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// 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 = kasan_get_alloc_meta(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 = kasan_get_alloc_meta(cache, object);
return &alloc_meta->free_track[0];
}
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