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authorDmitry Vyukov <dvyukov@google.com>2017-05-08 15:56:48 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-05-08 17:15:12 -0700
commitf61e869d519c0c11a8d80a503cfdfb4897df855a (patch)
tree4befe4405314621e224b7118b42632364dc9be52
parent8c733420bdd5a6cc2d8540fb5aa32d1fbf3cb3ff (diff)
kcov: simplify interrupt check
in_interrupt() semantics are confusing and wrong for most users as it also returns true when bh is disabled. Thus we open coded a proper check for interrupts in __sanitizer_cov_trace_pc() with a lengthy explanatory comment. Use the new in_task() predicate instead. Link: http://lkml.kernel.org/r/20170321091026.139655-1-dvyukov@google.com Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: James Morse <james.morse@arm.com> Cc: Alexander Popov <alex.popov@linux.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--kernel/kcov.c9
1 files changed, 1 insertions, 8 deletions
diff --git a/kernel/kcov.c b/kernel/kcov.c
index 85e5546cd791..cd771993f96f 100644
--- a/kernel/kcov.c
+++ b/kernel/kcov.c
@@ -60,15 +60,8 @@ 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 || (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_OFFSET
- | NMI_MASK)))
+ if (!t || !in_task())
return;
mode = READ_ONCE(t->kcov_mode);
if (mode == KCOV_MODE_TRACE) {