lttng: probe callbacks

Implement the LTTng probe callbacks. One notable file here is
lttng-events.h, which is the core implementation of the LTTng
TRACE_EVENT macros for generation of probes and tracepoint decription
from the TRACE_EVENT declarations.

Signed-off-by: Mathieu Desnoyers <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

drivers/staging/lttng/probes/Makefile

@@ -0,0 +1,37 @@
+#
+# Makefile for the LTT probes.
+#
+
+ccflags-y += -I$(PWD)/probes
+obj-m += lttng-types.o
+
+obj-m += lttng-probe-lttng.o
+
+obj-m += lttng-probe-sched.o
+obj-m += lttng-probe-irq.o
+
+ifneq ($(CONFIG_KVM),)
+obj-m += lttng-probe-kvm.o
+endif
+
+ifneq ($(CONFIG_BLOCK),)
+ifneq ($(CONFIG_EVENT_TRACING),)	# need blk_cmd_buf_len
+obj-m +=  $(shell \
+	if [ $(VERSION) -ge 3 \
+		-o \( $(VERSION) -eq 2 -a $(PATCHLEVEL) -ge 6 -a $(SUBLEVEL) -ge 38 \) ] ; then \
+		echo "lttng-probe-block.o" ; fi;)
+endif
+endif
+
+ifneq ($(CONFIG_KPROBES),)
+obj-m += lttng-kprobes.o
+endif
+
+
+ifneq ($(CONFIG_KRETPROBES),)
+obj-m += lttng-kretprobes.o
+endif
+
+ifneq ($(CONFIG_DYNAMIC_FTRACE),)
+obj-m += lttng-ftrace.o
+endif

drivers/staging/lttng/probes/define_trace.h

@@ -0,0 +1,132 @@
+/*
+ * define_trace.h
+ *
+ * Copyright (C) 2009 Steven Rostedt <[email protected]>
+ * Copyright (C) 2010-2011 Mathieu Desnoyers <[email protected]>
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+/*
+ * Trace files that want to automate creationg of all tracepoints defined
+ * in their file should include this file. The following are macros that the
+ * trace file may define:
+ *
+ * TRACE_SYSTEM defines the system the tracepoint is for
+ *
+ * TRACE_INCLUDE_FILE if the file name is something other than TRACE_SYSTEM.h
+ *     This macro may be defined to tell define_trace.h what file to include.
+ *     Note, leave off the ".h".
+ *
+ * TRACE_INCLUDE_PATH if the path is something other than core kernel include/trace
+ *     then this macro can define the path to use. Note, the path is relative to
+ *     define_trace.h, not the file including it. Full path names for out of tree
+ *     modules must be used.
+ */
+
+#ifdef CREATE_TRACE_POINTS
+
+/* Prevent recursion */
+#undef CREATE_TRACE_POINTS
+
+#include <linux/stringify.h>
+/*
+ * module.h includes tracepoints, and because ftrace.h
+ * pulls in module.h:
+ *  trace/ftrace.h -> linux/ftrace_event.h -> linux/perf_event.h ->
+ *  linux/ftrace.h -> linux/module.h
+ * we must include module.h here before we play with any of
+ * the TRACE_EVENT() macros, otherwise the tracepoints included
+ * by module.h may break the build.
+ */
+#include <linux/module.h>
+
+#undef TRACE_EVENT
+#define TRACE_EVENT(name, proto, args, tstruct, assign, print)	\
+	DEFINE_TRACE(name)
+
+#undef TRACE_EVENT_CONDITION
+#define TRACE_EVENT_CONDITION(name, proto, args, cond, tstruct, assign, print) \
+	TRACE_EVENT(name,						\
+		PARAMS(proto),						\
+		PARAMS(args),						\
+		PARAMS(tstruct),					\
+		PARAMS(assign),						\
+		PARAMS(print))
+
+#undef TRACE_EVENT_FN
+#define TRACE_EVENT_FN(name, proto, args, tstruct,		\
+		assign, print, reg, unreg)			\
+	DEFINE_TRACE_FN(name, reg, unreg)
+
+#undef DEFINE_EVENT
+#define DEFINE_EVENT(template, name, proto, args) \
+	DEFINE_TRACE(name)
+
+#undef DEFINE_EVENT_PRINT
+#define DEFINE_EVENT_PRINT(template, name, proto, args, print)	\
+	DEFINE_TRACE(name)
+
+#undef DEFINE_EVENT_CONDITION
+#define DEFINE_EVENT_CONDITION(template, name, proto, args, cond) \
+	DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
+
+#undef DECLARE_TRACE
+#define DECLARE_TRACE(name, proto, args)	\
+	DEFINE_TRACE(name)
+
+#undef TRACE_INCLUDE
+#undef __TRACE_INCLUDE
+
+#ifndef TRACE_INCLUDE_FILE
+# define TRACE_INCLUDE_FILE TRACE_SYSTEM
+# define UNDEF_TRACE_INCLUDE_FILE
+#endif
+
+#ifndef TRACE_INCLUDE_PATH
+# define __TRACE_INCLUDE(system) <trace/events/system.h>
+# define UNDEF_TRACE_INCLUDE_PATH
+#else
+# define __TRACE_INCLUDE(system) __stringify(TRACE_INCLUDE_PATH/system.h)
+#endif
+
+# define TRACE_INCLUDE(system) __TRACE_INCLUDE(system)
+
+/* Let the trace headers be reread */
+#define TRACE_HEADER_MULTI_READ
+
+#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
+
+/* Make all open coded DECLARE_TRACE nops */
+#undef DECLARE_TRACE
+#define DECLARE_TRACE(name, proto, args)
+
+#ifdef LTTNG_PACKAGE_BUILD
+#include "lttng-events.h"
+#endif
+
+#undef TRACE_EVENT
+#undef TRACE_EVENT_FN
+#undef TRACE_EVENT_CONDITION
+#undef DECLARE_EVENT_CLASS
+#undef DEFINE_EVENT
+#undef DEFINE_EVENT_PRINT
+#undef DEFINE_EVENT_CONDITION
+#undef TRACE_HEADER_MULTI_READ
+#undef DECLARE_TRACE
+
+/* Only undef what we defined in this file */
+#ifdef UNDEF_TRACE_INCLUDE_FILE
+# undef TRACE_INCLUDE_FILE
+# undef UNDEF_TRACE_INCLUDE_FILE
+#endif
+
+#ifdef UNDEF_TRACE_INCLUDE_PATH
+# undef TRACE_INCLUDE_PATH
+# undef UNDEF_TRACE_INCLUDE_PATH
+#endif
+
+/* We may be processing more files */
+#define CREATE_TRACE_POINTS
+
+#endif /* CREATE_TRACE_POINTS */

drivers/staging/lttng/probes/lttng-events-reset.h

@@ -0,0 +1,84 @@
+/*
+ * lttng-events-reset.h
+ *
+ * Copyright (C) 2010-2011 Mathieu Desnoyers <[email protected]>
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+/* Reset macros used within TRACE_EVENT to "nothing" */
+
+#undef __field_full
+#define __field_full(_type, _item, _order, _base)
+
+#undef __array_enc_ext
+#define __array_enc_ext(_type, _item, _length, _order, _base, _encoding)
+
+#undef __dynamic_array_enc_ext
+#define __dynamic_array_enc_ext(_type, _item, _length, _order, _base, _encoding)
+
+#undef __dynamic_array_len
+#define __dynamic_array_len(_type, _item, _length)
+
+#undef __string
+#define __string(_item, _src)
+
+#undef tp_assign
+#define tp_assign(dest, src)
+
+#undef tp_memcpy
+#define tp_memcpy(dest, src, len)
+
+#undef tp_memcpy_dyn
+#define tp_memcpy_dyn(dest, src, len)
+
+#undef tp_strcpy
+#define tp_strcpy(dest, src)
+
+#undef __get_str
+#define __get_str(field)
+
+#undef __get_dynamic_array
+#define __get_dynamic_array(field)
+
+#undef __get_dynamic_array_len
+#define __get_dynamic_array_len(field)
+
+#undef TP_PROTO
+#define TP_PROTO(args...)
+
+#undef TP_ARGS
+#define TP_ARGS(args...)
+
+#undef TP_STRUCT__entry
+#define TP_STRUCT__entry(args...)
+
+#undef TP_fast_assign
+#define TP_fast_assign(args...)
+
+#undef __perf_count
+#define __perf_count(args...)
+
+#undef __perf_addr
+#define __perf_addr(args...)
+
+#undef TP_perf_assign
+#define TP_perf_assign(args...)
+
+#undef TP_printk
+#define TP_printk(args...)
+
+#undef DECLARE_EVENT_CLASS
+#define DECLARE_EVENT_CLASS(_name, _proto, _args, _tstruct, _assign, _print)
+
+#undef DECLARE_EVENT_CLASS_NOARGS
+#define DECLARE_EVENT_CLASS_NOARGS(_name, _tstruct, _assign, _print)
+
+#undef DEFINE_EVENT
+#define DEFINE_EVENT(_template, _name, _proto, _args)
+
+#undef DEFINE_EVENT_NOARGS
+#define DEFINE_EVENT_NOARGS(_template, _name)
+
+#undef TRACE_EVENT_FLAGS
+#define TRACE_EVENT_FLAGS(name, value)