143 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			143 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0 */
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| /*
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|  * The Kernel Concurrency Sanitizer (KCSAN) infrastructure. For more info please
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|  * 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 _KERNEL_KCSAN_KCSAN_H
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| #define _KERNEL_KCSAN_KCSAN_H
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| 
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| #include <linux/atomic.h>
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| #include <linux/kcsan.h>
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| #include <linux/sched.h>
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| 
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| /* The number of adjacent watchpoints to check. */
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| #define KCSAN_CHECK_ADJACENT 1
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| #define NUM_SLOTS (1 + 2*KCSAN_CHECK_ADJACENT)
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| 
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| extern unsigned int kcsan_udelay_task;
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| extern unsigned int kcsan_udelay_interrupt;
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| 
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| /*
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|  * Globally enable and disable KCSAN.
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|  */
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| extern bool kcsan_enabled;
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| 
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| /*
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|  * Save/restore IRQ flags state trace dirtied by KCSAN.
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|  */
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| void kcsan_save_irqtrace(struct task_struct *task);
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| void kcsan_restore_irqtrace(struct task_struct *task);
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| 
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| /*
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|  * Statistics counters displayed via debugfs; should only be modified in
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|  * slow-paths.
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|  */
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| enum kcsan_counter_id {
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| 	/*
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| 	 * Number of watchpoints currently in use.
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| 	 */
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| 	KCSAN_COUNTER_USED_WATCHPOINTS,
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| 
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| 	/*
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| 	 * Total number of watchpoints set up.
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| 	 */
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| 	KCSAN_COUNTER_SETUP_WATCHPOINTS,
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| 
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| 	/*
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| 	 * Total number of data races.
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| 	 */
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| 	KCSAN_COUNTER_DATA_RACES,
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| 
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| 	/*
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| 	 * Total number of ASSERT failures due to races. If the observed race is
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| 	 * due to two conflicting ASSERT type accesses, then both will be
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| 	 * counted.
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| 	 */
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| 	KCSAN_COUNTER_ASSERT_FAILURES,
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| 
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| 	/*
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| 	 * Number of times no watchpoints were available.
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| 	 */
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| 	KCSAN_COUNTER_NO_CAPACITY,
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| 
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| 	/*
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| 	 * A thread checking a watchpoint raced with another checking thread;
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| 	 * only one will be reported.
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| 	 */
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| 	KCSAN_COUNTER_REPORT_RACES,
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| 
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| 	/*
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| 	 * Observed data value change, but writer thread unknown.
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| 	 */
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| 	KCSAN_COUNTER_RACES_UNKNOWN_ORIGIN,
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| 
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| 	/*
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| 	 * The access cannot be encoded to a valid watchpoint.
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| 	 */
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| 	KCSAN_COUNTER_UNENCODABLE_ACCESSES,
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| 
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| 	/*
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| 	 * Watchpoint encoding caused a watchpoint to fire on mismatching
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| 	 * accesses.
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| 	 */
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| 	KCSAN_COUNTER_ENCODING_FALSE_POSITIVES,
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| 
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| 	KCSAN_COUNTER_COUNT, /* number of counters */
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| };
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| extern atomic_long_t kcsan_counters[KCSAN_COUNTER_COUNT];
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| 
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| /*
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|  * Returns true if data races in the function symbol that maps to func_addr
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|  * (offsets are ignored) should *not* be reported.
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|  */
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| extern bool kcsan_skip_report_debugfs(unsigned long func_addr);
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| 
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| /*
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|  * Value-change states.
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|  */
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| enum kcsan_value_change {
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| 	/*
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| 	 * Did not observe a value-change, however, it is valid to report the
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| 	 * race, depending on preferences.
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| 	 */
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| 	KCSAN_VALUE_CHANGE_MAYBE,
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| 
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| 	/*
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| 	 * Did not observe a value-change, and it is invalid to report the race.
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| 	 */
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| 	KCSAN_VALUE_CHANGE_FALSE,
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| 
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| 	/*
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| 	 * The value was observed to change, and the race should be reported.
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| 	 */
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| 	KCSAN_VALUE_CHANGE_TRUE,
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| };
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| 
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| /*
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|  * The calling thread hit and consumed a watchpoint: set the access information
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|  * to be consumed by the reporting thread. No report is printed yet.
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|  */
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| void kcsan_report_set_info(const volatile void *ptr, size_t size, int access_type,
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| 			   unsigned long ip, int watchpoint_idx);
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| 
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| /*
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|  * The calling thread observed that the watchpoint it set up was hit and
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|  * consumed: print the full report based on information set by the racing
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|  * thread.
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|  */
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| void kcsan_report_known_origin(const volatile void *ptr, size_t size, int access_type,
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| 			       unsigned long ip, enum kcsan_value_change value_change,
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| 			       int watchpoint_idx, u64 old, u64 new, u64 mask);
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| 
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| /*
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|  * No other thread was observed to race with the access, but the data value
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|  * before and after the stall differs. Reports a race of "unknown origin".
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|  */
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| void kcsan_report_unknown_origin(const volatile void *ptr, size_t size, int access_type,
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| 				 unsigned long ip, u64 old, u64 new, u64 mask);
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| 
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| #endif /* _KERNEL_KCSAN_KCSAN_H */
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