Merge tag 'trace-fixes-v3.14-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull trace fix from Steven Rostedt:
 "Vaibhav Nagarnaik discovered that since 3.10 a clean-up patch made the
  array index in the trace event format bogus.

  He supplied an elegant solution that uses __stringify() and also
  removes the need for the event_storage and event_storage_mutex and
  also cuts off a few K of overhead from the trace events"

* tag 'trace-fixes-v3.14-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix array size mismatch in format string

4 files changed, 4 insertions, 20 deletions

diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index 4e4cc28623ad..4cdb3a17bcb5 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -495,10 +495,6 @@ enum {
         FILTER_TRACE_FN,
 };
 
-#define EVENT_STORAGE_SIZE 128
-extern struct mutex event_storage_mutex;
-extern char event_storage[EVENT_STORAGE_SIZE];
-
 extern int trace_event_raw_init(struct ftrace_event_call *call);
 extern int trace_define_field(struct ftrace_event_call *call, const char *type,
                               const char *name, int offset, int size,
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 1a8b28db3775..1ee19a24cc5f 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -310,15 +310,12 @@ static struct trace_event_functions ftrace_event_type_funcs_##call = {	\
 #undef __array
 #define __array(type, item, len)                                        \
         do {                                                            \
-                mutex_lock(&event_storage_mutex);                       \
+                char *type_str = #type"["__stringify(len)"]";           \
                 BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);                 \
-                snprintf(event_storage, sizeof(event_storage),          \
-                         "%s[%d]", #type, len);                         \
-                ret = trace_define_field(event_call, event_storage, #item, \
+                ret = trace_define_field(event_call, type_str, #item,   \
                                  offsetof(typeof(field), item),         \
                                  sizeof(field.item),                    \
                                  is_signed_type(type), FILTER_OTHER);   \
-                mutex_unlock(&event_storage_mutex);                     \
                 if (ret)                                                \
                         return ret;                                     \
         } while (0);
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index f3989ceb5cd5..7b16d40bd64d 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -27,12 +27,6 @@
 
 DEFINE_MUTEX(event_mutex);
 
-DEFINE_MUTEX(event_storage_mutex);
-EXPORT_SYMBOL_GPL(event_storage_mutex);
-
-char event_storage[EVENT_STORAGE_SIZE];
-EXPORT_SYMBOL_GPL(event_storage);
-
 LIST_HEAD(ftrace_events);
 static LIST_HEAD(ftrace_common_fields);
 
diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c
index 7c3e3e72e2b6..ee0a5098ac43 100644
--- a/kernel/trace/trace_export.c
+++ b/kernel/trace/trace_export.c
@@ -95,15 +95,12 @@ static void __always_unused ____ftrace_check_##name(void)		\
 #undef __array
 #define __array(type, item, len)                                        \
         do {                                                            \
+                char *type_str = #type"["__stringify(len)"]";           \
                 BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);                 \
-                mutex_lock(&event_storage_mutex);                       \
-                snprintf(event_storage, sizeof(event_storage),          \
-                         "%s[%d]", #type, len);                         \
-                ret = trace_define_field(event_call, event_storage, #item, \
+                ret = trace_define_field(event_call, type_str, #item,   \
                                  offsetof(typeof(field), item),         \
                                  sizeof(field.item),                    \
                                  is_signed_type(type), filter_type);    \
-                mutex_unlock(&event_storage_mutex);                     \
                 if (ret)                                                \
                         return ret;                                     \
         } while (0);