[mirror_ubuntu-jammy-kernel.git] / include / linux / kcsan.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * The Kernel Concurrency Sanitizer (KCSAN) infrastructure. Public interface and
 * data structures to set up runtime. See kcsan-checks.h for explicit checks and
 * modifiers. For more info please see Documentation/dev-tools/kcsan.rst.
 *
 * Copyright (C) 2019, Google LLC.
 */

#ifndef _LINUX_KCSAN_H
#define _LINUX_KCSAN_H

#include <linux/kcsan-checks.h>
#include <linux/types.h>

#ifdef CONFIG_KCSAN

/*
 * Context for each thread of execution: for tasks, this is stored in
 * task_struct, and interrupts access internal per-CPU storage.
 */
struct kcsan_ctx {
	int disable_count; /* disable counter */
	int atomic_next; /* number of following atomic ops */

	/*
	 * We distinguish between: (a) nestable atomic regions that may contain
	 * other nestable regions; and (b) flat atomic regions that do not keep
	 * track of nesting. Both (a) and (b) are entirely independent of each
	 * other, and a flat region may be started in a nestable region or
	 * vice-versa.
	 *
	 * This is required because, for example, in the annotations for
	 * seqlocks, we declare seqlock writer critical sections as (a) nestable
	 * atomic regions, but reader critical sections as (b) flat atomic
	 * regions, but have encountered cases where seqlock reader critical
	 * sections are contained within writer critical sections (the opposite
	 * may be possible, too).
	 *
	 * To support these cases, we independently track the depth of nesting
	 * for (a), and whether the leaf level is flat for (b).
	 */
	int atomic_nest_count;
	bool in_flat_atomic;

	/*
	 * Access mask for all accesses if non-zero.
	 */
	unsigned long access_mask;

	/* List of scoped accesses. */
	struct list_head scoped_accesses;
};

/**
 * kcsan_init - initialize KCSAN runtime
 */
void kcsan_init(void);

#else /* CONFIG_KCSAN */

static inline void kcsan_init(void)			{ }

#endif /* CONFIG_KCSAN */

#endif /* _LINUX_KCSAN_H */
Commit	Line	Data
dfd402a4	1	/* SPDX-License-Identifier: GPL-2.0 */
bd0ccc4a ME	2	/*
	3	* The Kernel Concurrency Sanitizer (KCSAN) infrastructure. Public interface and
	4	* data structures to set up runtime. See kcsan-checks.h for explicit checks and
	5	* modifiers. For more info please see Documentation/dev-tools/kcsan.rst.
	6	*
	7	* Copyright (C) 2019, Google LLC.
	8	*/
dfd402a4 ME	9
	10	#ifndef _LINUX_KCSAN_H
	11	#define _LINUX_KCSAN_H
	12
	13	#include <linux/kcsan-checks.h>
	14	#include <linux/types.h>
	15
	16	#ifdef CONFIG_KCSAN
	17
	18	/*
	19	* Context for each thread of execution: for tasks, this is stored in
	20	* task_struct, and interrupts access internal per-CPU storage.
	21	*/
	22	struct kcsan_ctx {
	23	int disable_count; /* disable counter */
	24	int atomic_next; /* number of following atomic ops */
	25
	26	/*
	27	* We distinguish between: (a) nestable atomic regions that may contain
	28	* other nestable regions; and (b) flat atomic regions that do not keep
	29	* track of nesting. Both (a) and (b) are entirely independent of each
	30	* other, and a flat region may be started in a nestable region or
	31	* vice-versa.
	32	*
	33	* This is required because, for example, in the annotations for
	34	* seqlocks, we declare seqlock writer critical sections as (a) nestable
	35	* atomic regions, but reader critical sections as (b) flat atomic
	36	* regions, but have encountered cases where seqlock reader critical
	37	* sections are contained within writer critical sections (the opposite
	38	* may be possible, too).
	39	*
	40	* To support these cases, we independently track the depth of nesting
	41	* for (a), and whether the leaf level is flat for (b).
	42	*/
	43	int atomic_nest_count;
	44	bool in_flat_atomic;
81af89e1 ME	45
	46	/*
	47	* Access mask for all accesses if non-zero.
	48	*/
	49	unsigned long access_mask;
757a4cef ME	50
	51	/* List of scoped accesses. */
	52	struct list_head scoped_accesses;
dfd402a4 ME	53	};
	54
	55	/**
	56	* kcsan_init - initialize KCSAN runtime
	57	*/
	58	void kcsan_init(void);
	59
dfd402a4 ME	60	#else /* CONFIG_KCSAN */
dfd402a4 ME	61
5cbaefe9	62	static inline void kcsan_init(void) { }
dfd402a4 ME	63
	64	#endif /* CONFIG_KCSAN */
	65
	66	#endif /* _LINUX_KCSAN_H */