6 files changed, 45 insertions, 9 deletions

diff --git a/arch/x86/include/asm/trace/irq_vectors.h b/arch/x86/include/asm/trace/irq_vectors.h
index 2874df24e7a4..4cab890007a7 100644
--- a/arch/x86/include/asm/trace/irq_vectors.h
+++ b/arch/x86/include/asm/trace/irq_vectors.h
@@ -72,6 +72,17 @@ DEFINE_IRQ_VECTOR_EVENT(x86_platform_ipi);
 DEFINE_IRQ_VECTOR_EVENT(irq_work);
 
 /*
+ * We must dis-allow sampling irq_work_exit() because perf event sampling
+ * itself can cause irq_work, which would lead to an infinite loop;
+ *
+ *  1) irq_work_exit happens
+ *  2) generates perf sample
+ *  3) generates irq_work
+ *  4) goto 1
+ */
+TRACE_EVENT_PERF_PERM(irq_work_exit, is_sampling_event(p_event) ? -EPERM : 0);
+
+/*
  * call_function - called when entering/exiting a call function interrupt
  * vector handler
  */
diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index 9abbe630c456..8c9b7a1c4138 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -248,6 +248,9 @@ struct ftrace_event_call {
 #ifdef CONFIG_PERF_EVENTS
 	int				perf_refcount;
 	struct hlist_head __percpu	*perf_events;
+
+	int	(*perf_perm)(struct ftrace_event_call *,
+			     struct perf_event *);
 #endif
 };
 
@@ -317,6 +320,19 @@ struct ftrace_event_file {
 	}								\
 	early_initcall(trace_init_flags_##name);
 
+#define __TRACE_EVENT_PERF_PERM(name, expr...)				\
+	static int perf_perm_##name(struct ftrace_event_call *tp_event, \
+				    struct perf_event *p_event)		\
+	{								\
+		return ({ expr; });					\
+	}								\
+	static int __init trace_init_perf_perm_##name(void)		\
+	{								\
+		event_##name.perf_perm = &perf_perm_##name;		\
+		return 0;						\
+	}								\
+	early_initcall(trace_init_perf_perm_##name);
+
 #define PERF_MAX_TRACE_SIZE	2048
 
 #define MAX_FILTER_STR_VAL	256	/* Should handle KSYM_SYMBOL_LEN */
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index ebeab360d851..f16dc0a40049 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -267,6 +267,8 @@ static inline void tracepoint_synchronize_unregister(void)
 
 #define TRACE_EVENT_FLAGS(event, flag)
 
+#define TRACE_EVENT_PERF_PERM(event, expr...)
+
 #endif /* DECLARE_TRACE */
 
 #ifndef TRACE_EVENT
@@ -399,4 +401,6 @@ static inline void tracepoint_synchronize_unregister(void)
 
 #define TRACE_EVENT_FLAGS(event, flag)
 
+#define TRACE_EVENT_PERF_PERM(event, expr...)
+
 #endif /* ifdef TRACE_EVENT (see note above) */
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 52594b20179e..6b852f60f8ae 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -90,6 +90,10 @@
 #define TRACE_EVENT_FLAGS(name, value)					\
 	__TRACE_EVENT_FLAGS(name, value)
 
+#undef TRACE_EVENT_PERF_PERM
+#define TRACE_EVENT_PERF_PERM(name, expr...)				\
+	__TRACE_EVENT_PERF_PERM(name, expr)
+
 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 
 
@@ -140,6 +144,9 @@
 #undef TRACE_EVENT_FLAGS
 #define TRACE_EVENT_FLAGS(event, flag)
 
+#undef TRACE_EVENT_PERF_PERM
+#define TRACE_EVENT_PERF_PERM(event, expr...)
+
 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 
 /*
diff --git a/kernel/events/core.c b/kernel/events/core.c
index d724e7757cd1..72348dc192c1 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -5680,11 +5680,6 @@ static void swevent_hlist_put(struct perf_event *event)
 {
 	int cpu;
 
-	if (event->cpu != -1) {
-		swevent_hlist_put_cpu(event, event->cpu);
-		return;
-	}
-
 	for_each_possible_cpu(cpu)
 		swevent_hlist_put_cpu(event, cpu);
 }
@@ -5718,9 +5713,6 @@ static int swevent_hlist_get(struct perf_event *event)
 	int err;
 	int cpu, failed_cpu;
 
-	if (event->cpu != -1)
-		return swevent_hlist_get_cpu(event, event->cpu);
-
 	get_online_cpus();
 	for_each_possible_cpu(cpu) {
 		err = swevent_hlist_get_cpu(event, cpu);
diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index 78e27e3b52ac..e854f420e033 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -24,6 +24,12 @@ static int	total_ref_count;
 static int perf_trace_event_perm(struct ftrace_event_call *tp_event,
 				 struct perf_event *p_event)
 {
+	if (tp_event->perf_perm) {
+		int ret = tp_event->perf_perm(tp_event, p_event);
+		if (ret)
+			return ret;
+	}
+
 	/* The ftrace function trace is allowed only for root. */
 	if (ftrace_event_is_function(tp_event) &&
 	    perf_paranoid_tracepoint_raw() && !capable(CAP_SYS_ADMIN))
@@ -173,7 +179,7 @@ static int perf_trace_event_init(struct ftrace_event_call *tp_event,
 int perf_trace_init(struct perf_event *p_event)
 {
 	struct ftrace_event_call *tp_event;
-	int event_id = p_event->attr.config;
+	u64 event_id = p_event->attr.config;
 	int ret = -EINVAL;
 
 	mutex_lock(&event_mutex);