1 files changed, 25 insertions, 24 deletions

diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index a71181655958..3ff9caa4a71b 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -16,7 +16,7 @@ static char __percpu *perf_trace_buf[PERF_NR_CONTEXTS];
 
 /*
  * Force it to be aligned to unsigned long to avoid misaligned accesses
- * suprises
+ * surprises
  */
 typedef typeof(unsigned long [PERF_MAX_TRACE_SIZE / sizeof(unsigned long)])
 	perf_trace_t;
@@ -157,7 +157,7 @@ static void perf_trace_event_unreg(struct perf_event *p_event)
 	int i;
 
 	if (--tp_event->perf_refcount > 0)
-		goto out;
+		return;
 
 	tp_event->class->reg(tp_event, TRACE_REG_PERF_UNREGISTER, NULL);
 
@@ -176,8 +176,6 @@ static void perf_trace_event_unreg(struct perf_event *p_event)
 			perf_trace_buf[i] = NULL;
 		}
 	}
-out:
-	module_put(tp_event->mod);
 }
 
 static int perf_trace_event_open(struct perf_event *p_event)
@@ -224,10 +222,10 @@ int perf_trace_init(struct perf_event *p_event)
 	list_for_each_entry(tp_event, &ftrace_events, list) {
 		if (tp_event->event.type == event_id &&
 		    tp_event->class && tp_event->class->reg &&
-		    try_module_get(tp_event->mod)) {
+		    trace_event_try_get_ref(tp_event)) {
 			ret = perf_trace_event_init(tp_event, p_event);
 			if (ret)
-				module_put(tp_event->mod);
+				trace_event_put_ref(tp_event);
 			break;
 		}
 	}
@@ -241,6 +239,7 @@ void perf_trace_destroy(struct perf_event *p_event)
 	mutex_lock(&event_mutex);
 	perf_trace_event_close(p_event);
 	perf_trace_event_unreg(p_event);
+	trace_event_put_ref(p_event->tp_event);
 	mutex_unlock(&event_mutex);
 }
 
@@ -252,16 +251,12 @@ int perf_kprobe_init(struct perf_event *p_event, bool is_retprobe)
 	struct trace_event_call *tp_event;
 
 	if (p_event->attr.kprobe_func) {
-		func = kzalloc(KSYM_NAME_LEN, GFP_KERNEL);
-		if (!func)
-			return -ENOMEM;
-		ret = strncpy_from_user(
-			func, u64_to_user_ptr(p_event->attr.kprobe_func),
-			KSYM_NAME_LEN);
-		if (ret == KSYM_NAME_LEN)
-			ret = -E2BIG;
-		if (ret < 0)
-			goto out;
+		func = strndup_user(u64_to_user_ptr(p_event->attr.kprobe_func),
+				    KSYM_NAME_LEN);
+		if (IS_ERR(func)) {
+			ret = PTR_ERR(func);
+			return (ret == -EINVAL) ? -E2BIG : ret;
+		}
 
 		if (func[0] == '\0') {
 			kfree(func);
@@ -292,6 +287,7 @@ void perf_kprobe_destroy(struct perf_event *p_event)
 	mutex_lock(&event_mutex);
 	perf_trace_event_close(p_event);
 	perf_trace_event_unreg(p_event);
+	trace_event_put_ref(p_event->tp_event);
 	mutex_unlock(&event_mutex);
 
 	destroy_local_trace_kprobe(p_event->tp_event);
@@ -347,6 +343,7 @@ void perf_uprobe_destroy(struct perf_event *p_event)
 	mutex_lock(&event_mutex);
 	perf_trace_event_close(p_event);
 	perf_trace_event_unreg(p_event);
+	trace_event_put_ref(p_event->tp_event);
 	mutex_unlock(&event_mutex);
 	destroy_local_trace_uprobe(p_event->tp_event);
 }
@@ -355,10 +352,16 @@ void perf_uprobe_destroy(struct perf_event *p_event)
 int perf_trace_add(struct perf_event *p_event, int flags)
 {
 	struct trace_event_call *tp_event = p_event->tp_event;
+	struct hw_perf_event *hwc = &p_event->hw;
 
 	if (!(flags & PERF_EF_START))
 		p_event->hw.state = PERF_HES_STOPPED;
 
+	if (is_sampling_event(p_event)) {
+		hwc->last_period = hwc->sample_period;
+		perf_swevent_set_period(p_event);
+	}
+
 	/*
 	 * If TRACE_REG_PERF_ADD returns false; no custom action was performed
 	 * and we need to take the default action of enqueueing our event on
@@ -400,7 +403,8 @@ void *perf_trace_buf_alloc(int size, struct pt_regs **regs, int *rctxp)
 	BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(unsigned long));
 
 	if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
-		      "perf buffer not large enough"))
+		      "perf buffer not large enough, wanted %d, have %d",
+		      size, PERF_MAX_TRACE_SIZE))
 		return NULL;
 
 	*rctxp = rctx = perf_swevent_get_recursion_context();
@@ -421,11 +425,8 @@ NOKPROBE_SYMBOL(perf_trace_buf_alloc);
 void perf_trace_buf_update(void *record, u16 type)
 {
 	struct trace_entry *entry = record;
-	int pc = preempt_count();
-	unsigned long flags;
 
-	local_save_flags(flags);
-	tracing_generic_entry_update(entry, type, flags, pc);
+	tracing_generic_entry_update(entry, type, tracing_gen_ctx());
 }
 NOKPROBE_SYMBOL(perf_trace_buf_update);
 
@@ -444,13 +445,13 @@ perf_ftrace_function_call(unsigned long ip, unsigned long parent_ip,
 	if (!rcu_is_watching())
 		return;
 
-	if ((unsigned long)ops->private != smp_processor_id())
-		return;
-
 	bit = ftrace_test_recursion_trylock(ip, parent_ip);
 	if (bit < 0)
 		return;
 
+	if ((unsigned long)ops->private != smp_processor_id())
+		goto out;
+
 	event = container_of(ops, struct perf_event, ftrace_ops);
 
 	/*