X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=include%2Flttng%2Ftracepoint.h;h=49db615a0996e49b067534e388baaa360a820292;hb=106ff4dab82c51bd7bf022220bf43f15fb04f8bc;hp=6e3faad6e26c2e3a6220007e8c8afde9ee40996b;hpb=f4624de20f5e39725cc2838b9cb538e4bbf261d7;p=lttng-ust.git diff --git a/include/lttng/tracepoint.h b/include/lttng/tracepoint.h index 6e3faad6..49db615a 100644 --- a/include/lttng/tracepoint.h +++ b/include/lttng/tracepoint.h @@ -1,28 +1,12 @@ -#ifndef _LTTNG_TRACEPOINT_H -#define _LTTNG_TRACEPOINT_H - /* - * Copyright 2011-2012 - Mathieu Desnoyers - * - * Permission is hereby granted, free of charge, to any person obtaining a copy - * of this software and associated documentation files (the "Software"), to deal - * in the Software without restriction, including without limitation the rights - * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell - * copies of the Software, and to permit persons to whom the Software is - * furnished to do so, subject to the following conditions: - * - * The above copyright notice and this permission notice shall be included in - * all copies or substantial portions of the Software. - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE - * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER - * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, - * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE - * SOFTWARE. + * SPDX-License-Identifier: MIT + * + * Copyright (C) 2011-2012 Mathieu Desnoyers */ +#ifndef _LTTNG_TRACEPOINT_H +#define _LTTNG_TRACEPOINT_H + #include #include #include @@ -31,13 +15,30 @@ #include #include /* for dlopen */ #include /* for memset */ + #include /* for sdt */ #include +#include #ifdef LTTNG_UST_HAVE_SDT_INTEGRATION -#define SDT_USE_VARIADIC +/* + * Instead of using SDT_USE_VARIADIC from 'sys/sdt.h', use our own namespaced + * macros since the instrumented application might already have included + * 'sys/sdt.h' without variadic support. + */ #include -#define LTTNG_STAP_PROBEV STAP_PROBEV + +#define _LTTNG_SDT_NARG(...) \ + __LTTNG_SDT_NARG(__VA_ARGS__, 12,11,10,9,8,7,6,5,4,3,2,1,0) + +#define __LTTNG_SDT_NARG(_0,_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12, N, ...) N + +#define _LTTNG_SDT_PROBE_N(provider, name, N, ...) \ + _SDT_PROBE(provider, name, N, (__VA_ARGS__)) + +#define LTTNG_STAP_PROBEV(provider, name, ...) \ + _LTTNG_SDT_PROBE_N(provider, name, _LTTNG_SDT_NARG(0, ##__VA_ARGS__), ##__VA_ARGS__) + #else #define LTTNG_STAP_PROBEV(...) #endif @@ -160,17 +161,18 @@ extern "C" { */ #define _DECLARE_TRACEPOINT(_provider, _name, ...) \ extern struct lttng_ust_tracepoint __tracepoint_##_provider##___##_name; \ -static inline __attribute__((always_inline, unused)) lttng_ust_notrace \ -void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__)); \ +static inline \ +void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__)) \ + __attribute__((always_inline, unused)) lttng_ust_notrace; \ static \ void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__)) \ { \ - struct lttng_ust_tracepoint_probe *__tp_probe; \ + struct lttng_ust_tracepoint_probe *__tp_probe; \ \ if (caa_unlikely(!TP_RCU_LINK_TEST())) \ return; \ - tp_rcu_read_lock_bp(); \ - __tp_probe = tp_rcu_dereference_bp(__tracepoint_##_provider##___##_name.probes); \ + tp_rcu_read_lock(); \ + __tp_probe = tp_rcu_dereference(__tracepoint_##_provider##___##_name.probes); \ if (caa_unlikely(!__tp_probe)) \ goto end; \ do { \ @@ -181,11 +183,12 @@ void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__)) \ (_TP_ARGS_DATA_VAR(__VA_ARGS__)); \ } while ((++__tp_probe)->func); \ end: \ - tp_rcu_read_unlock_bp(); \ + tp_rcu_read_unlock(); \ } \ -static inline lttng_ust_notrace \ +static inline \ void __tracepoint_register_##_provider##___##_name(char *name, \ - void (*func)(void), void *data); \ + void (*func)(void), void *data) \ + lttng_ust_notrace; \ static inline \ void __tracepoint_register_##_provider##___##_name(char *name, \ void (*func)(void), void *data) \ @@ -193,9 +196,10 @@ void __tracepoint_register_##_provider##___##_name(char *name, \ __tracepoint_probe_register(name, func, data, \ __tracepoint_##_provider##___##_name.signature); \ } \ -static inline lttng_ust_notrace \ +static inline \ void __tracepoint_unregister_##_provider##___##_name(char *name, \ - void (*func)(void), void *data); \ + void (*func)(void), void *data) \ + lttng_ust_notrace; \ static inline \ void __tracepoint_unregister_##_provider##___##_name(char *name, \ void (*func)(void), void *data) \ @@ -211,40 +215,33 @@ extern int __tracepoint_probe_unregister(const char *name, void (*func)(void), /* * tracepoint dynamic linkage handling (callbacks). Hidden visibility: * shared across objects in a module/main executable. + * + * IMPORTANT: this structure is part of the ABI between instrumented + * applications and UST. Fields need to be only added at the end, never + * reordered, never removed. + * + * The field @struct_size should be used to determine the size of the + * structure. It should be queried before using additional fields added + * at the end of the structure. */ struct lttng_ust_tracepoint_dlopen { + uint32_t struct_size; + void *liblttngust_handle; int (*tracepoint_register_lib)(struct lttng_ust_tracepoint * const *tracepoints_start, int tracepoints_count); int (*tracepoint_unregister_lib)(struct lttng_ust_tracepoint * const *tracepoints_start); -#ifndef _LGPL_SOURCE - void (*rcu_read_lock_sym_bp)(void); - void (*rcu_read_unlock_sym_bp)(void); - void *(*rcu_dereference_sym_bp)(void *p); -#endif + void (*rcu_read_lock_sym)(void); + void (*rcu_read_unlock_sym)(void); + void *(*rcu_dereference_sym)(void *p); + + /* End of base ABI. Fields below should be used after checking struct_size. */ }; extern struct lttng_ust_tracepoint_dlopen tracepoint_dlopen; extern struct lttng_ust_tracepoint_dlopen *tracepoint_dlopen_ptr; -/* Disable tracepoint destructors. */ -int __tracepoints__disable_destructors __attribute__((weak)); - -/* - * Programs that have threads that survive after they exit, and - * therefore call library destructors, should disable the tracepoint - * destructors by calling tracepoint_disable_destructors(). This will - * leak the tracepoint instrumentation library shared object, leaving - * its teardown to the operating system process teardown. - */ -static inline void tracepoint_disable_destructors(void) -{ - __tracepoints__disable_destructors = 1; -} - -#if defined(TRACEPOINT_DEFINE) || defined(TRACEPOINT_CREATE_PROBES) - /* * These weak symbols, the constructor, and destructor take care of * registering only _one_ instance of the tracepoints per shared-ojbect @@ -255,7 +252,9 @@ int __tracepoint_registered int __tracepoint_ptrs_registered __attribute__((weak, visibility("hidden"))); struct lttng_ust_tracepoint_dlopen tracepoint_dlopen - __attribute__((weak, visibility("hidden"))); + __attribute__((weak, visibility("hidden"))) = { + .struct_size = sizeof(struct lttng_ust_tracepoint_dlopen), +}; /* * Deal with gcc O1 optimisation issues with weak hidden symbols. gcc * 4.8 and prior does not have the same behavior for symbol scoping on @@ -269,9 +268,53 @@ struct lttng_ust_tracepoint_dlopen tracepoint_dlopen struct lttng_ust_tracepoint_dlopen *tracepoint_dlopen_ptr __attribute__((weak, visibility("hidden"))); +/* + * Tracepoint dynamic linkage handling (callbacks). Hidden visibility: shared + * across objects in a module/main executable. The callbacks are used to + * control and check if the destructors should be executed. + * + * IMPORTANT: this structure is part of the ABI between instrumented + * applications and UST. Fields need to be only added at the end, never + * reordered, never removed. + * + * The field @struct_size should be used to determine the size of the + * structure. It should be queried before using additional fields added + * at the end of the structure. + */ +struct lttng_ust_tracepoint_destructors_syms { + uint32_t struct_size; + + void (*tracepoint_disable_destructors)(void); + int (*tracepoint_get_destructors_state)(void); + + /* End of base ABI. Fields below should be used after checking struct_size. */ +}; + +extern struct lttng_ust_tracepoint_destructors_syms tracepoint_destructors_syms; +extern struct lttng_ust_tracepoint_destructors_syms *tracepoint_destructors_syms_ptr; + +struct lttng_ust_tracepoint_destructors_syms tracepoint_destructors_syms + __attribute__((weak, visibility("hidden"))) = { + .struct_size = sizeof(struct lttng_ust_tracepoint_destructors_syms), +}; +struct lttng_ust_tracepoint_destructors_syms *tracepoint_destructors_syms_ptr + __attribute__((weak, visibility("hidden"))); + +static inline void tracepoint_disable_destructors(void) +{ + if (!tracepoint_dlopen_ptr) + tracepoint_dlopen_ptr = &tracepoint_dlopen; + if (!tracepoint_destructors_syms_ptr) + tracepoint_destructors_syms_ptr = &tracepoint_destructors_syms; + if (tracepoint_dlopen_ptr->liblttngust_handle + && tracepoint_destructors_syms_ptr->tracepoint_disable_destructors) + tracepoint_destructors_syms_ptr->tracepoint_disable_destructors(); +} + #ifndef _LGPL_SOURCE -static inline void lttng_ust_notrace -__tracepoint__init_urcu_sym(void); +static inline void +__tracepoint__init_urcu_sym(void) + lttng_ust_notrace; static inline void __tracepoint__init_urcu_sym(void) { @@ -281,51 +324,58 @@ __tracepoint__init_urcu_sym(void) * Symbols below are needed by tracepoint call sites and probe * providers. */ - if (!tracepoint_dlopen_ptr->rcu_read_lock_sym_bp) - tracepoint_dlopen_ptr->rcu_read_lock_sym_bp = + if (!tracepoint_dlopen_ptr->rcu_read_lock_sym) + tracepoint_dlopen_ptr->rcu_read_lock_sym = URCU_FORCE_CAST(void (*)(void), dlsym(tracepoint_dlopen_ptr->liblttngust_handle, - "tp_rcu_read_lock_bp")); - if (!tracepoint_dlopen_ptr->rcu_read_unlock_sym_bp) - tracepoint_dlopen_ptr->rcu_read_unlock_sym_bp = + "tp_rcu_read_lock")); + if (!tracepoint_dlopen_ptr->rcu_read_unlock_sym) + tracepoint_dlopen_ptr->rcu_read_unlock_sym = URCU_FORCE_CAST(void (*)(void), dlsym(tracepoint_dlopen_ptr->liblttngust_handle, - "tp_rcu_read_unlock_bp")); - if (!tracepoint_dlopen_ptr->rcu_dereference_sym_bp) - tracepoint_dlopen_ptr->rcu_dereference_sym_bp = + "tp_rcu_read_unlock")); + if (!tracepoint_dlopen_ptr->rcu_dereference_sym) + tracepoint_dlopen_ptr->rcu_dereference_sym = URCU_FORCE_CAST(void *(*)(void *p), dlsym(tracepoint_dlopen_ptr->liblttngust_handle, - "tp_rcu_dereference_sym_bp")); + "tp_rcu_dereference_sym")); } #else -static inline void lttng_ust_notrace -__tracepoint__init_urcu_sym(void); +static inline void +__tracepoint__init_urcu_sym(void) + lttng_ust_notrace; static inline void __tracepoint__init_urcu_sym(void) { } #endif -static void lttng_ust_notrace __attribute__((constructor)) -__tracepoints__init(void); +static void +__tracepoints__init(void) + lttng_ust_notrace __attribute__((constructor)); static void __tracepoints__init(void) { - if (__tracepoint_registered++) + if (__tracepoint_registered++) { + if (!tracepoint_dlopen_ptr->liblttngust_handle) + return; + __tracepoint__init_urcu_sym(); return; + } if (!tracepoint_dlopen_ptr) tracepoint_dlopen_ptr = &tracepoint_dlopen; if (!tracepoint_dlopen_ptr->liblttngust_handle) tracepoint_dlopen_ptr->liblttngust_handle = - dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW | RTLD_GLOBAL); + dlopen(LTTNG_UST_TRACEPOINT_LIB_SONAME, RTLD_NOW | RTLD_GLOBAL); if (!tracepoint_dlopen_ptr->liblttngust_handle) return; __tracepoint__init_urcu_sym(); } -static void lttng_ust_notrace __attribute__((destructor)) -__tracepoints__destroy(void); +static void +__tracepoints__destroy(void) + lttng_ust_notrace __attribute__((destructor)); static void __tracepoints__destroy(void) { @@ -335,20 +385,32 @@ __tracepoints__destroy(void) return; if (!tracepoint_dlopen_ptr) tracepoint_dlopen_ptr = &tracepoint_dlopen; - if (!__tracepoints__disable_destructors - && tracepoint_dlopen_ptr->liblttngust_handle - && !__tracepoint_ptrs_registered) { - ret = dlclose(tracepoint_dlopen_ptr->liblttngust_handle); - if (ret) { - fprintf(stderr, "Error (%d) in dlclose\n", ret); - abort(); - } - memset(tracepoint_dlopen_ptr, 0, sizeof(*tracepoint_dlopen_ptr)); + if (!tracepoint_destructors_syms_ptr) + tracepoint_destructors_syms_ptr = &tracepoint_destructors_syms; + if (!tracepoint_dlopen_ptr->liblttngust_handle) + return; + if (__tracepoint_ptrs_registered) + return; + /* + * Lookup if destructors must be executed using the new method. + */ + if (tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state + && !tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state()) { + /* + * The tracepoint_get_destructors_state symbol was found with + * dlsym but its returned value is 0 meaning that destructors + * must not be executed. + */ + return; } + ret = dlclose(tracepoint_dlopen_ptr->liblttngust_handle); + if (ret) { + fprintf(stderr, "Error (%d) in dlclose\n", ret); + abort(); + } + memset(tracepoint_dlopen_ptr, 0, sizeof(*tracepoint_dlopen_ptr)); } -#endif - #ifdef TRACEPOINT_DEFINE /* @@ -389,22 +451,23 @@ extern struct lttng_ust_tracepoint * const __stop___tracepoints_ptrs[] __attribute__((section("__tracepoints_strings"))) = \ #_provider ":" #_name; \ struct lttng_ust_tracepoint __tracepoint_##_provider##___##_name \ - __attribute__((section("__tracepoints"))) = \ - { \ + __attribute__((section("__tracepoints"))) = { \ + sizeof(struct lttng_ust_tracepoint), \ __tp_strtab_##_provider##___##_name, \ 0, \ NULL, \ _TRACEPOINT_UNDEFINED_REF(_provider), \ _TP_EXTRACT_STRING(_args), \ - { }, \ }; \ static struct lttng_ust_tracepoint * \ __tracepoint_ptr_##_provider##___##_name \ - __attribute__((used, section("__tracepoints_ptrs"))) = \ + __attribute__((section("__tracepoints_ptrs"), used)) \ + __lttng_ust_variable_attribute_no_sanitize_address = \ &__tracepoint_##_provider##___##_name; -static void lttng_ust_notrace __attribute__((constructor)) -__tracepoints__ptrs_init(void); +static void +__tracepoints__ptrs_init(void) + lttng_ust_notrace __attribute__((constructor)); static void __tracepoints__ptrs_init(void) { @@ -414,9 +477,11 @@ __tracepoints__ptrs_init(void) tracepoint_dlopen_ptr = &tracepoint_dlopen; if (!tracepoint_dlopen_ptr->liblttngust_handle) tracepoint_dlopen_ptr->liblttngust_handle = - dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW | RTLD_GLOBAL); + dlopen(LTTNG_UST_TRACEPOINT_LIB_SONAME, RTLD_NOW | RTLD_GLOBAL); if (!tracepoint_dlopen_ptr->liblttngust_handle) return; + if (!tracepoint_destructors_syms_ptr) + tracepoint_destructors_syms_ptr = &tracepoint_destructors_syms; tracepoint_dlopen_ptr->tracepoint_register_lib = URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint * const *, int), dlsym(tracepoint_dlopen_ptr->liblttngust_handle, @@ -425,6 +490,14 @@ __tracepoints__ptrs_init(void) URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint * const *), dlsym(tracepoint_dlopen_ptr->liblttngust_handle, "tracepoint_unregister_lib")); + tracepoint_destructors_syms_ptr->tracepoint_disable_destructors = + URCU_FORCE_CAST(void (*)(void), + dlsym(tracepoint_dlopen_ptr->liblttngust_handle, + "tp_disable_destructors")); + tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state = + URCU_FORCE_CAST(int (*)(void), + dlsym(tracepoint_dlopen_ptr->liblttngust_handle, + "tp_get_destructors_state")); __tracepoint__init_urcu_sym(); if (tracepoint_dlopen_ptr->tracepoint_register_lib) { tracepoint_dlopen_ptr->tracepoint_register_lib(__start___tracepoints_ptrs, @@ -433,8 +506,9 @@ __tracepoints__ptrs_init(void) } } -static void lttng_ust_notrace __attribute__((destructor)) -__tracepoints__ptrs_destroy(void); +static void +__tracepoints__ptrs_destroy(void) + lttng_ust_notrace __attribute__((destructor)); static void __tracepoints__ptrs_destroy(void) { @@ -444,10 +518,13 @@ __tracepoints__ptrs_destroy(void) return; if (!tracepoint_dlopen_ptr) tracepoint_dlopen_ptr = &tracepoint_dlopen; + if (!tracepoint_destructors_syms_ptr) + tracepoint_destructors_syms_ptr = &tracepoint_destructors_syms; if (tracepoint_dlopen_ptr->tracepoint_unregister_lib) tracepoint_dlopen_ptr->tracepoint_unregister_lib(__start___tracepoints_ptrs); - if (!__tracepoints__disable_destructors - && tracepoint_dlopen_ptr->liblttngust_handle + if (tracepoint_dlopen_ptr->liblttngust_handle + && tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state + && tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state() && !__tracepoint_ptrs_registered) { ret = dlclose(tracepoint_dlopen_ptr->liblttngust_handle); if (ret) { @@ -522,7 +599,7 @@ __tracepoints__ptrs_destroy(void) * How to use the TRACEPOINT_EVENT macro: * * An example: - * + * * TRACEPOINT_EVENT(someproject_component, event_name, * * * TP_ARGS takes from 0 to 10 "type, field_name" pairs * @@ -533,23 +610,23 @@ __tracepoints__ptrs_destroy(void) * * TP_FIELDS describes the event payload layout in the trace * * * TP_FIELDS( - * * Integer, printed in base 10 * + * * Integer, printed in base 10 * * ctf_integer(int, field_a, arg0) * - * * Integer, printed with 0x base 16 * + * * Integer, printed with 0x base 16 * * ctf_integer_hex(unsigned long, field_d, arg1) * * * Enumeration * * ctf_enum(someproject_component, enum_name, int, field_e, arg0) * - * * Array Sequence, printed as UTF8-encoded array of bytes * + * * 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 * + * * String, printed as UTF8-encoded string * * ctf_string(field_e, string) * - * * Array sequence of signed integer values * + * * Array sequence of signed integer values * * ctf_array(long, field_f, arg4, FIXED_LEN4) * ctf_sequence(long, field_g, arg4, size_t, arg4_len) * )