diff options
Diffstat (limited to 'kernel/kcsan/core.c')
| -rw-r--r-- | kernel/kcsan/core.c | 31 |
1 files changed, 21 insertions, 10 deletions
diff --git a/kernel/kcsan/core.c b/kernel/kcsan/core.c index f1c38620e3cf..4d8ea0fca5f1 100644 --- a/kernel/kcsan/core.c +++ b/kernel/kcsan/core.c @@ -69,7 +69,6 @@ static DEFINE_PER_CPU(struct kcsan_ctx, kcsan_cpu_ctx) = { * slot=9: [10, 11, 9] * slot=63: [64, 65, 63] */ -#define NUM_SLOTS (1 + 2*KCSAN_CHECK_ADJACENT) #define SLOT_IDX(slot, i) (slot + ((i + KCSAN_CHECK_ADJACENT) % NUM_SLOTS)) /* @@ -171,12 +170,16 @@ try_consume_watchpoint(atomic_long_t *watchpoint, long encoded_watchpoint) return atomic_long_try_cmpxchg_relaxed(watchpoint, &encoded_watchpoint, CONSUMED_WATCHPOINT); } -/* - * Return true if watchpoint was not touched, false if consumed. - */ -static inline bool remove_watchpoint(atomic_long_t *watchpoint) +/* Return true if watchpoint was not touched, false if already consumed. */ +static inline bool consume_watchpoint(atomic_long_t *watchpoint) { - return atomic_long_xchg_relaxed(watchpoint, INVALID_WATCHPOINT) != CONSUMED_WATCHPOINT; + return atomic_long_xchg_relaxed(watchpoint, CONSUMED_WATCHPOINT) != CONSUMED_WATCHPOINT; +} + +/* Remove the watchpoint -- its slot may be reused after. */ +static inline void remove_watchpoint(atomic_long_t *watchpoint) +{ + atomic_long_set(watchpoint, INVALID_WATCHPOINT); } static __always_inline struct kcsan_ctx *get_ctx(void) @@ -322,7 +325,8 @@ static noinline void kcsan_found_watchpoint(const volatile void *ptr, if (consumed) { kcsan_report(ptr, size, type, KCSAN_VALUE_CHANGE_MAYBE, - KCSAN_REPORT_CONSUMED_WATCHPOINT); + KCSAN_REPORT_CONSUMED_WATCHPOINT, + watchpoint - watchpoints); } else { /* * The other thread may not print any diagnostics, as it has @@ -470,7 +474,7 @@ kcsan_setup_watchpoint(const volatile void *ptr, size_t size, int type) value_change = KCSAN_VALUE_CHANGE_TRUE; /* Check if this access raced with another. */ - if (!remove_watchpoint(watchpoint)) { + if (!consume_watchpoint(watchpoint)) { /* * Depending on the access type, map a value_change of MAYBE to * TRUE (always report) or FALSE (never report). @@ -500,7 +504,8 @@ kcsan_setup_watchpoint(const volatile void *ptr, size_t size, int type) if (is_assert && value_change == KCSAN_VALUE_CHANGE_TRUE) kcsan_counter_inc(KCSAN_COUNTER_ASSERT_FAILURES); - kcsan_report(ptr, size, type, value_change, KCSAN_REPORT_RACE_SIGNAL); + kcsan_report(ptr, size, type, value_change, KCSAN_REPORT_RACE_SIGNAL, + watchpoint - watchpoints); } else if (value_change == KCSAN_VALUE_CHANGE_TRUE) { /* Inferring a race, since the value should not have changed. */ @@ -510,9 +515,15 @@ kcsan_setup_watchpoint(const volatile void *ptr, size_t size, int type) if (IS_ENABLED(CONFIG_KCSAN_REPORT_RACE_UNKNOWN_ORIGIN) || is_assert) kcsan_report(ptr, size, type, KCSAN_VALUE_CHANGE_TRUE, - KCSAN_REPORT_RACE_UNKNOWN_ORIGIN); + KCSAN_REPORT_RACE_UNKNOWN_ORIGIN, + watchpoint - watchpoints); } + /* + * Remove watchpoint; must be after reporting, since the slot may be + * reused after this point. + */ + remove_watchpoint(watchpoint); kcsan_counter_dec(KCSAN_COUNTER_USED_WATCHPOINTS); out_unlock: if (!kcsan_interrupt_watcher) |