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