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-rw-r--r--include/linux/hardirq.h15
1 files changed, 15 insertions, 0 deletions
diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h
index f83288347dda..f3cf86e1465b 100644
--- a/include/linux/hardirq.h
+++ b/include/linux/hardirq.h
@@ -61,6 +61,12 @@
#error PREEMPT_ACTIVE is too low!
#endif
+#define NMI_OFFSET (PREEMPT_ACTIVE << 1)
+
+#if NMI_OFFSET >= 0x80000000
+#error PREEMPT_ACTIVE too high!
+#endif
+
#define hardirq_count() (preempt_count() & HARDIRQ_MASK)
#define softirq_count() (preempt_count() & SOFTIRQ_MASK)
#define irq_count() (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_MASK))
@@ -73,6 +79,11 @@
#define in_softirq() (softirq_count())
#define in_interrupt() (irq_count())
+/*
+ * Are we in NMI context?
+ */
+#define in_nmi() (preempt_count() & NMI_OFFSET)
+
#if defined(CONFIG_PREEMPT)
# define PREEMPT_INATOMIC_BASE kernel_locked()
# define PREEMPT_CHECK_OFFSET 1
@@ -167,6 +178,8 @@ extern void irq_exit(void);
#define nmi_enter() \
do { \
ftrace_nmi_enter(); \
+ BUG_ON(in_nmi()); \
+ add_preempt_count(NMI_OFFSET); \
lockdep_off(); \
rcu_nmi_enter(); \
__irq_enter(); \
@@ -177,6 +190,8 @@ extern void irq_exit(void);
__irq_exit(); \
rcu_nmi_exit(); \
lockdep_on(); \
+ BUG_ON(!in_nmi()); \
+ sub_preempt_count(NMI_OFFSET); \
ftrace_nmi_exit(); \
} while (0)