kmsan-checks.h
/* SPDX-License-Identifier: GPL-2.0 */
/*
* KMSAN checks to be used for one-off annotations in subsystems.
*
* Copyright (C) 2017-2022 Google LLC
* Author: Alexander Potapenko <glider@google.com>
*
*/
#ifndef _LINUX_KMSAN_CHECKS_H
#define _LINUX_KMSAN_CHECKS_H
#include <linux/types.h>
#ifdef CONFIG_KMSAN
/**
* kmsan_poison_memory() - Mark the memory range as uninitialized.
* @address: address to start with.
* @size: size of buffer to poison.
* @flags: GFP flags for allocations done by this function.
*
* Until other data is written to this range, KMSAN will treat it as
* uninitialized. Error reports for this memory will reference the call site of
* kmsan_poison_memory() as origin.
*/
void kmsan_poison_memory(const void *address, size_t size, gfp_t flags);
/**
* kmsan_unpoison_memory() - Mark the memory range as initialized.
* @address: address to start with.
* @size: size of buffer to unpoison.
*
* Until other data is written to this range, KMSAN will treat it as
* initialized.
*/
void kmsan_unpoison_memory(const void *address, size_t size);
/**
* kmsan_check_memory() - Check the memory range for being initialized.
* @address: address to start with.
* @size: size of buffer to check.
*
* If any piece of the given range is marked as uninitialized, KMSAN will report
* an error.
*/
void kmsan_check_memory(const void *address, size_t size);
/**
* kmsan_copy_to_user() - Notify KMSAN about a data transfer to userspace.
* @to: destination address in the userspace.
* @from: source address in the kernel.
* @to_copy: number of bytes to copy.
* @left: number of bytes not copied.
*
* If this is a real userspace data transfer, KMSAN checks the bytes that were
* actually copied to ensure there was no information leak. If @to belongs to
* the kernel space (which is possible for compat syscalls), KMSAN just copies
* the metadata.
*/
void kmsan_copy_to_user(void __user *to, const void *from, size_t to_copy,
size_t left);
#else
static inline void kmsan_poison_memory(const void *address, size_t size,
gfp_t flags)
{
}
static inline void kmsan_unpoison_memory(const void *address, size_t size)
{
}
static inline void kmsan_check_memory(const void *address, size_t size)
{
}
static inline void kmsan_copy_to_user(void __user *to, const void *from,
size_t to_copy, size_t left)
{
}
#endif
#endif /* _LINUX_KMSAN_CHECKS_H */