[tip: x86/entry] nmi, tracing: Make hardware latency tracing noinstr safe

[tip-bot2 for Thomas Gleixner]

The following commit has been merged into the x86/entry branch of tip:

Commit-ID:     1e826b1d2265d1e8ba5f51827a8dba2aa0295f6c
Gitweb:        https://git.kernel.org/tip/1e826b1d2265d1e8ba5f51827a8dba2aa0295f6c
Author:        Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate:    Thu, 21 May 2020 22:05:14 +02:00
Committer:     Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Tue, 26 May 2020 19:06:27 +02:00

nmi, tracing: Make hardware latency tracing noinstr safe

The hardware latency tracer calls into instrumentable functions. Move the
calls into the RCU watching sections and annotate them.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Acked-by: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Paul E. McKenney <paulmck@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20200521202116.904176298@xxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 include/linux/hardirq.h | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h
index e07cf85..29b862a 100644
--- a/include/linux/hardirq.h
+++ b/include/linux/hardirq.h
@@ -87,20 +87,24 @@ extern void rcu_nmi_exit(void);
 		arch_nmi_enter();				\
 		printk_nmi_enter();				\
 		lockdep_off();					\
-		ftrace_nmi_enter();				\
 		BUG_ON(in_nmi() == NMI_MASK);			\
 		__preempt_count_add(NMI_OFFSET + HARDIRQ_OFFSET);	\
 		rcu_nmi_enter();				\
 		lockdep_hardirq_enter();			\
+		instrumentation_begin();			\
+		ftrace_nmi_enter();				\
+		instrumentation_end();				\
 	} while (0)
 
 #define nmi_exit()						\
 	do {							\
+		instrumentation_begin();			\
+		ftrace_nmi_exit();				\
+		instrumentation_end();				\
 		lockdep_hardirq_exit();				\
 		rcu_nmi_exit();					\
 		BUG_ON(!in_nmi());				\
 		__preempt_count_sub(NMI_OFFSET + HARDIRQ_OFFSET);	\
-		ftrace_nmi_exit();				\
 		lockdep_on();					\
 		printk_nmi_exit();				\
 		arch_nmi_exit();				\