Commit 4f0dfd76 authored by Jeremy Linton's avatar Jeremy Linton Committed by Steven Rostedt (VMware)
Browse files

tracing: define TRACE_DEFINE_SIZEOF() macro to map sizeof's to their values 

Perf has a problem that if sizeof() macros are used within TRACE_EVENT()
macro's they end up in userspace as "sizeof(kernel structure)" which
cannot properly be parsed. Add a macro which can forward this data
through the eval_map for userspace utilization.

Link: http://lkml.kernel.org/r/20170531215653.3240-10-jeremy.linton@arm.com



Signed-off-by: default avatarJeremy Linton <jeremy.linton@arm.com>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent 67ec0d85

include/linux/tracepoint.h

+1 −0
Original line number Diff line number Diff line
@@ -88,6 +88,7 @@ extern void syscall_unregfunc(void); 
#define PARAMS(args...) args



#define TRACE_DEFINE_ENUM(x)

#define TRACE_DEFINE_SIZEOF(x)



#endif /* _LINUX_TRACEPOINT_H */

include/trace/trace_events.h

+16 −0
Original line number Diff line number Diff line
@@ -46,6 +46,19 @@ TRACE_MAKE_SYSTEM_STR(); 
	__attribute__((section("_ftrace_eval_map")))	\

	*TRACE_SYSTEM##_##a = &__##TRACE_SYSTEM##_##a



#undef TRACE_DEFINE_SIZEOF

#define TRACE_DEFINE_SIZEOF(a)				\

	static struct trace_eval_map __used __initdata	\

	__##TRACE_SYSTEM##_##a =			\

	{						\

		.system = TRACE_SYSTEM_STRING,		\

		.eval_string = "sizeof(" #a ")",	\

		.eval_value = sizeof(a)			\

	};						\

	static struct trace_eval_map __used		\

	__attribute__((section("_ftrace_eval_map")))	\

	*TRACE_SYSTEM##_##a = &__##TRACE_SYSTEM##_##a



/*

 * DECLARE_EVENT_CLASS can be used to add a generic function

 * handlers for events. That is, if all events have the same
@@ -158,6 +171,9 @@ TRACE_MAKE_SYSTEM_STR(); 
#undef TRACE_DEFINE_ENUM

#define TRACE_DEFINE_ENUM(a)



#undef TRACE_DEFINE_SIZEOF

#define TRACE_DEFINE_SIZEOF(a)



#undef __field

#define __field(type, item)

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