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authorIngo Molnar <mingo@kernel.org>2016-11-11 08:25:07 +0100
committerIngo Molnar <mingo@kernel.org>2016-11-11 08:25:07 +0100
commit4c8ee71620d734c8ad129fad085167f56f9ce351 (patch)
tree87208b0144aa664c96dd8b43bbcaaf1f25af606b /kernel/kcov.c
parentc7faee2109f978f3ef826c48b7e60609061fda4f (diff)
parent27bcd37e0240bbe33f0efe244b5aad52104115b3 (diff)
Merge branch 'linus' into locking/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/kcov.c')
-rw-r--r--kernel/kcov.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/kernel/kcov.c b/kernel/kcov.c
index 8d44b3fea9d0..30e6d05aa5a9 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) {