diff options
Diffstat (limited to 'kernel/kcsan/report.c')
| -rw-r--r-- | kernel/kcsan/report.c | 43 |
1 files changed, 31 insertions, 12 deletions
diff --git a/kernel/kcsan/report.c b/kernel/kcsan/report.c index 7cd34285df74..3bc590e6be7e 100644 --- a/kernel/kcsan/report.c +++ b/kernel/kcsan/report.c @@ -34,11 +34,11 @@ static struct { } other_info = { .ptr = NULL }; /* - * Information about reported data races; used to rate limit reporting. + * Information about reported races; used to rate limit reporting. */ struct report_time { /* - * The last time the data race was reported. + * The last time the race was reported. */ unsigned long time; @@ -57,7 +57,7 @@ struct report_time { * * Therefore, we use a fixed-size array, which at most will occupy a page. This * still adequately rate limits reports, assuming that a) number of unique data - * races is not excessive, and b) occurrence of unique data races within the + * races is not excessive, and b) occurrence of unique races within the * same time window is limited. */ #define REPORT_TIMES_MAX (PAGE_SIZE / sizeof(struct report_time)) @@ -74,7 +74,7 @@ static struct report_time report_times[REPORT_TIMES_SIZE]; static DEFINE_SPINLOCK(report_lock); /* - * Checks if the data race identified by thread frames frame1 and frame2 has + * Checks if the race identified by thread frames frame1 and frame2 has * been reported since (now - KCSAN_REPORT_ONCE_IN_MS). */ static bool rate_limit_report(unsigned long frame1, unsigned long frame2) @@ -90,7 +90,7 @@ static bool rate_limit_report(unsigned long frame1, unsigned long frame2) invalid_before = jiffies - msecs_to_jiffies(CONFIG_KCSAN_REPORT_ONCE_IN_MS); - /* Check if a matching data race report exists. */ + /* Check if a matching race report exists. */ for (i = 0; i < REPORT_TIMES_SIZE; ++i) { struct report_time *rt = &report_times[i]; @@ -114,7 +114,7 @@ static bool rate_limit_report(unsigned long frame1, unsigned long frame2) if (time_before(rt->time, invalid_before)) continue; /* before KCSAN_REPORT_ONCE_IN_MS ago */ - /* Reported recently, check if data race matches. */ + /* Reported recently, check if race matches. */ if ((rt->frame1 == frame1 && rt->frame2 == frame2) || (rt->frame1 == frame2 && rt->frame2 == frame1)) return true; @@ -142,11 +142,12 @@ skip_report(bool value_change, unsigned long top_frame) * 3. write watchpoint, conflicting write (value_change==true): report; * 4. write watchpoint, conflicting write (value_change==false): skip; * 5. write watchpoint, conflicting read (value_change==false): skip; - * 6. write watchpoint, conflicting read (value_change==true): impossible; + * 6. write watchpoint, conflicting read (value_change==true): report; * * Cases 1-4 are intuitive and expected; case 5 ensures we do not report - * data races where the write may have rewritten the same value; and - * case 6 is simply impossible. + * data races where the write may have rewritten the same value; case 6 + * is possible either if the size is larger than what we check value + * changes for or the access type is KCSAN_ACCESS_ASSERT. */ if (IS_ENABLED(CONFIG_KCSAN_REPORT_VALUE_CHANGE_ONLY) && !value_change) { /* @@ -178,11 +179,27 @@ static const char *get_access_type(int type) return "write"; case KCSAN_ACCESS_WRITE | KCSAN_ACCESS_ATOMIC: return "write (marked)"; + + /* + * ASSERT variants: + */ + case KCSAN_ACCESS_ASSERT: + case KCSAN_ACCESS_ASSERT | KCSAN_ACCESS_ATOMIC: + return "assert no writes"; + case KCSAN_ACCESS_ASSERT | KCSAN_ACCESS_WRITE: + case KCSAN_ACCESS_ASSERT | KCSAN_ACCESS_WRITE | KCSAN_ACCESS_ATOMIC: + return "assert no accesses"; + default: BUG(); } } +static const char *get_bug_type(int type) +{ + return (type & KCSAN_ACCESS_ASSERT) != 0 ? "assert: race" : "data-race"; +} + /* Return thread description: in task or interrupt. */ static const char *get_thread_desc(int task_id) { @@ -268,13 +285,15 @@ static bool print_report(const volatile void *ptr, size_t size, int access_type, * Do not print offset of functions to keep title short. */ cmp = sym_strcmp((void *)other_frame, (void *)this_frame); - pr_err("BUG: KCSAN: data-race in %ps / %ps\n", + pr_err("BUG: KCSAN: %s in %ps / %ps\n", + get_bug_type(access_type | other_info.access_type), (void *)(cmp < 0 ? other_frame : this_frame), (void *)(cmp < 0 ? this_frame : other_frame)); } break; case KCSAN_REPORT_RACE_UNKNOWN_ORIGIN: - pr_err("BUG: KCSAN: data-race in %pS\n", (void *)this_frame); + pr_err("BUG: KCSAN: %s in %pS\n", get_bug_type(access_type), + (void *)this_frame); break; default: @@ -427,7 +446,7 @@ void kcsan_report(const volatile void *ptr, size_t size, int access_type, /* * With TRACE_IRQFLAGS, lockdep's IRQ trace state becomes corrupted if * we do not turn off lockdep here; this could happen due to recursion - * into lockdep via KCSAN if we detect a data race in utilities used by + * into lockdep via KCSAN if we detect a race in utilities used by * lockdep. */ lockdep_off(); |