cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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kcsan.h (3658B)

      1/* SPDX-License-Identifier: GPL-2.0 */
      2/*
      3 * The Kernel Concurrency Sanitizer (KCSAN) infrastructure. For more info please
      4 * see Documentation/dev-tools/kcsan.rst.
      5 *
      6 * Copyright (C) 2019, Google LLC.
      7 */
      8
      9#ifndef _KERNEL_KCSAN_KCSAN_H
     10#define _KERNEL_KCSAN_KCSAN_H
     11
     12#include <linux/atomic.h>
     13#include <linux/kcsan.h>
     14#include <linux/sched.h>
     15
     16/* The number of adjacent watchpoints to check. */
     17#define KCSAN_CHECK_ADJACENT 1
     18#define NUM_SLOTS (1 + 2*KCSAN_CHECK_ADJACENT)
     19
     20extern unsigned int kcsan_udelay_task;
     21extern unsigned int kcsan_udelay_interrupt;
     22
     23/*
     24 * Globally enable and disable KCSAN.
     25 */
     26extern bool kcsan_enabled;
     27
     28/*
     29 * Save/restore IRQ flags state trace dirtied by KCSAN.
     30 */
     31void kcsan_save_irqtrace(struct task_struct *task);
     32void kcsan_restore_irqtrace(struct task_struct *task);
     33
     34/*
     35 * Statistics counters displayed via debugfs; should only be modified in
     36 * slow-paths.
     37 */
     38enum kcsan_counter_id {
     39	/*
     40	 * Number of watchpoints currently in use.
     41	 */
     42	KCSAN_COUNTER_USED_WATCHPOINTS,
     43
     44	/*
     45	 * Total number of watchpoints set up.
     46	 */
     47	KCSAN_COUNTER_SETUP_WATCHPOINTS,
     48
     49	/*
     50	 * Total number of data races.
     51	 */
     52	KCSAN_COUNTER_DATA_RACES,
     53
     54	/*
     55	 * Total number of ASSERT failures due to races. If the observed race is
     56	 * due to two conflicting ASSERT type accesses, then both will be
     57	 * counted.
     58	 */
     59	KCSAN_COUNTER_ASSERT_FAILURES,
     60
     61	/*
     62	 * Number of times no watchpoints were available.
     63	 */
     64	KCSAN_COUNTER_NO_CAPACITY,
     65
     66	/*
     67	 * A thread checking a watchpoint raced with another checking thread;
     68	 * only one will be reported.
     69	 */
     70	KCSAN_COUNTER_REPORT_RACES,
     71
     72	/*
     73	 * Observed data value change, but writer thread unknown.
     74	 */
     75	KCSAN_COUNTER_RACES_UNKNOWN_ORIGIN,
     76
     77	/*
     78	 * The access cannot be encoded to a valid watchpoint.
     79	 */
     80	KCSAN_COUNTER_UNENCODABLE_ACCESSES,
     81
     82	/*
     83	 * Watchpoint encoding caused a watchpoint to fire on mismatching
     84	 * accesses.
     85	 */
     86	KCSAN_COUNTER_ENCODING_FALSE_POSITIVES,
     87
     88	KCSAN_COUNTER_COUNT, /* number of counters */
     89};
     90extern atomic_long_t kcsan_counters[KCSAN_COUNTER_COUNT];
     91
     92/*
     93 * Returns true if data races in the function symbol that maps to func_addr
     94 * (offsets are ignored) should *not* be reported.
     95 */
     96extern bool kcsan_skip_report_debugfs(unsigned long func_addr);
     97
     98/*
     99 * Value-change states.
    100 */
    101enum kcsan_value_change {
    102	/*
    103	 * Did not observe a value-change, however, it is valid to report the
    104	 * race, depending on preferences.
    105	 */
    106	KCSAN_VALUE_CHANGE_MAYBE,
    107
    108	/*
    109	 * Did not observe a value-change, and it is invalid to report the race.
    110	 */
    111	KCSAN_VALUE_CHANGE_FALSE,
    112
    113	/*
    114	 * The value was observed to change, and the race should be reported.
    115	 */
    116	KCSAN_VALUE_CHANGE_TRUE,
    117};
    118
    119/*
    120 * The calling thread hit and consumed a watchpoint: set the access information
    121 * to be consumed by the reporting thread. No report is printed yet.
    122 */
    123void kcsan_report_set_info(const volatile void *ptr, size_t size, int access_type,
    124			   unsigned long ip, int watchpoint_idx);
    125
    126/*
    127 * The calling thread observed that the watchpoint it set up was hit and
    128 * consumed: print the full report based on information set by the racing
    129 * thread.
    130 */
    131void kcsan_report_known_origin(const volatile void *ptr, size_t size, int access_type,
    132			       unsigned long ip, enum kcsan_value_change value_change,
    133			       int watchpoint_idx, u64 old, u64 new, u64 mask);
    134
    135/*
    136 * No other thread was observed to race with the access, but the data value
    137 * before and after the stall differs. Reports a race of "unknown origin".
    138 */
    139void kcsan_report_unknown_origin(const volatile void *ptr, size_t size, int access_type,
    140				 unsigned long ip, u64 old, u64 new, u64 mask);
    141
    142#endif /* _KERNEL_KCSAN_KCSAN_H */