path: root/include/linux/kasan.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_KASAN_H
#define _LINUX_KASAN_H

#include <linux/bug.h>
#include <linux/kasan-enabled.h>
#include <linux/kasan-tags.h>
#include <linux/kernel.h>
#include <linux/static_key.h>
#include <linux/types.h>

struct kmem_cache;
struct page;
struct slab;
struct vm_struct;
struct task_struct;

#ifdef CONFIG_KASAN

#include <linux/linkage.h>
#include <asm/kasan.h>

#endif

typedef unsigned int __bitwise kasan_vmalloc_flags_t;

#define KASAN_VMALLOC_NONE		((__force kasan_vmalloc_flags_t)0x00u)
#define KASAN_VMALLOC_INIT		((__force kasan_vmalloc_flags_t)0x01u)
#define KASAN_VMALLOC_VM_ALLOC		((__force kasan_vmalloc_flags_t)0x02u)
#define KASAN_VMALLOC_PROT_NORMAL	((__force kasan_vmalloc_flags_t)0x04u)
#define KASAN_VMALLOC_KEEP_TAG		((__force kasan_vmalloc_flags_t)0x08u)

#define KASAN_VMALLOC_PAGE_RANGE 0x1 /* Apply exsiting page range */
#define KASAN_VMALLOC_TLB_FLUSH  0x2 /* TLB flush */

#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)

#include <linux/pgtable.h>

/* Software KASAN implementations use shadow memory. */

#ifdef CONFIG_KASAN_SW_TAGS
/* This matches KASAN_TAG_INVALID. */
#define KASAN_SHADOW_INIT 0xFE
#else
#define KASAN_SHADOW_INIT 0
#endif

#ifndef PTE_HWTABLE_PTRS
#define PTE_HWTABLE_PTRS 0
#endif

extern unsigned char kasan_early_shadow_page[PAGE_SIZE];
extern pte_t kasan_early_shadow_pte[MAX_PTRS_PER_PTE + PTE_HWTABLE_PTRS];
extern pmd_t kasan_early_shadow_pmd[MAX_PTRS_PER_PMD];
extern pud_t kasan_early_shadow_pud[MAX_PTRS_PER_PUD];
extern p4d_t kasan_early_shadow_p4d[MAX_PTRS_PER_P4D];

int kasan_populate_early_shadow(const void *shadow_start,
				const void *shadow_end);

#ifndef kasan_mem_to_shadow
static inline void *kasan_mem_to_shadow(const void *addr)
{
	return (void *)((unsigned long)addr >> KASAN_SHADOW_SCALE_SHIFT)
		+ KASAN_SHADOW_OFFSET;
}
#endif

int kasan_add_zero_shadow(void *start, unsigned long size);
void kasan_remove_zero_shadow(void *start, unsigned long size);

/* Enable reporting bugs after kasan_disable_current() */
extern void kasan_enable_current(void);

/* Disable reporting bugs for current task */
extern void kasan_disable_current(void);

#else /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */

static inline int kasan_add_zero_shadow(void *start, unsigned long size)
{
	return 0;
}
static inline void kasan_remove_zero_shadow(void *start,
					unsigned long size)
{}

static inline void kasan_enable_current(void) {}
static inline void kasan_disable_current(void) {}

#endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */

#ifdef CONFIG_KASAN_HW_TAGS

#else /* CONFIG_KASAN_HW_TAGS */

#endif /* CONFIG_KASAN_HW_TAGS */

static inline bool kasan_has_integrated_init(void)
{
	return kasan_hw_tags_enabled();
}

#ifdef CONFIG_KASAN
void __kasan_unpoison_range(const void *addr, size_t size);
static __always_inline void kasan_unpoison_range(const void *addr, size_t size)
{
	if (kasan_enabled())
		__kasan_unpoison_range(addr, size);
}

void __kasan_poison_pages(struct page *page, unsigned int order, bool init);
static __always_inline void kasan_poison_pages(struct page *page,
						unsigned int order, bool init)
{
	if (kasan_enabled())
		__kasan_poison_pages(page, order, init);
}

bool __kasan_unpoison_pages(struct page *page, unsigned int order, bool init);
static __always_inline bool kasan_unpoison_pages(struct page *page,
						 unsigned int order, bool init)
{
	if (kasan_enabled())
		return __kasan_unpoison_pages(page, order, init);
	return false;
}

void __kasan_poison_slab(struct slab *slab);
static __always_inline void kasan_poison_slab(struct slab *slab)
{
	if (kasan_enabled())
		__kasan_poison_slab(slab);
}

void __kasan_unpoison_new_object(struct kmem_cache *cache, void *object);
/**
 * kasan_unpoison_new_object - Temporarily unpoison a new slab object.
 * @cache: Cache the object belong to.
 * @object: Pointer to the object.
 *
 * This function is intended for the slab allocator's internal use. It
 * temporarily unpoisons an object from a newly allocated slab without doing
 * anything else. The object must later be repoisoned by
 * kasan_poison_new_object().
 */
static __always_inline void kasan_unpoison_new_object(struct kmem_cache *cache,
							void *object)
{
	if (kasan_enabled())
		__kasan_unpoison_new_object(cache, object);
}

void __kasan_poison_new_object(struct kmem_cache *cache, void *object);
/**
 * kasan_poison_new_object - Repoison a new slab object.
 * @cache: Cache the object belong to.
 * @object: Pointer to the object.
 *
 * This function is intended for the slab allocator's internal use. It
 * repoisons an object that was previously unpoisoned by
 * kasan_unpoison_new_object() without doing anything else.
 */
static __always_inline void kasan_poison_new_object(struct kmem_cache *cache,
							void *object)
{
	if (kasan_enabled())
		__kasan_poison_new_object(cache, object);
}

void * __must_check __kasan_init_slab_obj(struct kmem_cache *cache,
					  const void *object);
static __always_inline void * __must_check kasan_init_slab_obj(
				struct kmem_cache *cache, const void *object)
{
	if (kasan_enabled())
		return __kasan_init_slab_obj(cache, object);
	return (void *)object;
}

bool __kasan_slab_pre_free(struct kmem_cache *s, void *object,
			unsigned long ip);
/**
 * kasan_slab_pre_free - Check whether freeing a slab object is safe.
 * @object: Object to be freed.
 *
 * This function checks whether freeing the given object is safe. It may
 * check for double-free and invalid-free bugs and report them.
 *
 * This function is intended only for use by the slab allocator.
 *
 * @Return true if freeing the object is unsafe; false otherwise.
 */
static __always_inline bool kasan_slab_pre_free(struct kmem_cache *s,
						void *object)
{
	if (kasan_enabled())
		return __kasan_slab_pre_free(s, object, _RET_IP_);
	return false;
}

bool __kasan_slab_free(struct kmem_cache *s, void *object, bool init,
		       bool still_accessible, bool no_quarantine);
/**
 * kasan_slab_free - Poison, initialize, and quarantine a slab object.
 * @object: Object to be freed.
 * @init: Whether to initialize the object.
 * @still_accessible: Whether the object contents are still accessible.
 *
 * This function informs that a slab object has been freed and is not
 * supposed to be accessed anymore, except when @still_accessible is set
 * (indicating that the object is in a SLAB_TYPESAFE_BY_RCU cache and an RCU
 * grace period might not have passed yet).
 *
 * For KASAN modes that have integrated memory initialization
 * (kasan_has_integrated_init() == true), this function also initializes
 * the object's memory. For other modes, the @init argument is ignored.
 *
 * This function might also take ownership of the object to quarantine it.
 * When this happens, KASAN will defer freeing the object to a later
 * stage and handle it internally until then. The return value indicates
 * whether KASAN took ownership of the object.
 *
 * This function is intended only for use by the slab allocator.
 *
 * @Return true if KASAN took ownership of the object; false otherwise.
 */
static __always_inline bool kasan_slab_free(struct kmem_cache *s,
					    void *object, bool init,
					    bool still_accessible,
					    bool no_quarantine)
{
	if (kasan_enabled())
		return __kasan_slab_free(s, object, init, still_accessible,
					 no_quarantine);
	return false;
}

void __kasan_kfree_large(void *ptr, unsigned long ip);
static __always_inline void kasan_kfree_large(void *ptr)
{
	if (kasan_enabled())
		__kasan_kfree_large(ptr, _RET_IP_);
}

void * __must_check __kasan_slab_alloc(struct kmem_cache *s,
				       void *object, gfp_t flags, bool init);
static __always_inline void * __must_check