--- /dev/null
+#ifndef _UST_TRACEPOINT_H
+#define _UST_TRACEPOINT_H
+
+/*
+ * Copyright (C) 2008-2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * Copyright (C) 2009 Pierre-Marc Fournier
+ * Copyright (C) 2009 Steven Rostedt <rostedt@goodmis.org>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * Heavily inspired from the Linux Kernel Markers.
+ *
+ * Ported to userspace by Pierre-Marc Fournier.
+ */
+
+#include <urcu-bp.h>
+#include <urcu/list.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct tracepoint_probe {
+ void *func;
+ void *data;
+};
+
+struct tracepoint {
+ const char *name; /* Tracepoint name */
+ char state; /* State. */
+ struct tracepoint_probe *probes;
+};
+
+/*
+ * Tracepoints should be added to the instrumented code using the
+ * "tracepoint()" macro.
+ */
+#define tracepoint(name, args...) __trace_##name(args)
+
+/*
+ * it_func[0] is never NULL because there is at least one element in the array
+ * when the array itself is non NULL.
+ */
+#define __DO_TRACE(tp, proto, args) \
+ do { \
+ struct tracepoint_probe *__tp_it_probe_ptr; \
+ void *__tp_it_func; \
+ void *__tp_cb_data; \
+ \
+ rcu_read_lock(); \
+ __tp_it_probe_ptr = rcu_dereference((tp)->probes); \
+ if (__tp_it_probe_ptr) { \
+ do { \
+ __tp_it_func = __tp_it_probe_ptr->func; \
+ __tp_cb_data = __tp_it_probe_ptr->data; \
+ URCU_FORCE_CAST(void(*)(proto), __tp_it_func)(args); \
+ } while ((++__tp_it_probe_ptr)->func); \
+ } \
+ rcu_read_unlock(); \
+ } while (0)
+
+#define TP_PARAMS(args...) args
+#define TP_PROTO(args...) args
+#define TP_ARGS(args...) args
+
+#define __CHECK_TRACE(name, proto, args) \
+ do { \
+ if (caa_unlikely(__tracepoint_##name.state)) \
+ __DO_TRACE(&__tracepoint_##name, \
+ TP_PROTO(proto), TP_ARGS(args)); \
+ } while (0)
+
+/*
+ * Make sure the alignment of the structure in the __tracepoints section will
+ * not add unwanted padding between the beginning of the section and the
+ * structure. Force alignment to the same alignment as the section start.
+ */
+#define __DECLARE_TRACEPOINT(name, proto, args, data_proto, data_args) \
+ extern struct tracepoint __tracepoint_##name; \
+ static inline void __trace_##name(proto) \
+ { \
+ __CHECK_TRACE(name, TP_PROTO(data_proto), \
+ TP_ARGS(data_args)); \
+ } \
+ static inline int \
+ __register_trace_##name(void (*probe)(data_proto), void *data) \
+ { \
+ return __tracepoint_probe_register(#name, (void *)probe,\
+ data); \
+ } \
+ static inline int \
+ __unregister_trace_##name(void (*probe)(data_proto), void *data)\
+ { \
+ return __tracepoint_probe_unregister(#name, (void *)probe, \
+ data); \
+ }
+
+/*
+ * The need for the _DECLARE_TRACEPOINT_NOARGS() is to handle the prototype
+ * (void). "void" is a special value in a function prototype and can
+ * not be combined with other arguments. Since the DECLARE_TRACEPOINT()
+ * macro adds a data element at the beginning of the prototype,
+ * we need a way to differentiate "(void *data, proto)" from
+ * "(void *data, void)". The second prototype is invalid.
+ *
+ * DECLARE_TRACEPOINT_NOARGS() passes "void" as the tracepoint prototype
+ * and "void *__tp_cb_data" as the callback prototype.
+ *
+ * DECLARE_TRACEPOINT() passes "proto" as the tracepoint protoype and
+ * "void *__tp_cb_data, proto" as the callback prototype.
+ */
+#define _DECLARE_TRACEPOINT_NOARGS(name) \
+ __DECLARE_TRACEPOINT(name, void, , void *__tp_cb_data, __tp_cb_data)
+
+#define _DECLARE_TRACEPOINT(name, proto, args) \
+ __DECLARE_TRACEPOINT(name, TP_PARAMS(proto), TP_PARAMS(args), \
+ TP_PARAMS(void *__tp_cb_data, proto), \
+ TP_PARAMS(__tp_cb_data, args))
+
+/*
+ * __tracepoints_ptrs section is not const (read-only) to let the linker update
+ * the pointer, allowing PIC code.
+ */
+#define _DEFINE_TRACEPOINT(name) \
+ static const char __tpstrtab_##name[] \
+ __attribute__((section("__tracepoints_strings"))) = #name; \
+ struct tracepoint __tracepoint_##name \
+ __attribute__((section("__tracepoints"))) = \
+ { __tpstrtab_##name, 0, NULL }; \
+ static struct tracepoint * __tracepoint_ptr_##name \
+ __attribute__((used, section("__tracepoints_ptrs"))) = \
+ &__tracepoint_##name;
+
+
+#define __register_tracepoint(name, probe, data) \
+ __register_trace_##name(probe, data)
+#define __unregister_tracepoint(name, probe, data) \
+ __unregister_trace_##name(probe, data)
+
+/*
+ * Connect a probe to a tracepoint.
+ * Internal API.
+ */
+extern
+int __tracepoint_probe_register(const char *name, void *probe, void *data);
+
+/*
+ * Disconnect a probe from a tracepoint.
+ * Internal API.
+ */
+extern
+int __tracepoint_probe_unregister(const char *name, void *probe, void *data);
+
+extern
+int tracepoint_register_lib(struct tracepoint * const *tracepoints_start,
+ int tracepoints_count);
+extern
+int tracepoint_unregister_lib(struct tracepoint * const *tracepoints_start);
+
+/*
+ * These weak symbols, the constructor, and destructor take care of
+ * registering only _one_ instance of the tracepoints per shared-ojbect
+ * (or for the whole main program).
+ */
+extern struct tracepoint * const __start___tracepoints_ptrs[]
+ __attribute__((weak, visibility("hidden")));
+extern struct tracepoint * const __stop___tracepoints_ptrs[]
+ __attribute__((weak, visibility("hidden")));
+int __tracepoint_registered
+ __attribute__((weak, visibility("hidden")));
+
+static void __attribute__((constructor)) __tracepoints__init(void)
+{
+ if (__tracepoint_registered++)
+ return;
+ tracepoint_register_lib(__start___tracepoints_ptrs,
+ __stop___tracepoints_ptrs -
+ __start___tracepoints_ptrs);
+}
+
+static void __attribute__((destructor)) __tracepoints__destroy(void)
+{
+ if (--__tracepoint_registered)
+ return;
+ tracepoint_unregister_lib(__start___tracepoints_ptrs);
+}
+
+#ifndef TRACEPOINT_EVENT
+/*
+ * Usage of the TRACEPOINT_EVENT macro:
+ *
+ * In short, an example:
+ *
+ * TRACEPOINT_EVENT(< [com_company_]project_[component_]event >,
+ * TP_PROTO(int arg0, void *arg1, char *string, size_t strlen,
+ * long *arg4, size_t arg4_len),
+ * TP_ARGS(arg0, arg1, string, strlen, arg4, arg4_len),
+ * TP_FIELDS(
+ *
+ * * Integer, printed in base 10 *
+ * ctf_integer(int, field_a, arg0)
+ *
+ * * Integer, printed with 0x base 16 *
+ * ctf_integer_hex(unsigned long, field_d, arg1)
+ *
+ * * Array Sequence, printed as UTF8-encoded array of bytes *
+ * ctf_array_text(char, field_b, string, FIXED_LEN)
+ * ctf_sequence_text(char, field_c, string, size_t, strlen)
+ *
+ * * String, printed as UTF8-encoded string *
+ * ctf_string(field_e, string)
+ *
+ * * Array sequence of signed integer values *
+ * ctf_array(long, field_f, arg4, FIXED_LEN4)
+ * ctf_sequence(long, field_g, arg4, size_t, arg4_len)
+ * )
+ * )
+ *
+ * In more detail:
+ *
+ * We define a tracepoint, its arguments, and its 'fast binary record'
+ * layout.
+ *
+ * Firstly, name your tracepoint via TRACEPOINT_EVENT(name,
+ *
+ * The name should be a proper C99 identifier.
+ * The "name" MUST follow these rules to ensure no namespace clash
+ * occurs:
+ *
+ * For projects (applications and libraries) for which an entity
+ * specific to the project controls the source code and thus its
+ * tracepoints (typically with a scope larger than a single company):
+ *
+ * either:
+ * project_component_event
+ * or:
+ * project_event
+ *
+ * Where "project" is the name of the project,
+ * "component" is the name of the project component (which may
+ * include several levels of sub-components, e.g.
+ * ...component_subcomponent_...) where the tracepoint is located
+ * (optional),
+ * "event" is the name of the tracepoint event.
+ *
+ * For projects issued from a single company wishing to advertise that
+ * the company controls the source code and thus the tracepoints, the
+ * "com_" prefix should be used:
+ *
+ * either:
+ * com_company_project_component_event
+ * or:
+ * com_company_project_event
+ *
+ * Where "company" is the name of the company,
+ * "project" is the name of the project,
+ * "component" is the name of the project component (which may
+ * include several levels of sub-components, e.g.
+ * ...component_subcomponent_...) where the tracepoint is located
+ * (optional),
+ * "event" is the name of the tracepoint event.
+ *
+ *
+ * As an example, let's consider a user-space application "someproject"
+ * that would have an internal thread scheduler:
+ *
+ * TRACEPOINT_EVENT(someproject_sched_switch,
+ *
+ * *
+ * * A function has a regular function arguments
+ * * prototype, declare it via TP_PROTO():
+ * *
+ *
+ * TP_PROTO(struct rq *rq, struct task_struct *prev,
+ * struct task_struct *next),
+ *
+ * *
+ * * Define the call signature of the 'function'.
+ * * (Design sidenote: we use this instead of a
+ * * TP_PROTO1/TP_PROTO2/TP_PROTO3 ugliness.)
+ * *
+ *
+ * TP_ARGS(rq, prev, next),
+ *
+ * *
+ * * Fast binary tracing: define the trace record via
+ * * TP_FIELDS(). You can think about it like a
+ * * regular C structure local variable definition.
+ * *
+ * * This is how the trace record is structured and will
+ * * be saved into the ring buffer. These are the fields
+ * * that will be exposed to readers.
+ * *
+ * * ctf_integer(pid_t, prev_pid, prev->pid) is equivalent
+ * * to a standard declaraton:
+ * *
+ * * pid_t prev_pid;
+ * *
+ * * followed by an assignment:
+ * *
+ * * prev_pid = prev->pid;
+ * *
+ * * ctf_array(char, prev_comm, prev->comm, TASK_COMM_LEN) is
+ * * equivalent to:
+ * *
+ * * char prev_comm[TASK_COMM_LEN];
+ * *
+ * * followed by an assignment:
+ * *
+ * * memcpy(prev_comm, prev->comm, TASK_COMM_LEN);
+ * *
+ *
+ * TP_FIELDS(
+ * ctf_array(char, prev_comm, prev->comm, TASK_COMM_LEN)
+ * ctf_integer(pid_t, prev_pid, prev->pid)
+ * ctf_integer(int, prev_prio, prev->prio)
+ * ctf_array(char, next_comm, next->comm, TASK_COMM_LEN)
+ * ctf_integer(pid_t, next_pid, next->pid)
+ * ctf_integer(int, next_prio, next->prio)
+ * )
+ * )
+ *
+ * Do _NOT_ add comma (,) nor semicolon (;) after the TRACEPOINT_EVENT
+ * declaration.
+ *
+ * The TRACEPOINT_SYSTEM must be defined when declaring a
+ * TRACEPOINT_EVENT. See ust/tracepoint-event.h for information about
+ * usage of other macros controlling TRACEPOINT_EVENT.
+ */
+
+#define TRACEPOINT_EVENT(name, proto, args, fields) \
+ _DECLARE_TRACEPOINT(name, TP_PARAMS(proto), TP_PARAMS(args))
+
+#define TRACEPOINT_EVENT_CLASS(name, proto, args, fields)
+#define TRACEPOINT_EVENT_INSTANCE(template, name, proto, args) \
+ _DECLARE_TRACEPOINT(name, TP_PARAMS(proto), TP_PARAMS(args))
+
+/*
+ * Declaration of tracepoints that take 0 argument.
+ */
+#define TRACEPOINT_EVENT_NOARGS(name, fields) \
+ _DECLARE_TRACEPOINT_NOARGS(name)
+
+#define TRACEPOINT_EVENT_CLASS_NOARGS(name, fields)
+#define TRACEPOINT_EVENT_INSTANCE_NOARGS(template, name) \
+ _DECLARE_TRACEPOINT_NOARGS(name)
+
+#endif /* #ifndef TRACEPOINT_EVENT */
+
+#ifndef TRACEPOINT_LOGLEVEL
+
+/*
+ * Tracepoint Loglevel Declaration Facility
+ *
+ * This is a place-holder the tracepoint loglevel declaration,
+ * overridden by the tracer implementation.
+ *
+ * Typical use of these loglevels:
+ *
+ * 1) Declare the mapping between loglevel names and an integer values
+ * within TRACEPOINT_LOGLEVEL_ENUM, using TP_LOGLEVEL for each tuple.
+ * Do _NOT_ add comma (,) nor semicolon (;) between the
+ * TRACEPOINT_LOGLEVEL_ENUM entries. Do _NOT_ add comma (,) nor
+ * semicolon (;) after the TRACEPOINT_LOGLEVEL_ENUM declaration. The
+ * name should be a proper C99 identifier.
+ *
+ * TRACEPOINT_LOGLEVEL_ENUM(
+ * TP_LOGLEVEL( < loglevel_name >, < value > )
+ * TP_LOGLEVEL( < loglevel_name >, < value > )
+ * ...
+ * )
+ *
+ * e.g.:
+ *
+ * TRACEPOINT_LOGLEVEL_ENUM(
+ * TP_LOGLEVEL(LOG_EMERG, 0)
+ * TP_LOGLEVEL(LOG_ALERT, 1)
+ * TP_LOGLEVEL(LOG_CRIT, 2)
+ * TP_LOGLEVEL(LOG_ERR, 3)
+ * TP_LOGLEVEL(LOG_WARNING, 4)
+ * TP_LOGLEVEL(LOG_NOTICE, 5)
+ * TP_LOGLEVEL(LOG_INFO, 6)
+ * TP_LOGLEVEL(LOG_DEBUG, 7)
+ * )
+ *
+ * 2) Then, declare tracepoint loglevels for tracepoints. A
+ * TRACEPOINT_EVENT should be declared prior to the the
+ * TRACEPOINT_LOGLEVEL for a given tracepoint name. The first field
+ * is the name of the tracepoint, the second field is the loglevel
+ * name.
+ *
+ * TRACEPOINT_LOGLEVEL(< [com_company_]project_[component_]event >,
+ * < loglevel_name >)
+ *
+ * The TRACEPOINT_SYSTEM must be defined when declaring a
+ * TRACEPOINT_LOGLEVEL_ENUM and TRACEPOINT_LOGLEVEL. The tracepoint
+ * loglevel enumeration apply to the entire TRACEPOINT_SYSTEM. Only one
+ * tracepoint loglevel enumeration should be declared per tracepoint
+ * system.
+ */
+
+#define TRACEPOINT_LOGLEVEL_ENUM()
+#define TRACEPOINT_LOGLEVEL(name, loglevel)
+
+#endif /* #ifndef TRACEPOINT_LOGLEVEL */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _UST_TRACEPOINT_H */
projects / ust.git / blobdiff