cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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tags.c (1332B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * This file contains common tag-based KASAN code.
      4 *
      5 * Copyright (c) 2018 Google, Inc.
      6 * Copyright (c) 2020 Google, Inc.
      7 */
      8
      9#include <linux/init.h>
     10#include <linux/kasan.h>
     11#include <linux/kernel.h>
     12#include <linux/memory.h>
     13#include <linux/mm.h>
     14#include <linux/static_key.h>
     15#include <linux/string.h>
     16#include <linux/types.h>
     17
     18#include "kasan.h"
     19
     20void kasan_set_free_info(struct kmem_cache *cache,
     21				void *object, u8 tag)
     22{
     23	struct kasan_alloc_meta *alloc_meta;
     24	u8 idx = 0;
     25
     26	alloc_meta = kasan_get_alloc_meta(cache, object);
     27	if (!alloc_meta)
     28		return;
     29
     30#ifdef CONFIG_KASAN_TAGS_IDENTIFY
     31	idx = alloc_meta->free_track_idx;
     32	alloc_meta->free_pointer_tag[idx] = tag;
     33	alloc_meta->free_track_idx = (idx + 1) % KASAN_NR_FREE_STACKS;
     34#endif
     35
     36	kasan_set_track(&alloc_meta->free_track[idx], GFP_NOWAIT);
     37}
     38
     39struct kasan_track *kasan_get_free_track(struct kmem_cache *cache,
     40				void *object, u8 tag)
     41{
     42	struct kasan_alloc_meta *alloc_meta;
     43	int i = 0;
     44
     45	alloc_meta = kasan_get_alloc_meta(cache, object);
     46	if (!alloc_meta)
     47		return NULL;
     48
     49#ifdef CONFIG_KASAN_TAGS_IDENTIFY
     50	for (i = 0; i < KASAN_NR_FREE_STACKS; i++) {
     51		if (alloc_meta->free_pointer_tag[i] == tag)
     52			break;
     53	}
     54	if (i == KASAN_NR_FREE_STACKS)
     55		i = alloc_meta->free_track_idx;
     56#endif
     57
     58	return &alloc_meta->free_track[i];
     59}