| 1 | #ifndef _UST_TRACEPOINT_H |
| 2 | #define _UST_TRACEPOINT_H |
| 3 | |
| 4 | /* |
| 5 | * Copyright (C) 2008 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> |
| 6 | * Copyright (C) 2009 Pierre-Marc Fournier |
| 7 | * |
| 8 | * This library is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU Lesser General Public |
| 10 | * License as published by the Free Software Foundation; either |
| 11 | * version 2.1 of the License, or (at your option) any later version. |
| 12 | * |
| 13 | * This library is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 16 | * Lesser General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU Lesser General Public |
| 19 | * License along with this library; if not, write to the Free Software |
| 20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 21 | * |
| 22 | * Heavily inspired from the Linux Kernel Markers. |
| 23 | * |
| 24 | * Ported to userspace by Pierre-Marc Fournier. |
| 25 | */ |
| 26 | |
| 27 | #define _LGPL_SOURCE |
| 28 | #include <urcu-bp.h> |
| 29 | #include <ust/immediate.h> |
| 30 | #include <ust/core.h> |
| 31 | |
| 32 | struct module; |
| 33 | struct tracepoint; |
| 34 | |
| 35 | struct tracepoint { |
| 36 | const char *name; /* Tracepoint name */ |
| 37 | DEFINE_IMV(char, state); /* State. */ |
| 38 | void **funcs; |
| 39 | } __attribute__((aligned(32))); /* |
| 40 | * Aligned on 32 bytes because it is |
| 41 | * globally visible and gcc happily |
| 42 | * align these on the structure size. |
| 43 | * Keep in sync with vmlinux.lds.h. |
| 44 | */ |
| 45 | |
| 46 | #define TP_PROTO(args...) args |
| 47 | #define TP_ARGS(args...) args |
| 48 | |
| 49 | #define CONFIG_TRACEPOINTS |
| 50 | #ifdef CONFIG_TRACEPOINTS |
| 51 | |
| 52 | /* |
| 53 | * it_func[0] is never NULL because there is at least one element in the array |
| 54 | * when the array itself is non NULL. |
| 55 | */ |
| 56 | #define __DO_TRACE(tp, proto, args) \ |
| 57 | do { \ |
| 58 | void **it_func; \ |
| 59 | \ |
| 60 | rcu_read_lock(); /*ust rcu_read_lock_sched_notrace(); */ \ |
| 61 | it_func = rcu_dereference((tp)->funcs); \ |
| 62 | if (it_func) { \ |
| 63 | do { \ |
| 64 | ((void(*)(proto))(*it_func))(args); \ |
| 65 | } while (*(++it_func)); \ |
| 66 | } \ |
| 67 | rcu_read_unlock(); /*ust rcu_read_unlock_sched_notrace(); */ \ |
| 68 | } while (0) |
| 69 | |
| 70 | #define __CHECK_TRACE(name, generic, proto, args) \ |
| 71 | do { \ |
| 72 | if (!generic) { \ |
| 73 | if (unlikely(imv_read(__tracepoint_##name.state))) \ |
| 74 | __DO_TRACE(&__tracepoint_##name, \ |
| 75 | TP_PROTO(proto), TP_ARGS(args)); \ |
| 76 | } else { \ |
| 77 | if (unlikely(_imv_read(__tracepoint_##name.state))) \ |
| 78 | __DO_TRACE(&__tracepoint_##name, \ |
| 79 | TP_PROTO(proto), TP_ARGS(args)); \ |
| 80 | } \ |
| 81 | } while (0) |
| 82 | |
| 83 | /* |
| 84 | * Make sure the alignment of the structure in the __tracepoints section will |
| 85 | * not add unwanted padding between the beginning of the section and the |
| 86 | * structure. Force alignment to the same alignment as the section start. |
| 87 | * |
| 88 | * The "generic" argument, passed to the declared __trace_##name inline |
| 89 | * function controls which tracepoint enabling mechanism must be used. |
| 90 | * If generic is true, a variable read is used. |
| 91 | * If generic is false, immediate values are used. |
| 92 | */ |
| 93 | #define DECLARE_TRACE(name, proto, args) \ |
| 94 | extern struct tracepoint __tracepoint_##name; \ |
| 95 | static inline void trace_##name(proto) \ |
| 96 | { \ |
| 97 | __CHECK_TRACE(name, 0, TP_PROTO(proto), TP_ARGS(args)); \ |
| 98 | } \ |
| 99 | static inline void _trace_##name(proto) \ |
| 100 | { \ |
| 101 | __CHECK_TRACE(name, 1, TP_PROTO(proto), TP_ARGS(args)); \ |
| 102 | } \ |
| 103 | static inline int register_trace_##name(void (*probe)(proto)) \ |
| 104 | { \ |
| 105 | return tracepoint_probe_register(#name, (void *)probe); \ |
| 106 | } \ |
| 107 | static inline int unregister_trace_##name(void (*probe)(proto)) \ |
| 108 | { \ |
| 109 | return tracepoint_probe_unregister(#name, (void *)probe);\ |
| 110 | } |
| 111 | |
| 112 | #define DEFINE_TRACE(name) \ |
| 113 | static const char __tpstrtab_##name[] \ |
| 114 | __attribute__((section("__tracepoints_strings"))) = #name; \ |
| 115 | struct tracepoint __tracepoint_##name \ |
| 116 | __attribute__((section("__tracepoints"), aligned(32))) = \ |
| 117 | { __tpstrtab_##name, 0, NULL } |
| 118 | |
| 119 | extern void tracepoint_update_probe_range(struct tracepoint *begin, |
| 120 | struct tracepoint *end); |
| 121 | |
| 122 | #else /* !CONFIG_TRACEPOINTS */ |
| 123 | #define DECLARE_TRACE(name, proto, args) \ |
| 124 | static inline void trace_##name(proto) \ |
| 125 | { } \ |
| 126 | static inline void _trace_##name(proto) \ |
| 127 | { } \ |
| 128 | static inline int register_trace_##name(void (*probe)(proto)) \ |
| 129 | { \ |
| 130 | return -ENOSYS; \ |
| 131 | } \ |
| 132 | static inline int unregister_trace_##name(void (*probe)(proto)) \ |
| 133 | { \ |
| 134 | return -ENOSYS; \ |
| 135 | } |
| 136 | |
| 137 | #define DEFINE_TRACE(name) |
| 138 | #define EXPORT_TRACEPOINT_SYMBOL_GPL(name) |
| 139 | #define EXPORT_TRACEPOINT_SYMBOL(name) |
| 140 | |
| 141 | static inline void tracepoint_update_probe_range(struct tracepoint *begin, |
| 142 | struct tracepoint *end) |
| 143 | { } |
| 144 | #endif /* CONFIG_TRACEPOINTS */ |
| 145 | |
| 146 | /* |
| 147 | * Connect a probe to a tracepoint. |
| 148 | * Internal API, should not be used directly. |
| 149 | */ |
| 150 | extern int tracepoint_probe_register(const char *name, void *probe); |
| 151 | |
| 152 | /* |
| 153 | * Disconnect a probe from a tracepoint. |
| 154 | * Internal API, should not be used directly. |
| 155 | */ |
| 156 | extern int tracepoint_probe_unregister(const char *name, void *probe); |
| 157 | |
| 158 | extern int tracepoint_probe_register_noupdate(const char *name, void *probe); |
| 159 | extern int tracepoint_probe_unregister_noupdate(const char *name, void *probe); |
| 160 | extern void tracepoint_probe_update_all(void); |
| 161 | |
| 162 | struct tracepoint_iter { |
| 163 | //ust// struct module *module; |
| 164 | struct tracepoint_lib *lib; |
| 165 | struct tracepoint *tracepoint; |
| 166 | }; |
| 167 | |
| 168 | extern void tracepoint_iter_start(struct tracepoint_iter *iter); |
| 169 | extern void tracepoint_iter_next(struct tracepoint_iter *iter); |
| 170 | extern void tracepoint_iter_stop(struct tracepoint_iter *iter); |
| 171 | extern void tracepoint_iter_reset(struct tracepoint_iter *iter); |
| 172 | extern int tracepoint_get_iter_range(struct tracepoint **tracepoint, |
| 173 | struct tracepoint *begin, struct tracepoint *end); |
| 174 | |
| 175 | /* |
| 176 | * tracepoint_synchronize_unregister must be called between the last tracepoint |
| 177 | * probe unregistration and the end of module exit to make sure there is no |
| 178 | * caller executing a probe when it is freed. |
| 179 | */ |
| 180 | static inline void tracepoint_synchronize_unregister(void) |
| 181 | { |
| 182 | //ust// synchronize_sched(); |
| 183 | } |
| 184 | |
| 185 | struct tracepoint_lib { |
| 186 | struct tracepoint *tracepoints_start; |
| 187 | int tracepoints_count; |
| 188 | struct list_head list; |
| 189 | }; |
| 190 | |
| 191 | extern int tracepoint_register_lib(struct tracepoint *tracepoints_start, |
| 192 | int tracepoints_count); |
| 193 | extern int tracepoint_unregister_lib(struct tracepoint *tracepoints_start); |
| 194 | |
| 195 | #define TRACEPOINT_LIB \ |
| 196 | extern struct tracepoint __start___tracepoints[] __attribute__((weak, visibility("hidden"))); \ |
| 197 | extern struct tracepoint __stop___tracepoints[] __attribute__((weak, visibility("hidden"))); \ |
| 198 | static void __attribute__((constructor)) __tracepoints__init(void) \ |
| 199 | { \ |
| 200 | tracepoint_register_lib(__start___tracepoints, \ |
| 201 | (((long)__stop___tracepoints)-((long)__start___tracepoints))/sizeof(struct tracepoint)); \ |
| 202 | } \ |
| 203 | \ |
| 204 | static void __attribute__((destructor)) __tracepoints__destroy(void) \ |
| 205 | { \ |
| 206 | tracepoint_unregister_lib(__start___tracepoints); \ |
| 207 | } |
| 208 | |
| 209 | #endif /* _UST_TRACEPOINT_H */ |