
+                       break;
+       }
+       if (i == KASAN_NR_FREE_STACKS)
+               i = alloc_meta->free_track_idx;
+#endif
+
+       return &alloc_meta->free_track[i];
+}