Merge tag 'core-rcu-2020-06-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull RCU updates from Ingo Molnar:
 "The RCU updates for this cycle were:

   - RCU-tasks update, including addition of RCU Tasks Trace for BPF use
     and TASKS_RUDE_RCU

   - kfree_rcu() updates.

   - Remove scheduler locking restriction

   - RCU CPU stall warning updates.

   - Torture-test updates.

   - Miscellaneous fixes and other updates"

* tag 'core-rcu-2020-06-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (103 commits)
  rcu: Allow for smp_call_function() running callbacks from idle
  rcu: Provide rcu_irq_exit_check_preempt()
  rcu: Abstract out rcu_irq_enter_check_tick() from rcu_nmi_enter()
  rcu: Provide __rcu_is_watching()
  rcu: Provide rcu_irq_exit_preempt()
  rcu: Make RCU IRQ enter/exit functions rely on in_nmi()
  rcu/tree: Mark the idle relevant functions noinstr
  x86: Replace ist_enter() with nmi_enter()
  x86/mce: Send #MC singal from task work
  x86/entry: Get rid of ist_begin/end_non_atomic()
  sched,rcu,tracing: Avoid tracing before in_nmi() is correct
  sh/ftrace: Move arch_ftrace_nmi_{enter,exit} into nmi exception
  lockdep: Always inline lockdep_{off,on}()
  hardirq/nmi: Allow nested nmi_enter()
  arm64: Prepare arch_nmi_enter() for recursion
  printk: Disallow instrumenting print_nmi_enter()
  printk: Prepare for nested printk_nmi_enter()
  rcutorture: Convert ULONG_CMP_LT() to time_before()
  torture: Add a --kasan argument
  torture: Save a few lines by using config_override_param initially
  ...

2 files changed, 12 insertions, 1 deletions

diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index b4f0e37b83eb..97656d20b9ea 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -71,7 +71,6 @@ config SUPERH32
 	select HAVE_FUNCTION_TRACER
 	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_DYNAMIC_FTRACE
-	select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
 	select ARCH_WANT_IPC_PARSE_VERSION
 	select HAVE_FUNCTION_GRAPH_TRACER
 	select HAVE_ARCH_KGDB
diff --git a/arch/sh/kernel/traps.c b/arch/sh/kernel/traps.c
index 63cf17bc760d..2130381c9d57 100644
--- a/arch/sh/kernel/traps.c
+++ b/arch/sh/kernel/traps.c
@@ -170,11 +170,21 @@ BUILD_TRAP_HANDLER(bug)
 	force_sig(SIGTRAP);
 }
 
+#ifdef CONFIG_DYNAMIC_FTRACE
+extern void arch_ftrace_nmi_enter(void);
+extern void arch_ftrace_nmi_exit(void);
+#else
+static inline void arch_ftrace_nmi_enter(void) { }
+static inline void arch_ftrace_nmi_exit(void) { }
+#endif
+
 BUILD_TRAP_HANDLER(nmi)
 {
 	unsigned int cpu = smp_processor_id();
 	TRAP_HANDLER_DECL;
 
+	arch_ftrace_nmi_enter();
+
 	nmi_enter();
 	nmi_count(cpu)++;
 
@@ -190,4 +200,6 @@ BUILD_TRAP_HANDLER(nmi)
 	}
 
 	nmi_exit();
+
+	arch_ftrace_nmi_exit();
 }