diff options
| author | Marco Elver <elver@google.com> | 2020-02-11 17:04:22 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2020-03-21 09:44:08 +0100 |
| commit | 81af89e15862909881ff010a0adb67148487e88a (patch) | |
| tree | d2cc4b1598e5136a418154244fbbff9997fde592 /kernel/kcsan/report.c | |
| parent | b738f6169f1260b4ed5bd9f220b1c84d79f3ab8d (diff) | |
kcsan: Add kcsan_set_access_mask() support
When setting up an access mask with kcsan_set_access_mask(), KCSAN will
only report races if concurrent changes to bits set in access_mask are
observed. Conveying access_mask via a separate call avoids introducing
overhead in the common-case fast-path.
Acked-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/kcsan/report.c')
| -rw-r--r-- | kernel/kcsan/report.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/kernel/kcsan/report.c b/kernel/kcsan/report.c index d871476dc134..11c791b886f3 100644 --- a/kernel/kcsan/report.c +++ b/kernel/kcsan/report.c @@ -132,6 +132,9 @@ static bool rate_limit_report(unsigned long frame1, unsigned long frame2) static bool skip_report(enum kcsan_value_change value_change, unsigned long top_frame) { + /* Should never get here if value_change==FALSE. */ + WARN_ON_ONCE(value_change == KCSAN_VALUE_CHANGE_FALSE); + /* * The first call to skip_report always has value_change==TRUE, since we * cannot know the value written of an instrumented access. For the 2nd @@ -493,7 +496,15 @@ void kcsan_report(const volatile void *ptr, size_t size, int access_type, kcsan_disable_current(); if (prepare_report(&flags, ptr, size, access_type, cpu_id, type)) { - if (print_report(ptr, size, access_type, value_change, cpu_id, type) && panic_on_warn) + /* + * Never report if value_change is FALSE, only if we it is + * either TRUE or MAYBE. In case of MAYBE, further filtering may + * be done once we know the full stack trace in print_report(). + */ + bool reported = value_change != KCSAN_VALUE_CHANGE_FALSE && + print_report(ptr, size, access_type, value_change, cpu_id, type); + + if (reported && panic_on_warn) panic("panic_on_warn set ...\n"); release_report(&flags, type); |