[for-next][PATCH 5/5] tracing: Add __get_dynamic_array_len() macro for trace events

[Steven Rostedt]

From: "Steven Rostedt (Red Hat)" <rostedt@xxxxxxxxxxx>

If a trace event uses a dynamic array for something other than a string
then there's currently no way the TP_printk() can figure out what size
it is. A __get_dynamic_array_len() is required to know the length.

This also simplifies the __get_bitmask() macro which required it as well,
but instead just hardcoded it.

Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
 include/trace/ftrace.h | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 9b7a989dcbcc..0fd06fef9fac 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -203,6 +203,10 @@
 #define __get_dynamic_array(field)	\
 		((void *)__entry + (__entry->__data_loc_##field & 0xffff))
 
+#undef __get_dynamic_array_len
+#define __get_dynamic_array_len(field)	\
+		((__entry->__data_loc_##field >> 16) & 0xffff)
+
 #undef __get_str
 #define __get_str(field) (char *)__get_dynamic_array(field)
 
@@ -211,7 +215,7 @@
 	({								\
 		void *__bitmask = __get_dynamic_array(field);		\
 		unsigned int __bitmask_size;				\
-		__bitmask_size = (__entry->__data_loc_##field >> 16) & 0xffff; \
+		__bitmask_size = __get_dynamic_array_len(field);	\
 		ftrace_print_bitmask_seq(p, __bitmask, __bitmask_size);	\
 	})
 
@@ -636,6 +640,7 @@ static inline void ftrace_test_probe_##call(void)			\
 #undef __print_symbolic
 #undef __print_hex
 #undef __get_dynamic_array
+#undef __get_dynamic_array_len
 #undef __get_str
 #undef __get_bitmask
 
@@ -700,6 +705,10 @@ __attribute__((section("_ftrace_events"))) *__event_##call = &event_##call
 #define __get_dynamic_array(field)	\
 		((void *)__entry + (__entry->__data_loc_##field & 0xffff))
 
+#undef __get_dynamic_array_len
+#define __get_dynamic_array_len(field)	\
+		((__entry->__data_loc_##field >> 16) & 0xffff)
+
 #undef __get_str
 #define __get_str(field) (char *)__get_dynamic_array(field)
 
-- 
2.0.0.rc2


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