1 files changed, 63 insertions, 27 deletions

diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 513de9ceb80e..120531268abf 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -400,6 +400,20 @@ static bool process_string(const char *fmt, int len, struct trace_event_call *ca
 	return true;
 }
 
+static void handle_dereference_arg(const char *arg_str, u64 string_flags, int len,
+				   u64 *dereference_flags, int arg,
+				   struct trace_event_call *call)
+{
+	if (string_flags & (1ULL << arg)) {
+		if (process_string(arg_str, len, call))
+			*dereference_flags &= ~(1ULL << arg);
+	} else if (process_pointer(arg_str, len, call))
+		*dereference_flags &= ~(1ULL << arg);
+	else
+		pr_warn("TRACE EVENT ERROR: Bad dereference argument: '%.*s'\n",
+			len, arg_str);
+}
+
 /*
  * Examine the print fmt of the event looking for unsafe dereference
  * pointers using %p* that could be recorded in the trace event and
@@ -470,6 +484,7 @@ static void test_event_printk(struct trace_event_call *call)
 			case '%':
 				continue;
 			case 'p':
+ do_pointer:
 				/* Find dereferencing fields */
 				switch (fmt[i + 1]) {
 				case 'B': case 'R': case 'r':
@@ -498,6 +513,12 @@ static void test_event_printk(struct trace_event_call *call)
 						continue;
 					if (fmt[i + j] == '*') {
 						star = true;
+						/* Handle %*pbl case */
+						if (!j && fmt[i + 1] == 'p') {
+							arg++;
+							i++;
+							goto do_pointer;
+						}
 						continue;
 					}
 					if ((fmt[i + j] == 's')) {
@@ -556,11 +577,9 @@ static void test_event_printk(struct trace_event_call *call)
 			}
 
 			if (dereference_flags & (1ULL << arg)) {
-				if (string_flags & (1ULL << arg)) {
-					if (process_string(fmt + start_arg, e - start_arg, call))
-						dereference_flags &= ~(1ULL << arg);
-				} else if (process_pointer(fmt + start_arg, e - start_arg, call))
-					dereference_flags &= ~(1ULL << arg);
+				handle_dereference_arg(fmt + start_arg, string_flags,
+						       e - start_arg,
+						       &dereference_flags, arg, call);
 			}
 
 			start_arg = i;
@@ -571,11 +590,9 @@ static void test_event_printk(struct trace_event_call *call)
 	}
 
 	if (dereference_flags & (1ULL << arg)) {
-		if (string_flags & (1ULL << arg)) {
-			if (process_string(fmt + start_arg, i - start_arg, call))
-				dereference_flags &= ~(1ULL << arg);
-		} else if (process_pointer(fmt + start_arg, i - start_arg, call))
-			dereference_flags &= ~(1ULL << arg);
+		handle_dereference_arg(fmt + start_arg, string_flags,
+				       i - start_arg,
+				       &dereference_flags, arg, call);
 	}
 
 	/*
@@ -615,7 +632,6 @@ EXPORT_SYMBOL_GPL(trace_event_raw_init);
 bool trace_event_ignore_this_pid(struct trace_event_file *trace_file)
 {
 	struct trace_array *tr = trace_file->tr;
-	struct trace_array_cpu *data;
 	struct trace_pid_list *no_pid_list;
 	struct trace_pid_list *pid_list;
 
@@ -625,9 +641,11 @@ bool trace_event_ignore_this_pid(struct trace_event_file *trace_file)
 	if (!pid_list && !no_pid_list)
 		return false;
 
-	data = this_cpu_ptr(tr->array_buffer.data);
-
-	return data->ignore_pid;
+	/*
+	 * This is recorded at every sched_switch for this task.
+	 * Thus, even if the task migrates the ignore value will be the same.
+	 */
+	return this_cpu_read(tr->array_buffer.data->ignore_pid) != 0;
 }
 EXPORT_SYMBOL_GPL(trace_event_ignore_this_pid);
 
@@ -790,7 +808,9 @@ static int __ftrace_event_enable_disable(struct trace_event_file *file,
 				clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
 			}
 
-			call->class->reg(call, TRACE_REG_UNREGISTER, file);
+			ret = call->class->reg(call, TRACE_REG_UNREGISTER, file);
+
+			WARN_ON_ONCE(ret);
 		}
 		/* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
 		if (file->flags & EVENT_FILE_FL_SOFT_MODE)
@@ -1818,28 +1838,28 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
 	return cnt;
 }
 
-static ssize_t
-system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
-		   loff_t *ppos)
+/*
+ * Returns:
+ *   0 : no events exist?
+ *   1 : all events are disabled
+ *   2 : all events are enabled
+ *   3 : some events are enabled and some are enabled
+ */
+int trace_events_enabled(struct trace_array *tr, const char *system)
 {
-	const char set_to_char[4] = { '?', '0', '1', 'X' };
-	struct trace_subsystem_dir *dir = filp->private_data;
-	struct event_subsystem *system = dir->subsystem;
 	struct trace_event_call *call;
 	struct trace_event_file *file;
-	struct trace_array *tr = dir->tr;
-	char buf[2];
 	int set = 0;
-	int ret;
 
-	mutex_lock(&event_mutex);
+	guard(mutex)(&event_mutex);
+
 	list_for_each_entry(file, &tr->events, list) {
 		call = file->event_call;
 		if ((call->flags & TRACE_EVENT_FL_IGNORE_ENABLE) ||
 		    !trace_event_name(call) || !call->class || !call->class->reg)
 			continue;
 
-		if (system && strcmp(call->class->system, system->name) != 0)
+		if (system && strcmp(call->class->system, system) != 0)
 			continue;
 
 		/*
@@ -1855,7 +1875,23 @@ system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
 		if (set == 3)
 			break;
 	}
-	mutex_unlock(&event_mutex);
+
+	return set;
+}
+
+static ssize_t
+system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
+		   loff_t *ppos)
+{
+	const char set_to_char[4] = { '?', '0', '1', 'X' };
+	struct trace_subsystem_dir *dir = filp->private_data;
+	struct event_subsystem *system = dir->subsystem;
+	struct trace_array *tr = dir->tr;
+	char buf[2];
+	int set;
+	int ret;
+
+	set = trace_events_enabled(tr, system ? system->name : NULL);
 
 	buf[0] = set_to_char[set];
 	buf[1] = '\n';