76 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			76 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0 */
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| /*
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|  * The Kernel Concurrency Sanitizer (KCSAN) infrastructure. Public interface and
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|  * data structures to set up runtime. See kcsan-checks.h for explicit checks and
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|  * modifiers. For more info please see Documentation/dev-tools/kcsan.rst.
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|  *
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|  * Copyright (C) 2019, Google LLC.
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|  */
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| 
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| #ifndef _LINUX_KCSAN_H
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| #define _LINUX_KCSAN_H
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| 
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| #include <linux/kcsan-checks.h>
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| #include <linux/types.h>
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| 
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| #ifdef CONFIG_KCSAN
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| 
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| /*
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|  * Context for each thread of execution: for tasks, this is stored in
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|  * task_struct, and interrupts access internal per-CPU storage.
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|  */
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| struct kcsan_ctx {
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| 	int disable_count; /* disable counter */
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| 	int disable_scoped; /* disable scoped access counter */
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| 	int atomic_next; /* number of following atomic ops */
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| 
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| 	/*
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| 	 * We distinguish between: (a) nestable atomic regions that may contain
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| 	 * other nestable regions; and (b) flat atomic regions that do not keep
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| 	 * track of nesting. Both (a) and (b) are entirely independent of each
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| 	 * other, and a flat region may be started in a nestable region or
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| 	 * vice-versa.
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| 	 *
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| 	 * This is required because, for example, in the annotations for
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| 	 * seqlocks, we declare seqlock writer critical sections as (a) nestable
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| 	 * atomic regions, but reader critical sections as (b) flat atomic
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| 	 * regions, but have encountered cases where seqlock reader critical
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| 	 * sections are contained within writer critical sections (the opposite
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| 	 * may be possible, too).
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| 	 *
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| 	 * To support these cases, we independently track the depth of nesting
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| 	 * for (a), and whether the leaf level is flat for (b).
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| 	 */
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| 	int atomic_nest_count;
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| 	bool in_flat_atomic;
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| 
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| 	/*
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| 	 * Access mask for all accesses if non-zero.
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| 	 */
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| 	unsigned long access_mask;
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| 
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| 	/* List of scoped accesses; likely to be empty. */
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| 	struct list_head scoped_accesses;
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| 
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| #ifdef CONFIG_KCSAN_WEAK_MEMORY
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| 	/*
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| 	 * Scoped access for modeling access reordering to detect missing memory
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| 	 * barriers; only keep 1 to keep fast-path complexity manageable.
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| 	 */
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| 	struct kcsan_scoped_access reorder_access;
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| #endif
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| };
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| 
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| /**
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|  * kcsan_init - initialize KCSAN runtime
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|  */
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| void kcsan_init(void);
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| 
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| #else /* CONFIG_KCSAN */
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| 
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| static inline void kcsan_init(void)			{ }
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| 
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| #endif /* CONFIG_KCSAN */
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| 
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| #endif /* _LINUX_KCSAN_H */
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