diff options
| author | Andrey Konovalov <andreyknvl@google.com> | 2016-10-27 17:46:21 -0700 |
|---|---|---|
| committer | Paul Lawrence <paullawrence@google.com> | 2017-12-18 09:41:57 -0800 |
| commit | d1c5c9c2c635018f06f3f0c726f4b9ff2283a406 (patch) | |
| tree | f8e589516f5c757c29eedf5eb9ca70a32bd8f8a5 | |
| parent | f82dbb707f3dcc992acf162af2c9e245a7f151a9 (diff) | |
UPSTREAM: kcov: properly check if we are in an interrupt
in_interrupt() returns a nonzero value when we are either in an
interrupt or have bh disabled via local_bh_disable(). Since we are
interested in only ignoring coverage from actual interrupts, do a proper
check instead of just calling in_interrupt().
As a result of this change, kcov will start to collect coverage from
within local_bh_disable()/local_bh_enable() sections.
Link: http://lkml.kernel.org/r/1476115803-20712-1-git-send-email-andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Nicolai Stange <nicstange@gmail.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: James Morse <james.morse@arm.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Bug: 64145065
(cherry-picked from b274c0bb394c6a69ac12feac7c2db81f5aff5a55)
Change-Id: I91364ef699f9af0a57959caf65372a6559d7a6b0
Signed-off-by: Paul Lawrence <paullawrence@google.com>
| -rw-r--r-- | kernel/kcov.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/kernel/kcov.c b/kernel/kcov.c index a02f2dddd1d7..e9bb8f59711f 100644 --- a/kernel/kcov.c +++ b/kernel/kcov.c @@ -53,8 +53,15 @@ void notrace __sanitizer_cov_trace_pc(void) /* * We are interested in code coverage as a function of a syscall inputs, * so we ignore code executed in interrupts. + * The checks for whether we are in an interrupt are open-coded, because + * 1. We can't use in_interrupt() here, since it also returns true + * when we are inside local_bh_disable() section. + * 2. We don't want to use (in_irq() | in_serving_softirq() | in_nmi()), + * since that leads to slower generated code (three separate tests, + * one for each of the flags). */ - if (!t || in_interrupt()) + if (!t || (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_OFFSET + | NMI_MASK))) return; mode = READ_ONCE(t->kcov_mode); if (mode == KCOV_MODE_TRACE) { |