X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=include%2Fust%2Ftracepoint.h;h=e39a3849bc8b928bc7aaff2e5d4f5192eb300a5b;hb=d4419b81b243bc3a6bdd4a09b3ca2216d044a1c7;hp=56c62b0c6d3c884b1a6115cb4984eb9b17cb3de5;hpb=aa08b4413291fabcbd1b1144377d37034ad361de;p=lttng-ust.git diff --git a/include/ust/tracepoint.h b/include/ust/tracepoint.h index 56c62b0c..e39a3849 100644 --- a/include/ust/tracepoint.h +++ b/include/ust/tracepoint.h @@ -1,14 +1,15 @@ -#ifndef _LINUX_TRACEPOINT_H -#define _LINUX_TRACEPOINT_H +#ifndef _UST_TRACEPOINT_H +#define _UST_TRACEPOINT_H /* - * Copyright (C) 2008 Mathieu Desnoyers + * Copyright (C) 2008-2011 Mathieu Desnoyers * Copyright (C) 2009 Pierre-Marc Fournier + * Copyright (C) 2009 Steven Rostedt * * 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; either - * version 2.1 of the License, or (at your option) any later version. + * 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 @@ -24,35 +25,29 @@ * Ported to userspace by Pierre-Marc Fournier. */ -//#include -//#include -//#include - -#define _LGPL_SOURCE #include +#include -#include -#include +#ifdef __cplusplus +extern "C" { +#endif -struct module; -struct tracepoint; +struct tracepoint_probe { + void *func; + void *data; +}; struct tracepoint { const char *name; /* Tracepoint name */ - DEFINE_IMV(char, state); /* State. */ - void **funcs; -} __attribute__((aligned(32))); /* - * Aligned on 32 bytes because it is - * globally visible and gcc happily - * align these on the structure size. - * Keep in sync with vmlinux.lds.h. - */ - -#define TPPROTO(args...) args -#define TPARGS(args...) args + char state; /* State. */ + struct tracepoint_probe *probes; +}; -#define CONFIG_TRACEPOINTS -#ifdef CONFIG_TRACEPOINTS +/* + * 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 @@ -60,154 +55,369 @@ struct tracepoint { */ #define __DO_TRACE(tp, proto, args) \ do { \ - void **it_func; \ + struct tracepoint_probe *__tp_it_probe_ptr; \ + void *__tp_it_func; \ + void *__tp_cb_data; \ \ - rcu_read_lock(); /*ust rcu_read_lock_sched_notrace(); */ \ - it_func = rcu_dereference((tp)->funcs); \ - if (it_func) { \ + rcu_read_lock(); \ + __tp_it_probe_ptr = rcu_dereference((tp)->probes); \ + if (__tp_it_probe_ptr) { \ do { \ - ((void(*)(proto))(*it_func))(args); \ - } while (*(++it_func)); \ + __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(); /*ust rcu_read_unlock_sched_notrace(); */ \ + rcu_read_unlock(); \ } while (0) -#define __CHECK_TRACE(name, generic, proto, args) \ +#define TP_PARAMS(args...) args +#define TP_PROTO(args...) args +#define TP_ARGS(args...) args + +#define __CHECK_TRACE(name, proto, args) \ do { \ - if (!generic) { \ - if (unlikely(imv_read(__tracepoint_##name.state))) \ - __DO_TRACE(&__tracepoint_##name, \ - TPPROTO(proto), TPARGS(args)); \ - } else { \ - if (unlikely(_imv_read(__tracepoint_##name.state))) \ - __DO_TRACE(&__tracepoint_##name, \ - TPPROTO(proto), TPARGS(args)); \ - } \ + 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. - * - * The "generic" argument, passed to the declared __trace_##name inline - * function controls which tracepoint enabling mechanism must be used. - * If generic is true, a variable read is used. - * If generic is false, immediate values are used. */ -#define DECLARE_TRACE(name, proto, args) \ +#define __DECLARE_TRACEPOINT(name, proto, args, data_proto, data_args) \ extern struct tracepoint __tracepoint_##name; \ - static inline void trace_##name(proto) \ - { \ - __CHECK_TRACE(name, 0, TPPROTO(proto), TPARGS(args)); \ - } \ - static inline void _trace_##name(proto) \ + static inline void __trace_##name(proto) \ { \ - __CHECK_TRACE(name, 1, TPPROTO(proto), TPARGS(args)); \ + __CHECK_TRACE(name, TP_PROTO(data_proto), \ + TP_ARGS(data_args)); \ } \ - static inline int register_trace_##name(void (*probe)(proto)) \ + static inline int \ + __register_trace_##name(void (*probe)(data_proto), void *data) \ { \ - return tracepoint_probe_register(#name, (void *)probe); \ + return __tracepoint_probe_register(#name, (void *)probe,\ + data); \ } \ - static inline int unregister_trace_##name(void (*probe)(proto)) \ + static inline int \ + __unregister_trace_##name(void (*probe)(data_proto), void *data)\ { \ - return tracepoint_probe_unregister(#name, (void *)probe);\ + return __tracepoint_probe_unregister(#name, (void *)probe, \ + data); \ } -#define DEFINE_TRACE(name) \ +/* + * 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"), aligned(32))) = \ - { __tpstrtab_##name, 0, NULL } - -#define EXPORT_TRACEPOINT_SYMBOL_GPL(name) \ - EXPORT_SYMBOL_GPL(__tracepoint_##name) -#define EXPORT_TRACEPOINT_SYMBOL(name) \ - EXPORT_SYMBOL(__tracepoint_##name) - -extern void tracepoint_update_probe_range(struct tracepoint *begin, - struct tracepoint *end); - -#else /* !CONFIG_TRACEPOINTS */ -#define DECLARE_TRACE(name, proto, args) \ - static inline void trace_##name(proto) \ - { } \ - static inline void _trace_##name(proto) \ - { } \ - static inline int register_trace_##name(void (*probe)(proto)) \ - { \ - return -ENOSYS; \ - } \ - static inline int unregister_trace_##name(void (*probe)(proto)) \ - { \ - return -ENOSYS; \ - } + __attribute__((section("__tracepoints"))) = \ + { __tpstrtab_##name, 0, NULL }; \ + static struct tracepoint * __tracepoint_ptr_##name \ + __attribute__((used, section("__tracepoints_ptrs"))) = \ + &__tracepoint_##name; -#define DEFINE_TRACE(name) -#define EXPORT_TRACEPOINT_SYMBOL_GPL(name) -#define EXPORT_TRACEPOINT_SYMBOL(name) -static inline void tracepoint_update_probe_range(struct tracepoint *begin, - struct tracepoint *end) -{ } -#endif /* CONFIG_TRACEPOINTS */ +#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, should not be used directly. + * Internal API. */ -extern int tracepoint_probe_register(const char *name, void *probe); +extern +int __tracepoint_probe_register(const char *name, void *probe, void *data); /* * Disconnect a probe from a tracepoint. - * Internal API, should not be used directly. + * Internal API. */ -extern int tracepoint_probe_unregister(const char *name, void *probe); - -extern int tracepoint_probe_register_noupdate(const char *name, void *probe); -extern int tracepoint_probe_unregister_noupdate(const char *name, void *probe); -extern void tracepoint_probe_update_all(void); +extern +int __tracepoint_probe_unregister(const char *name, void *probe, void *data); -struct tracepoint_iter { -//ust// struct module *module; - struct tracepoint_lib *lib; - struct tracepoint *tracepoint; -}; - -extern void tracepoint_iter_start(struct tracepoint_iter *iter); -extern void tracepoint_iter_next(struct tracepoint_iter *iter); -extern void tracepoint_iter_stop(struct tracepoint_iter *iter); -extern void tracepoint_iter_reset(struct tracepoint_iter *iter); -extern int tracepoint_get_iter_range(struct tracepoint **tracepoint, - struct tracepoint *begin, struct tracepoint *end); +extern +int tracepoint_register_lib(struct tracepoint * const *tracepoints_start, + int tracepoints_count); +extern +int tracepoint_unregister_lib(struct tracepoint * const *tracepoints_start); /* - * tracepoint_synchronize_unregister must be called between the last tracepoint - * probe unregistration and the end of module exit to make sure there is no - * caller executing a probe when it is freed. + * 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). */ -static inline void tracepoint_synchronize_unregister(void) +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) { -//ust// synchronize_sched(); + if (__tracepoint_registered++) + return; + tracepoint_register_lib(__start___tracepoints_ptrs, + __stop___tracepoints_ptrs - + __start___tracepoints_ptrs); } -struct tracepoint_lib { - struct tracepoint *tracepoints_start; - int tracepoints_count; - struct list_head list; -}; +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. + */ -extern int tracepoint_register_lib(struct tracepoint *tracepoints_start, - int tracepoints_count); +#define TRACEPOINT_EVENT(name, proto, args, fields) \ + _DECLARE_TRACEPOINT(name, TP_PARAMS(proto), TP_PARAMS(args)) -#define TRACEPOINT_LIB \ - extern struct tracepoint __start___tracepoints[] __attribute__((visibility("hidden"))); \ - extern struct tracepoint __stop___tracepoints[] __attribute__((visibility("hidden"))); \ - static void __attribute__((constructor)) __tracepoints__init(void) \ - { \ - tracepoint_register_lib(__start___tracepoints, \ - (((long)__stop___tracepoints)-((long)__start___tracepoints))/sizeof(struct tracepoint)); \ - } +#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 */