2 * (C) Copyright 2009-2011 -
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
5 * LTTng function tracer integration module.
7 * Dual LGPL v2.1/GPL v2 license.
10 #include <linux/module.h>
11 #include <linux/ftrace.h>
12 #include <linux/slab.h>
13 #include "../ltt-events.h"
14 #include "../wrapper/ringbuffer/frontend_types.h"
15 #include "../ltt-tracer.h"
18 int lttng_ftrace_handler(unsigned long ip
, unsigned long parent_ip
, void **data
)
20 struct ltt_event
*event
= *data
;
21 struct ltt_channel
*chan
= event
->chan
;
22 struct lib_ring_buffer_ctx ctx
;
25 unsigned long parent_ip
;
29 if (!ACCESS_ONCE(chan
->session
->active
))
31 lib_ring_buffer_ctx_init(&ctx
, chan
->chan
, NULL
,
32 sizeof(payload
), ltt_alignof(payload
), -1);
33 ret
= chan
->ops
->event_reserve(&ctx
);
37 payload
.parent_ip
= parent_ip
;
38 lib_ring_buffer_align_ctx(&ctx
, ltt_alignof(payload
));
39 chan
->ops
->event_write(&ctx
, &payload
, sizeof(payload
));
40 chan
->ops
->event_commit(&ctx
);
45 * Create event description
48 int lttng_create_ftrace_event(const char *name
, struct ltt_event
*event
)
50 struct lttng_event_field
*fields
;
51 struct lttng_event_desc
*desc
;
54 desc
= kzalloc(sizeof(*event
->desc
), GFP_KERNEL
);
57 desc
->name
= kstrdup(name
, GFP_KERNEL
);
63 desc
->fields
= fields
=
64 kzalloc(2 * sizeof(struct lttng_event_field
), GFP_KERNEL
);
65 fields
[0].name
= "ip";
66 fields
[0].type
.atype
= atype_integer
;
67 fields
[0].type
.u
.basic
.integer
.size
= sizeof(unsigned long);
68 fields
[0].type
.u
.basic
.integer
.alignment
= ltt_alignof(unsigned long);
69 fields
[0].type
.u
.basic
.integer
.signedness
= 0;
70 fields
[0].type
.u
.basic
.integer
.reverse_byte_order
= 0;
71 fields
[0].type
.u
.basic
.integer
.base
= 16;
72 fields
[0].type
.u
.basic
.integer
.encoding
= lttng_encode_none
;
74 fields
[1].name
= "parent_ip";
75 fields
[1].type
.atype
= atype_integer
;
76 fields
[1].type
.u
.basic
.integer
.size
= sizeof(unsigned long);
77 fields
[1].type
.u
.basic
.integer
.alignment
= ltt_alignof(unsigned long);
78 fields
[1].type
.u
.basic
.integer
.signedness
= 0;
79 fields
[1].type
.u
.basic
.integer
.reverse_byte_order
= 0;
80 fields
[1].type
.u
.basic
.integer
.base
= 16;
81 fields
[1].type
.u
.basic
.integer
.encoding
= lttng_encode_none
;
93 struct ftrace_probe_ops lttng_ftrace_ops
= {
94 .func
= lttng_ftrace_handler
,
97 int lttng_ftrace_register(const char *name
,
98 const char *symbol_name
,
99 struct ltt_event
*event
)
103 ret
= lttng_create_ftrace_event(name
, event
);
107 event
->u
.ftrace
.symbol_name
= kstrdup(name
, GFP_KERNEL
);
108 if (!event
->u
.ftrace
.symbol_name
)
111 ret
= register_ftrace_function_probe(symbol_name
,
112 <tng_ftrace_ops
, event
);
118 kfree(event
->u
.ftrace
.symbol_name
);
120 kfree(event
->desc
->name
);
125 EXPORT_SYMBOL_GPL(lttng_ftrace_register
);
127 void lttng_ftrace_unregister(struct ltt_event
*event
)
129 unregister_ftrace_function_probe(event
->u
.ftrace
.symbol_name
,
130 <tng_ftrace_ops
, event
);
131 kfree(event
->u
.ftrace
.symbol_name
);
132 kfree(event
->desc
->name
);
135 EXPORT_SYMBOL_GPL(lttng_ftrace_unregister
);
137 MODULE_LICENSE("GPL and additional rights");
138 MODULE_AUTHOR("Mathieu Desnoyers");
139 MODULE_DESCRIPTION("Linux Trace Toolkit Ftrace Support");