146 lines
3.3 KiB
C
146 lines
3.3 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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#ifndef _KERNEL_KCSAN_KCSAN_H
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#define _KERNEL_KCSAN_KCSAN_H
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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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/* 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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extern unsigned int kcsan_udelay_task;
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extern unsigned int kcsan_udelay_interrupt;
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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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* 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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* 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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* 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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* 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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* 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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* 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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* 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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* 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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* 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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* 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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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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* 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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* 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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* 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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* 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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enum kcsan_report_type {
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/*
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* The thread that set up the watchpoint and briefly stalled was
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* signalled that another thread triggered the watchpoint.
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*/
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KCSAN_REPORT_RACE_SIGNAL,
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/*
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* A thread found and consumed a matching watchpoint.
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*/
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KCSAN_REPORT_CONSUMED_WATCHPOINT,
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/*
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* No other thread was observed to race with the access, but the data
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* value before and after the stall differs.
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*/
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KCSAN_REPORT_RACE_UNKNOWN_ORIGIN,
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};
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/*
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* Print a race report from thread that encountered the race.
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*/
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extern void kcsan_report(const volatile void *ptr, size_t size, int access_type,
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enum kcsan_value_change value_change,
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enum kcsan_report_type type, int watchpoint_idx);
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#endif /* _KERNEL_KCSAN_KCSAN_H */
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